~· 

Short Papers in the 

Geologic and Hydrologic 

' Sciences, Articles 14 7-2 92 

GEOLOGICAL SURVEY RESEARCH 1961 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 424-C 

Sc£entific notes and summaries of investigations 

prepared by members of the Geologic and Water 

Resources Divisions in the fields of geology, 

hydrology, and allied sciences 

UNI!ED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington 25, D.C. 
FOREWORD 

The sciet\tific and economic results of work by the United States Geological Survey during 

the fiscal year 1961, the 12 months ending June 30, 1961, is being summarized in four volumes. 

This volume includes 146 short papers on subjects in the fields of geology, hydrology, and related 

sciences, prepared by members of the Geologic and Water Resources Divisions of the Survey. 

Some or these papers n,nnounce new discoveries or present observations on problems of limited 

scope; the others draw conclusions from more extensive or continuing investigations that in 

huge pn,rt will be described in greater detail in reports to be published at a later date. 

Other volumes in the series are Professional Paper 424-A, which gives a synopsis of the 

n1ore importt1nt new findings resulting from work during the fiscal year, and Professional 

Papers 424-B and 424-D, which contain additional short 'papers like those in the present 

volume. 

Thomas B. Nolan, 

Director. 

m 

CONTENTS 

Page 

Foreword--------------------------------------------------------------------------------------------------- III 

Geology of metalliferous deposits 

147. Gold deposits in the French Gulch-Deadwood district, Shasta and Trinity Counties, California, by John P. Albers_ C-1 

148. Paleotopographic control of a uranium mineral belt, Shirley Basin, Wyoming, by E. N. Harshman ___ --------- 4 

149. Origin and evolution of ore and gangue-forming solutions, Silverton caldera, San Juan Mountains, Colorado, by 

Wilbur S. Burbank and Robert G. Luedke----------------------------------------------------------- 7 

150. Geologic events culminating in primary metallization in the Central mining district, Grant County, New Mexico, 

by W. R. Jones, R. M. Hernon, and W. P. Pratt------------------------------------------------------ . 11 

Geology of light metals and industrial minerals 

151. Beryllium in stream sediments from the tin-tungsten provinces of the Seward Peninsula, Alaska, by C. L. Sainsbury, 

Armin W. Helz, Charles S. Annell, and Harold WestleY-----------------------------:------------------- 16 

152. Slate from the Greenville quadrangle, Maine, as potential lightweight aggregate material, by Gilbert H. Espenshade 

and Howard P. Hamlin ___ --------- _____________ ------------_______________________________________ 18 

Geology of fuels 

153. Spheroidal co~tl in the Trinidad coal field, south-central Colorado, by Ross B. Johnson______________________ 20 

154. Potential oil-shale reserves of the Green River form~tion in the southeastern Uinta Basin, Utah and Colorado, by 

W. B. Cashion____________________________________________________________________________________ 22 

Hydrologic studies 

155. Boulton's integral for pumpin.g-test analysis, by R. W. Stallman__________________________________________ 24 

156. Influence of riparian vegetation on channel shape, northeastern Arizona, by Richard F. Hadley--------------- 30 

157. Relation between median grain size and permeability in the Arkansas River valley, Arkansas, by M.S. Bedinger_ 31 

158. Influence of piezometer hole diameter on depth determinations in a smooth open channel, by W. W. Emmett___ 32 

159. Variation of Manning's nina smooth rectangular open channel, by Carl M. Lester__________________________ 34 

160. Variation of flood ratios with size of drainage area, by D. R. Dawdy_______________________________________ 36 

161. Errors in streamflow measurement, by I. E. Anderson--------------------------------------------------- 37 

162. Computation of homogeneous flows in tidal reaches by finite-difference method, by R. A. Baltzer and John Shen _ 39 

163. Observation of unsteady phenomena in an open channel, by Richard G. Godfrey ________________________ ..:___ 42 

164. Specific yield of sediments of the Humboldt River Valley, Humboldt County, Nevada, by Philip Cohen________ 43 

165. Variable depth-discharge relations in alluvial channels, by D. B. Simons, E. V. Richardson, and W. L. Haushild_ 45 

166. Lowest multi~year moving average compared with minimum independent multi-year means, by Clayton H. 

Hardison----------------------------------------------------------------------------------------- 47 

167. Bankfull depth and depth of flow for mean annual flood, Piedmont Province, by F. A. Kilpatrick ___ ·__________ 49 

Geology and hydrology of eastern United States 

168. Boundary Mountain anticlinorium, west-central Maine and northern New Hampshire, by Arden L. Albee______ 51 

169. Axial-plane folding in southeastern Connecticut, by Richard Goldsmith ________________________ --- ___ ------ 54 

170. A frost-wedged bedrock locality in southeastern Massachusetts, by Carl Koteff __________________ --- _-------- 57 

171. Late-glacial marine deposits in the Salem quadrangle, Massachusetts, by Robert N. Oldale___________________ 59 

172. End moraines on Kittatinny Mountain, Sussex County, New Jersey, by James P. Minard____________________ 61 

173. Redefinition of the Mount Laurel sand (Upper Cretaceous) in New Jersey, by James P. Minard, James P. Owens, 

and Ruth Todd---------------------~------------------------------------------------------------- 64 

174. The Brevard fault in North and South Carolina, by John C. Reed, Jr., HenryS. Johnson, Jr., Bruce Bryant,. Henry 

Bell III, and William C. Overstreet---------------------.--------------------------------------------- 67 

175. Annual minimum streamflows in a permeable basin in Ohio, by William J. Schneider _______________________ -- 70 

176. Classification of glacial deposits in the Killbuck lobe, northeast-central Ohio, by George W. White ________ --- _ 71 

177. Rotational block of the Cumberland overthrust sheet in southeastern Kentucky and northeastern Tennessee, by 

Kenneth J. Englund------------------------------------------------------------------------------- 74 

178. Folds and faults in the eastern part of the Marquette iron range, Michigan, by J. E. Gair, R. E. Thaden, and B. F. 

Jones-------------------------~------------------------------------------------------------------ 76 

179. Silicification of the Kona dolomite in the eastern part of the Marquette iron range, Michigan, by J. E. Gair, R. E. 

Thaden, and B. F. Jones---------------------------------~----------------------------------------- 78 

180. Thickness trends in the Hartshorne sandstone and the McAlester formation in northwestern Arkansas, by Boyd 

R. HaleY----------------------------------------------------------------------------------------- 80 

v 
VI CONTENTS 

Geology and hydrology of eastern United States-Continued 

181. Possible bentonite beds in the Atoka formation in Arkansas and Oklahoma, by Sherwood E. Frezon and Leonard 

G. Schultz---------------------------------------------------------------------------------------

182. Thickening of the Atoka formation in the ~entral part of the Arkansas Valley, northwestern Arkansas, by E. 

A. ~erewether ___________________________________________________________________________________ _ 

Geology and hydrology of western cont~rminous United States 

183. The quartz diorite line in northwestern North America, by James G. Moore, Arthur Grantz, and~- C. Blake, Jr __ 

184. Production and use of fresh water from the Ashley Valley oil field, Uintah County, Utah, by R. D. Feltis and 

H. D. Goode ____________________________________________________________________________________ _ 

185. Relation of the deep and shallow artesian aquifers near Lynndyl, Utah, by R. W. ~ower ___________________ _ 

186. A reinterpretation of two of G. K. Gilbert's Lake Bonneville sections, Utah, by David J. Varnes and Richard 

Van Horn----------------------------------------------------------------------------------------

187 .. Revision of stratigraphic norr:.enclature of Cambrian rocks, Nevada Test Site and vicinity, Nevada, by Harley Barnes and Allison R. Palmer ______________________________________________________________________ _ 

188. Windfall formation (Upper Cambrian) of Nevada Test Site and vicinity, Nevada, by Harley Barnes and F. ~- Byers, Jr ________________________________________________________________________________________ _ 

189. Revised subdivision of Ordovician system at the Nevada Test Site and vicinity, Nevada, by F. ~- Byers, Jr., 

Harley Barnes, F. G. Poole, and R. J. Ross, Jr ______________________________________________________ _ 

190. Lithologic character of the Diamond Peak formation (Mississippian) at the type locality, Eureka and White 

Pine Counties, Nevada, by David A. Brew--_---------------------------_- __________________________ _ 

191. Relation of Chainman shale to Bold Bluff thrust fault, southern Diamond Mountains, Eureka and White Pine 

Counties, Nevada, by David A. Brew ______ -_-----------------------------_- ________ --- _____________ _ 

192. Major westward thrusting of post-~iddle Triassic age in northwestern Nevada, by Ronald Willden __________ _ 

193. Geology of the ~ount Wheeler mine area, White Pine County, Nevada, by Donald H. Whitebread and Donald 

E. Lee----------------------------------------------------------~-------------------------------·· 

194. Tritium-age of ground water at the Nevada Test Site, Nye County, Nevada, by Alfred Clebsch, Jr ___________ _ 

195. Proposed classification of ground-water provinces, hydrologic units, and chemical types of ground water in the 

Upper Colorado River Basin, by David A. Phoenix----------------------------------~-----------------

196. Metamorphism and structural history of the Coal Creek area, Front Range, Colorado, by John D. Wells, Douglas ~- Sheridan, and Arden L. Albee ________ -- _______ --- ________ ---- __________________________________ _ 

197. Early and late growth of the Gypsum Valley salt anticline, San Miguel County, Colorado, by E. R. Landis, E. 

M. Shoemaker, and D. P. Elston _______ -:- ___ - ________________ ----_- ________________________________ _ 

198. Emplacement 'of the Wilson Peak stock and aRsociated intrusive rocks, San ~iguel Mountains, Colorado, by Calvin S. Bromfield- ___________________ -- __________________ ----- _______________________________ -.-_ 

199. Stream directions in Triassic rocks of the Colorado Plateau, by F. G. Poole ________________________________ _ 

200. Soda rhyolite (pantellerite?) from Lake County, Oregon, by George W. Walker_ ___________________________ _ 

201. Prehnite-pumpellyite metagraywacke facies of Upper Triassic rocks, Aldrich Mountains, Oregon, by C. Ervin 

Brown-------------------------------------------------------------------------------------------

202. Computation of the total flow of the Columbia River at the mouth, by Hollis~- Orem _____________________ _ 

203. DeforJ?ed basaltic caprock as an aquifer at Cow Valley, Oregon, by Bruce L. Foxworthy ____________________ _ 

204. Facies distribution and hydrology of intermontane basin fi11,- Safford basin, Arizona, by Edward S. DavidsotL __ _ 

205. ~iocene and Pliocene history of central Arizona, by F. R. Twenter _______________________________________ _ 

206. Correlation of Permian rocks in northeastern Arizona and adjoining parts of New ~exico and Utah, by Charles B. 

Read and A. A. Wanek----------------------------------------------------------------------------

207. Troy quartzite (younger Precambrian) and Bolsa and Abrigo formations (Cambrian), northern Galiuro Mountains, 

southeastern Arizona, by ~edora H. Krieger ________________________________________________________ _ 

208. Trap-door intrusion of the Cameron Creek laccolith, near Silver City, New Mexico, by Walden P. Pratt and 

Willian1 R. Jones ____________________________________________ --- _________________ -------_- ________ _ 

209. Middle and upper Tertiary rocks of southeastern Wyoming and adjoining areas, by N. ~- Denson and M. H. 

Bergendahl ______________________________________________________________________________________ _ 

210. Clays in the Inyan Kara group (Cretaceous), Black Hills, Wyoming and South Dakota, by Leonard G. Schultz 

and William J. ~a peL ____________________________________________________________________________ _ 

211. Cobern ~ountain overthrust, Lewis and Clark County, Montana, by Robert George Schmidt and Peter Zubovic __ 

212. A redefinition and restriction of the term Challis volcanics, by Clyde P. Ross ______________________________ _ 

213. Upper Paleozoic rocks in the Deep Creek ~ountains, Idaho, by Wilfred .J. Carr and Donald E. Trimble _______ _ 

214. Tide-affected flow of Sacramento River at Sacramento, California, by Franklin C. Craig ____________________ _ 

215. Interchange of surface water and ground water along tributary streams in the Central Valley, California, by S. 

E. Rantz and Donald Richardson __________________________________________________________________ _ 

216. Silurian and Devonian rocks of the Klamath Mountains, California, by C. W. ~erriam _______________ ..: _____ _ 

217. City College fault, San Francisco, California, by M.G. Bonilla __________________________________________ _ 

Pagtl 

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186 

188 

190 
CONTENTS 

Geology and hydrology of Alaska and Hawaii 

218. Orientation of phenoclasts in laminated glaciolacustrine deposits, Copper River Basin, Alaska, by Henry R. 

Schlnoll------------------------------------------------------------------------------------------

219. Weathered basalt in the eastern part of Kauai, Hawaii, by Sam H. Patterson and C. E. Roberson ____________ _ 

220. Sorting of beach sediment, northwestern Alaska, by George W. Moore _____________________________ ,.. ______ _ 

Geology and hydrology of Puerto Rico, Pacific Islands, and Antarctica 

221. Water-bearing properties of the rocks in the Arecibo-Barceloneta area, Puerto Rico, by Ted Arnow __ ---------

222. Ground-water conditions in the lower Tallaboa Valley, 'Puerto Rico, by I. G. Grossman _____________________ _ 

223. Volcanic suite of Pagan, Mariana Islands, by Gilbert Corwin-----------------------'----------------------

224. Structure of Lower Taylor Glacier, South Victoria Land, Antarctica, by Warren Hamilton and Philip T. Hayes_ 

225. Petrochemistry o~ probable Paleozoic granite rocks from the Ross Sea region, Antarctica, by Warren Hamilton __ 

Geology and hydrology of other Countries 

226. Investigation of the principal fluorspar districts of Mexico, by Ralph E. Van Alstine ________________________ _ 

227. Evidence for local glacier stagnation in East Greenland, by Joseph H. Hartshorn ___________________________ _ 

228. Thermal regime during the thaw of Centrum S!ll, northeast Greenland, by D. B. Krinsley ___________________ _ 

229. Facies change in Neocomian rocks of the Teresita-Chula area, Atacama Province, Chile, by Kenneth Segerstrom_ 

230. Rhyolite tuff, a source of the salts of northern Chile, by George E. Ericksen _______________________________ _ 

Paleontology, geomorphology, and plant ecology 

231. Correlation of the Arctic Permian, by J. Thomas Dutro, Jr ______________________________________________ _ 

232. Age of the Keechelus andesitic series of the Cascade Range, Washington, by Jack A. Wolfe __________________ _ 

233. Age and correlation of the Puget group, King County, Washington, by Jack A. Wolfe, Howard D. Gower, and 

Ja1nes D. Vine------------------------------------------------------------------------------------

234. Early Mississippian faunas in southwestern Elko County, Nevada, by Mackenzie Gordon, Jr., and Helen Duncan_ 

235. Continental vertebrates and their stratigraphic correlation with marine mollusks, eastern Caliente Range, California, by C. A. Repenning and J. G. Vedder---------------------------------------------------------

236. Stratigraphic distribution of endothyrid Foraminifera in Carboniferous rocks of the Mackay quadrangle, Idaho, 

by Betty A. L. SkiPP------------------------------------------------------------------------------

237. Ancient erosional cycles of the Little Colorado River, Arizona and New Mexico, by Maurice E. Cooley and Jay 

P. Akers-----------------------------------------------------------------------------------------

238. Vegetation in relation to flood frequency near Washington, D.C., by RobertS. Sigafoos _____________________ _ 

239. Soil-water availability and use by grasslands on adjacent stony and shale-derived soils in Colorado, by F. A. 

Branson, R. F. Miller, and I. S. McQueen------------------------------------------------------------

Geophysics 

240. A seismic record of Mesozoic rocks on Block Island, Rhode Island, by Curtis R. Tuttle, William B. Allen, and 

Glenn W. Hahn _________________________________________________________________________ - ________ _ 

241. Electrical properties of sulfide-mineralized gabbro, St. Louis County, Minnesota, by C. J. ZablockL-- ________ _ 

242. Structure of plutons from gravity measurements, by Martin lf. Kane_-_--- ______ ---_----------------------

243. Relation between gravity and structure of part of the western flank of the Black Hills, South Dakota and Wyo- ming, by R. A. Black and J. C. Roller_ _____________________________________________________________ _ 

244. Gravity profile along Roberts Tunnel, Colorado, by Donald Plouff _______________________________________ _ 

245. A detailed gravity profile across the southern Rocky Moun.tains, Colorado, by David J. Stuart and Ronald R. 

Wahl--------------------------------------------------------------------------------------------

246. Aftershock-energy release versus tidal effects, Hebgen Lake earthquake, Montana, by Renner B. Hofmann ____ _ 

247. Determination of thickness of a basalt flow by electrical resistivity method on Buckboard Mesa, Nevada Test 

Site, Nye County, Nevada, by J. C. Roller and R. A. Black ___________________________________________ _ 

248. Gravity study of crustal structure in western Washington, by David J. Stuart _____________________________ _ 

249. Regional magnetic and gravity anomalies in the Darwin area, California, by Don R. Mabey _________________ _ 

Mineralogy, geochemistry, and petrology 

250. Vanadium and associated elements in the Phosphoria formation in the Afton area, western Wyoming, by J. D. 

Love--------------------------------------------------------------------------------------------

251. Some geochemical aspects of ground water in northern St. Lawrence County, New York, by Ralph C. Heath 

and Edward H. Salvas-----------------------------------------------------------------------------

252. X-ray determinative curve for some natural plagioclases of composition An60- 85, by Everett D. Jackson ________ _ 

253. Boron in bentonite and shale from the Pierre shale, South Dakota, Wyoming, and Montana, by Harry A. Tourtelot, Leonard G. Schultz, and Claude Huffman, Jr ____________________________________________________ _ 

254. Accessory bastnaesite in the Pikes Peak granite, Colorado, by John W. Adams and Edward J. Young _________ _ 

255. Tunellite, a new hydrous strontium borate from the Kramer borate district, Ca.lifornia, by Richard C. Erd, 

Vincent Morgan, and Joan R. Clark ____________________________________________________ -- __________ _ 

256. Hydrozircon from the Wind River formation, Wyoming, by R. G. Coleman and R. C. Erd ___________________ _ 

257. Microtexture of artificially consolidated aragonitic mud, by John C. Hathaway and Eugene C. Robertson _____ _ 

258. Fluorine during hydration of rhyolitic glass, by Irving Friedman and Joseph Harris ________________________ _ 

VII I 

Page 

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304 
VIII CONTENTS 

Mineralogy, geochemistry, and petrology-Continued 

259. A critical review of analyses of chloritoid, by Margaret D. Foster ___________ -_-_- ________________________ _ 

260. X-ray crystallography and optical properties of synthetic monoclinic KFeSi30s, iron-sanidine, by David R. Wones 

and Daniel E. Appleman __ ------------------------ ____ ---- ________________________________________ _ 

261. A review of the chemical composition of gases from volcanic fumaroles and igneous rocks, by Donald E. White and G. A. Waring ________________________________________________________________________________ _ 

262. Variations in properties of hornblendes formed during progressive metamorphism of amphibolites, northwest 

Adirondack Mountains, New York, by A. E. J. Engel, Celeste G. Engel, and R. G. Havens. _______________ _ 

26:1. Distribution of clay-sized sediments in the Coastal Plain formations near Trenton, New Jersey, hy James P. 

Owens, James P. Minard, and Paul D. Blackmon ____________________________________________________ _ 

264. A heulandite-like mineral associated with clinoptilolite in tuffs of Oak Spring formation, Nevada Test Site, Nye 

County, Nevada, by A. 0. Shepard ______ - ____ -_----- ________________________________________________ _ 

265. Particle-size distribution of stream bed material in the Middle Rio Grande basin, New Mexico, by Carl F. Nordin, 

Jr., and James K. Culbertson _____ ------ __ -_-----------------_- _________ - ___ - ______________________ _ 

266. Worldwide runoff of dissolved solids, by W. H. Durum, S. G. Heidel, and L. J. Tison _______________________ _ 

267. Metal content of some black shales of the western United States, by D. F. Davidson and H. W. Lakin _______ _ 

268. Cordierite hornfels from Litchfield, Connecticut, by Fred Barker--- ______________________________________ _ 

269. Field measurements of silica in water from hot springs and geysers in Yellowstone National Park, by G. W. 

Morey, R. 0. Fournier, J. J. Remley, and J .. J. Rowe _________________________________________________ _ 

270. Anthophyllite-biotite-hypersthene-rhodolite assemblage, Mason Mountain, North Carolina, by Fred Barker ___ _ 

271. Two occurrences of thorium-bearing minerals with rhabdophane-like structure, by J. R. Dooley, Jr., and John 

C. HathawaY-------------------------------------------------------------------------------------

272. Effects of impact on thermoluminescene of Yule marble, by C. H. Roach, G. R. Johnson, J. G. McGrath, and 

F. H. Spence ____________________________________________________________________________________ _ 

273. X-ray powder data for herzenbergite, teallite, and tin trisulfide, by Shirley Mosburg, Daphne R. Ross, Philip M. Bethke, and Priestley Toulmin 3d. ______________________________________________________________ . 

Geology and hydrology applied to engineering and public health 

274. Deformation and stress distribution around coal mine workings in Sunnyside No. 1 mine, Utah, by Frank W. 

Osterwald----------------------------------------------------------------------------------------

275. Hydrologic effects of urban growth-sorr..e characteristics of urban runoff, by Arvi 0. Waananen _____________ _ 

276. Engineering geology and the Chilean earthquakes of 1960, by Ernest Dobrovolny and Richard W. Lemke _____ _ 

277. Effect of tunnel construction on flow of springs and small streams in the Tecolote Tunnel area of Santa Barbara 

County, California, by S. E. Rantz _________________________________________________________________ _ 

278. Influence of natural fractures on the shape of explosion-produced craters, by D. D. Dickey and Ross B. Johnson_ 

Exploration and mapping techniques 

279. New equipment for measurements in the unsaturated zone, by R. W. Stallman and R. P. Moston ____________ _ 

280. Equipment for field measurement of electrochemical potentials, by William Back and I van Barnes ___________ _ 

281. Transfer of geologic data from aerial photographs to topographic maps by direct tracing, by Russell H. CampbelL 

282. A remanent magnetometer and magnetic susceptibility bridge, by Lennart A. Anderson _____________________ _ 

Analytical and petrographic methods 

283. A method for determining the specific gravity of sand and ground rock or minerals, by Joseph J. Fahey _______ _ 

284. Measurement of sodium activities in clay suspensions with cationic-sensitive electrodes, by Alfred M. Pommer_ 

285. Evaluation of the use of dichromate oxidation"to estimate the organic carbon content of rocks, by I. C. Frost. ___ _ 

286. Determining the distribution of beryllium in rocks by a contact-print method, by Wallace R.. Griffitts and Lorraine 

E. Patten-------------------~---------~----------------------------------------------------------

287. Some factors affecting the determination of beryllium by the gamma-ray activation method, by Wayne Mountjoy 

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and H. H. LiPP----------------------------------------------------------------------------------- 379 

288. Determination of beryllium with a direct-reading spectrograph, by Armin W. Helz and Charles S. AnnelL _ _ _ _ _ 380 

289. Use of bathophenanthroline for determining traces of iron in zircon, by Frank Cuttitta and Jesse J. Warr _ _ _ _ _ _ 383 

290. Dithizone mixed-color method for determining small amounts of thallium in manganese ores, by Frank Cuttitta_ 384 

291. Determination of ferrous iron in magnetite and ilmenite in the presence of amphiboles and pyroxenes, by Joseph 

J. FaheY----------------------------------------------------------------------------------------- 386 

292. Density comparison method for the determination of 018/016 ratios in prepared waters, by J. H. McCarthy, Jr., 

T. S. Lovering, and H. W. Lakin____________________________________________________________________ 387 

Index 

Subject_________________________________________________________________________________________________ 391 

Author-----------------------------~------------------------------------------------------------------- 397 

Finding list of article page numbers ________________________________________________ ·________________________ 398 
I ' 

GEOLOGICAL SURVEY RESEARCH 1961 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

GEOLOGY OF METALLIFEROUS DEPOSITS 

147. GOLD DEPOSITS IN THE FRENCH GULCH-DEADWOOD DISTRICT, SHASTA AND TRINITY 

COUNTIES, CALIFORNIA 

By JOHN P. ALBERS, Menlo Park, Calif. 

Wo1·J;; rlonc ·i:n cooperation with the State of California, Department of Natu-ral Reso'ttroes, DiviS'i-on of Mines 

The :French Gulch-Deadwood gold mnung district 

forms an east-west belt about 9 miles long and 1 mile 

wide in the northern part of the French Gulch quadrangle, California. Production, mostly prior to 193~, 

Rmounts to about 29.2 million dollars if price is reckoned at $35 per ounce. Each of five mines has yielded 

gold valued at more than one million dollars. Those 

mines having the largest yield have been the Brown 

Bear (about 15.2 million dollars) and the Gladstone 

(about ().!) million dollars). ;From 1942 to 1961 the 

district was inact.i ve except for small lessee operations. 

Figure 147.1 shows the French Gulch-Deadwood 

district proper and some additional area to give the 

reader a broader picture of the geologic setting. Rock 

t.mit-s, :ft·om oldest to youngest, are: Copley greenstone, 

Balaklala rhyolite, J(ennett formation, Bragdon formation, Shasta Bally batholith, and dikes and sills of 

silicic porphyries. 'rhe Copley (Devonian) and 

Baln.kln:Jn. (Devonian) formations are mafic volcanic 

rocks a.nd silicic volcanic rocks, respectively. The 

Kennett and Bragdon formations, which overlie the 

volcanic units, consist chiefly of shale, siltstone, and 

conglomerate. Actually, the map includes only a very 

snmll body of siliceous shale thought to be Kennett 

fonnnJion, near the southeastern corner. The Bragdon 

:formation is in:fonnally subdivided into a lower unit 

o:f shale n.nd siltstone, and an upper unit in which 

sandstone and conglomerate ·are about as abundant as 

shale. Because the Bragdon formation is markedly 

discordant on the underlying rocks in most places it 

is inferred to overlie a thrust fault, here called the 

Spring Creek thrust. The thrusting predates the intrusive rocks of the area. 

The Paleozoic rocks are intruded by the Shasta 

Bally batholith of leucocratic granitoid quartz diorite 

and granodiorite, and by dikes and sills of "birdseye" 

porphyry. Under the locally used term of "birdseye" 

porphyry several_ compositional varieties, ranging 

from nonquartzose diorite porphyry to highly silicic 

quartz porphyry, are included. Nearly all have euhedral to subhedral phenocrysts of plagioclase in a 

sugary or aphanitic groundmass; and in some varieties 

quartz, biotite, and hornblende also form phenocrysts. 

One dike that has a granitoid texture is nearly identical with the quartz diorite of the batholith, and all 

the dikes are regarded as apophyses of the batholith. 

Pertinent structural features are the low irregular 

eastward-trending arch shown by the outcrop pattern 

of the Copley-Balaklala unit in the northern part of 

figure ·147.1, and a mile-wide zone of fractured Bragdon formation lying just south of the· arch, marked in 

its western part by numerous dikes and sills of "birdseye" porphyry (figs. 147.1 and 147.2). The more productive gold deposits are in this zone. The geometry 

of the arch is highly irregular and difficult to describe, 

partly because it is gr,eatly complicated by faults and 

0-1 
C-2 GEOLOGICAL SURVEY RESEARCH 1 9 61 

122"45' 

40"45' 

0 

EXPLANATION 

Diorite porphyry 

-

and quartz 

porphyry dikes and sills 

Locally designated "birdseye" 

porphyry 

Shasta Bally batholith 

(quartz diorite) 

VI 

:::> 

0 

LJJ 

u 

c( 

1-

LJ.J 

a::: 

u 

a::: 

0 

u 

u; 

VI 

c( 

a::: 

:; 

E3 ~~ c(_ 

a.. za.. . ceu; Kennett(?) and Bragdon fonnat10ns, z VI 

undifferentiated ~ ~ 

Upper conglomerate unit of LJJ :E 

Bragdon shown by stipple 0 z 

pattern }e~ M~.i~i:;:;;:rJ ~ ~ 00 Copley and Balaklala formations, G:j 0 

undifferentiated o ~ 

Contact 

Dashed where approximately 

located 

+---+ 

Approximate axis of arch 

U po 

D 

Fault, showing dip 

Dashed where approximately 

located. U, upthrown side; 

D, downthrown side 75 

.r... 

Quartz vein, showing dip 

---...... ................ Spring Creek thrust beneath 

Bragdon formation 

Dashed where approximately 

located 

X 

Pit, trench, or adit 

2 3 MILES 

LIST OF MINES 

1. Accident mine 

2. American mine 

3. Bright Star mine 

4. Brown Bear mine 

5. Brunswick mine 

6. Calmich mine 

7. Centenial mine 

8. Eldorado mine 

9. Franklin mine 

10. Gladstone mine 

11. Greenhorn mine 

(sulfide) 

12. Honeycomb mine 

13. JIC mine 

14. Larry mine 

15. Mad Mule mine 

16. Milkmaid mine 

17. Niagara mine 

18. Niagara Summit mine 

19. Philadelphia mine 

20. Scorpion mine 

21. Three Sisters mine 

22. Summit mine 

23. Tom Green mine 

24. Truscott mine 

25. Vermont and 

Montezuma mines 

26. Washington mine 

FIGURE 147.1.-Generalized geology of the French Gulch-Deadwood district and distribution of mines and prospects. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-3 

FmuuE 147.2.-Dingrnm showing relation of "birdseye" porphyry dikes and gold lodes to eastward-trending arch 

(dashed line) and to inferred subjncent salient of Shasta 

Bully batholith. Cg, Copley greenstone and Balaklala 

rhyolite ; Bl, lower unit, Bragdon formation ; Bu, upper 

unit, Brngdon formation; bp, "birdseye" porphyry. Brown 

Bear mine is at near end of diagram and Gladstone mine 

is nt fur end. 

partly because the Bragdon formation was folded before the arch was formed. The arch seems to plunge 

u,t n, low angle from the west edge of the area shown 

on the nHtp (fig. 147.1) eastward to Clear Creek where 

it turns northeastward and rises again in Shirttail 

Peale This rise is at least partly due to faulting. The 

arch is inferred to be underlain by a salient of the 

Shasta Bally batholith, which crops out 2 miles west 

of the map area. The marked mineralogical similarity between the dikes and the bathholith, the textural 

and mineralogical similarity of one dike to the batholith, and the nrangement of the dikes parallel to the 

crest of the arch support this inference. Tension fractures tlutt are rough~y parallel in strike to the axis of 

the salient would be formed by the upward push of 

the magma., and become occupied by dikes and quartz 

veins as shown diagrammatically on figure 147.2. 

The gold deposits are of two main types: (a) moderate to gently dipping quartz and quartz-calcite veins 

along the thrust contact below the Bragdon formation, 

and (b) steeply dipping quartz and quartz-calcite 

fissure veins in the Bragdon formation. "Birdseye" 

porphyry intrusives are commonly associated with 

both types, and, as the veins clearly cut the porphyry, 

they are younger. From veins of the first type has 

come most of the gold of the Washington mine and 

numerous small pocket deposits. Veins of the second 

type were mined at the ;Brown Bear, Niagara, American, Gladstone, and Summit mines. Ore shoots in the 

Brown Bear mine, from which over half the gold in 

the district has come, are mainly at intersections of 

veins with opposing dips or at the intersection of veins 

with contacts between shale and porphyry. The ore 

shoots are nearly horizontal, owing to . the general 

parallelism in strike of the main structures. In the 

Niagara, American, and Summit mines ore shoots are 

also commonly at the intersection of veins with each 

other or \~ith contacts· between different rocks. . In the 

Gladstone mine, for which we have only meager data, 

it s¢ems likely that ore controls are similar. Where 

steeps veins cut the Copley greenstone, as in the Washington' mine, they are commonly narrow and of poor 

grade, and only at the contact with the Bragdon and 

above have they been very productive. 

The mineral composition of the veins shows little 

variation. Quartz is the chief gangue mineral; calcite 

and mica are present in minor amounts, and locally 

manganese oxide occurs near the surface. Pyrite, 

galena, sphalerite, arsenopyrite, and rarely chalcopyrite are sulfide minerals commonly present. Gold is in 

the sulfide minerals, but occurs mainly as free goldmuch of it coarse enough to be seen with the unaided 

eye. 

~1uch of the gold, reportedly, was along contacts 

between the veins and black slickensided graphitic 

shale, or associated with inclusions of graphitic shale 

in the vein. Hershey (1910, p. 741-742), Ferguson 

(1914, p. 40-43), and Emmons (1937, p. 35-36) have 

noted the importance of carbon or graphite as a precipitating agent for gold, and Hershey thought that 

the common localization of gold deposits along the contact between the Copley and Bragdon formations resulted from precipitation of gold being carried in 

ascending solutions when they passed from the Copley 

greenstone into the carbonaceous material at the Bragdon contact. Certainly the ·presence of the Washington 

mine and numerous small deposits at this contract suggest that the change in rock type was partly responsible for the localization of the gold. Inasmuch as the 

gold in the rich veins in the Bragdon came from 

ascending solutions, it represents a residue that must 

have come past the favorable contact, and the possibility of finding additional ore at depth in mines that 

have not penetrated to this contact appears promising. 

The depths to which mines have penetrated in relation 

to the inferred depth of the Copley contact are shown 

on the geologic section (fig. 14 7.3). 
C-4 GEOLOGICAL SURVEY RESEARCH 1961 

Larry American JIC 

n n FiA' 

I I I I 

I I I 

SEA 

? 2 3 MILES I I 

EXPLANATION 

D ~ ~ B ---- - " " .... 

Diorite porphl'ey Uld. Brqdon formatioR, Bracdon formation, Copley. and Balak1ala Contact Fault Vein or lode 

quartz porphyry upper~t lower unit formations, IJaalwfl !17Mre G~_,.. 

dikes aDd ai.lla undifferentiated . loeGCed 

~.~ 

~~"~.,-. 

FIGURE 147.3.-Geologic section along French Gulch-Deadwood district. Approximate depth and lateral extent of workings (projected to plane of section) are shown by shaded areas. 

As most of the mines were inaccessible during our 

field studies, for this report I have relied heavily on 

maps and private reports prepared during periods 

when the mines were in operation. I am most grateful 

to the property owners who have kindly made the information available to me. 

REFERENCES 

Emmons, W. H., 1937, Gold deposits of the world: New York, 

McGraw-Hill Book Co., Inc., 562 p. 

Ferguson, H. G., 1914, Gold lodes of the Weaverville quadrangle, California: U.S. Geol. Survey Bull. 540, p. 22-79. 

Hershey, 0. H., 1910, Origin of gold pockets in northern California: Mining and Sci. Press, v. 101, p. 741-742. 

148. PALEOTOPOGRAPHIC CONTROL OF A URANIUM MINERAL BELT, SHIRLEY BASIN, WYOMING 

By E.- N. HARSHMAN, Denver, Colo. 

The Shirley Basin, about 35 miles south of Casper, 

Wyo., contains one of the major uranium ore reserves 

in the United States. Geologic studies of the basin 

have established a relation between the pre-Wind 

River topography and a mineral belt containing the 

major uranium deposits. 

At least 5,000 holes have been drilled in the Shirley 

Basin; most of them penetrated Cretaceous rocks that 

underlie the ore-bearing Wind River formation. Drill 

cuttings from about 800 of these holes have been 

logged by Geological Survey personnel; and lithologic, 

gamma ray, and resistivity logs of additional holes 

have been made available to the Geological Survey by 

mine operators in the basin. These data are the basis 

for a paleotopographic map of the eastern part of the 

Shirley Basin and for conclusions about factors that 

may have controlled deposition of the major ore 

bodies. 

The Wind River formation of Eocene age, host for 

the Shirley Basin uranium deposits, consists of intertoilguing and interbedded compacted but uncemented 

or poorly cemented gravel, sand, silt, and clay of continental. origin. It is overlain unconformably by 

tuffaceous claystone, siltstone, and sandstone of the 

"Vl1ite River formation of Oligocene age; but along 

the north rim of the basin, conglomerate, sandstone, 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-5 

and tuff of the Arikaree · formation, Miocene in age, 

overlie the White River rocks. The Tertiary strata 

have been tilted about 1° north. 

~iost of the Wind River sediments were derived 

from granitic rocks west and (or) southwest of the 

Shirley Basin. They were deposited in a low area 

that was eroded in Cretaceous and older rocks and that 

lay between the Laramie Mountains to the northeast 

and the Shirley Mountains to the southwest. 

Individual uranium deposits in the Shirley Basin 

contain from a few thousand to several hundred thousand tons of ore. · ~iaterial now being mined contains 

about 0.60 percent U30 8, and selected samples contain 

as much as 10 percent U30 8 • The ore is unoxidized. 

It is from 100 to 500 feet below the ground surface 

and from a few to 400 feet below the present water 

table. The ore-bearing zones are predominantly 

coarse- to medium-grained sandstone; however, silt 

nnd clay are present in appreciable amounts. Crossbeds, sand-filled channels, cut banks, carbonized plant 

debris, and other features common to most uranium 

deposits in sandstone characterize the ore ·zones in the 

Shirley Basin. 

Minera.logic studies of a few high-grade ore samples 

show the uranium mineral to be fine-grained uraninite 

associated with fine-grained pyrite, marcasite, and organic material. Uraninite coats sand grains, fills interstices between grains, and occasionally fills fractures 

in sand grains. 

Figure 148.1 (p. C-6), a generalized paleotopographic map of the eastern part of the Shirley Basin, 

shows a prominent ridge on the pre-Wind River erosion 

sm.·face. This ridge is held up by the indurated Wall 

Creek sandstone member at the top of the Frontier formation of Late Cretaceous age. In the mapped area, 

the i·idge is buried 125 to 350 feet deep by Wind River 

and (or) White River strata. One mile southeast of the 

rna pped area the Tertiary formations are eroded a way, 

and the ridge is a conspicuous feature of the present 

landscape. Where exposed, the Wall Creek sandstone 

member strikes about N. 85° "T· and dips 6° SW.; 

drill-hole data indicate a smiliar strike but slightly 

flatter dip for the rocks in the buried extension of the 

ridge. In the northern part of the basin the buried 

ridge has a relief of about 400 feet; southward the relief gradually decreases to about 100 feet. The buried 

part of the ridge has been breached by ancient drainage channels in at least two areas. 

The largest and highest grade uranium deposits now 

developed in the Shirley Basin are in a belt that lies 

along the west slope of the buried ridge (fig. 148.1). 

Although simple in plan view the belt is composite, 

c.onsisting of an upper and lower ore zone separated 

by silty clay 50 to 75 feet thick. In the northern part 

of the belt the larger deposits are in the upper zone; 

in the southern part they are restricted to the lower 

zone. Most of the ore deposits in the mineral beit lie 

below the elevation of the crest of the ridge. 

The buried ridge is believed to have controlled the 

position of the belt of favorable Wind River strata. 

Streams originating west of the ridge and flowing 

easterly were diverted parallel to the ridge and deposited sediment against it. Early in the cycle of 

basin filling, swampy flood-plain conditions developed 

near the west toe of the ridge; these conditions persisted until the ridge was buried by Wind River sediments. Burial was accomplished in relatively early 

Wind Rivet: times in the southern part of the area 

where the ridge was low and in late Wind River times 

in the northern part where the ridge was high. As 

a result of the depositional environme1~t, strata just 

west of the ridge consisted of permeable sand interbedded with silt, clay, and organic material, an ideal 

environment for subsequent deposition of uranium. 

In addition to its influence on vVind River lithology, 

the ridge diverted eastward-flowing uranium-bearing 

ground water through the chemically and physically 

favorable belt of vVind River strata. The combination 

of favorable ground and the migration of uraniumbearing ground water through it is believed to have 

resulted in the present mineral belt and its large highgrade uranium deposits. 

Other deposits have been discovered in the Shirley 

Basin both east and west of the belt where physical 

and geochemical conditions locally were favorable for 

uranium deposition. 
EXPLANATION 

~ 

Steele shale 

[Bill 

Niobrara formation 

[ill 

Frontier formation 

li§tl 

Mowry and Thermopolis shales·· 

-rso~ 

IJ) 

::J 

0 

w 

u 

< 1-

w 

a: 

u 

'\. I ........... _ .... , \ ', '\ '\ \ \ ', \', I '\ I ,, \ \ "\ 

' 106.15' ,__ ---... ' \ '~\ '\ ',' ~ I or-, l ,., ' ' ' ' '- ----- ' \ ,s•+ \' \ ' ' \ \ I Q) 1 '\ I \ \ 01 \ 01 '- ------ \ \ \ - ' ' ' \ \ ' 0 1 I \ I 01 \ CJI I ID '\. .. , · ' \ \ \ ', \\ '' ', \ \ \ ' OJ I 1 -l \ 0 \ 0 '\.. , '---------... _,,--,, \ ', ', \ \ ,, ', ',, \ \ \ \ / " <6 \ 9 I 0 

"\. ' ..... , - , ... - .... , ', ',' ', \ ', \ \ ',, '-c,. \ ~~ \ ,_/ / \ \ } I : J 

\ , ::-_::------ -.. __ ...... J ',, \ \, \\\\ ',, es>o0'\ 

0

0, ',, ,/ Kf \~mt/ J // / ' ' ------- I / \ \ \ ' ' ' ', / I I I I I ------------------ \ ' ', .... , ................. _ -----, I // \ \: \ \ \\ ', \ ', ', --- -< ... I I I I I 

----.... \ ........................... :---=:-.......... / / // , ~ '~n Kt ) ~ '" .................. A~A 'X , / / , ' ..... ..... e:.~ '--:.::.:_--: ........... .: .......... __ , l , ',, ~ " ', '\, ,\ (_, ,./ /', ... \ / .t X/ ' l __ ..... ' 

., ............... ',, '6"s., ~ \ ' ', \\ \ ($'\ \ 1\ : (--..... __ / : \ ',', '---, ) /, 

,____ ~ ',,,'',, oo_-' ') ",.~... ''\,'--~d) / ) / ~\ \ ',~}-.. ',_~,S--, 

..... ,\ \\ ',, ' ..... ,.... _ ........ ,/ ~ ... ~ ........ \ ' ................. :- ( ('_ ', \, ~ { {, (-"'-c;,-J_) ,,/"/ 

....... ------, : --\--... , \, ,__ ~ \ '"- \ r:._'-.., '·\ ~' '\ \ \,' .... ::-'S":..-~', - ,"" , , , .... , ............... \ \'\ ~ ' .... ) , , , """C. )..,. ............ __ ........ r ..... ,, ', ,"'' ~_,/' / ,' \ '-..._ __ ,,----..... , -~600.,. ., \ '\ 0 ::I "'C." '"\ ',1'' \',.::---"' -- ___ .,, _, I : ', - ..... ,, ', '',\ <=t / I ~ /"'--.. , t- -4 .{ ', ''-:::-- //> 

- / ' r I Ks \ Kn ' ' ' ', '\ ' I/ / / ,--, ' f / / > ,,... ,) / 

N 

r 

Contact on pre-Wind River erosion 

surface approxim~tely located 

showing dip 

// i \ \ ___ \ . . . ',, -... ____ ',<<~ l.JfC~~-::_:.~\ \ f / /, \----// _______ / I I \._/ -, \Ore pnnclpally In "upper" sandstone ) I \.,..,I .. ~,~:/ \\\ \ \ ' ~ r I I " ------

. Ks / \ ',, , of Wind River formation // />.--',' (( 1-"'\ \\\' \ ~ \ \ : 1' \ __ _ 

--6500--

Contour on pre-Wind River surface 

Contour interval 50 feet; datum is 

mean sea level 

Y2 0 1 MILE 

// } , __ \"\ / / , 11 \'' IJ I \\\\ \ \ ""C..., 1 \ \ ' ..... __ t.-::=-- // 1 ,-....... , "' / ' / tt---'j I ,,,, ', \ \ ~-c., ', '---1-- ..... -, } / : /" '~ ~ I/~//,.-"'~ ""~\\~\\\ : -------t--' / / ' "-"' .- i ..- 1 1 ,,/ -...... o 11 1111 , KfiKmt., 1 / 

_,... ... \ '----, f . ~ ,"" ' ' J I // \ ~f!_// J I: \ \ /,' ,' II I 

: ) \ \---- \ I .' ~--------r--/ / \, \ /X.,///, : /' 1 \ 01 , , ___ -sgoor ,/... .J ' ', ,/ \ , 1 0 

: / \ \ ~ --,_...-----{~----- } ': // // /.j g _ : 1 , \ ~ 0o-k ... ------ , /' " ' ,......,_(() ---- I \ ,.--, \ \ --68 I{ -------" /' .-" / \ " ................ ' ' { ', ', -- \ ', ----..... r: ..... ----- ,' / ' -' ............ \\ \ : ' ..... , , __ .... \ \ '......... \ ',\ \. //..... ) / \ ', \ I I ' I ,''\ \ ',, \ r/ 1\,' I 6700-- / I \ -------------------- ', ' I I \ I 1 I ---------- \ 0// \ ,__ '1 ' I ', 

--... , \ \ I I 1 \ I I \ 1 '-109) / / I : I 

',_ , \ '... I 01 ,,1 : . 1 I ', \ ---- \ I 01 

- , \ ', ',, / ~ , Ks \ Kn I I ' \ / I ' \ ~ I I \ ' I 0 \ \ I I K I Kf { \ \ q ---------------------... , : ,,"'' ',, ',,_/' ', ''---.... , \ ~ \ .... _~\ :', \ \, ', \ t I ' ' \ .... --._, ~ I ..._ ' I \ \ \ " ' 

42° 20' : \ I ', '-., '---\ ',, _, ...... ~ _ \\ \ \ 42_;-20'' 

: \ \ . ., ..... ------....... ............ ', \ ~ "~~o: \ : \ ............. --------'\ I ', ', , .... "' C5".,g ' .... _____ ..... -------.... ',, \ I ( 1 i>U I \--... - 1 \ \ : .......... ...__ 00 ..... , ...... _____ , ,' \\.E) .~ ', 

~ I '---- '-----------..._ \ \ \ /' ' ,-J \ ,--..... ,J : \ ----........ \ \ / ,'v - \ : 

I \ ',, _..-~, ~ : / (~\ "' ~ _ ......... --\ ~ ' .... ___ ', / \ : : ,' ,.--.. \', "\. ' ..... ) 

\, \. ---....................... \\ / \\ : / ,/ . //~ \, \ ',, .... ___ .... Kf 

' \ ....... \ I ' I I I / \ ' ', so + )\.' 

\ ', ~Q \ / \ I ,' t~--"'/ ~ ", ', - ---~ ', ', 0~ I I \ 1 ~ I '\. \ ...... - -"' ', '------.... , ', : , \ \ , , '\. ',... // ""t6eo0 

'~ ',,_ \ II ! l \ ',,_ \ " , ____ ... / /~, \ 

/a ' ... _ \ ,_ .... .1 I ', ', \ '- . 1 ___ ...... ...../C;,-y I 0 ...... ----- \ ___ / '--... ',, 1 Ore principally in "lower" sandstone 1 ,/ , ( ~' 1 

-----... '\ \ '-- ' 1 \ \ of Wind River formation t ', (() \\~ ...... , ~ \ ------.... , _,.J .... ) \ " t - \..'--- ............. : \ / , ..... - , .... '..... '.......... ' ,---.- ---,, 1 \ 1 1 1 ---- "- Kn' Kf 

', \ \ I \ \ Ks ---, " -...... 

\\ \ ',, \ \ \ ', " ' \ ', '........ \ \ \ \ " ---; \\ ',, ................. ', \ \\ \ " , ........... 

-----... Ks 

',,'':.., 

WYOMING \ ' ... , ............. \ \ \ / " ' ............ ""'"' \ ' "'\ ' \ \ ,/ ' --- oCasper 

• Map area 

\} ',\ j \, \, '\ ""' ..... ""'"' Ks '\ Kn ~--

,,, /, t ~ \ \ ______ .... ,..,-'----... ,, '\. \ /"' , ' I I I .... --- .,...... \ \ 1 ,' // : / / : , ... ,-- ___ , __ ..... ', \ ' 

/, /,"/ ,' /// .,' ,' ------------- \, \ : 

' : ,................ ,-.... ~" ., ...... "'loso {~· "',,' ......... ---------- \ \ ~ \ ~ ', _ .... ,......... __ , ......... ,.--....... I (: _____ ., .......---..... .................. \ \ ' 

FIGURE 148.1.-Generalized paleotopographic map of the eastern part of the Shirley Basin, Wyoming, showing relation of a mineral belt to the pre-Wind River 

erosion surface, and paleogeology. 

? 

~ 

C) 

tr1 

0 

~ 

0 

C) 

~ 

~ ::0 

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~ 

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tr1 

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...,. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-7 

149. ORIGIN AND EVOLUTION OF ORE AND GANGUE-FORMING SOLUTIONS, SILVERTON CALDERA, 

SAN JUAN MOUNTAINS, COLORADO 

By WILBUR S. BuRBANK and RoBERT G. LuEDKE, Exeter, N.H., and Washington, D.C. 

Work done in cooperation with the Colorado State Metal Mining Fund Board 

Comparative evolutions of vein, chimney, and hotspring deposits about the Silverton caldera indicate 

considerable mixing of primitive ore-forming solutions 

with solutions containing end-products of rock alteration and with meteoric waters. Gangue-rich vein deposits and sulfide-rich and gangue-poor chimney deposits were formed. 

This outline omits supporting evidence for some 

assertions and includes speculations not susceptible of 

proof, but it affords a working hypothesis that has 

proved of value in a continuing study of the ore deposits. 

The setting of the ore deposits (fig. 149.1) comprises a volcanic pile of Tertiary age, a mile or more 

thick and aggregating more than a thousand cubic 

miles in volume, centering about the Silverton caldera. 

Following a late volcanic caldron subsidence within 

the caldera bounds, the central complex and its surroundings were subjected to igneous intrusion of deep 

origin, n.rching of the formations, radial fissuring, and 

a final collapse1 that resulted in radial and peripheral 

graben structures. Radial fissures were invaded in 

turn by igneous dikes,· by injections of clastic debris, 

and by numerous stages of vein-forming solutions that 

yielded the compound type of veins illustrated in figure 149.2. 

In certain belts where tensional stresses were evidently minimized, both intrusive bodies .and later ore 

deposits tended to assume pipelike or chimney forms 

(fig. 149.1). 

Gn.ngue minerals commonly were deposited first 

upon each reopening of fissures and were followed by 

sulfides mixed with gangue or devoid of gangue. The 

first-stn.ge gangues are commonly quartz (rarely carbonate, fig. 149.2/3), followed by the bulk of the base- . 

met'n.l sulfides. In some veins of outer zones, barite 

is an early mineral, but not uncommonly it is partly 

or largely replaced by quartz. Rhodochrosite (or 

manganocalcite) is here later than barite. Where inner and outer zones overlap, early quartz and sulfides 

have preceded barite and sulfides. Rhodonite gangue 

follows early quartz and the bulk of the base-metal 

sulfides (fig. 149.2A). Additional quartz and sulfides, 

locally with adularia, fluorite, and carbonate, follow. 

In more complex manganese silicate gangues, friedelite and tephroite are early, but later reaction with 

Si02 for,ms rhodonite, or reaction with C02 forms 

rhodochrosite (Burbank, 1933). Free gold and silverrich sulfosalts generally accompany later gangue assemblages, and barren quartz-calcite or quartz may terminate vein £ormation. Traces of fluorite are common 

with quartz intergrown with sulfides, but the fluorite 

may be partly leached or replaced by quartz .. Sparse 

hubnerite is associated locally with late quartz-pyrite 

gangue. Sericite is a common alteration product of 

early vein stages and clay minerals of later ones, but 

zonal alteration also developed in vein walls. 

In chimney deposits the massive sulfi,des with some 

intergrown barite, sericite, and clayey products of rock 

decomposition fill leached cavernous openings in silicified rocks (fig. 149.3). A little late fluorite, rhodochrosite, and free gold occur in some deposits, and 

fluorite is localiy capped with gypsum. Enargite is a 

common copper mineral of chimneys but not of veins. 

Certain events of vein evolution may be correlated 

with the then-existing environment by reference to 

figure 149.3. Accompanying late intrusions of gabbroic and granodioritic magmas, the caldera core and 

its surroundings were invaded by gases and solutions 

causing widespread pre-ore propylitization of the 

rocks (Burbank, 1960). Initial openings of fissures 

resulted in explosive injections of clastic dikes, indicating that a considerable pressure of fluids had been 

built up in the root zones. With succeeding reopenings, at diminished pressures, the fluids in fractured 

rocks were forced by expanding gases into newly 

formed spaces, carrying with them fractionated endproducts of rock decomposition. These solutions in 

considerable part yielded .the early gangues that followed fissure openings. Solutions from deeper magmatic sources, which had little (if any) role in propylitic alteration, then entered the partly gangue-choked 

fissures, mixing to some extent with solutions from 

altered rock, and deposited sulfide and sulfide-gangue 

ores. As these mixed solutions reac11ed the levels of 

meteoric circulation in fissures, partial oxidation and 

further dilution took place. Certain geochemical 
c~s GEOLOGICAL SURVEY RESEARCH 19 61 

I 

UPLIFTED AND SUNKEN BLOCK 

\ 

37°50' 

107"45' 107°40' 

FIGURE 149.1.-Structural map of Silverton caldera and vicinity. Larger intrusive bodies, V-pattern; volcanic pipes, stippled 

pattern; faults, heavy lines; dikes and veins, light lines; locations of hot spring and meteoric water samples, X. Uplift of 

caldera core and northeast arch and their subsequent collapse caused compression along rim belt. Magmas and ore solutions 

worked upward along narrow vertical channels as contrasted with outer belts of tensional stresses. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-9 

FISSURE SYSTEMS CHIMNEY SYSTEMS 

... ~ 

) 

Q 

A METEORIC 

1 4 ZONE 

l't .: 

\ ;·. 

. ""(·· . \ .. . 

······ ... 

A : 

I 

; ":I ·. ( ~: t I 

I, 

~ 1 FOOT I 

B PROPYLITIC 

,, 

I 

a a 

r ) 1:)' tl ;;; .. ; 

\ •. ! 

ZONE 

..... ~ 

'=' 

v v 

c 

FmunE '149.2.-l\:lncro-structures of compound veins, Silverton ! 

calderu. A., No-Nume vein, Eureka Gulch, northeust graben · .1 ' nren; u, course quartz with pyrite and a little sphalerite·; 

b, mainly sphnlerite, chnlcopyrite, and galena intergrown 

with quartz (50 to 70 percent sulfides by weight) ; c, rhodonite ribs with patches of tephroite, friedelite, and carbonate; d, qunrtz. B, Mendota vein, Telluride district, outer 

northwest radial vein systems (after Purington, 1898) ; 

l, C'onnt1·y roek, pyritized nnd sericitized near walls; 2 (left) 

sphnlerite with cnlcite; 2 (right) sphnlerite nnd galena; 3, 

white quartz ; 4, rhodochrosite; 5; bluish quartz with finely 

dissentinated sulfides and sulfosalts. 0, London vein, Mineral 

Point, northeast radinl vein system (nfter Ransome, 1901) ; 

a, country rock; b, quartz and chalcopyrite; c, tetrahedrite; 

d, quartz ; e, galena ; f, quartz. 

depth zones were thus established in the vein channels 

(fig. 149.3). 

Igneous emn.nations causing propylitization consisted largely of C02 , H 2 0, minor H 2S, and presumnbly halogens, but much of the sulfur evidently remained behind in complexes of the sulfide solutions at 

their sources. Processes in the root zones and walls 

of fissures involving these early fluids would have certain predictn.ble effects on the evolutions of gangu~­

forming solutions. (a) Release of gases from altering solutions would tend to fractionate solutions as 

801.680 0-61--2 

ROOT 

,.. 

ZONE 

FIGURE 149.3.-Deptb zones in fissure and chimney systems 

of Silverton caldera mineralized belts. A, Zone of mixing 

of mineralizing solutions with partly oxygenated meteoric 

waters (locally 3,000 to 4,000 feet deep) ; B, zone of influx 

of fractionated end-products of rock alteration and of mixing with meteoric waters from above and sulfide solutions 

from below; 0, zone of influx of primitive ore solutions and 

products of deep rock alteration. Chimney deposits are in 

rocks locally preheated by volcanic pipes, with only minor 

influx of solutions from zone B. Chimney feeders are not 

reo~ned as frequently as feeders of fissure systems. S, 

siliceous envelope of altered and mineralized ground; black 

areas indicate sulfide deposits. Propylitic zone represents 

rocks charged with carbon dioxide and other gases under 

pressure, coming from deep-seated sources of caldera core. 

Dotted arrows indicate general movements of gases, solid 

arrows movement of solutions. 
C-10 GEOLOGICAL SURVEY RESEARCH 19 61 

they moved towards the fissures, leaving behind less 

soluble substances. (b) Solid solution and decomposition (as in carbonates) and reaction relations in other 

mineral series would tend to enrich esc~ping solutions 

in certain constituents. For example, Ca-Mn mixed 

carbonates subjected to isothermal loss of C02 pressure tend to become depleted in the Mn· molecule, 

which is enriched in any fluid remainder (Goldsmith 

and Graff, 1957). The formation of pyrite and chlorite would tend to fix Fe and Mg. Thus, remaining 

solutions, highly fractionated and subjected to mixing 

or reaction with siliceous solutions or minerals, could 

form the manganese silicate gangues or the manganese 

oxides of hot-spring de.posits (analysis 1, table 149.1; 

analyses 1 to 3, 5, table 149.2). 

The early q':lartz of the base-metal stage (fig. 149.2) 

could result from attack of C02 solutions on . ferromagnesian minerals with formation of mixed carbonates and release of silica (Knopf, 1929, p. 44-45). 

Source rocks at depth accordingly might have been 

partly desilicated prior to secretion of manganese. 

Early tephroite and friedelite of the manganese silicate stiite indicate that initial solutions were locally 

deficient in silica. Fluorides seem unaccountably late 

·in many vein sequences and in their continuing deposition from Recent hot-spring waters (analysis 2, 

TABLE 149.1-Chemical analyses of some hot-spring and meteoric 

waters of the Silverton caldera, San Juan Mountains, Colo. 

[In parts per million; ----• not looked for] 

Ouray hot Wagonwheel Treasury Tunnel meteoric 

spring Gap hot spring waters 

-----------1----------:--------·-

Sample 1 Sample 2 Sample 3 Sample 4 

Si 02 ___ .,. - ____ 49 92 96 47 Fe __ · ________ . 42 . 02 36 . 36 Mn _________ . 92 . 31 .2 Ca __________ ----------

Mg 376 67 310 44. 7 _________ 6. 1 0 13. 5 5. 6 Na __________ 111 477 126. 5 169. 2 K ___________ 8. 0 40 21. 5 54 LL _____ - - _ - - 1.0 2. 3 H C02 ---------- ---------- __ - ____ 128 1,020 48 98.2 

804- - - ------ 1,030 169 990 477 Cl ___________ 45 206 1. 4 1.0 F ___________ 3. 0 6. 8 PO. _________ ---------- ---------- . 06 11 B ___________ ---------- ---------- 23 6. 8 H2S- ---------- ---------- ________ .0 7 ---------- ---------- Solids _______ 1, 760 1, 560 1, 630 990 

pH-- - - - - - - - - 6. 8 6. 7 ---------- ---------- Temperature_ 143°F 144°F cold cold 

Discharge ____ 15 gpm 20 gpm ---------- ----------

R~W'~:~i~~ab. no. 850; H. C. Whitehead, analyst; collected by D. E. White and 

Sample 2; lab. no. 849; H. C. Whitehead, analyst; collected by D. E. White and 

R. W. Lakin. 

Sample a; lab. no. 6456: E. T. Erickson, analyst: collected by W. S. Burbank: 

from fissure 1,390 feet from portal Treasury Tunnel (about 650 feet vertically underground). 

Sample 4: lab. no. 6458; E. T. Erickson, analyst; collected by W. S. Burbank; 

from fissure vein 2,864 feet from portal Treasury Tunnel (about 800 feet vertically . underground). 

TABLE 149.2.-Semiquantitative spectrographic analyses of hotspring deposits and of manganese silicate gangue of late Tertiary 

veins, San Juan Mountains, Colo. 

[In percent: M, greater than 10 percent; ----• not looked for; (a) not detectable, wet chemical tests] 

Ouray hot springs Wagon- No-Name 

wheel Gap vein 

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 

Si _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X _ _ _ _ _ _ _ _ _ ______ _ AI_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . X _ _ _ _ _ _ _ _ _ ______ _ 

Fe______ 7. 0 X 0. 7 _______ _ Mg_____ . 15 ____________ . 07 _______ _ Ca______ __________ X _______________ _ Na _____________ :.__ . X _______________ _ 

K ______ -------------------------------------- Mn_____ 15.0 XX 30 _______ _ 

Ag_----- ---------- ------------ -------- -------- Ba_ _ _ _ _ _ . 7 X . 7 0. 045 

B ________ · _________ ------------ -------- -------- Be______ . 015 . OX . 001 _______ _ 

Cu_____ _ . 0015 . OX . 03 (a) 

Pb______ .07 .OOX .7 (a) Sb______ . 02 . OX . 3 _______ _ 

Zn______ . 02 . OX . 2 . 007 

w______ . 2 x 1. o _______ _ F _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . 22 

M 

.3 

M 

. 15 

.3 

.7 

.0 

.0 

. 003 

.0 

. 007 

. 0003 

. 015 

.3 

.0 

. 15 

.0 

Sample 1; lab. no. 58-1145; U. Oda, E. F. Cooley, analysts: collected by D. E. 

White and R. W. Lakin; from material being deposited at time of sampling, Pavillion spring. Sample 2; lab. no. 52-1637; R. C. Havens, analyst; collected by W. S. Burbank 

and C. T. Pierson; from old travertine Pavillion spring. Sample 3;lab. no. 58-1139; U. Oda, E. F. Cooley, analysts; collected by D. E. White 

and R. W. Lakin; from oxide vein in fissure occupied by hot waters. Sample 4; Wagonwheel Gap; George Steiger, analyst; Emmons and Larsen, 1913; 

travertine. 

Sample 5; lab. no. 287139; N. M. Conklin, analyst; collected by W. S. Burbank 

and R. G. Luedke· manganese silicate gangue from 5-foot rib of vein (fig. 149.2A), Sunnyside mineJ northeast graben area (fig. 149). Chemical analysis of a separate sample from a aump, representing considerable early friedelite and tephroite with 

rhodonite and selected for volatile determinations gave (in percent): Mn, 40.4; As, 

0.043; C02, 0.30; total S, 0.18; sulfide S, 0.04; H20+, 3.94; H20-, 0.05; P205, 0.01; 

C1, ~.64; F, 0.21; E. J. Fennelly, I. C. Frost, D. L. Skinner, E. L. Munson, analysts. 

table 149.1; analysis 4, table 149.2). The association 

of early barite with fluorite, creedite, and gearksutite 

in the vein at Wagonwheel Gap (Emmons and Larsen, 1913, Larsen and Wells, 1916), and the presence 

of some H 2S in associated 'hot-spring waters (analysis 

2, table 149.1) are permissive evidence that partial 

oxidation of H 2S could have taken place. Thus, some 

fluorine may have been leached by action of nascent 

S04--on wall rocks or on earlier sericite and fluorite 

gangue of deeper vein zones. But· part of sulfate in 

spring waters is probably of connate or meteoric origin (analyses 3 and 4, table 149.1) and some possibly 

of magmatic origin. ·Leaching of fluorite and its replacemep.t by quartz, noted in late Tertiary veins, also 

indicates that fluorine in its various mineral associations advanced surfacewards by repeated deposition 

and resolution. The same is true in some degree for 

barium. 

Comparison of bulk composition of oxide deposits of 

Ouray hot springs with manganese silicates of the NoName vein (analyses 1-3, 5, table 149.2) indicates 

that the spring waters could be similar to those of the 

gangue solutions of the veins, except in degree of dilu-
SHORT PAPERS IN THE GEOLO.GIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-11 

tion and oxidation. An exceptio11 is tungsten in the 

oxides but not in the silicates, perhaps indicative that 

leaching of previously formed gangue assemblages 

could be a factor in origin of the hot-spring waters. 

The overall low base-metal content of some vein 

gangues and spring deposits is consistent with a low 

sulfide content of corresponding gangue-forming solutions; hence a different source for these solutions is 

suggested from those forming the bulk of the sulfides. 

It is noteworthy that in chimney channels, where reopening and pressure release were minimized, the ore 

deposits are characteristically low in gangue content. 

These ore solutions, coming directly from depth with 

less dilution from wall-rock sources, deposited chiefly 

sulfides with abrupt loss of pressure in shallow ground 

and with partial mixing with oxygenated waters of 

the solfu,taric zone. These more primitive sulfide solutions contained considerable H 2S as shown by widespren.d pyritic and solfataric alteration of the enclos~ 

ing rocks. 

REFERENCES 

Burbank, W. S., 1933, The manganese minerals of the Sunnyside veins, Eureka Gulch; Colorado : Am. Mineralogist, v. 

18, p. 513-527. 

-- 1960, Pre-ore propylitization, Silverton caldera, Colorado, in Short papers in the geolo~ical sciences: U.S. 

Geol. Survey Prof. Paper 400-B, p. B12-B13. 

Emmons, W. 1f., and Larsen, E. S., 1913, The hot springs 

and mineral deposits of Wagonwheel Gap, Colo.: Econ. 

Geology, v. 8, p. 233-236. 

Goldsmith, J. R., and Graff, D. L., 1957, The system Ca0-

Mn0-C02; solid solution and decomposition relations: 

Geochim. et Cosmochim. Acta, v. 11, p. 310-334. 

Knopf, Adolph, 1929, The Mother Lode system of California : 

U.S. Geol. Survey Prof. Paper 157, 88 p. 

Larsen, E. S., and Wells, R. C., 1916, Some minerals from the 

fluorite-barite vein near Wagonwheel Gap, Colo.: Natl. 

Acad. Sci. Proc., v. 2, p. 360. 

Purington, 0. W., 1898, Preliminary report on the mining industries of the Telluride quadrangle, Colorado: U.S. Geol. 

Survey Ann. Rept. 18, pt. 3, p. 745-748. 

Ransome, F. L., 1901, A report on economic geology of the 

Silverton quadrangle, Colorado: U.S. Geol. Survey Bull. 

182, 265 p. 

150. GEOWGIC EVENTS CULMINATING IN PRIMARY METALLIZATION IN THE CENTRAL MINING DISTRICT, 

GRANT COUNTY, NEW MEXICO 

By W. R. JoNEs, R. M. HERNON, and W. P. PRATT, Denver, Colo. 

In the C~ntral mining district of New Mexico, where 

recorded production of minerals now exceeds one billion dollars, a sequence of geologic events in the interval between Late Cretaceous and Miocene time culminated in the formation of ores of iron, copper, zinc, 

lead, molybdenum, and silver. 

Although the age of primary metallization is not 

known in terms of years or even in terms of the early 

Tertiary epochs, there being no strata of these epochs 

present, it is known relative to a sequence of rocks intruded within the Late Cretaceous to Miocene time 

interval. Some 30 or more distinct varieties of intrusive rocks, assignable to four age groups, have been 

re·cognized in the district. From oldest to youngest, 

these groups are: 

1. GeneraJly concordant plutons-thin and thick sills, 

laccoliths, and bysmaliths. 

2. Mafic plugs and dike swarms spatially and temporally related to mafic flows and breccia. 

3. Discordant plutons-stocks and apophyses and upward-flaring masses. 

4. Dike swarms and plugs. 

Few age relations are known between units of 

groups 1, 2, or 3 owing to the lack of cross-cutting relations. However, relative ages of units of group 4 are 

well established; the units are assignaljlle to five subgroups, which are, from oldest to youngest : 

1. Granodiorite porphyry dikes (2 or 3 varieties). 

2. Quartz monzonite porphyry dikes (1 variety). .. 

3. Quartz latite porphyry of the Republic and Turnerville dike complexes ( 1 or ·2 varieties). 

4. Quartz latite porphyry plugs and dikes (3 or 4 

varieties) . 

5. Rhyodacite porphyry plug and dikes ( 3 or 4 varieties). 

The ranges in modal and normative composition of 

several rocks of the four groups are shown on figure 

150.1. The distribution of the four main age groups 
C-12 GEOLOGICAL SURVEY RESEARCH 19 61 

or 

A. MODE 

Granite 

Syenite 

B. NORM 

Concordant plutons Age group 1 1. .. · .. · · . Syenodiorite porphyry 

2 ......... Quartz diorite porphyry 

3., 3a.· · · ·.Hornblende quartz diorite porphyry 

4. · · · · · · · · Rhyolite porphyry 

Mafic plutons Age group 2 

5. · · · · · · · · Calcitrachyte porphyry 

Discordant plutons Age group 3 

6., 6a. · · · · Granodiorite of Hanover-Fierro pluton 

6. South lobe; 6a. main mass. 

7. · ....... Quartz monzonite of Santa Rita stock 

8. · · · · · · · · Quartz latite of Copper Fl~t pluton 

Dike swarms and plugs Age group 4 

9a., 9b., 9c.Granodiorite porphyry dikes 

10. ·······Quartz monzonite porphyry dike 

11. · · · · · · · Rhyodacite porphyry dike (post ore) 

Plagioclase 

an <50 

an+ ab 

FIGURE 150.1.-l\fodes and norms of some intrusive rocks in 

the Central mining district, Grant County, N. Mex. Limiting proportions in modal plot, A, are those used by Nockolds 

(1954) ; limiting proportions in normative plot, B, are derived empirically from plot of Nockolds' average norms. 

at the pref)ent level of truncation is shown on figures 

150.2 and 150.3. 

The groups and units of the intrusive sequence 

serve as time-markers within the Late CretaceousMiocene interval and reveal stages of folding, faulting, and mineralization that otherwise might appear 

to have occurred during a single episode. Use of the 

intrusive sequence for chronological purposes is beset, 

of course, by several inherent difficulties and must be 

supplemented by geological reasmnng. 

108"07'30" 108"00'00" 

32"45'nn··L----------------------------------------~ 

108"07'30" 

32"52' 

A. Granodiorite porphyry dikes 

l . ~ ' Hanove 11 11 \ 

/ 1 1 I 

(~.·\ (1 

. 32• 45'0o"L----------------------------------------....J 

B.· Quartz mon2onite porphyry dikes 

EXPLANATION 

Edge of Miocene and younger rocks 

0 2 MILES 

FIGURE 150.2.-Granodiorite porphyry and quartz monzonite 

porphyry dike swarms within Santa Rita quadrangle, New 

Mexico. 

... 
32"52' 

32"45' 

>· .............. . 

.,.:.\ \ 

\ 

P · 

'IJos 

\~ ..... 

"' ...... 

~ltos 

0 

108"0 

fTi'IIJge 

' 

I 

Hurley 0 

I 

SANTA RITA ADRANG~ 

Cobre Mountains 

0 I 2 MILES 

Santa Fe 0 

Albuquerque 

NEW/ MEXICO 0' Socorro 

Los Cruces 

INDEX MAP 

·v·"-. !: ~ • 0 0 • 

z u 

. 

~ . £ ' !; 

< 

EXPLANATION 

5J 

Edge of Miocene and younger 

rocks 

3rd age group 

Disco1·dant pLutons 

~~IIHTill 2nd age group 

TKi , maj'ic plutons. 

T Kv, mafic volcanic rocks of 

Tertiary or Cr etaceous age 

1st 

-

age group 

Concordant plutons 

Late Cretac

~ eous and older strata 

Beartooth quartzite stippled 

~----- Contact, showing dip 

Dashed where approximately 

located 

~ '----...... . Major normal fault 

Das hed w here a pproximately 

located, dotted where concealed. 

Bar and ball on downthrown 

side 

Minor 

~ 

normal faults and 

f ractures A----------- Anticline, approximately located 

Showi'ri.{J trace of axial plane and 

bearing and plunge of axis 

x--------- Syncline. approximately located 

Showing trace of ax-ial plane 

'\ 

Strike and <lip of beds 

Geology east of 108' after Kuellmer (19 56), west 

of 108' by U. S Geolog1cal Survey 

FIGU RE 150.3.-Structural setting of the Central mining district, Grant County, N. Mex. 

U1 

s 

~ 

8 

"d 

> "d 

1:'.1 

!:0 

U1 

z 

~ 1:'.1 

0 

1:'.1 

0 

t"' 

0 

0 

,_. 

("') 

~ t::l 

~ t::l 

!:0 

0 

t"' 

0 

0 

,_. 

("') 

U1 

8 

1:'.1 

~ 1:'.1 

Ul 

> 

§ 

~ 1:'.1 

U1 

.... 

... 

-.:, 

I 

"" "' "" 

Q 

I 

-

Cl.j 
C-14 GEOLOGICAL SURVEY RESEARCH 1 9 61 · 

TABLE 150.1.-Chronological summary of igneous activity, deformation, and mineralization from Late Cretaceous time to time of primary . ore deposition, Central mining district, Grant County, N. Mex. 

Igneous activity 

Intrusion of ~enerally concordant 

plutons: 

Syenodiorite porphyry 

Augite-hornblende andesite porphyry 

Rhyolite porphyry 

Quartz diorite porphyry 

Hornblende-quartz diorite porphyry 

Volcanic epoch: 

Andesite breccia, agglomerate, and 

mafic flows, and intrusion of thousands of m,afic porphyry dikes. 

Plugs and itregular plutons of orthoclase gabbro, calcitrachyte, and 

augite syenite intrud.ed into core of 

great volcano centered west of 

Central mining district. 

Intrusion of discordant stocks and 

upward-flaring plutons: 

Granodiorites of the Hanover-Fierro 

pluton. 

Quartz monzonites of the Santa Rita 

stock. 

Quartz latites of the Copper Flat 

pluton. 

Intrusion of grandiorite porphyry dike swarm. (See fig. 150.2A.) These 

dikes invade fissures in walls of major 

faults as well as the faults themselves. 

Dikes extending from Santa Rita 

stock may be stock apophyses, hence 

somewhat older than the others. 

[Earliest events at top of table; most recent events at bottom] 

Deformation 

Great domal uplift by multiple injection of 

sills and laccoliths as much as 1,100 feet 

thick, largely in shales of Upper Cretace- ous Colorado shale, but also in upper 

Paleozoic strata. Some trapdoor-type 

uplifts produced faults of large displacement. Overlapping sills. and laccoliths 

centered along line south of Barringer 

fault underlie Fort Bayard arch (fig. 150.3). 

Major normal faulting, and differential subsidence in area of domal uplift. Result is 

the Santa Rita horst (fig. 150.3), some 40 square miles in area, and several small 

horsts and grabens formed along its 

southern margin. Strata bent along 

major faults. Area of subsidence extends 

south and north of the mining district 

under younger Miocene volcanic rocks 

and valley-fill. 

Erosional epoeb 

Fracturing largely to the west and northwest of the Santa Rita horst, development 

of radial and broad arcuate fracture 

patterns. (Dike swarms omitted from 

figure 150.3 for simplicity.) 

Great deformation caused by forcible intrusion of granodiorite in area between 

Hanover and Fierro; earliest surge ex- panded just below level of present surface, 

compressing strata in peripheral folds and 

thrusting them outward a short distance. 

A later, stronger surge created an elongate 

piercement dome normal to the axis of 

the Fort Bayard arch; strata along west 

and east margins were turned sharply 

upward and thinned. Emplacement of 

quartz monzonite stock at Santa Rita 

created a northwest-trending dome and 

obliterated several major faults, but, 

unlike the Hanover pluton, barely reached 

the level of the present surface; pulsations 

during emplacement brecciated large area west and northwest of the stock. Surges 

of magma at Copper Flat expanded near level of present surface, causing some doming and folding in wall rocks. 

Steep fractures of dominantly north and 

northeast trend and a few of northwest 

trend developed as shown by the pattern 

of dikes in figure 150.2A. 

Mineralization 

Alteration largely confined to the porphyries. 

Very little evidence of thermal metamorphism of contiguous siliceous carbonate 

rocks; residual interstitial aqueous fluid 

either failed to collect and migrate from 

magma or was consumed in hydrolysis and 

hydration of silicates. Pervasive propylitic alteration in all concordant plutons. 

Andesite breccia pervasively propylitized and 

thermally metamorphosed for several tens 

of feet around mafic plutons; zeolite and 

hematite alteration locally. 

Any thermal or metasomatic effects in the 

wall rocks of the discordant plutons cannot 

be distinguished from later effects of 

hypogene fluids that rose along the margins 

of the plutons following intrusion of the 

granodiorite porphyry dikes. Some chalcopyrite blebs disseminated in unaltered 

parts of the Santa Rita stock may have 

formed during consolidation of the quartzorthoclase matrix. 

Any thermal or metasomatic effects in wall 

rocks cannot be distinguished from later 

effects of hypogene fluids that rose along 

these dikes after consolidation and re- opening. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROL.OGIC SCIENCES, ARTICLES 147-292 C-15 

TABLE 150.1.-Chronological summary of igneous activity, deformation, and mineralization frorri Late Cretc;,ceous time to time of primary ore deposition, Central mining district, Grant County, N. Mex.-Continued 

Igneous activity 

Intrusion of q tutrtz monzonite porphyry 

dike swarm. (See fig. 150.2B). 

[Earliest events at top of table; most recent events at bottom] 

Deformation 

Erosional Epoch-Continued 

Existing faults reactivated, breaking the 

stocks and granodiorite dikes loose from 

their wall rocks, thus providing deep 

conduits for the hypogene fluids accum·u- lated below. Breccia pipes within the 

Santa Rita stock and in the area to 

the west and northwest may have developed at this time, if not earlier. Santa 

Rita stock crackled and the part of 

Hanover-Fierro pluton near Fierro 

sheared at this time. 

Renewed fracturing along earlier faults into 

which granodiorite dikes were intruded. 

(Compare fig. 150.2A and B.) Composite 

dikes common. Minor reopening and fracturing along 

quartz monzonite dikes. 

Mineralization 

Main epoch of primary metallization. Large 

surge of hypogene fluid rose along margins 

of stocks and obliquely up faults intersecting those margins, causing pyrometasomatic alteration in wall rocks for considerable distance from conduits. Carbonate 

rocks silica ted and recrystallized; shales 

baked, epidotized, or converted to hornfels; 

granodiorite dikes, many of which were major channelways, and older porphyries 

epidotized and chloritized. Porphyries in 

Bayard area altered to calcite-sericite-clayquartz rock close to veins and to chloritesericite-epidote for several tens of feet 

away from veins, grading into mildly 

propylitized rock. 

MagPetite-chalcopyrite ores formed in car- bonate rocks close to parts of the Santa 

Rita and Hanover-Fierro plutons. Chalcopyrite, molybdenite, adularia, quartz, and 

chlorite filled fissures in propylitized parts 

of Santa Rita stock, apparently somewhat 

before the argillic phase of alteration and 

the metallization that accompanied it .. Sphalerite with only minor galena and 

chalcopyrite formed replacement bodies in 

carbonate rocks between Hanover and 

Santa Rita, and around the south lobe . of the Hanover-Fierro pli.1ton. Sphaleritegalena, and sphalerite-galena-chalcopyrite 

veins and replacement bodies formed along 

major taults (Groundhog, Hobo, Mirror, 

Barringer), along most granodiorite dikes, 

and around pluton at Copper Flat. 

During a late phase of the metallization, 

great volumes of porphyry at Santa Rita, 

both sills and stock, were altered to 

montmorillonite and biotite, and also to 

kaolin-alunite-illite-quartz rock in which 

pyrite and chalcopyrite formed disseminations and veins. Small volumes of porphyry were completely silicified. Similar 

but less widespread alteration took place in 

the. Hanover-Fier-ro pluton near Fierro. 

Supergen«? processes subsequently intensified this primary argillic alteration. 

Thermal and metasomatic effects insignificant. Dikes are mildly to moderately 

propylitized and sericitized although locally 

intensely a.rgillized by supergene waters. 

Dikes in Santa Rita stock contain some chalcopyrite and, locally, much pyrite. 

West of the stock, dikes are cut by a few 

veinlets containing galena and sphalerite. 

Dikes were intruded during waning of 

metallization, or were followed by a. second, 

much weaker, period of metallization. 
C-16 GEOLOGICAL SURVEY RESEARCH 1 9 61 

The chronology of the area from Late Cretaceous 

time ~o the time of primary ore deposition is summarized in table 150.1. The geologic history prior to Late 

Cretaceous time has been described elsewhere (Hernon, .Jones, and l\1oore, 1953) ; in brief, at the onset 

of Laramide igneous activity, flat-lying and uncleformed sedimentary rocks of Paleozoic and Late 

Cretaceous age, aggregating about 6,000 feet in thickness, blanketed the Precambrian crystalline basement 

complex. 

Clearly, the porphyries, the folds and faults, the altered rock, and the ore deposits in the Paleozoic and 

Cretaceous strata are all genetically related to a large 

body of magma emplaced in the basement rocks, and 

to its cooling and consolidation during early Tertiary 

time. 

REFERENCES 

Hernon, R. 1\f., Jones, W. R., and Moore, S. L., 1953, Some 

geologic features of the Santa Rita quadrangle, New 

Mexico, in New Mexico Geol. Soc. Guidebook 4th Ann. 

Field Conf., 1953: p. 117-130. 

Kuellmer, F. J., compiler, 1956, Geologic map of Hillsboro 

Peak thirty-minute quadrangle: New Mexico Bur. Mines 

and Mineral Resources, 30-minute Quad. Ser., no. 1 [Geol. 

Map 1]. 

Nockolds, S. R., 1954, Average chemical compositions of some 

igneous rocks: Geol. Soc. America Bull., v. 65, p. 1007-

1032. 

GEOLOGY OF LIGHT METALS AND IND.USTRIAL METALS 

151. BERYLLIUM IN STREAM SEDIMENTS FROM THE TIN-TUNGSTEN PROVINCES OF THE SEWARD 

PENINSULA, ALASKA 

By C. L. SAINSBURY, ARMIN W. lliLz, CHARLES S. ANNELL, and HAROLD WESTLEY, Menlo Park, Calif., and 

Washington, D.C. 

Previous work summarized by McKelvey ( 1960, p. 

A5) has shown that the tin districts of the Seward 

Peninsula, Alaska, contain promising amounts of 

beryllium. Geochemical reconnaissance 1 of the principal areas of tin-tungsten lode deposits of the Seward 

Peninsula, has shown that beryllium is concentrated 

in the stream sediments of Cassiterite Creek near 

the Lost River mine in the Teller B-5 quadrangle 

(fig. 151.1). Total sediments downstream or· downslope from the Lost River mine contain as much as 

160 ppm (parts per million) beryllium. The east extension of a dike that contains the main tin ore shoot 

of the Lost River mine is within the drainage basin of 

nearby Camp Creek, and sediments from Camp Creek 

consistently contain more than 110 ppm (fig. 151.1). 

Upstream from the Lost River mine the beryllium content of stream sediments decreases abruptly to less 

than 3 ppm, ·which is the regional background value of 

sediments from streams that drain the limestone bedrock. 

1 Field work by C. L. Sainsbury; laboratory determinations of 

beryllium by Armin Helz, Charles Annen, and Harold Westley by use 

of the direct-reading spectrograph. ' 

Other sediment samples in the vicinity of Lost River 

that are rich in beryJ.lium (fig. 151.1) include samples 

from below the Bessie and Mabel prospect, which contains tin and tungstein in an altered dike similar to 

the ore deposits at the Lost River mine; samples from 

an altered area along the north contact of a granite 

stock on Tin Creek; and samples of stream sediments 

and slope wash from granite at the head-waters of 

Lost River. Samples from the last-named locality 

contain up to 47 ppm beryllium, the richer samples 

being slope wash from disintegrating contact rock rich 

in idocrase. Idocrase from the Lost River area is 

kn-own t<;> be consistently high in beryllium (Mcl(elvey, 1960, p. A5) . 

Some randomly selected samples of banded fluoritetactite rock at the Lost River mine contain up to 0.15 

percent beryllium, and all the specimens of fluoritetactite rock contained more than 3 ppm beryllium. 

The beryllium content is highest in samples of fluorite-tactite rock from the walls of the tin-bearing 

dike where banded fluorite-tactite rock constitutes continuous bodies of minable size but of u.nknown average 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-17 

,•'"'-

................ 

"\ 

,/ 

···-··.'--···/·· 

I 

·--

\ 45: 

_ ...... ~33 

I \ J: 

1- I\.) fha -IJ 

;-.......,c_ ......... 10 

.;- 3 

_..-"· 

N 

I 

\ 

EXPLANATION 

lt \ 1 1 

Granite 

D 

Limestone 

• 41 Sediment sample 

with Be content 

1 MILE in ppm 

l!'IOURE l.Ci1.l.-Mnp showing location and beryllium content 

of sediment snmples, Lost River areu, Seward Peninsula, 

Alnslw. 

grade of beryllium. Beryl, phenacite, and chrysoberyl 

occur at the Lost River mine; secondary beryllium minerals perhaps will be found. 

Stream sediments from the Ear Mountain area 50 

miles northeast of Lost River contain less than 20 

ppm beryllium, although a broad zone surrounding 

the granite stock which intrudes limestone and limy 

schists at this locality contains more than the background, which appears to be less than 3 ppm beryl-

·lium. Rock samples from a tin-tungsten prospect at 

the Winfield shaft on the north contact of the granite 

at Ear ~1ountain contain up to 380 ppm beryllium, the 

higher values being in fluorite-tactite rock rich in 

idocrase. 

A granite stock intrudes limestone at the Cape 

Mountain area, 30 miles northwest of the Lost River 

mine. Sediment samples in this area generally contaim~d less beryllium than those from the Ear Mountain and Lost River areas. Only one sample contained 

as much as 20 ppm. This sample \Yas slope wash from 

an old dump at a tin prospect on a tourmalinized dike. 

The analyses reported above and other work in the 

Seward Peninsula (Mcl(elvey, 1960, p. A5) suggest 

that the bedrock source of beryllium in the str'eam 

sediments is both the granite and the tin lodes. Beryllium is particularly concentrated in or near tin-bearing greisen and fluoritized tactite, and in local areas 

of argillic alteration of hypothermal origin, particularly in the Lost River area. 

REFERENCES 

McKelvey, V. E., compiler, 1960, Geological Survey research 

1960, synopsis of geologic results: U.S. Geol. Survey Prof. 

Paper 400-A, 136 p . 

Sainsbury, C. I ... , 1960, Metallization and post-mineral hypogene 

argillization, Lost River tin mine, Alaska: Econ. Geology, 

v. 55, p. 1478-1506. 

Sharp, ,V. N., and Hawley, C. C., 1960, Bertrandite-bearing 

greisen, a new beryllium ore, in the Lake George district, Colorado, in Short papers in the geological sciences : 

U.S. Geol. Survey Prof. Paper 400-B, p. B73-B74. 
C-18 GEOLOGICAL SURVEY RESEARCH 1 9 61 

152. SLATE FROM THE GREENVILLE QUADRANGLE, MAINE, AS POTENTIAL LIGHTWEIGHT 

AGGREGATE MATERIAL 

By GILBERT H. EsPENSHADE and HowARD P. HAMLIN, Washington, D.C., and Bureau of Mines, Norris, Tenn. 

In the course of mapping the geology of the Greenville quadrangle in the western part of the "slate belt" 

of central l\1aine, a large sample of slate· was collected· 

from a roadside exposure by G. H. Espenshade, and 

was tested for suitability as source material for 

bloated lightweight aggregate by H. P. Hamlin. The 

test results indicate that slate of the type sampled, 

which underlies many square miles of the region, expands when fired in a rotary kiln under controlled 

conditions to produce lightweight aggregate of good 

quality. 

Two stratigraphic units have been recognized in 

mapping the Greenville quadrangle; their age relation 

has been worked out by determination of the upper 

boundary from graded bedding at numerous localities. 

The older unit consists mainly of dark reddish-brown 

fine·-grained limy sandstone and thin beds of slate, 

and the younger unit is predominantly dark-gray slate 

and some beds of dark-gray siltstone and fine-grained 

sandstone. The dark-gray slate is composed mainly 

of white mica, chlorite, and very fine grained quartz; 

some biotite and very fine pyrite and graphitic material are characteristically present. The age of the 

younger unit cannot be conclusively determined from 

the few known. fossils, but an Early Devonian age is 

indicated by the lithologic similarity to the Seboomook formation about 30 miles farther north (Boucot 

and others, 1960) ; the older unit may be Silurian or 

Devonian. 

The rocks are folded in northeast-trending isoclinal 

folds 'vith the younger unit exposed in the southeast 

quarter of the Greenville quadrangle in synclines underlying Doe Hill, Buck- Hill, and Doughty Hill, and 

in the northern half of the quadrangle in a folded belt 

nearly 10 miles wide. A large body of gabbro and 

two smaller bodies of granitic rock have intruded 

these rocks, and have formed contact aureoles of 

hornfels and andalusite schist that are very similar to 

the contact metamorphic rocks around the Onawa 

pluton, a few miles east in the Sebec Lake quadrangle 

(Philbrick, 1936). The major geologic features that 

have been mapped in the Greenville quadrangle by 

Espenshade are shown on the map by Boucot and 

others ( 1960) . 

Slate has been quarried for material for the manufacture of milled slate for electrical switchboards and 

for other uses from ·3 linear belts near Monson and 

Blanchard, apparently from two distinct stratigraphic 

horizons. A group of quarries near the Shirley-Blanchard townline and a group of quarries near Parrot 

and Monson seem to be in slate beds that are at the 

base of the younger tlnit. Quarries extending in a 

line southwest from the Farm quarries and the Hillside quarry of the Portland-l\1onson Slate Co. (U.S. 

Geol. Survey topographic map of Sebec Lake quadrangle, 1950) are in slate beds higher in the younger 

unit. At both stratigraphic positions, the slate is in 

beds that are commonly 1 to 10 feet thick and are 

interbedded with sandstone beds of similar thickness. 

Slaty cleavage seems to be developed best where slate 

and sandstone are interbedded; several intersecting 

sets of poor slaty cleavage generally occur where sandstone beds are absent. 

Previous tests of the dark-gray slate from the 

Monson area, reported by Conley (1942), Trefethen 

( 1955), and Caldwell ( 1959), showed that the slate 

had bloating characteristics. Because these samples 

were presumably ttt.ken from quarries or dumps at 

places where slate is closely interbedded with sandstone that probably is nonbloating, it seemed advisable 

to test a large sample from a stratigraphic position 

where sandstone was scarce or absent. Accordingly, 

a chip sample of slate weighing about 230 pounds and 

representing about 280 feet across strike was taken 

from the prominent roadside exposure on the hilltop 

about 0.6 mile southeast of Lower Shirley Corner, on 

State Highway 15 between Greenville and Monson. 

The beds of slate at this exposure appear to be more 

than 1,000 feet stratigraphically above the base of the 

younger unit. 

Preliminary tests were made on small portions of 

the slate sample to determine bloating temperature, 

general firing characteristics, and some other properties as shown on figure 152.1 and table 152.:t. Data 

from these preliminary tests showed that the slate 

had a short firing range, but probably would be 

amenable to the rotary kiln method of processing. 

The slate sample was tested by the procedures described by IGinefelter and Hamlin ( 1957) for evaluating raw materials for manufacture of lightweight 

aggregate by the rotary kiln process. . These tests 

yielded data shown on tables 152.2 to 152.4. 
·SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-19 

Crushing tests of three slate samples yielded the 

size fractions given in table 152.2. Samples crushed 

through roll and jaw crushers gave elongate, thin, 

platy particles; some improvement resulted when the 

samples were processed by a gyratory crusher (sample 

2) , but further study of crushing techniques and 

equipment is recommended. 

A preliminary rotary kiln test of a 25-pound sample 

(ranging from <l-inch to dust size) was made 

to determine the general processing characteristics 

and to adjust the kiln variables (rotation speed, slope, 

feed rate, and so forth). Excessive sticking and 

logging prevented completion of the test; examination 

of the fired material showed that the < 1-inch->%,-

inch particles we~·e not expanded, whereas the <8-

mesh material was overtired and partially melted. 

Consequently, all <8-mesh material was removed from 

subsequent samples. 

160~--------------------------------------~ 

140 

..... 

g 120 ~ 

u 

~ 100 u 

0:: 

UJ 

Q.. 80 (/) 

0 

z 

::J 60 ~ 

40 

20 

1800 1900 2000 2100 2200 2300 

TE~PERATURE (

0 F.) 

FIGURE 152.1.-Results of preliminary bloating tests of sample 

of slate from Maine compared with test of sample of shale 

that is used commercially as raw material for lightweight 

aggregate. Time interval indicates retention time of sample 

in kiln. 

TABJ,E 152.1.-Preliminary bloating tests of slate sample from Maine heated in electric kiln for different time periods 

Retention time 

'l'empernture, degrees F 

5 minutes 10 minutes 15 minutes 

Pounds per Absorption Remarks Pounds per Absorption Remarks Pounds per Absorption Remarks 

cublcfoot (percent) cubic foot (percent) cubic foot (percent) 

1800 152. 0 3. 2 No bloating _______ 150. 8 3. 2 No bloating _______ 148. 8 3.0 No bloating. 

1900 151. 4 3. 2 No bloating _______ 132. 7 4. 9 No bloating _______ 140. 5 5. 3 No bloating. 

2000 129. 6 5. 6 Slight bloating ____ 110. 3 7. 3 Fair bloating ______ 108.4 3. 6 Fair bloating. 

2100 99. 1 8. 3 Fair bloating ______ 77. 9 9. 4 Good bloating _____ 72. 2 9. 0 Good bloating, 

slightly sticky. 

2200 78. 5 8. 9 Good bloating, 55. 4 10. 5 Good bloating, 55. 4 7. 8 Good bloating, 

slightly sticky. slightly sticky. sticky. 

2300 65. 4 11. 6 Good bloating, 39. 2 10. 4 Overbloated, 33. 0 9. 7 Overbloated, 

very sticky. 

TABLI~ 152.2.-Screen analyses of crushed slate samples (unfired) 

[In percent] 

U.S. Sttmdnrd screen sizes Sample 

2 3 

13. 4 -------- -------- 10. 0 10. 2 -------- 30. 5 30.8 25. 2 

12. 2 22. 5 40. 8 

1- to 1~-inch __________________ _ %-to l-inch ___________________ _ ~-to %-inch ___________________ _ 

4-mesh to ~-inch _______________ _ 

8-mesh to 4-mesh _______________ _ 14. 6 20.0 13. 6 <8-mesh ______________________ _ 19. 3 16. 5 20. 4 

1-------1-------·1------- Totals __________________ _ 100.0 100. 0 100.0 

The results of rotary kiln tests on samples of· three 

different feed sizes are given by table 152.3. During 

tests 1 and 2, when the expanding temperature of the 

larger particles was reached, the >8-mesh material 

wns overfired and very sticky. Considerable logging 

occurred, and the kiln temperature had to be reduced 

very sticky. very sticky. 

before the material would flow evenly through the 

kiln. The aggregate from test 3, using kiln feed of 

<%,-inch->8-mesh size range, proved to be superior 

to the aggregate produced in tests 1 and 2, showing 

that a very good aggregate can be made from the slate 

if the kiln feed size range is closely controlled. Screen 

analyses of aggregate from these three tests crushed to 

<%-inch (the usual crushing size for concrete building. units) are given by table 152.4. 

Standard 2-inch concrete cubes were made from 

the aggregate of rotary kiln test 3 ; the characteristics 

of this concrete compare favorably with the properties 

of concrete made from two commercial aggregates 

as shown by table 152.5. 

It is concluded that slate from Maine of the type 

tested, which underlies many square miles of the 

region, will make a good-quality lightweight aggregate. 
C-20 GEOLOGICAL SURVEY RESEARCH 19 61 

TABLE 152.3.-Rotary kiln tests 

Sample 

1 2 3 

Feed ~ze _________________ 1~-inch l-inch %-inch 

to 8- to 8- to 8-

mesh. mesh. mesh. 

Weight of raw material 89.6_---- 88.5 _____ 86.0. 

(pounds per cubic foot). 

Tem~~~l~~~~e_g_r~~~ -~~ ___ 2075 _____ 2075 _____ 2085. Optimum _____________ 2060 _____ 2050 _____ 2040. 

Minimum ____________ 2030 _____ 2020 _____ 2010. 

Weight of aggregate 

(pounds K£r cubic foot): 

A.S.T .. container 62.5 _____ 47.5 _____ 48.0. 

method. 

Laboratory suspended 87.9 _____ 75.3 _____ 73.0. 

weight method. 

Absorption (percent) _______ 6.8 ______ 6. 7------ 9.5. 

Effect of quenching ________ Delete- Delete- Deleterio us. rio us. rio us. Processing characteristics ___ Poor _____ Fair_ ____ Good. 

TABLE 152.4.-Screen analyses of fired aggregate crushed to less 

than %-inch 

[In percent] 

U.S. Standard screen sizes Sample 

1 2 3 

4-mesh to %-inch ________________ 35. 6 32. 2 29. 6 

8-mesh to 4-mesh ________________ 32. 5 39. 6 40. 5 

20-mesh to 8-mesh _______________ 18. 6 20.0 17. 1 

65-mesh to 20-mesh ______________ 5. 2 6. 0 6. 6 < 65-mesh ______________________ 8. 1 2. 2 6. 2 

TotaL ___________________ 100. 0 100. 0 100.0 

TABLE 152.5.-Concrete performance tests 

Lightweight ag- Commercial lightweight aggregate 

grW~fn~~~he 1------.,.-------

Batch composition, per- cent of sizes: %-inch to 4-mesh ______ 50 ________________ 50 ________________ 50. 

< 4-mesh_________________ 50________________ 50________________ 50. 

2 

Mixing characteristics 1__ Fairly smooth Harsh and short Very harsh 

Two-inch cubes: 2 

working. working. working. 

Bulk density __ -------- 1.59. ___ ---------- 1.39 ____ ---------- 1.63. Pounds per cubic foot a_ 99.1. _ ------------ 86.6. _ ------------ 101.5. Absorption (percent) __ 12.0 ______________ 21.8 ______________ 12.5. 

Compression (pounds 7500 ______________ 2500-------------- 5800. 

per square inch). 

1 Mix: 1 volume cement to 5 volumes aggregate. 2 Concrete made of aggregate sized to A.S.T.M. specifications. a Laboratory suspended weight method. 

REFERENCES 

Boucot, A. J., Griscom, Andrew, Allingham, J. ·w., and 

Dempsey, W. J., 1960, Geologic and aeromagnetic map of 

northern Maine, scale 1 :250,000: U.S. Geol. Survey openfile report. 

Caldwell, D. W., 1959, Glacial lake and glacial marine clays 

of the Farmington area, Maine. Origin and possible use 

as lightweight aggregate : Maine Geol. Survey Spec. Geol. 

Studies Series no. 3. 

Conley, J. E., 1942, Waste slate as a raw-material source of 

lightweight aggregates: Am. Inst. Mining Metall. Petroleum Engineers Trans., v. 148, p. 161-166. 

Klinefelter, T. A., and Hamlin, H. P., 1957, Syllabus of clay 

testing: U.S. Bur. Mines Bull. 565. 

Philbrick, S. S., 1936, The contact metamorphism of the 

Onawa pluton, Piscataquis County, Maine: Am. Jour. Sci., 

5th ser., v. 31, p. 1-40. 

Trefethen, J. M., 1955, Lightweight aggregate in Maine, in 

Report of the State Geologist, 1953-1954: Maine Devel. 

Corum., p. 83-85. 

GEOWGY OF FUELS 

153. SPHEROIDAL COAL IN THE TRINIDAD COAL FIELD, SOUTH-CENTRAL COLORADO 

By Ross B. JoHNSON, Denver, Colo. 

Coal in the Trinidad coal field, Huerfano and Las 

Animas Counties, Colo., locally exhibits two distinct 

types of spheroidal structures that are here called 

type A and type B. Spheroids of type A are mainly 

non-banded and are composed of many closely spaced 

layers separated by subconcentric fracture planes. 

Spheroids of type B are usually banded, and are not 

composed of closely spaced layers. The spheroids occur in beds in the Vermejo formation of Late Cretaceous age and in the Raton formation of Late Cretaceous 

and Paleocene age (Wood and others, 1951; Wood, 

Johnson, and Dixon, 1956). The coal-bearing formations underlie the trough of the structural Raton basin 

(Johnson and Wood, 1956, p. 707). 

The spheroid-bearing coal is of high volatile A, B, 

and 0 bituminous ra:nk. .The two types· of spheroids 
f' 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-21 

range from 'less than 1 inch to about 5 inches in the 

gren,test dimension. The size is determined laterally 

by nearly vertical joints and vertically by siltstone 

and shale partings in the coal. Most of the spheroids 

occur with the long axis normal to bedding planes. 

The sides of the spheroids are flattened along joint 

phtnes against adjoining spheroids. Curved surfaoes 

of the spheroids apparently cut across banding (if 

present) and cleat and cleavage without displacement 

of these features. 

~fost of the spheroidal structures in the coal field 

are o:f type A, and they are most common in the Raton 

formation. Type A spheroidal coal is not usually near 

any known igneous rocks or faults and folds, and is 

not associated with any particular sedimentary structure. It is confined mainly to an area near the axis 

of the basin west of Trinidad, Colo. In this area most 

of the coal is normally banded, nonspheroidal, and 

commonly has coking properties. Spheroidal coal 

occurs n,t isolated localities where one or more of the 

coal beds are made up all or in part of the spheroidal 

structures. Spheroids of type A are composed mainly 

of nonbanded, finely cleated, evenly textured, glossy 

coal. They exhibit many closely spaced layers separated by subconcentric fracture planes. The curved 

surfaces formed by the fracture planes are bright, 

smooth, and polished. Locally, only the upper half 

of the spheroids are clearly developed. 

Bright, smooth, and polished curved surfaces that 

characterize type A spheroids are possibly due to 

tectonic movements. Lateral movement of siltstone 

and shale partings along the upper and lower surfaces 

of the conl lnyers, as a result of the subsidence of the 

basin, may have produced stresses responsible for the 

curved fractures. As an alternative mode of origin, 

type A spheroids may have been produced by shrinkage during lithification of uniformly nonbanded coal 

in local areas in which the coal had an original high 

content of water; hmYever, shrinkage does not account 

for the polishing of the fracture surfaces. 

The second type of spheroidal coal, type B, is found 

locally near mafic dikes and sills (Moore, 1947, p. 

247-250), and may extend outward from these intrusive rocks as much as several hundred feet. Spheroids 

of type B are most abundant in the eastern and northeastern parts of the coal field near "Valsenburg, Colo., 

where igneous rocks are conimon. They differ from 

type A in that they are usually banded, and contain 

no subconcentric fracture planes. Spheroids of type 

B occur in coals without coking properties, but may 

also be found in coals with coking properties. These 

spheroids are uniformly microbanded internally with 

incipient cleat and cleavage, and there is neither mega- · 

scopic nor microscopic evidence of original or healed 

subconcentric fractures within the spheroids. The 

banding extends from spheroid to spheroid without 

apparent displacement. Where spheroidal coal is near 

a sill, there is little or no alteration of sandstone, siltstone, or shale beds that lie between the igneous rocks 

and the spheroidal coal, and the coal itself does not 

appear to be changed significantly in rank. No 

spheroidal structures have been observed in coal next 

to a sill or dike. These spheroids are not fragmentary 

coal-pebbles (Stutzer and Noe, 1940, p. 253-255), concretionary coal-balls (~foore, 1947, p. 242-243; p. 246-

247), or natural briquettes (Schopf, 1949, p. 82). 

Analyses of type B spheroidal coal (~foore, 1947, p. 

248) show that these structures locally contain no 

moisture, and, at some places, nearly 15 percent less 

volatile matter than ordinary nonspheroidal coal from 

the same beds (Johnson, 1958, p. 579). Spheroidal 

coal of type B seems to be due to shrinkage caused by 

some of the moisture and volatile matter in the coal 

being driven off by the heat of the intrusive rock. 

REFERENCES 

Johnson, R. B., 1958, Geology and coal resources of the Walsenburg area, Huerfano County, Colo.: U.S. Geol. Survey 

Bull. 1042-0, p. 557-583. 

Johnson, R. B., and Wood, G. H., 1956, Stratigraphy of Upper 

Cretaceous and Tertiary rocks of Raton basin, Colorado 

and New Mexico: Am. Assoc. Petroleum Geologists Bull., 

v. 40, no. 4, p. 707-721. 

Moore, E. S., 1947, Coal: New York, John Wiley and Sons, 

473 p. 

Schopf, J. M., 1949, Naturally briquetted coal from a bed in 

western Pennsylvania: Jour. Geology, v. 57, no. 1, p. 79-82. 

Stutzer, Otto, and Noe, A. C., 1940, Geology of coal: Chicago, 

Ill., Univ. Chicago Press, 461 p. 

Wood, G. H., Johnson, R. B., and Dixon, G. H., 1956, Geology 

and coal resources of the Gulnare, Cuchara Pass, and 

Stonewall area, Huerfano and Las Animas Counties, 

Colo.: U.S. Geol. Survey Coal Inv. Map C-26. 

Wood, G. H., Johnson, R. B., Eargle, D. H., Duffner, R. T., 

and Major, Harald, 1951, Geology and coal resources of 

the Stonewall-Tercio area, Las Animas County, Colo.: 

U.S. Geol. Survey Coal Inv. Map C-4. 
C-22 GEOLOGICAL SURVEY RESEARCH 19 61 

154. POTENTIAL Ofi..-SHALE RESERVES OF THE GREEN RIVER FORMATION IN THE SOUTHEASTERN 

UINTA BASIN, UTAH AND COLORADO 

By W. B. CASHION, Denver, Colo. 

The Green River formation, composed of lacustrine 

sediments deposited during Eocene time, underlies 

large areas in Colorado, Wyoming, and Utah and 

contains many oil-shale beds which have potential 

economic importance. In Utah the Green River formation is largely confined to the Uinta Basin, a 

depositional and structural basin that includes a large 

area in northeastern Utah and a small adjoining part 

of western Colorado. The potential oil yield of the 

Green River formation in part of the eastern Uinta 

Basin was estimated earlier (Cashion, 1957, p. 135) 

to be 100 billion barrels; this estimate was. for an 

oil-shale sequence 15 or more feet thick in an area of 

1,000 square miles, which has an average oil yield of 

15 gallons per ton of rock. The new and more reliable estimate presented here is for the same sequence 

in an area of 690 square miles lying within the 1,000 

square miles considered in the earlier estimate. The 

new estimate of the potential shale-oil reserves of this 

690-square-mile area is about 53 billion barrels, whereas the estimate for the same area based on data available in 1957 was about 42 billion barrels. The new 

estimate of shale-oil reserves is based on assays of samples from 39 core holes, 15 exploratory wells, and 20 

outcrops. These data represent additional oil-yield 

determinations on samples from 26 more core holes 

and exploratory wells than were available in 1957. 

Oil-shale beds.-The oil shales of the Green River 

formation are more or less magnesian maristones containing organic matter derived chiefly from aquatic 

organisms or waxy spores and pollen grains (Bradley, 

1931, p. 7, 8, and 52). The organic matter is only 

slightly soluble in ordinary petroleum solvents, but a 

large proportion is distillable into artificial petroleum. 

The Mahogany oil-shale bed, which crops out in a 

large area in the southeastern part of the Uinta Basin 

(fig. 154.1), is the thickest oil-rich shale bed in the 

Green River formation. The Mahogany bed has its 

maximum thickness along a depositional axis which 

trends approximately east-west (fig. 154.1) and lies 

near the confluence of White River and Evacuation 

Creek. The thickness of the Mahogany bed ranges 

from about 2 feet in T. 18 S., R. 19 E. to about 8 

feet in T. 10 S., R. 25 E. A stratigraphic sequence 

that is rich in organic matter extends as much as 

300 feet above the Mahogany bed and as much as 400 

feet below it. Only part of this sequence, however, 

has an average oil yield of 15 gallons per ton. The 

oil yields of samples from the area of the map range 

from a fraction of a gallon per ton to 95 gallons per 

ton. Each of these 2 extreme assays are of samples 

representing units 1 foot thick. 

Classification of reserves.-Because oil-shale deposits in the United States are not being commercially 

exploited at present, but perhaps will be developed at 

some future time, they may be classified as potential 

reserves. The potential reserves described in this report are divided into two categories, indicated and 

inferred, which are intended to show the relative reliability of the data used in making estimates of potential oil yield. This breakdown is patterned after the 

one used by Donnell (1957, p. 260) in estimating oilshale reserves of the Piceance Creek basin. The 

estimates of indicated potential reserves are based on 

assays of samples from core holes and drill cuttings 

from exploratory wells because weathered oil-shale 

beds may have lost much of their original oil content. 

Assays of core samples are more reliable than assays 

of drill cuttings because drill-cutting samples may be 

contaminated by rock fragments from units higher in 

the drill hole, and also because they represent thick 

sample UIJ.its, generally 10 feet. Assays of drill. cuttings are adequate, however, for estimating indicated 

potential reserves of oil shale. The estimates of inferred potential reserves are based on assays of outcrop samples or interpolation between widely spaced 

exploratory wells and core holes. The oil yield of 

samples from outcrop is somewhat dependent on the 

degree of weathering of the beds sampled and are less 

reliable, therefore, for making estimates of oil-shale 

reserves. For example, a sample of weathered shale 

from the Mahogany bed of the Green River formation 

assayed at 12.8 gallons of oil per ton, whereas a sample 

of unweathered shale taken 2 ~eet beneath the surface 

assayed at 45.5 gallons per ton (Guthrie, 1938, p. 99) . 

Although assay oil yields of weathered samples are 
SHORT PAPERS IN THE ·GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-23 

5 

T. 

11 

5. 

0 

EXPLANATION 

Area of indicated potential reserves 

D 

Area of inferred potential reserves 

Outcrop of Mahogany 

~ 

oil-shale bed 

---65----

Isopach lines 

Thickness in feet, of a continuous sequence of 

oil·s ha·le beds that yields an average of 15 

gallons of oil per ton. Interval 10 feet 

except wMre lines are closely spaced 

5 MILES '-'--'-.I.......L-'-----' 

Salt Lake 

City · • 

T. 

10 

5. 

R. 104 W. R. 103 W. 

• Denver 

COLORADO 

T. 

2 

N. 

T. 

1 

5. 

T. 

2 

5. 

T. 

3 

5. 

FIGURE 154.1.-Map showing outcrop of the Mahogany oil-shale bed and thickness of oil-shale sequence in the Green River formation (Eocene) that yields an average of 15 gallons of oil per ton. 

T. 

1 

N. 
C-24 GEOLOGICAL SURVEY RESEARCH 19 61 

known to be low, a constant upgrading factor cannot 

he· applied because of great variation in the weathering of oil-shale beds. 

In preparing oil-shale reserve maps of the Uinta 

Basin, such as that shown on figure 154.1, core-hole and 

exploratory well localities are designated as primary 

control points, and outcrop localities are designated 

as secondary control points. Areas of indicated potential reserves are delineated on the map by an en-· 

circling boundary drawn approximately·2 miles from 

an isolated primary control point, or approximately 

2 miles from the outermost primary control points of 

a group in which any two adjacent points are less than 

6 miles apart. Areas of inferred potential reserves are 

defined by boundaries based on data from secondary 

control points. 

Oil yield of the deposits-All figures given here of 

potential oil-shale reserves pertain to a sequence of 

rocks 15 or more feet thick that has an average oil 

yield of 15 gallons per ton. No allowances have been 

made for losses in mining and retorting. 

The area shown in figure 154.1 includes about 315 

square miles underlain by oil-shale beds classed as indicated potential reserves, and about 375 square miles 

underlain by oil-shale beds classed as inferred potential reserves. Using the information shown on figure 

154.1 and assuming a potential oil yield of 1,157 barrels of shale oil per acre-foot (Stanfield and others, 

1957, p. 2-5), it is estimated that the area contains 

about 27 billion barrels of shale oil classed as indicated 

potential reserves and about 26 billion barrels of shale 

oil classed as inferred potential reserves. 

Overburden.-Tlrickness of overburden above the 

oil-shale sequence ranges from a few feet near the outcrop to about 1,300 feet at some localities along the 

northern boundary of the area. The overburden is 

about 400 feet thick where the oil-shale sequence is 

thickest. 

REFERENCES 

Bradley, W. H., 1931, Origin and microfossils of the oil shale 

of the Green River formation of Colorado and Utah: 

U.S. Geol. Survey Prof. Paper 168, 58 p. 

Cashion, W. B., 1957, Stratigraphic relations and oil shale of 

the Green River formation in the eastern Uinta Basin, 

in Intermountain Assoc. Petroleum Geologists Guidebook, 

8th Ann. Field Conf., Geology of the Uinta Basin: p. 

131-135. 

Donnell, J. R., 1957, Preliminary report on ·oil-shale resources 

of Piceance Creek Basin northwestern Colorado: U.S. 

Geol. Survey Bull. 1042-H, p. 255-271. 

Guthrie, Boyd, 1938, Studies of certain properties of oil shale. 

and shale oil: U.S. Bur. Mines Bull. 415, 159 p. 

Stanfield, K. E., Rose, C. K., McAuley, W. S., and Tesch, 

W. J., Jr., 1957, Oil yields of sections of Green River 

oil shale in Colorado, 1952-54: U.S. Bur. Mines Rept. 

Inv. 5321, 132 p. 

HYDROLOGIC STUDIES 

155. BOULTON'S INTEGRAL FOR PUMPING-TEST ANALYSIS 

By R. W. STALJ:MAN, Denver, Colo. 

Boulton ( 1954) derived an integral equation relating dra wdown at the water table to time and the 

radius from a pumping well, which is founded partly 

on a consideration of vertical flow components not included in Theis' equation ( 1935). Flow conditions 

assumed by Boulton are shown schematically on figure 

155.1, and may be stated as follows: (a) The aquifer 

is homogeneous and of infinite areal extent; (b) storage changes take place only by dewatering as the 

water table is lowered during pumping. The specific 

yield is constant with time and radius; (c) the 

pumped well fully penetrates the aquifer; (d) the 

velocity of flow at the well face is uniform throughout 

the aquifier thickness; (e) the rate of discharge of the 
~ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-25 

Gl .c:l 

VI 

N 

'I:, I 

0 

l 

,t~ f-4 

~ 

0' 

.... 

.... 

Gl 

) 

h 

w 

Initial water-table position 

h 

8 

<%> • h when t • 0 e 

0<%> + _T_ 0<%> • 0 along z • h ot b s ~z e e Y 

8 <%> • pressure head 

+ potential head 

h 

dl> • 0 

oz 

h 

e 

FIGURE 155.1.-Boundary conditions satisfied by Boulton's 

solution. 

pumped well is constant with time; (f) all flow lines 

originnte at the water table and terminate at the well 

face; (g) changes in potential due to dewatering are 

defined along the static water-table position, where 

radial flow components are always negligible, or zero; 

and (h) changes in saturated thickness of the aquifer, 

due to dewntering, are negligible. 

Boulton's integral (1954, p. 569, eq. 9) satisfying 

these n,ssumptions may be written in algebraic form as 

8 

114;f Q 2[V (p, r)] (1) 

in which 8 is the change in water-table position, in feet; 

Q is the ru,te of discharge of the pum.ped well in gpm; T 

is the nquifer transmissibility, in gallons per dn,y per foot 

before dewatering t11kes plnce. The terms p and r are 

nondimensiorml n.nd n,re defined 1tS 

nnd 

p=r/he 

Tt 

r=0.134 S

11

h82 

(2) 

(3) 

in which r is the distance from the center of the discharging well to the point nt which 8 is observed, in feet; 

601530 0-61-3 

he is the initial saturated thickness of the aquifer, in feet; 

Sv is the specific yield; and, tis the elapsed time between 

commencement of pumping and the instant of observing 

8, in days. It may be noted that p and r are the two 

fundamental nondimensional factors of the familiar "u" 

in the Theis (1935) analysis, to which they are related 

by 

1.87 r2S 

Tt . (4) 

Direct comparison between the Theis and Boulton 

equations is made possible by means of equation 4. 

Boulton's integral, represented here by the term 

2[V (p, r)] in equation 1, is not easy to evaluate numerically. In his original work, Boulton published a short 

table of V(p, r) covering 4 values of r and 6 values of p . 

Although informative, this table is insufficient for field 

use and for making detailed comparisons with the Theis 

equation. In 1958 the U.S. Geological Survey's Branch 

of Computation calculated additional numerical values 

of Boulton's integral expanding the range of the table of 

values to 1 x 10-4 ~r~ 17.78 and 1 x 10-3 ~P~ 10.00. 

This set of computations was made to determine the 

general shape of the curves resulting from the integral 

and to serve as a guide for future detailed tabulation. 

The writer is indebted to James R. Marsheck and 

Edward Monasterski, ma'thematicians, U.S. Geological 

Survey, for all the mathematical investigation, computer programming, and computer operation incident to 

calculating values of 2[V (p, r)] presented here. Thanks 

are due to Prof. Boulton for his advice on the numerical 

formulas used for evaluating the integral. 

Results of the com.putations and corresponding values 

of l/u are given in table 155.1. Values of Boulton's integral m.ay be found in tliis table from the example that 

follows: For p=3.162X 10-2 and r= l.OOOX 10-1 ; the 

diagonal drawn upward and toward the right fron1 

r=l.OOOX 10.- 1 is followed to thecolumnp=3.162X 10-2

• 

There the· value of the integral is found to be 3.6065, 

and the value of 1/u is found on the. same line at the 

right side of the table to be 4.000X 102• Curves of 

2[V (p, r)] versus 1/u are shown on figure 155.2 for individual values of p. Logarithmic plots of 8 versus t or 8 

versus t/r2 from an individual observation well may be 

m.a.tched with the appropriate p-curve of figure 155.2 to 

solve for T and Sv in the same way as in the standard 

graphical solution of the Theis equation (see Brown, 

1953, for example). However, it is to be noted that, for 

sm~ll values of p, large segments of the type curves have 

no characteristic curvature suitable for obtaining a 

graphical solution. Where the curves form essentially 

straight lines in figure 155.2, corresponding match points 
C-26 GEOLOGICAL SURVEY RESEARCH 19 61 

TABLE 155.1.-Values of Boulton's (1954) integral for analysis of water-table drawdowns observed near a pumping well in an unconfined · · aquifer 

p:. L llu= T= Tl 

0.134....IL he 

1.87r2sy s h 2 ,, 10"3 1.78xKr 3 3.16xl0'3 5.62xi0" 3 I.OOOxi0" 2 1.778xl0·2 3.162xi0"2 5.623xl0"2 1.000xl0" 1 1.778xl0"1 3.162xi0" 1 5.623x 10"1 Y e 1.000 1.778 3.162 5.623 10.000 

0002306 .0002560 l/~01774 1.265x 10"3 

.0004042 .0004474 .0003172 2.249 

I/XX?4986 .0007212 1/~8010 .0005636 1!~01578 4.000 

0008954 .0012574 0014272 .0009876 .0002838 7.112 

l/.~898 0015898 /0022388 .0025362 !/':0'7900 .0005186 1.265xi0·2 

0017858 .0027858 0039848 .0045176 .0032224 .0009694 2.249 

I /0018632 .0031610 1/~04986< 0070766 1['0080494 .0058168 lf·OOI 8770 0002098 4.000 

0033604 0055298 0088342 012593 .014379 .010397 .0038410 .0006358 7.112 

l/0034358 .0059588 l/009885'1 .015704 lr22437- .025762 lr.019593J .0084142 [,.0022624 0007910 1.265xl0"1 

0061902 .010428 .017579 .027919 .040081 ,046375 .037417 .020048 .0089866 .0044668 2.249 

l/0062040 .010940 /{018633 .031207 lr49682 .071279 lr084017J .073740 lr.o51156J .033930 lr·o26908 4.000 

011173 019153 .033231 055502 .088574 .12739 .15372 .14723 .13184 096570 .091474 7.112 

v.011127 .019803 /{034355 .058884 1!098977 .15738 rr-22763-= .28296 17.30172-= .30952 11':31328-= 1.265xl0 

.020010 .034654 060932 .10469 .17562 27931 .40516 .51455 .58068 .613:'-.J .62657 2.249 

lr019867 035554 lr62029 .10803 1[:18605 .31113 lr49241- .70715 lr·886BO...J .98613 1.0252 4000 

.035761 .062322 .11016 .19191 33045 .54718 .84916 1.1700 1.3851 1.4765 J 1.5065 7.112 

lr035454 .063568 1!.11121 .19523 lr·34175- .58208 lr-94365~ 1.3897 1.7625.-J 1.9464 2.0096..J 1.265xl0 

.063809 .11121 .19752 .34597 .59900 .99700 1.5390 2.0751 2.4019 2.524:J 2.5629 2.249 lr .063149 .11340 lf.l9834 .34928 lr-61033- 1.0310 lrl.6334- 2.3039 2.8059 .J 3.0319 1.-3.1046 4.000 

.11363 .19822 3518 I 61438 1.0491 1.6896 2.4551 3.1288 I 35072 3.6421 J 3.6833 7.112 

lr.·'l217- .20177 lr35271- .61778 lri.0606J 1.7212 2.5503--' 3.3601 3.9202..1 4.1618 4.2378 _, 1.265xl0 2 

20167 .35186 62097 1.0646 1.7394 2.6049 3.5124 4.2459 4.6509 4.782:J 4.8248 2.249 

I.Ox 10" 4 f-.19954 .35722 Jr.·62148 1.0683 1!:1.7495- 2.6382 3.6065 J 4.4787 5.0730J 5.3064 5.3834 4.000 

1.8 .35785 61853 1.0718 1.7554 2.6559 3.6624 4.6547 5.4032 5.7972 5.9306 J 5.9729 7.112 

3.2 .62913 1{'·0703- 1.7586 lr2.6675- 3.6942 lr4.7388J 5.6257 62206.J 6.4552 65330--:.:r 1.265xl0 3 

5.6 1.0677 1.7604 2.6725 3.7145 4.7805 5.7778 6.5510 6.9472 7.0805 7.1234 2.249 

I.OOx 10" 3 -1.7614-J 2.6726 [3.7252) 4.8140 lt8702..J 6.7737 7.3623 _J 7.6059 7.6834 j 4000 

1.78 2.6790 3,7267 4.8334 5.9252 6.9254 7.6915 80980 8.2315 8.2740 7.112 

3.16 3.7316 lr4.8408-' 5.9567 lt-0193-' 7.9236 lr·5133J 8.7570 [r8.8346j 1.265xl0 4 

5.62 4.8472 5.9710 7.0734 80768 8.8422 9.2454 9.3828 9.4253 2.249 

1.000xl0"2 "-5.9833-1 7.1012 [8.1697-' 9.0757 r9.6642~ 9.9098 9.9857 _} 4.000 

1.778 7.1208 8.2202 9.2268 99946 10.396 10.535 1 10.577 7.112 

3.162 8.2533 I..-9.3173...J 10.228 10817__; 11.060 lr-11.133.J 1.265xl0 5 

5.623 9.3731 10.375 11.14~) 11.549 11.685 11.710 2.249 

1.000xi0" 1 10 .470_} 11.376 .-11.971 12.212 r-12.284_) 4.000 

I. 778 II .528 12.888 12-!00 12.842 12.868 7.112 

3.162 12.529 13.119_] 13.364 13.436_] I 1.265xl0 6 I 

5.623 13.441 13.855 13,999 2.249 

1.000 - 14.272_} 14.511 lr14.586.J 4.000 

1.778 15.008 15.130 7.112 

3.162 15.651 15.716_] 1.265xl0 7 

5.623 16.38~_} 2.249 

10.00- 16.697 4.000 

17.78 

on the data plot and type curve may be selected such 

that the ratio s/2 [V (p, T)] can take on a wide range of 

values. Thus, the solution for T by equation 1 is indeterminate for small values of p. Similarly the solution 

for T/811 is indeterminate where the curves of figure 

155.2 are essentially straight. 

of making comparisons, similar curves were calculated by 

means of the Theis equation and plotted in figure 155.3 

for the same T-values as used in the construction of 

profiles determined from the Boulton equation. 

The general limits of usefulness of the Boulton solution for analyzing pumping-test data may be ascertained 

by comparing it with the Theis equation, and inspecting 

the type curves shown on figures 155.2 and 155.3. 

With limits defined only approximately, it can be concluded that: (a) The Boulton solution is practically 

identical with the Theis equation for T >5 and (or) 

p>lO; (b) T and 811 may be calculated by graphical 

Figure 155.3 (p. C-28) shows the nature of 'drawdown 

profiles, and changes in them, as the time of pumping increases. Curves for small values of r (less than a,bout 

1 X 10-2

) exhibit little or no characteristic curvature, 

and therefore the solution for T and 811 from field observations is indeterminate in that region. For the purl?ose 

{' 
... 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-27 

102 ~------~------~--------~------~-------r------~~------.-------~--------r-------. 

-:;, 

'i' 

!-< 

0 

.....: 

~ 

0: 

~ (\J 

10° 

10-1 

10-2 

10+2 

1/u 

10+5 10 

1;-IGURE 155.2.-Boulton's integral versus 1/u for selected values of p. (u= 1.87 r2S 11/Tt; and, p=r/he.) 

solution of Boulton's equation from logarithmic plots 

of observed drawdown versus radius over the interval 

5XI0-2<T<5; (c) T and 811 may be calculated by 

graphical solution of Boulton's equation from logarithInic plots of observed drawdown versus time over the 

interval 3<p<IO; and, (d) solutions for T and 811 by 

the Boulton equation are indeterminate for T < 5 X l0- 2 

and p<3. 

Three sets of pmnping-test data reported by Wenzel 

(1942, p. 127 and following) are shown on figure 155.4 

(p. C-29). The solid curves are plots of drawdown versus 

t/'r2 for individual wells; the dotted cui·ves were cawulnted by substitbting in equation 3 Wenzel's values ofT, 

sll, and the initin.l nnd finn.l times of observation. 

Each test wn.s mo.de, usi11g fully penetrating pumped 

wells, in shnllow unconfined sands nnd gravels. Because nll the computed vnlues of T in figure 155.4 are 

nenrly equnl to or greater than 5, it follows that the 

plotted data from each test should define n single 

curve congruent with the Theis curve. Obviously 

this result is not realized. Thus, it appears highly 

probable that the flow conditions in the vicinity of 

the pumped well n,re not described adequntely by 

either the Theis or Boulton expression. Previously 

it has been assumed that analyses of pumping tests in 

unconfined aquifers, using the Theis equation, were 

inaccurate because the effects of verticnl flow components were not considered. Evidently if we are 

to achieve n significa.nt improvmnent in test analyses, 

other factors must also be tnken into account in the 

derivation of analytical equations which state the 

relationships among known variables of flow. 

REFERENCES 

Boulton, N. S., 1954, The drawdown of the water-table under 

nonsteady conditions near a pumped well in an unconfined formation: Inst. Civil Engineers Proc., Part III, 

564-579. 

Brown, R. H., 1953, Selected procedures for analyzing aquifer 

test data: Am. \Vater 'Vorks Assoc. Jour., p. 844-866 

Theis, C. V., 1935, The relation between the lowering of the 

piezometric surface and the rate and duration of discharge 

of a well using groundwater storage: Am. Geophys. Union 

Trans., p. 519-524. 

Wenzel, I ..... K., 1942, .Methods for determining permeability of 

water-bearing materials: U.S. Geol. Survey ·water-Supply 

Paper 887, 192 p. 
_I 

C-28 GEOLOGICAL SURVEY RESEARCH 19 61 

........ 

..:, 

:3 

~ 

0 

........ 1:-' 

.. a. 

........... 

E::. 

C\J 

10 P-----------------~------------------~------------------~------------------, 

100 

10-1 

r p .. -

h 

e 

FrauRE 155.3.-Boulton's integral and W(u) versus p for selected values of T. (W(u) defined by Wenzel, 1942, p. 88, eq. (88); 

p=r/he; and T=0.34 Tt/S 11 he2.) 
£-4 

w 

w 

"" z 

t-l 

; 

~ 

Q 

~ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-29 

10~----------------~--------------~~---------------,-----------------,-----------------. !t================t==============~==========~p~=~0~.~1~~;;~~~==~:f~~·~·:·:::::=====~ ·,.· =· 3·.3 

4~------------~~--------~~~-----=~~1=.0=4~·-·~·t---------------r--------------1 

10 

8 

6 

4 

2 

10 

8 

6 

4 

2 

1 

. 8 

.6 

0.134 __!!_"' T = 

s h 2 

Y e 

.__.-

3 

~ 

1.1x10, . ~Wl·~ 

~ ~ 

1 2 . ,. 

~ 

"'7x 0 .. · 

............ ~ ~ 

.;C_ 

t/r~ day/ft2 

24-hour test, Kearney, Nebr. 

f---:::::--:. . .2Jl 

\,. = 61 ~ 

18-day 

·- r p .. h e 

test, Wichita, 

I 

I 

-2 10 

= 1.82 

Kan. 

-1 10 

p = 2.94 r-- - ~}~14 ~_11.2 1 

~~ I 

24-hour test, Gothenburg, Nebr. 

10 -3 

FIGURE 155.4.-Pumping-test data from unconfined aquifers in Kansas and Nebraska (after Wenzel, 1942, p. 127 and following). 
C-30 GEOLOGICAL SURVEY RESEARCH 19 61 

156. INFLUENCE OF RIPARIAN VEGETATION ON CHANNEL SHAPE, NORTHEASTERN ARIZONA 

By RICHARD F. HADLEY, Denver, Colo. 

About 80 percent of the vegetation is saltcedar 

(Tamarix pmitandra) within the arroyo walls of 

Oraibi Wash, ·which empties into the Little Colorado 

River in northeastern Arizona. Saltcedar is an aggressive, naturalizing, and spreading shrub that is 

native in the area extending from western Europe to 

the Himalaya Mountains (Robinson, 1958, p. 74), and 

that probably was introduced to northern Arizona late 

in the 19th century. The seeds from saltcedar shrubs 

are easily spread over large areas by water and wind, 

and they germinate rapidly where there is plentiful 

moisture, which in semiarid areas is primarily along 

channels and on flood plains of streams. A photograph taken in 1909 by H. E. Gregory near the mouth 

of Oraibi Wash shows no saltcedar in an area that 

was overgrown with it in 1960. 

Seedlings of saltcedar are shown in figure 156.1 

growing along the bank of Oraibi Wash. The highwater line of a recent flow runs through the center of 

the photograph from top to bottom. Any seedlings 

that might have been growing on the channel (left) 

side of the high-water line have been washed away by 

the current. Dietz ( 1952, p. 250) has noted the establishment of seedlings along the high-water lines in 

stream channels, and he commented on the importance 

of this process in forming channel bars. Clearly, any 

flooding while the plants are small will inundate them, 

and their influence on channel shape and roughness 

FIGURE 156.1.-Saltcedar seedlings less than 2 inches high 

along the channel bank of Oraibi Wash, Ariz. 

will be negligible. If relatively small amounts of 

water flow down the channel for a few years after 

germination of the seeds, however, the shrubs may become large enough to promote sedimentation along the 

channel banks and on the flood plain by increasing 

roughness and thus reducing velocity of flow. 

Planetable maps were made of a reach of the channel of Oraibi Wash where the growth of riparian 

vegetation and channel shape could be measured. The 

reach is 250 feet long and the bed and banks of the 

channel are composed of fine to medium sand and silt. 

A survey was made in October 1958, and another in 

August 1960. 

The larger saltcedar shrubs in the reach at the time 

of the first survey ranged in height from 1.5 to 3.5 

feet; many seedlings were less than 2 inches high. 

Growth-ring counts showed that some of these shrubs 

had reached heights of 1.5 to 2 feet in 1 year. In 1960, 

the same shrubs ranged in height from 4 to 6 feet; 

many of the seedlings had been washed away or buried 

by floods. 

Changes in the channel geometry during the 2 years 

between observations are quite apparent. The average 

width of the channel was 20.9 feet in 1958 and 17.8 

feet in 1960. The mean channel depth was 1.1 feet in 

1958 and 1.3 feet in 1960. The channel slope increased 

from .0037 ft/ ft to .0042 ft/ ft between 1958 and 1960. 

FIGURE 156.2.-0raibi Wash channel in lower reach showing 

dense growth of saltcedar and fresh sediment deposits along 

banks. 
.I 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 1 4 7-2 9 2 C-31 

The channel in this reach, therefore, is being restricted and degraded under the influence of the encroaching vegetation. Deposition is occurring on the 

banks and flood plain among the rows of saltcedar 

shrubs. Fresh sediment as much as 0.5 foot thick was 

measured on the flood plain in 1960. The rapid growth 

of the shrubs doubtless will continue to increase 

roughness and induce deposition on the banks and 

flood plain and gradually reduce the channel width 

nntil all fiood waters will be forced over the banks 

and onto the flood plain. Observations In the lower 

reaches of Oraibi 'Vash (see fig. 156.2) where saltcedar shrubs are more firmly established indicate that 

this is the probable sequence of events in this drainage 

basin. · 

REFERENCES 

Dietz, R. A., 1952, The evolution of a gravel bar: Missouri 

Bot. Garden Annals, v. 39, p. 250. 

Robinson, T. lV., 1958, Phreatophytes: U.S. Geol. Survey 

'Vater-Supply Paper 1423, 84 p. 

157. RELATION BETWEEN MEDIAN GRAIN SIZE AND PERMEABILITY IN THE ARKANSAS RIVER 

VALLEY, ARKANSAS 

By M. S. BEDINGER, Little Rock, Ark. 

Work done in cooperation with the U.S. Army, Corps of Engineers 

I-Iydrogeologic studies in the Arkansas River valley 

required that the transmissibility (permeability times 

thickness) of the alluvial materials be determined at 

many places in a large area. Logs of many test holes 

were a vail able, but only at a few places was it feasible 

to determine permeabilities of the aquifer by laboratory determinations and pumping tests. 

1-

0 

2 

...... 

0:: 

<( 

::::> 

g 

1000 

Very fine Fine 

,---'A " 

,-r:. 

. 

SAND SIZES 

Medium 

" 

... 

I. . v. 

-~ 

The laborator? determinations of permeability were 

made on disturbed samples from drill holes. Recomposition of a sample to its original state is not possible; however, laboratory determinations give the approximate order of magnitude of permeability and 

are useful in indicating relative values of permeability. 

To determine the relation between grain size and 

permeability, laboratory determinations of median 

grain size and permeability were plotted on a graph 

as shown by figure 157.1. A scattering of points is 

to be expected because of differences in sorting, sphericity, and arrangement of the grains. However, in 

spite of the scatter, a relation between median grain 

size and permeability is apparent. The relation shown 

by the graph can be expressed as 

ffi 

c.. 

>- <( 

Cl 

ffi 10 0 

·; II 

. . • 

k=Od2 

c.. 

VI 

z 

~ <( 

<-' 

~ 

~ :::; 

iii 

<( • 

...... 

~ 

0:: 

...... 

c.. 

I/ . v . I 

0 

I . _IL lL • . J . .. I 

v . 

L 

·; . . 

. 

I . 

Coarse 

_L 

II 

7 

VI . 

. 

where the permeability, k, is proportional to the 

square of the median· grain size, d; and 0 is a constant. 0.1 1.0 

MEDIAN GRAIN SIZE, IN MILLIMETERS 

Very coarse 

f\.._ 

"" 

This is the same relation found by Slichter ( 1899) 

for porous media of spheres of uniform size and ar- FIGURE 157.1.-Relation between median grain size and permeability in the Arkansas River valley, Arkansas. 
C-32 GEOLOGICAL SURVEY RESEARCH 19 61 

rangement, and a similar relation has been expressed 

by other investigators in dealing with natural materials. This relation is approximately true for unconsolidated earth materials, within the range of "sand" 

and "finer gravel" sizes that are rounded and well 

sorted. 

Using permeabilities read from the diagram (fig. 

157.1), the transmissibility was estimated from testhole logs at places where pumping tests had been 

made. In estimating the transmissibility a permeability was assigned to each lithologic unit in the log based 

on the approximate average grain size of the unit and 

degree of sorting as indicated by the description of 

the unit in the log. • 

The estimated transmissibilities were slightly lower 

than the transmissibilities from pumping tests. Consequently, the average permeabilities were arbitrarily 

assigned larger values so that the estimated transmissibilities agreed with the results of the pumping tests. 

The resulting permeabilities are given below. 

Choice of values within the indicated ranges is a 

matter of care and judgement in examination of the 

Permeabilities of alluvial materials of the Arkansas River valley 

[Gallons per day per square foot] 

Type of material 

Sand, very coarse, and very fine graveL _______ _ Sand, very coarse ___________________________ _ 

Sand, coarse and very coarse _________________ _ Sand, coarse _______________________________ _ 

Sand, medium and coarse ____________________ _ 

Sand, medium ________________________ ---- __ _ Sand, fine and medium ______________________ _ Sand, fine __________________________________ _ 

Sand, very fine and fine _____________________ _ Sand, very fine ________________________ - _- __ _ 

Range in 

field co- efficient or permeability 

6,000-15,000 

3,000- 9,000 

1,500- 4,000 

800- 2,000 

400- 1,000 

200- 500 

100- 250 

50- 140 

20- 60 

10- 30 

drill cuttings, but after a little experience this g~nerally can be done with fair to good accuracy. 

This method should be usable in many areas underlain by alluvial materials, but the values given above 

are not necessarily applicable to other areas. Comparisons between field and laboratory determinations 

should be made and adjusted as needed before attempting to apply the method elsewhere. 

REFERENCES 

Slichter, C. S., 1899, Theoretical investigation of the motion 

of ground waters: U.S. Geol. Survey 19th Ann. Rept., 

1897-98, pt. 2, p. 295-384. 

158. INFLUENCE OF PIEZOMETER HOLE DIAMETER ON DEPTH DETERMINATIONS IN A SMOOTH 

OPEN CHANNEL 

By W. W. EMMET!', Atlanta, Ga. 

The accuracy of flowing-liquid analyses, whether 

the flow be in open channels or enclosed conduits, is 

limited by the degree of accuracy with which flow 

measurements are possible. In open-channel flow, the 

depth is often measured by means of a piezometer; the 

piezometric head is recorded on a manometer. An 

alternative method of measuring the depth is by· a 

point gage. Commonly, simultaneous readings from 

a manometer and a point gage yield different values 

for the depth. These differences in values may be a 

significant percentage of the depth. A laboratory investigation 1 provides sufficient data to define the influence of piezometer hole diameter on piezometrichead measurements. 

1 Emmett, 1961, Piezometric measurement of depth In open channels : Unpublished thesis, Georgia lost. Tech. 

All tests for the investigation were conducted in the 

hydraulics laboratory of the Georgia Institute. of 

Techiwlogy. A piezometer test section was located at 

the downstream .end of a permanent laboratory flume, 

10 inches wide, 18 inches deep, and 22 feet long. An 

electrically operated jack permitted adjustment in 

slope of the flume. An adjustable sluice gate and a 

sliding tailgate provided controls for uniform flow. 

Discharges were measured by either weight-time 

measurements or by a calibrated bend meter in the 

supply line. 

A plan view of the piezometer test section is shown 

in figure 158.1. Twenty-four piezometer openings 

were carefully drilled into the stainless steel floor of 

the test section. An exception was the smallest opening which was drilled into a !Jt-inch brass plug. The 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-33 

0. 

0. 

Sections 1 to 8 0.2 foot apart 

2 3 4 5 6 7 

lR T R lT R lr R 

1 ft.r R Rlo.ri~s> R R 0.~~0) R R o.~~s> R 

1 ft. I IT IR lT IR T R tr 

(d= (d8 

IT. 

R o.c d'= 

375) 

R 

0.031) 0.093) (d0.156) (d0.250) 

T denotes test piezometer 

R denotes reference piezometer (d=0.0595 in.) 

d denotes diameter, In inches 

FIGURE 158.1.-Plan view of piezometer test section. 

brass plug was threaded into and finished flush with 

the stainless steel floor plate. The piezometers were 

a.rrn.nged n.t eight transverse sections, each section consisting of one test piezometer and two reference piezometers. From center to center, the piezometers at 

each section were located 0.1 foot apart. The test 

piezometer was one of the outer piezometers and its 

position was alternated from section to section. The 

piezometer sections were 0.2 foot apart. The last piezometer section was located 1.85 feet from the tailgate. 

Since only shallow depths were investigated, this distu.nce was considered to be upstream of any influence 

of curvilinear ftmy due to tailgate or brink conditions. 

The test-piezometer diameters ranged from 0.031 to 

0.375 inch and increased in the downstream direction. 

All reference piezometers were of constant diameter 

( 0.0595 inch) . 

For all piezometers the length-diameter ratio was 

kept constant at a value of three by drilling the proper 

piezometer length into brass blocks attached to the 

underside of the piezometer test section. Copper tubing connected each of the piezometer taps to a manifold from which any one piezometer could be connected to any of several recording devices. All leads 

were of equal length to avoid the possibility of a relative influence of tubing length. 

After establishment of uniform flow, piezometric 

heads were recorded for each of the 24 piezometer 

openings on two constant-displacement manometers 

(0.175 and 1.725 inches in diameter) and a differentialtype pressure transducer. An advantage of the small 

manometer was its rapid response to fluctuations in 

the piezometric level. The large manometer gave a 

time-average piezometric reading. Gage zeroes for the 

instruments corresponded to the channel-floor elevation. Depths were then recorded as the piezometric 

head above the channel floor. 

The range of conditions covered by the tests included. channel slopes from 0.00291 to 0.0349, Fronde 

numbers from 0.70 to 3.50, and depths from 0.084 to 

0.173 feet. 

PIEZOMETER HOLE DIAMETER, IN INCHES 

Frou&E 158.2.-Piezometric error, in percent of mean fiow 

depth, as a function of the piezometer bole diameter and 

Froude numb~r (F). 

To indicate the relative influence of piezometer size, 

the depth obtained from the centerline reference 

piezometer, D,, was subtracted from the depth obtained 

from the adjacent test piezometer, D,. The resulting 

difference, plotted as a function of the respective test 

diameter, expressed the relative error due to piezo,1neter 

diameter. In this manner, effects of slight nonuniform 

flow conditions were eliminated inasmuch as each 

reference piezometer was at the same channel section as 

the test piezometer. 

The relative-error curves obtained from the described 

procedure revealed that the error was not only a 

function of the piezometer hole diameter, but was 

also dependent on the depth and the velocity of flow. 

The effect of depth was eliminated by dividing the 

relative error of each test by the mean flow depth, Dm. 

The results were expressed as a percentage of the mean 

depth. This dimensionless relative-error parameter, 

(D,-D,)!Dm, is shown as a function of the piezomet~r 

hole diameter en figure 158.2 A. 

~ 2.5 

;: 

z 

UJ 

u 02.0 0::<( 

ww 

(l.J: 

<(> 

en !:::: 1. <Cu 

~~ 

ffi ~1. <( 

UL.tJ 

5 

0 

~ ~ .5 UJQ 

:E 

0 

N ii: 00 

_..,., 

---~ l----

~ L.---" 

./ 

v 

v .10 .20 .30 .40 

PIEZOMETER HOLE DIAMETER, IN INCHES 

FIGURE 158.3.-Piezometer error in percent of mean velocity 

head as a function of the piezometer hole diameter. 
C-34 GEOLOGICAL SURVEY RESEARCH 1 9 61 

To express the error in absolute rather than relative 

values, figure 158.2B was obtained from figure 158.2A 

by extrapolation to a zero dian1ete~ hole. The trend 

established by the curves in figure 158.2A indicated 

that there was no absolute error at a zero diameter 

hole. Thus, the curves were redrawn allowing the 

relative. error to correspond .. mth the absolute value. 

Many experiments have confirmed that the staticpressure error is proportional to the dynamic head. 

For each test, the absolute error was divided by the 

mean velocity head, V2j2g. When plotted as a function 

of the piezometer hole diameter, this dimensionlesserror parameter defined the single curve shown in 

figure 158.3. This curve shows the piezometric error 

as a function of the piezometer hole diameter. 

159. VARIATION OF M~NNING'S nINA SMOOTH RECTANGULAR OPEN CHANNEL 

By CARL M. LESTER, Atlanta, Ga. 

A study of uniform flow in a rigid open channel has 

resulted in an analysis of the variation of Manning's 

n ";ith the Froud~ number and the slope of the test 

channel. 

The study was made in the hydraulics laboratory of 

the Georgia Institute of Technology. The experimental channel used is 3Yz feet wide, 18 inches deep, 

and 81 feet long. The sides and bottom are constructed of steel plates; the inner surfaces are finished 

with synthetic enamel paint. Discharge is measured 

by venturi and orifice meters in the supply piping. 

Water surface levels are measured by point gages and 

floor piezometers. For a fixed discharge and slope, the 

depth of flow was regulated either by an adjustable 

head gate or tail gate, depending upon whether the 

flow was supercritical or subcritical. The normal flow 

depth was determined by a measurement of the surface profile at a depth just greater than the normal 

(M1 or 82 curve), and at· a depth just smaller than 

c 0010 

"' z 

~ 

~ 0009 

000701 

'ojg 

"'0 0~ ... Oo-0 

o~oo 

oOo o o o ;;....8...,o0 

""boo 

"'boooR 

10 

SLOPEx 10' 

I og,"o>o- ........... 

100 1000 

FIGURE 159.1.-Variation of Manning's n with slope for test 

data. 

the normal ( M2 or 83 curve). The normal depth was 

then interpolated between the two backwater curves. 

Twenty-four test runs were made in the subcritical 

flow range, and 25 in the supercritical flow range. The 

depth of flow, y, was varied from 0.10 to 0.50 foot, the 

discharge fron1 0.30 to 7.30 cubic foot per second, and 

the slope of the channd from 0.00007 to 0.0330. 

The computed value of l\1anning's n varied between 

0.0080 and 0.0114, a difference of about 42 percent. 

Analysis of the data disclosed an excellent correlation 

of the value of n both with flume slope, So, and Froude 

number, F = Vj{iif where V is mean velocity (figs. 

159.1 and 159.2). 

For fully developed turhulent flow in sn1ooth pipes, 

the generally accepted relation between the friction 

factor, f, and Reynolds number, R, is the KarmanPrandtl resistance equation: 

1 

{}=2 log R.J]-0.8. (1) 

The test results demonstrate that the san1e general 

form of resistance equation is applicable to the smooth 

open channel described above, provided that the 

hydraulic radius, r, is incorporated in the Reynolds 

number and the friction factor. The relation between ' 

the friction factor, f=8rSog/V2, and Reynolds number, 

R=4rV/v, (v is kinen1atic viscosity) for the laboratory 

channel is: 

JJ=2.03 log RJJ-1.30. (2) 

,' 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-35 

0.012 

0.011 

_, ~0 

~ ~0 'o o 0 "o 0 

0 .... 0 

'oo 

0~~0 

··r 

0010 

i 0009 

0008 

0007 0 

FIGURE 159.2.-Varintion of Manning's n with Fronde number 

for test data. 

Manning's n ttnd the friction factor fare related by 

the equation: 

1 1.486 r 116 • 

.Jj -/BY n 

(3) 

In order to clarify the relation shown in figures 159.1 

and 159.2, it is of interest to c01npute n directly f'rom 

equations 2 and 3 for the range of flow conditions 

tested. 

In figure 159.3, the value of n is shown as a function 

of channel slope. This relation was obtained from the 

simultDneous solution of equations 2 and 3 for a channel 

having the dimensions of the test channel. Slope was 

computed for arbitrarily assumed values of velocity 

and depth. The kinematic viscosity was assumed 

constant and equal to 1 X 10-5• The curve drawn O.ot I 

'0 EXPLANATION 

Srmbol Depth (It) 

0 0.100 

~ 0 0.300 

• 0.010 0.500 

.............. 0 

~ ............... 

'~- o,~ 

'o.. 0 ......... 

0~ 

.... ~ 

~ 0.009 

~ 

0.008 

0,00 1 10 1000 

SlOPt:x to• 

li'IGUUE 159.3.-Vnriation of Manning's n with slope by solution of equations 2 and 3. 

I 

EXPLANATION \I Symbol Dopth(lt) 

0 0.100 

~'{ 0 0.:100 

• 0.500 

)..... 

"-o!, ~ 0.009 0~~ 

~ ·--... I ----0 

-·~ 0.008 

0.007 0 

FIGURE 159.4.-Variation of Manning's n with Froude number 

by solution of equations 2 and 3. 

through the points is the same as the one shown on 

figure 159.1. There is a small residual correlation of 

n values with depth; however, a single curve is a 

satisfactory average of the three depths considered. 

In figure 159.4, equ'ations 2 and 3 are solved to show 

n as a function of Froude number. The curve shown 

is the same as the one on figure 159.2. Again, a small 

variation of n with depth is apparent. 

From equations 2 and 3 it is apparent that 

f= c.o(R), 

and 1/6 

r n =¢(j)=¢(R). (4) 

From equation 4, 

n=¢(R, r). (5) 

For a given channel the hydraulic radius, r, is a function of the depth of flow, y 

r=¢(y). (6) 

If kinematic viscosity is assumed constant, the basic 

variables of flow are reduced to three, only two of which 

are independ·ent. Therefore, if the velocity and depth 

are known, the Reynolds number is fixed. It follows 

that, 

R=¢(F, y). 

Combination of equations 5, and 6, and 7 leads to 

n=¢' (F, y). 

(7) 

(8) 

Figure 159.4 indicates that the influence of the depth 

of flow is small for the range of depths considered. 
C-36 GEOLOGICAL SURVEY RESEARCH 19 61 

160. VARIATION OF FLOOD RATIOS WITH SIZE OF DRAINAGE AREA 

By D. R. DAWDY, Phoenix, Ariz. 

The index-flood method for expressing regional 

flood-frequency relations consists of two parts. The 

first is a correlation of the mean annual flood with various parameters of the drainage basin, of which size of 

drainage area has been the most important and sometimes the only parameter used. The second part is 

the construction of a flood-frequency curve, that shows 

floods of any given recurrence interval as having a 

constant ratio to the niean annual flood. An assumption that the same ratio can be used for different basins 

is not in accord with the general observation that 

smaller drainage areas have steeper frequency curves. 

Some data have been examined that show the variation of the flood ratio with size of drainage area, and 

the results are described in this paper. 

In a study of flood-frequency relations in New 

England, peak discharge Qr, for various recurrence 

intervals, T, was related to drainage area size, A, by 

the regression equation 

Qr=aAb 

where a and b are constants. It was found that the 

effect of size of drainage area, as measured by the 

exponent, b, varied with recurrence interval as follows: 

T, in years 

2.33 ___________________________ _ 

5------------------------------ 10 ____________________________ _ 25 ____________________________ _ 50 ____________________________ _ 

b 

0. 845 

. 822 

. 794 

. 759 

. 680 

0 

-0.023 

-. 051 -. 086 

-.165 

The figures in the last column approximately determine 

the slope of the average curve relating the flood ratio 

Qr/Q2 .33 to size of drainage area. 

10 

Q 5 

~ 0::: 

3 

. • ----- . . 

·---=-==-~·--·---· •""~"--- • I. 

• .. • ···-· -;·~:::::::::::--·!._~· . • 

• .. . . ---.... -:-:-, 

100 1000 10,000 

DRAINAGE AREA (SQUARE MILES) 

FIGURE 160.1.-Relation of drainage area to the ratio of historical flood (estimated recurrence interval between 100 and 

199 years) to median flood for some New England streams. 

Additional data for historical flood peaks in New 

England were examined as a check on the findings. All 

historical floods were divided into three groups on the 

basis of estimated recurrence interval, and graphs were 

made relating the ratios of historical flood to median 

flood with drainage area. The regression slope of the 

resulting curve for each group is given below, and the 

curve for group 2 given on figure 160.1. 

Group 

Recurrence 

interval, in 

years 

1------------------------------ 50-99 _____ _ 2 ______________________________ 100-199 ___ _ 

3 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 200 or more_ 

Regression slope 

-0. 178 -. 160 -. 141 

Kuiper (1957) presents ratios of the 1 percent (100-

year) flood to the mean annual flood for 100 North 

American rivers. When these data were grouped by 

river basins, it was found that for all basins except 

the Arkansas, the flood ratios are inversely proportional to drainage area, and the average regression 

slope is about -0.10. Figure 160.2 shows the relation 

for the Missouri-Mississippi River basin, which has 

the largest range in sizes of drainage basins. 

Finally, using data from several statewide floodfrequency reports, ratios of 50-year flood to median 

flood were computed and plotted against drainage 

area. The resulting curve for each state showed a 

negative slope that averaged about -0.07 for all the 

curves. Figure 160.3 shows curves for 30 stations in 

Illinois for which the 50-year floods were satisfactorily 

defined by Mitchell ( 1954). Thirteen of the stations 

are in central Illinois, and 17 in northern or southern 

Illinois. Shown on figure 160.3 are the curves for the 

central division of Illinois and for the combined north8 

4 

0 

i= 

<( 

0::: 

2 

1 

1000 10,000 100,000 

DRAINAGE AREA (SQUARE MILES) 

FIGURE 160.2.-Relation of drainage area to the ratio of the 

100-year flood to mean flood for streams in the MissouriMississippi River basins. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-37 

0 

~ 

Sr-~--------------.---------------,--------, 

1 100 1000 10,000 

DRAINAGE AREA (SQUARE MILES) 

EXPLANATION 

. Central division 

)( 

Northern or southern divisions 

Stations treated separately 

FIGURE 160.3.-Relation of drainage area to the ratio of the 

50-year flood to the median flood for streams in Illinois. 

Data from Mitchell (1954). 

ern and southern divisions. Each curve slopes -0.10. 

Incidentally, the 'Vabash River stations, which drain 

mainly the central division, and the Illinois River 

stations, which drain mainly the northern division, 

have flood ratios that are consistent with others in 

their respective divisions. Mitchell (1954), who did 

not consider the relation of flood ratio to drainage 

area, provided a separate dimensionless frequency 

curve for the Illinois River, and included the Wabash 

in his northern-southern division . 

REFERENCES 

Kuiper, E., 1957, 100 frequency curves of North American 

Rivers: Am. Soc. Civil Engineers Proc., v. 83, no. HY 5, 

Paper 1395, 31 p. 

Mitchell, William D., 1954, Floods in Illinois, magnitude and 

frequency: Illinois Div. Waterways, 386 p. 

161. ERRORS IN STREAMFLOW MEASUREMENT 

By I. E. ANDERSON, Washington, D.C. 

The accuracy of measurement of a constant diseharge by the current-meter method depends on the 

number of observations of depth and velocity which 

are obtained and the reliability of the revolution-velocity rating of the current meter. This relation has 

been defined by a study of the individual components 

of the total error. 

The usual method of making a discharge measurement is explained by reference to figure 161.1. The 

depth of flow in the cross section is measured with a 

sounding line at locations 1, 2, 3, and so forth. As the 

l!"'JOURE 161.1.-Definition of method of discharge measurement. Dot shows place of velocity observation; d, depth; 

b, width. 

depth is measured, observations of velocity are obtained 

with the current meter at two points which are 0.2 of 

the depth and 0.8 of the depth from the water surface. 

Each observation of velocity represents the average 

velocity at the point during the period of observation 

which is about 45 seconds. The discharge is computed 

by: 

where Q is discharge in cubic feet per second, d is 

depth in feet, b is the distance between locations in 

feet, and Vis velocity in feet per second. 

Assuming no error in measurement of depth at a 

point or .in measurement of the width of the cross 

section, the component errors in the discharge measurement and the related assumptions are: 

1. The error, X,., due to the assumption that the revolutionvelocity rating of the current meter, which is based on 

towing the meter in still water, is unaffected by stream 

turbulence and the condition of the meter. 

2. The error, X 0 , due to the assumption that the mean of the 

velocity observations at· 0.2 depth and 0.8 depth equals 

the mean in the vertical at locations 1, 2, 3, and so .forth, 

during the time period of observation. 
C-38 GEOLOGICAL SURVEY RESEARCH 19 61 

3. The error, Xp, due to the assumption that the mean of the 

velocity observations at 0.2 and 0.8 depth at one location 

does not vary with time. 

4. The error, Xh, due to the assumption that the velocity and 

depth vary uniformly from locations 1 to 2 to 3, and so 

forth. 

Assuming that these errors are independent, the 

total error; X0 , is equal to the square root of the sum 

of the squares of the component errors. The errors 

Xm, Xv, Xp, Xh, and X0 are given in terms of the 

standard error of discharge in percent of mean. 

11/eter error, Xm.-The Price current meters used by 

the Geological Survey are individually rated at the 

National Bureau of Standards by towing the meter 

through still water. To check the accuracy of these 

ratings, a group of meters was ·also rated at the David 

Taylor Model Basin and at Colorado State University. 

The deviation of ratings for any one meter was less 

than 1 percent. 

The instrument error due to rating the meter in still 

water and operating it in turbulent flow is more difficult to evaluate. However, 10 duplicate measurements 

made on the Mississippi River at Vicksburg, Miss., 

first using the Ott current meter and then the Price 

current meter, agree within 1 percent. Similar comparative tests on the outflow rivers of the Great Lakes 

in 1959 led the Corps of Engineers to conclude that 

there is no significant difference in the result of veloc5 

4 

I=' 

z 

w 

(.) 

c:: 

w 

e:. 

X.s::.3 

ri 

0 

c:: 

c:: 

w 

I 

h: 

w 2 0 

I 

1: 

u 

0 

....1 

w 

> 1 

0 

l 

- ' 

,_____ 

I I I f 

0 20 40 60 80 100 NUMBER OF LOCATIONS 

FIGURE 161.2.-Relation of the velocity-depth error, x,., to the 

number of locations in a cross section at which observations 

of depth and velocity are obtained. 

I=' 

z 

w 

5 

~4 

w 

e:. C1 

X 

~ 

z 

w 

::2: 3 w 

c:: 

::l 

en 

~ 

::2: 

u. 

0 2 c:: 

0 

c:: 

c:: 

w 

0 

c:: 

<( 

~ 1 <( 

len 

0 

-

ITIIl_ .....__ 

0 20 40 60 80 100 

NUMBER OF LOCATIONS 

FIGURE 161.3.-Standard error of discharge measurements 

made by the 0.2 and 0.8 method using a 45-second time 

period for observation of velocity. 

ity observations with the Ott and Price meters. Because the Ott meter tends to under-register and the. 

Price to over-register in turbulent flows, these comparisons indicate that the effect of turbulence in measurement of stream flow is very small. 

On the basis of these and other comparative tests 

the meter error, Xm, is assigned a value of 1 percent. 

Velocity error, Xv.-The velocity error, Xv, due to 

the assumption that the average .of the velocity observations at 0.2 depth and 0.8 depth is equal to the 

mean of the velocities in the vertical profile from the 

stream bed to the water surface, has been evaluated 

empirically. Comparisons were made of the discparge 

at 100 different stream sites computed from velocity 

observations at 11 points in each vertical at each location shown as 1, 2, 3, and so forth on figure 161.1, and 

the discharge computed from the velocity observed at 

0.2 depth and 0.8 depth at these same locations. The 

error, Xv, determined by the comparison was 1.5 

percent. 

Velocity pulsation error, X 11 .-Because the velocity of 

flow at any point in a section of flow varies randomly 

with time, even with a constant discharge, an error, 

Xp, is introduced. This error in discharge is related 

to the time period of observation of the velocity at a 

point. The error was evaluated for a sample of 23 

streams by comparing the mean velocity at a point for 

short time periods with the mean for a 2-bour period. 

,. 

.-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-39 

The error, Xp, when individual velocities are observed 

for a 45-second time period, and the 0.2 depth and 0.8 

depth method of velocity observation is used at n locations, is equal to 4.3/.fii. 

Velocity-depth error, X11.-The enor due to nonuniform variation of depth and velocity from locations 

1 to 2 to 3 n.nd so forth (fig. 161.1) is a function of the 

number of locations at which observations are taken. 

'rhe error was evaluated at 130 stream sites by comparing the discharge computed fron1 observations at 100 

locations per site with the· discharge computed from 

observations at fewer locations. The relation between 

X11 and number of locations is shown on figure 161.2. 

Total error.-The discharge measurement error, X0 , 

based on the combination of the component errors, is 

given on figure 161.3 for a 45-second period of observation and the 0.2 depth and 0.8 depth method of velocity 

observation. According to this relation, if the velocity 

and depth are observed at 20 or mor~ locations in the 

cross section, the error in the total discharge is expected 

to be less than 3 percent for 67 percent of the discharge 

measurements. 

162. COMPUTATION OF HOMOGENEOUS FLOWS IN TIDAL REACHES BY FINITE-DIFFERENCE METHOD 

By R. A. BALTZER and JoHN SHEN, Lansing, Mich., and Washington, D.C. 

Unsteady flows in tidal reaches result from the intrusion of sequences of translatory waves through the 

coastal outlets. In its broad sense, river flow in tidal 

reaches is the composite flow resulting from the superposition of translatory-wave motion upon otherwise 

undisturbed open-channel streamflow. 

Astronomical tides, ·although known to be the primary cause of tidal flows, are seldom the only causative factor. Storm surges and seismic disturbances 

are also significant. Waves of the latter origins are 

neither periodic nor continuously sustained. Consequently, tidal flow can only be classified as a semiperiodic phenomenon. 

Fundamentally, tidal flow in an open channel can be 

described by two differential equations: one expressing 

the conservation of mass, or the equation of continuity; and the other expressing conservation of momentum, or the equation of motion. 

Under conditions of moderately unsteady, openchannel flow, the components ofvelocity and acceleration across the channel, and particularly the component 

of acceleration in the vertical direction, are all relatively 

insignificant and hence may be neglected. This 

simplification is valid provided that no abrupt wave 

such as· a tidal bore occurs. Thus, for an idealized 

tidal reach the flow is treated as one dimensional. 

Moreover, the density of the fluid is assumed to be 

homogeneous. On the basi's of these assumptions, the 

following system of equations may be derived: 

(1) 

and, 

oz u ou 1 ou A2 

ox +-g ox +g ()t+ululK2=0, (2) 

in which, xis the distance measured in the downstream 

direction along the channel; t is the time; Q is the 

discharge; A is the cross-sectional area of the channel; 

b is the width of the water surface, z is the water-surface 

elevation; g is the acceleration of gravity; u is the mean 

velocity of flow; and K is the conveyance of the channel. 

A schematic tidal reach is shown on figure 162.1. An 

annexsection, m, is also provided to simulate the overflow section. In general, the velocity of flow in the 

overflow portion is negligible and may thus be excluded 

from the dynamical equation. 

Th u ou . . . ll f 11 e term, - ~~ m equatiOn 2 1s genera y o sma 

g uX 

·magnitude and hence may be disregarded with practically no sacrifice in accuracy, provided the mathematical representation is limited to tidal flow in 

increments of channel of reasona~ly uniform cross 

section. 

With the foregoing assumptions, and by using the 

relations~ Q=Au, and b' =b+m, equations 1 and 2 may 

be written as: 

oQ +b' oz+ =0. 

ox ot q ' (3) 
C-40 GEOLOGICAL SURVEY RESEARCH 1 9 61 

z 

b' 

z 

' ' ' ' ' ' ' ' ' ' ' ', ' 

' ' '' ' ' '. 

' ' ' ' ~~~--~------------------------~~------------------~'~'~------~~-------------J----Y 

Cross section 2 

XY-Piane is datum plane X 

FIGURE 162.1.-A schematic tidal reach. 

and, 

(4) 

in which q represents any lateral diversion fron1. the 

reach, and >.. is a sign operator to be used to maintain 

the proper directional sense of the nonlinear resistance 

term. By definition, "A= IQI/Q. 

The above two equations are in the form of a set of 

first-order nonlinear hyperbolic partial differential 

equations in two independent variables. An explicit 

analytical solution of such a set of equations is not 

possible. Thus, one is forced to adopt numerical, 

finite-difference methods of solution. In addition, the 

initial conditions and the boundary conditions must 

also be satisfied to obtain a uniquely defined solution. 

Fourier series offer one possible means for evaluating the boundary-value problem (Dronkers and 

Schonfeld, 1955, p. 11-24). However, this technique is 

precluded because the superposed fluctuations are not 

strictly periodic. 

·Power series offers another means for evaluating the 

tidal-flow equations (Dronkers, 1949, p. 330-337, 479-

487). In fact, Taylor series is the basis for the particular evaluation technique developed as a result of 

this study. 

By expanding equations 3 and 4 in Taylor series 

about an arbitrarily selected point in a tidal reach at a 

particular moment of time, and using successive 

iterations, one gets 

Q2 X OQ Qb' X2 OZ b' X2 02

Z 

Zx=Zo->.. K2x- gA ~ +>.. K2 ot+2gA ()t2 

2 Q2b'r oQ 2 Qb'r o2Q (b') 2x3coz)2 

-3 K4 ()t - 3>.. gAK2 ot2 - >.. 3K2 ot 

>.. b'z3 (oQ)2 b'x3 o3Q Qx2 

-3gAK2 ot - 6(gA)2 o& +>.. K 2q 

The above expression represents only the first three 

terms of the Taylor-series expansion. Fortunately, 

this was found to be more than sufficient to accurately 

. [ 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-41 

12~--~------~--------~------~--------~----~-------.--------,--------,---. 

~ 10 (.) 

LL. 

0 

(/) 

0 

z 

<( 

(/) 

::::> 

~ 81---+------+---- 1-

z 

w 

(.!) 

c::: 

.<( 

:c 

(.) 

(/) 

0 6~-~----~-----~------~---------+------~---------L--------~--------~---~ 

0 Measured discharge 

• Computed discharge 

7 13 17 21 1 4 8 12 16 

TIME,IN HOURS 

FrouuE 162.2.-Comparison of computed and measured discharge for Sacramento River at Sacramento, Calif., during January 30--31, 

1957. 

represent the tidal-flow solution. Rewriting this 

expression in the form of increments and eliminating 

secondar·y quantities, one obtains the expression 

LlQ=[ ALlz_>.gAQ2+>.gAQb'Llx Llz+>.gAQqLlx · g Llx K 2 K 2 Llt K 2 

b' Llx Ll2z gA(b') 2(Llx) 2 (Llz)1 +2 Llt2 ->. 3K2 Llt JLlt, (6) 

in which LlQ is the change in discharge during an increm('nt of tin1e, At; and Az=z0 -Z:r:. This expression is 

valid provided the selected incren1ent of reach length, 

Ax, and the time increment1 Llt, are within .the limits of 

convergence of the power series. 

Thus, once the boundary values for a tidal reach, A, 

b, K, Llx and Llz are known, the value of LlQ becomes 

uniquely defined. Then, by computing the change in 

discharge during each time increment and adding this 

value to the to tal discharge occurring at the beginning 

of the increment, the discharge at the beginning of the 

next increment is known. This process is simply repeated to obtain a sequence of values of discharge at 

the select,ed point in a tidal reach. 

601530 0-61-4 

The method has been tested by con1puting the flow 

in the Sacramento River, Calif. Actual computations 

were carried out by a hio+ speed digital computer. 

The contputed results for the period of January 30-31, 

1957 are compared with the measured discharge in 

figure 162.2 and close agreement is shown. 

A similar test has also been made for Three-mile 

Slough in California with satisfactory results. An 

important characteristic of this technique is that even 

though an erroneous initial value of discharge may be 

assumed, the evaluation process converges to the correct 

values ·after on]y four or five cycles of computation 

provided that the power series is convergent. 

REFERENCES 

Dronkers, J. J., 1949, An iterative process for the solution 

of a boundary-value problem of a linear partial differential equation of the second order [Dutch text] : Koninkl 

Nederlandse Akad. Wetensch. Proc., v. 52. 

Dronkers, J. J. and Schonfeld, J. C., 1955, Tidal computation 

in shallow water: Am. Soc. Civil Engineers Proc., v. 81, 

Separate no. 714. 
C-42 GEOLOGICAL SURVEY RESEARCH 19 61 

163. OBSERVATION OF UNSTEADY PHENOMENA IN AN OPEN CHANNEL 

By RICHARD G. GoDFREY, Washington, D.C. 

Work done in cooperation with the U.S. Atomic Energy Commission 

Observations of hydraulic events are commonly 

made at a fixed point as the phenomena pass. An example is the recording of the stage of a flood wave as 

it passes a gaging station. If the flood wave is changing shape as it progresses, the shape recorded at the 

gage will be different from the shape which would be 

defined by many simultaneous observations at" points 

distributed throughout the length of the wave. This 

paper is concerned with measuring the longitudinal 

dispersion of a miscible tracer in water flowing in an 

open channel. The wave of tracer concentration is 

analyzed to demonstrate the differences between the 

time-concentration curve obtained from observations 

at one point over time and the distance-concentration 

curve obtained from simultaneous observations at 

many points. An example of the difference in the two 

curves is shown on figure 163.1. For the fixed observer 

the time from injection .to peak concentration is 

shortened and t~e magnitude of the peak is increased. 

Taylor (1954) has shown that for uniform flow the 

dispersion pattern has the following mathematical 

form in the one dimensional case: 

0 Bt-% -(X-Vt) 2 (

1) = exp 4Kt 

where 0 is the concentration; tis time after injection; 

X is distance from point of injection; Vis mean velocity; K is the coefficient of dispersion; and B is a constant. 

If the injection of the tracer is instantaneous in a 

line source across the stream, the constant may be 

evaluated as follows: 

M -(X-Vi) 2 

O A.Y21r -J2Kt exp 4Kt (

2) 

where M is the amount of tracer injected and A is the 

cross sectional area of the channel. Equation 2 can 

now be compared to the normal or Gaussian distribution 

N ·-(X-X) 2 

y= -J 27ru exp 2u 2 (3) 

where N is the number of observations, X is the mean of 

distribution, and u is the standard deviation of the 

distribution. The comparison shows that: 

X=Vt 

u=.J2Kt 

c: 

0 

+=' 

~ c: 

Q) 

g 

0 

(..) 

-

' \ 

"-\ Distance- concentration curve 

\ 

\ 

\ 

\ 

Time or distance 

\ 

\ 

\ 

' ~ 

FIGURE 163.1.-Relation between time-concentration and distance-concentration curves for same event. 

It can be seen that equation 2 is normal at any 

particular time, t. The peak value of concentration 

occurs when x= Vt and is: 

Om ax 

M (4) 

Thus the maximum concentration varies inversely with 

the square root of t. 

In dispersion experiments it is far more feasible to 

measure concentrations of a tracer over time at one 

point rather than to measure the conc~ntrations simultaneously at many points along a reach of channel. In 

conducting tests in a manner where x is held constant 

rather than t, something other than a normal distribution will be observed, as u=.J2Kt is not constant. 

By differentiating equation 2 with respect to t and 

setting the result equal to zero, the time of the maximum 

concentration tmax, is found to be: 

(W+X2V2 )t-K tmax (x is constant) V 2 (5) 

Differentiating equation 2 with respect to x yields 

lmax (tis constant)=~ (6) 

,• 

\ 

r 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-43 

The first case represents the stationary observer 

watching the event pass. The second represents a 

set of simultaneous observations. 

The ratio of equation 5 to equation 6, which is 

designated by RT, reduces to: 

RT=-J+(J2+1)i (7) 

where J is a dimensionless constant: 

J= K 

V...-Y 

Substituting equation 5 in equation 2 and dividing 

this result by equation 4 yields the ratio, RP, of the 

peak value of the time-concentration curve to· that of 

the distance-concentration curve. 

RP=[ -J+ (~+ 1)!]-! exp [~ [1- (J2+ 1)!]]! (8) 

Equations 7 and 8 are shown on figure 163.2. Note 

that the observed magnitude of RP changes almost 

linearly with J. RP can be closely approximated by: 

K Rp::::~ +4VX 

The relation between RT and J is more curvilinear, yet 

over the normally observed values of J (0 to 0.1) it can 

be approximated by: 

K 

RT::::s1-vx 

Dispersion tests have been conducted in 5 reaches of 

natural streams and 1 canal. The values of J have not 

exceeded 0.05 and were usually less than 0.01. From 

the above ann.lysis it can be seen that under these 

conditions the observations over time will yield the 

same results as simultaneous observations. 

1.3 

1.2 

1.1 

1.0 

0.9 

0.8 

0 0.7 

~ 0:: 0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

o~~~~--~--~--~--_.--~--~--~--~ 

0 0.1 0.2 0.3 0.4 0.5 0.6 0. 7 0.8 0.9 1.0 

K J=~ 

FIGURE 163.2.-Comparison of characteristics of time-concentration and distance-concentration curves. RP is ratio of 

peak concentrations; Rr is ratio of elapsed times from injection 

of the tracer to the observed peak. 

REFERENCES 

Taylor, G. I., 1954, The dispersion of matter in turbulent 

flow through a pipe : Royal Soc. London Proc., A-223, p. 

446-468. 

164. SPECIAL YIELD OF SEDIMENTS OF THE HUMBOLDT RIVER VALLEY, HUMBOLDT COUNTY, NEVADA 

By PHILIP CoHEN, Carson City, Nev. 

lVo·rk (tone in coope·ration with the Nevada Department of Co·nservation and Natural Resources 

Two hundred and nine sediment samples were collected in the fall of 1959 from the I-Iumboldt River 

Valley near the city of Winnemucca in north-central 

Nevada, and were analyzed for specific yield and 

pn.rticle-size distribution in the Hydrologic Laboratory of the Geological Survey, Denver, Colo. The 

specific yields are needed to compute changes in 

ground-water storage within the area. 

The specific yield of a rock or sediment was defined 

by l\1einzer (1923, p. 28) as "* * * the ratio of (1) the 

volume of water which, after being saturated, it will 

yield by gravity to (2) its own volume." This ratio 
C-44 GEOLOGICAL SURVEY RESEARCH 19 61 

multiplied by 100 expresses specific yield as a percentage. The definition does not state how long the sample 

should be allowed to drain; however, it is generally 

assumed that sufficient time is required to allow for 

complete gravity drainage. , 

Specific yields were determined in the laboratory by 

the indirect centrifuge-moisture-equivalent method. 

First, the porosities of the samples, expressed in percentages of the volume of the samples, were determined. Then the centrifuge-moisture equivalents, or 

the amounts of water retained by the samples after 

they were subjected to a force equal to 1,000 times the 

force of gravity for 1 hour, were determined, and were 

expressed, also, in percentages of the volume of the 

samples. Using a method described by Piper and 

others (1939, p. 118-119), the centrifuge-moisture 

equivalents were converted to specific retentions. The 

specific yields of the samples then were determined by 

the formulaSpecific yield =porosity - specific retention 

The results of the laboratory analyses are summarized 

in table 164.1. 

TABLE 164.1-Specific yield of sediment samples from the 

Humboldt River Valley, Humboldt County, Nev. 

Range of median diameters (millimeters) All 

sam- 0.004- 0.0625- 0.125- 0.25- 0.5-1 1-2 2-4 4-8 ples 0.0625 0.125 0.25 0.5 

---------------- Number of sam- ples _____________ 121 15 17 23 6 19 7 1 209 Mean specific yield percent_ ________ 19.1 21.4 25.9 25.9 22.2 20.8 17.4 17.4 20.7 Range of specific yield percent_ __ 1. 0- 2. 5- 7.0- 7. 2- 10.7- 4.6- 4.9- ------ 1.0- 34.1 36.5 35.4 39.5 35.3 36.2 27.4 ------ 39.5 

From these data it can be seen that there is a large 

range in specific yield within each median particle-size 

class. All other factors being equal, specific yields 

should tend to approach a constant value within each 

particle-size class and should increase as the median 

particle sizes increase. The large range in specific 

yields within each particle-size class for the sediments 

sampled probably is due to the presence of sedimentary 

structures (especially in some of the finegrained sediments), differences in the degree of compaction of the 

sediments, and complex interrelationships among specific retention; median particle size, porosity, and sorting 

coefficient. The observed relations among these parameters for the sediments of the Humboldt River Valley 

are: (a) specific retention tends to increase as median 

particle size decreases; (b) porosity tends to increase 

as median particle size decreases; (c) porosity tends to 

be independent of the sorting coefficient; and (d) sorting coefficient tends to increase as median particle size 

decreases. 

Table 164.1 shows that the mean specific yields for 

samples whose median particle sizes fall within the 

silt-size range is exceptionally high-about 19 percent. 

Piper and others (1939, p. 121) determined that the 

average specific yield of samples of very fine sand, silt, 

and clay is 4.2 percent. J(ues and Twogood ( 1954, p. 

33) . found that the average specific yield of clay, 

clayey silt, and silt ranges from about 2 to 14 percent. 

The relatively high specific yields associated with the 

fine-grained sediments of the Humboldt River Valley 

probably is due to the fact that most of the sediment 

samples whose median particle sizes fall within the 

silt-size· range were collected from recently deposited 

soil of the flood plain of the river. These sediments 

commonly are characterized by a moderately high 

secondary porosity caused by plant roots and burrowing invertebrate animals. In addition, because of the 

relatively shallow depth of burial, most of the finegrained sediments have not been subjected to significant compaction by the weight of overlying sediments. 

The meari specific yield of the 209 sediment samples is 

about 21 percent. While it is true that for some of the 

size classes the mean specific yields are somewhat lower 

or higher than 21 percent, it is significant that, for most 

size classes, these values do not differ substantially 

from 21 percent. The tendency for the mean specific 

yield to approach 21 percent probably is a consequence 

of relations (a) and (b) described above. As the median 

particle size changes, the porosity and specific retention 

tend to change in the same direction, aQd because porosity and specific retention tend to ·change at the same 

rate, the difference between the two (specific yield) 

tends to approach a constant value. 

Terzaghi (1949, p. 352-353) indicated that specific 

yields determined by the centrifuge-moisture-equivalent method are related to time by the equation 

t= (N2

) (i) 

According to this equation, the degree of drainage of a 

saturated sample of thickness H, subjected to a centrifugal force equal to N times the force of gravity for 

a timet is equal to the degree of drainage due to gravity 

from a bed of the same material of NH thickness in 

timet. The method used to obtain the laboratory data 

presented in . this paper involves subjecting samples 

approximately %-inch thick to a centrifugal force equal 

to 1,000 times the force of gravity for 1 hour. Thus, 

the laboratory specific yields are indicative of the degree of drainage that would occur in a layer of sediments 

approximately 40 feet thick during a period of about 

100 years. 

vVithin the limitations imposed by the variability of 

the data and the complexity of the geology, the labora-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-45 

tory data can be used to arrive at an approximation 

of the total amount of ground water in storage. The 

laboratory method must be modified to evaluate 

chnnges in ground-wnter storage that occur during 

relntively short periods of time at shallow depths. 

The problems involved are especially critical for finegrained sediments but nlso are serious for coarser 

sediments. 

REFERENCES 

Kues, H. A., and Twogood, D. A., 1954, San Luis unit, West 

San Joaquin Division, Central Valley Project (ultimate 

plan) inc~uding reconnaissance of A venal Gap unit, App., 

Local water resources: U.S. Bur. Reclamation open-file 

report, 81 p. 

Meinzer, 0. E., 1923, Outline of ground-water hydrology, with 

definitions: U.S. Geol. Survey Water-Supply Paper 494, 

71 p. 

Piper, A. M., Gale, H. S., Thomas, H. E., and Robinson, T. W., 

1939, Geology and ground-water hydrology of the Mokelumne area, California: U.S. Geol. Survey Water-Supply 

Paper 780, 230 p. 

Terzaghi, K. V., 1949, Soil moisture, in Meinzer, 0. E., Hydrology: New York, McGraw-Hill, p. 331-363. 

165. VARIABLE DEPTH-DISCHARGE RELATIONS IN ALLUVIAL CHANNELS 

By D. B. SIMONS, E. V. RICHARDSON, and W. L. HAUSHILD, Fort Collins, Colo. 

The large changes in resistance to flow that occur in 

an alluvial channel significantly effect the stage-discharge and depth-discharge relations. The changes in 

resistance to flow are related to the two regimes of flow 

and forms of bed roughness. These regimes and the 

possible corresponding forms of bed roughness are as 

follows: 

Regime 

Lower flow ___ _ 

Upper flow ___ _ 

Bed roughness 

Ripples; dunes with ripples superimposed; 

dunes. 

Transition zone connecting the two regimes of 

flow in which dunes are eliminated as boundary shear is increased. 

Plane bed; standing waves; antidunes; violent 

antidunes. 

The mngnitude of the resistance to flow cnn change 

three-fold with chnnges in bed form. For example, 

the Manning n can be as smnll ns 0.012 for a plane 

bed form nnd ns lnrge ns 0.036 for a dune bed form. 

The form of bed roughness depends on the magnitude of the shenr stress exerted by the water on the 

bed, the fall velocity of the bed material, the shape of 

the reach and cross section, and the rate of change of 

discharge. In addition, depth-discharge relations are 

a~ected to a minor extent by scour and fill, by wind 

action, vegetation, and seepage forces. 

Depth-discharge relations were studied in a recirculation-type laboratory flume 150 feet long, 8 feet wide, 

nnd 1.5 feet deep by using two different bed materials. 

Three general types of depth-discharge relations were 

found which are illustrated by the four curves shown 

on figure 165.1. 

With lower regime bed forms, the depths and discharges for each flood event are related as shown by 

figure 165.1A, B, in which the curves form a loop or 

even cross to form two loops. The shape of the curves 

for a given reach of channel are infinite in number, 

because each new runoff event yields a different set of 

curves unless the flows and channel conditions are 

identical. In general, the shape of the curves depends on the bed roughness, the time it takes for the 

bed roughness to form, and the rate of change of discharge. The above· three factors are determined primarily by the energy grade line, the fall velocity of 

the bed material, the magnitude of the discharge, and 

the rate of change of discharge with time. 

The main reason for the loop curve illustrated by 

figure 165.1A is that the formation and alteration of 

roughness elements and hence resistance to flow lags 

behind the change in discharge. For instance, when 

discharge increases, the dune size does not increase at 

a rate corresponding to the rate at which the discharge 

and shear stress increase. Conversely, when discharge 

decreases, the rate of decrease in size of the dunes 

formed at a greater depth lags behind the rate of decrease of discharge, and resistance to flow is relatively 

large. Thus, the curve for increasing discharge and 

depth is lower than the curve for decreasing discharge 

and depth. The curve shown by figure 165.1B results 
C-46 GEOLOGICAL SURVEY RESEARCH 19 6 1 

1-

LLJ 

LLJ 

Ll.. 

1. 1 

1.0 

0.9 

0.8 

t 0.7 a.. 

LLJ 

0 

1-

LLJ 

LLJ 

Ll.. 

~ 

:i 

·b: 

LLJ 

0 

0.6 

0.5 

0.4 

0.6 

0.5 

0.4 

0.3 

0.2 

A 

ffi 

v .,. 

Falling stage,.. ~ 

k--~ v 

~ 

/ v 

/~ v Rising stage 

I fl v 

cY 

7 9 11 13 15 17 19 21 

DISCHARGE, IN CUBIC FEET PER SECOND 

c 

Same on both rise and fall v b 

_/ 

--~~ v ~ ~ 

~ v ~-"'";-

. Q=58 (D-.10) 

~ 

/"" 

.7 9 11 13 15 17. 19 21 

1-

LLJ 

LLJ 

Ll.. 

1-

LLJ 

LLJ 

Ll.. 

1. 1 

1.0 

0.9 

0.8 

0.7 

0.6 

0.5 

0.4 

0.6 

0.5 

~ 0.4 

:i 

B 

~ l..-.E9 

~ " 1X _...a 

Rising stage_/ ~ ~ 

/ V ~~ Falling stage 

~ Small dunes developing 

~ ~ ~ I 

Dunes pevelo~ing 

v 

7 9 11 13 15 17 19 21 

DISCHARGE, IN CUBIC FEET PER SECOND 

D 

h 

J ~ 

Rising sta~el ~ ~ 

1 Falling sta~ 

) 

v ~~ ~ ~ i-'""'0' Dunes developing 

1-

a.. 

LLJ 

0 0.3 r/ ~ ,V 

0.2 

7 9 11 13 15 17 19 21 

DISCHARGE, IN CUBIC FEET PER SECOND DISCHARGE, IN CUBIC FEET PER SECOND 

0 

Ripples 

~ 

Large dunes 

8 

Standing waves 

• 0 ~ 

Ripples on dunes Sheared out dunes Standing waves and antidunes 

~ 

Dunes 

El1 

Plane 

0 

Antidunes 

FIGURE 165.1.-Depth, discharge, and form of bed roughness in alluvial channels. 

when the resistance of flow becomes larger with increasing depth and smaller with decreasing depth. 

A second type of depth -discharge relation occurs 

when the bed form is always in the upper flow regime 

regardless of the discharge (fig. 165.10). The depthdischarge curve is the same for both increasing and decreasing discharge inasmuch as only small changes in 

resistance to flow occur as the discharge and depth 

changes. 

The third general relation of depth to discharge results when the shear stress varies over such a wide 

range that ripples and (or) dunes form at small discharges, and a plane bed, standing waves, or antidunes 

form at large discharges (fig. 165.1D). With shallow 

depths and low discharges, the depth -discharge relation will be similar to the first type of curve, but there 

will be a change at some intermediate discharge and 

depth to the relation illustrated by the second type of 

·' 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-47 

curve. This change from the first type of curve to 

the second will result in a shift or break in the depthdischarge relation. The shift or break in the relation 

when the discharge is increasing will be to a shallower 

depth for the same discharge or a larger discharge for 

the same depth. 'Vhen the discharge is decreasing, the 

shift or break will be to a deeper depth for the same 

discharge or the same depth for a smaller discharge. 

A break or shift in the depth -discharge relation results 

from an increase or decrease in resistance to flow as the 

flow regime changes. The change from one depthdischarge relation to the other will not occur at the 

same depth and discharge for the rising and falling 

stages, nor will it occur at the same depth and discharge from one runoff event to another. 

Stage-discharge relations are affected by all the factors that determine the depth-discharge relations, but 

they are affected more by local scour and fill. Thus, 

stage-discharge curves may be similar to, or quite 

different from, corresponding depth-discharge curvesdepending on the amount of scour or fill and the 

change in porosity of the bed with change in the form 

of bed roughness. 

Colby (1960), Culbertson and Nordin (1960), and 

Dawdy (1961) find that the relations depicted on figure 165.1 apply in natural streams. 

REFERENCES 

Colby, D. R., 1960, Discontinuous rating curve for Pigeon 

Roost and Cuffawa Creeks in northern Mississippi: U.S. 

Dept. Agriculture, ARS 41-35. 

Culbertson, J. K., and Nordin, C. F., 1960, Discussion of discharge formula for straight alluvial channels: Am. Soc. 

Civil Eng. Jour., v. 86, no. HY6. 

Dawdy, D. R., 1961, Depth-discharge relation of alluvial 

streams: U.S. Geol. Survey Water-Supply Paper 1498-C. 

166. LOWEST MULTI-YEAR MOVING AVERAGE COMPARED WITH MINIMUM INDEPENDEN1 

MULTI-YEAR MEANS 

By Cr..AYTON H. HARDISON, Washington, D.C. 

In areas where the lowest streamflow is insufficient 

to meet the demand, storage reservoirs are designed 

to carry over water from years of surplus to years of 

deficiency. Thus, the number and severity of consecutive years of low flow are factors in the designs of 

such reservoirs, as is also the probable frequency with 

which such years can be expected to recur. Strict 

stn,tistical analysis o£ a record of given length requires 

that the frequency of occurrence of multi-year averages be computed by dividing the record. into equallength consecutive periods, and taking the minimum 

of these independent averages. In practice however, 

this arbitrary subdivision may obscure the lower dischn,rge of a period of years that fell partly in one 

period and partly in an adjoining period. In the rest 

of this paper, the minimum independent averages are 

ealled minimum independent means to avoid confusion 

with other averages. The study of random numbers 

reported in this paper was undertaken to determine 

the difference between the lowest moving average and 

the minimum independent mean to determine how to 

obtain the lowest moving average for a 50-year recurrenee interval from a distribution of independent 

multi-year means, such as given by the Corps of Engineers ( 1958). 

By· the use of random numbers from table 23 in 

Dixon and Massey, (1957) an estimate was obtained of 

the amount by which the lowest 10-year mean in 59 years 

of record is smaller than the 10-year minimum taken 

from 5 independent 10-year nieans. To make this 

estimate, the randon1 numbers in table 23 were assumed 

to represent annual runoff, and 10-year means were 

computed for 5 successive groups of 10 years starting 

with year number 1; the lowest 10-year mean thus 

computed is 1. 73. Then, starting with the second 

random number in table 23 and continuing through the 

the 51st random number, another set of five 10-year 

means was obtained of which the lowest is 1.87. This 

process was continued 8 more times, the last time starting with the lOth random number and ending with the 

59th random number. The average of the 10 lowest 

means thus obtained is 1.83, and the lowest of the 50 

means is 1. 71-a difference of 0.12. As the figure of 

1. 71 is also the lowest moving 10-year average for 
C-48 GEOLOGI·CAL SURVEY RESEARCH 19 61 

random numbers 1-59, this difference is an estimate of 

the probable difference between a minimum independent 10-year mean in a sample of 50 years and the 

lowest moving average to be plotted at the 50-year 

recurrence interval, because 

Recurrence interval n-t+l 

m 

where n is the number of years in the sample, m is the 

order number. and tis the number of years in the multi-. 

year average. The results are listed on the.first line of 

table 166.1. 

TABLE 166.1.-Computation of estimated difference between a minimum independent 10-year mean in 50 years of record and 

the lowest moving 10-year average at the 50-year recurrence interval · 

Average of 10 lowest Difference between figures or of 10 highest inde- shown in second or third 

pendent means columns and the lowest or Starting numbers highest moving averages 

Lowest Highest Lowest Highest 

1-10 _______________ 1. 83 2. 55 0. 12 0. 15 51-60 ______________ 1. 73 2. 50 . 09 . 32 101-110 ____________ 1. 58 2.04 .11 . 30 151-160 ____________ 1. 88 2. 58 . 05 . 16 

201-210 _____ ~-----~ 1. 64 2.33 . 15 . 27 251-260 ____________ 1. 56 2. 36 . 23 . 23 301-310 ____________ 1. 73 2. 38 . 13 . 10 351-360 ____________ 1. 72 2. 64 . 43 . 09 401-410 ____________ 1. 53 2. 22 . 20 . 13 451-460 ____________ 1. 63: 2. 12 . 19 . 09 

Average _____ 1. 68 1 2.37 0. 170 0. 184 

Overall 

average ____ 1. 66 0. 18 

I Used as 1.63, because if scales were reversed, 0.37 above the mean of 2.00 would 

correspond with 0.37 below the same mean. 

A second test was obtained by starting with the 51st 

random number, and 8 other estimates were obtained 

by starting with random numbers 50 items apart. The 

results are summarized in lines 2-10 of table 16(>.1. 

The average of the 10 averages is 1.68 and the average 

of the 10 differences is 0.170. The highest 10-year 

means in each 5 groups of 10 random numbers give 

another set of data which, when averaged with the results shown in columns 2 and 4 of table 166.1, give a 

mean of 1.66 and a difference of 0.18. 

The difference given by this experiment, which i"s 

applicable only when the original data have a mean of 

2.00 and a standard deviation of 1.00, can be applied 

to other normally distributed data by converting the 

difference in means to difference in their deficiency 

probability-the probability of occurrence of a mean 

equal to or less than a given amount.· The first step in 

making this conversion is to decide at what probability 

to plot the lowest of five independent 10-year means, 

and the second step is to use the computed difference 

to obtain the probability for the lowest 10 year moving average with a 50-year recurrence interval. 

On a cumulative probability distribution with a 

standard deviation of 0.316 (the theoretical standard 

deviation of 10-item means when the items have a 

standard deviation of i.OO), the 1.66 obtained from this 

experiment plots at a deficiency probability of about 15 

percent as compared to 16.7 percent computed by 

lOOm the formula n + 1 and 13 percent by the formula 

1 

100(1-.5 ;:;-). If the percent computed by the first 

formula, which is generally used in the Geological Survey, is accepted as giving the most probable plotting 

position for the lowest independent 10-item mean, the 

corresponding y value is 1.69, and when the average difference of 0.18 is subtracted from this, y is 1.51 and the 

corresponding percent becomes 6.3. (See fig. 166.1.) 

Thus, the lowest 10-year moving average with a recurrence interval of 50 years is enough smaller than the 

most probable minimum independent 10-year mean in 

50 years· to change the deficiency probability from 16.7 

percent to 6.3 percent . 

4.0-~-~----.----..-----.----'T'"--.--..----..--....., 

UJ 

(,!) 

< f!icn 

;( ~ 2.5 

u..~ 

o ..... o:::O 

Oa.. 

~:::! 

~ ~ 2.0 -(,!) 

::;< ..... ~0 

iii 

II 

>-

0

50 40 30 20 10 5 2 

DEFICIENCY PROBABILITY, IN PERCENT 

0.5 0.2 0.1 

FIGURE 166.1.-Plotting position of lowest moving 10-year average in a 59-event sample. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-49 

Results from similar experiments with moving averages of 2, 4, and 20 events in a series of 50 events, together with those for the 10-event groups are summarized in the following table: 

Number of events in the average__ 2 4 10 20 

Number of groups (n) in 50 years__ 25 12}~ 5 2% 

lOOm (d fi . b b'l't f n+l e mency pro a 11 y or 

minimum indt;Jpendent mean, 

in percent)___________________ 3. 8 7. 4 16. 7 28. 6 

Corresponding y for independent 

events_______________________ . 75 1. 28 1. 69 1. 87 

Average difference between independent and moving averages, from experiment______________ . 13 . 21 . 18· . 14 

Average y for moving averages____ . 62 1. 07 1. 51 1. 73 

Deficiency probability for moving 

averages with recurrence intervals of 50 years, in percent_____ 2. 4 2. 9 6. 3 11 

Based on this experiment, the percentages shown in 

the last line should be used if the lowest moving average with a recurrence interval of 50 years is to be obtained from a distribution of independent means. If 

the percentages are to be used to help define a cumulative frequency distribution of independent multi-year 

means,· the number of years in the sample should be 

increased by one less than the number of years in the 

multi-year average. For example, the figure to plot at I 

6.3 percent is the lowest 10-year average in 59 years. 

Although these percentages are but estimates based 

on a small experiment with normally distributed random numbers, they give an indication of the size of the 

difference between the lowest moving average of natural events and minimum independent means. 

REFERENCES 

Dixon, ,V. J., and Massey, F. J., Jr., 1957, Introduction to 

statistical analysis: 2d ed., _New York, McGraw-Hill Book 

Co., p. 452-456. 

U.S. Corps of Engineers, 1958, Long-duration runoff volumes, 

Flood volume studies, Tech. Bull. 5 : Sacramento, Calif., 

U.S. Army Engr. Dist. 

167. BANKFULL DEPTH AND DEPTH OF FLOW FOR MEAN ANNUAL FLOOD, PIEDMONT PROVINCE 

By F. A. J(u.rATRICK, Atlanta, Ga. 

The relation between bankfull depth and the depth 

of flow of the mean annual flood has been analyzed 

at 41 places in the Piedmont Province of the southenstern United States. The channel size and shape 

were determined along a reach of channe~ at each of 

26 sites where the frequency of flood discharge was 

known from gaging station records. Less detailed 

surveys were made at an additional 15 sites at which 

the frequency of flood discharge was interpolated 

from regional analysis of station records. An average 

of 12 cross sections spaced about 2 channel widths 

apart were measured at the 26 regular sites, and 2 or 

3 cross sections spaced about 7 channel widths apart 

were meastl.red at the 15 supplementary sites. Highwater marks for one or more floods per reach were 

noted. 

Bankfull depth, D n, is the difference in height bet. ween the top of the stream channel and the corresponding n.verage elevation of the stream bed. The 

top of the strenm channel may be taken as the average 

elevation of the flood plain, or a bench along the channel at a lower elevation. 

If bankfull elevations are plotted against distance 

along the channel, abrupt discontinuities are found at 

points where there is a major change in channel slope. 

Within a single reach of channel, bankfull stage 

does not always correspond to the same discharge. 

This may be due in part to the fact that bankfull 

stage is at the level of the flood plain in one subreach 

and at the level of a predominant bench at a lower 

elevation in another subreach. 

Several investigators ("V. B. Langbein, written 

communication, 1953; Wolman, 1955; Wolman and 

Leopold, 1957) have reported that the discharge at 

bankfull stage is roughly equal to the mean annual 

flood, and that it has an average recurrence interval 

of 2.33 years. Information from the present work 

shows (fig. 167.1) that the recurrence interval of bank-

. full discharge at the 40 sites in the Piedmont ranges 
C-50 GEOLOGI-CAL SURVEY RESEARCH 1 9 61 

. . . . . . .. ---~----·-···-··-··...a.......:·-·-·--· 

·. 

FIGURE 167.1.-Recurrence interval of bankfull discharge, in 

cubic feet per second, at 41 sites in the Piedmont. Line 

shows average recurrence interval according to some previous investigators. 

from 1 to 55 years, but that on the average the bankfull discharge does represent the mean annual flood. 

The depth of water, DF, during the mean annual 

flood can be related to bankfull depth and to the corresponding· longitudinal slope of the bench or flood plain. 

The slope of the benches is approximately equal to the 

slope of the water surface at bankfull stage. The stage 

during the mean annual flood is derived from discharge 

measurements. Where the stage of the mean annual 

o Supplementary sites 

• Regular sites 

I I d 

.001 

S (FT PER FT) 

• 

I I II 

.01 

FIGURE 167.2.-Relation of depth of water during the mean 

annual flood, bankfull depth, and slope in feet per foot, 

of the top of the channel for 41 sites in the Piedmont. 

..... 

UJ 

UJ 

LJ... 

~ 

ci 

0 

0 

....J 

LJ... 

z 

<( 

UJ 

:::iE 

LJ... 

0 

J: 

t 

UJ 

0 

10 

BANKFULL DEPTH, IN FEET 

FIGURE 167.3.-Relation of bankfull depth to depth of mean 

annual flood for different slope ( s) of the top of the channel. 

flood is greater than bankfull stage, the average bed 

elevation of the main channel is used to compute DF. 

The regression equation which expresses the relation 

among the depth of mean annual flood, bankfull depth, 

and slope of the bench or flood plain for 41 sites iR 

(1) 

The standard error is 12 percent. and both regression 

coefficients are significant at the 0.001 level. The 

relation is shown graphically on figure 167.2. 

In figure 167.3, equation (1) is shown for different 

slopes, and a line of equal depth is superposed. In 

general, where slopes are ge!ltle,.the mean annual flood 

will overflow the stream banks; where slopes are 

steep, the channel capacity is greater than that required. To the left of the equal-depth line bankfull 

stage is defined by flood plains and to the right by 

lower benches. 

REFERENCES 

Wolman, M. G., 1955, The natural channel of Brandywine 

Creek, Pennsylvania: U.S. Geol. Survey Prof. Paper 271, 

56 p. 

Wolman, M. G., and Leopold, L. B., 1957, River flood plains; 

some observations on their formation: U.S. Geol. Survey 

Prof. Paper 282-C, p. 87-109. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-51 

GEOLOGY AND HYDROLOGY OF EASTERN UNITED STATES 

168. BOUNDARY MOUNTAIN ANTICLINORIUM, WEST-CENTRAL MAINE AND NORTHERN NEW HAMPSHIRE 

By ARDEN L. ALBEE, Pasadena, Calif. 

Recent geologic mapping in west-central Maine, 

northern New Hampshire, and adjacent Quebec has 

resulted in a new stratigraphic and structural. interpretation. This summary and the accompanying map 

(fig. 168.1) is based upon the work of many other 

geologists as well as upon mapping by the author from 

1956 to 1959. Direct use has been made of A. J. 

Boucot's work in the Moose River synclinorium (Boncot, 1953 1 ; 1961; written and oral communications, 

1960), of R. A. Marleau's work in Quebec (Marleau, 

1957; 1958; thesis, 1958 2 , written and oral communications, 1960), of Albee and E. L. Boudette's work in 

the Attean quadrangle (fig. 168.1, B-5) and of a compilation edited by Boucot and A. Griscom (Boucot 

and others, 1960). Recent work by John Green (oral 

communication, 1960) in northern New Hampshire 

wns importnnt in crystallizing the author's interpretations. 

A mnjor nnticlinorium, the Boundary Mountain 

anticlinorium, extends from northern New Hampshire 

northeast into Maine; it is outlined on the map by a 

regional unconformity between rocks of probable 

Cn.mbrian and Ordovician age in its core, and units of 

Silurian n,nd Early Devonian on its margins. In 

l\faine a n1ajor unnamed anticline splits off to the east 

and extends about 65 miles to tlie northeast. The 

Moose Uiver synclinorium lies between the two anticlinoriums and contains a great thickness of welldated rock of Early Devonian age. Northwest of and 

parallel to the Boundary l\fountain anticlinorium a 

sandy facies of the Devonian outlines the core of the 

Frontenac synclinorium. The existence of the Frontenac synclinorium is best demonstrated by pillowbearing volcanic rocks on either limb, which· indicate 

the upper surfaces of the beds. (See footnote 2.) Cambr.in,n and Ordovician rocks crop out northwest of the 

Frontenac synclinorium in the core of the Green 

1\fountain-Sutton l\fountain anticlinorium. 

PRE-UPPER SILURIAN ROCKS 

Ueconnaissance mapping suggests that at least three 

mnjor units can be distinguished in the pre-Upper 

1 Boucot, A. J., 1953, The Lower Devonian rocks of west-central 

Maine: Unpub. Ph.D. thesis, Harvard Univ. 11 Marleau, R. A., 1958, Geology of the Woburn, East Megan tic and 

Armstrong nrens, Frontenac and Beauce counties, Quebec: Unpub. Ph.D. thesis, Univ. Laval. 

Silurian rocks, but the relative age of these units is 

not known. The two slate and phyllite units east of 

the l\foose River synclinorium include a felsic volcanic 

unit having l\fiddle Ordovician fossils. The eastern 

unit seems to be GOntinuous with rocks mapped as the 

Albee formation of Ordovician age by John Green 

(written communication, 1960) in northern New 

Hampshire. The northern part of the Boundary 

1\tlountain anticlinorium is underlain by a quartzofeldspathic granulite or gneiss containing abundant 

lithic fragments. Although the granulite is assigned 

to the Precambrian by Boucot (1961) it is unlike the 

known Precambrian rocks of central Vermont and of 

the Canadian Shield north of the St. Lawrence River 

and is believed to be of Cambrian and (or) Ordovician 

age. The rock is not too dissimilar to rocks in northern New Hampshire, which are assigned to the Ordovician, and seems to intertongue along the Maine-New 

Hampshire border with the extension of these rocks. 

More detailed mapping by John Green (oral communication, 1960) in the Second Lake quadrangle 

(D-2) also seems to support this interpretation. The 

pre-Silurian rocks are intruded by hornblende diorite 

or gabbro, which in turn is intruded in the Attean 

quadrangle (B-5) by coarse-grained porphyritic 

quartz monzonite. Similarity of lithologic characteristics and of stratigraphic relationships suggest that 

the quartz monzonite is equivalent to the Highlandcroft plutonic series of New Hampshire (Billings, 

1956, p. 46-48, 106). 

SILURIAN ROCKS 

The Silurian rocks occur in discontinuous lenticular 

units and include limestone, calcareous sandstone and 

mudstone, conglomerate, arkose, limestone conglomerate, and felsic volcanic rocks. l\fany units are dated • 

by paleontologic evidence as Late Silurian and one as 

Early Silurian, (northern edge of Stratton quadrangle, D-5) , but several can be accurately dated only as 

pre-Early Devonian. In the areas mapped by Boucot 

in the Spencer Lake quadrangle ( C-5) and by Albee 

and Boudette in the Attean quadrangle (B-5), several lines of evidence suggest that the Silurian rocks 

were deposited near a shore with strong local relief. 
';.S ~~{ '<!~ 

"1:!~ 

~Cl I 

~I 

11[ 

~~ 

~~ ~ 

~·~ 

~:;! 

t;tll 

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EXPLANATION 

[ +og+ lx d'd ~ 4' X X xl Intrusive rocks 

Dg, granitic plutonic rocks 

Dd, hornblende diorite and gabbro 

Lii:LEJ 

Sedimentary rocks 

D s, slaty facies 

Dss, sandy facies 

I DSIU I 

Sedtmentary rocks 

QE undivided . 

. Sedimentary and minor volcanic 

rocks undivided 

UNCONFORMITY 

Og, porphyritic quartz monzonite 

Od, hornblende diorite and gabbro 

Of ~ Felsic tuff 

z 

o( 

z 

0 

> 

UJ 

0 

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0 

l

zo: 

..:-z zoo: 

..:- -U 

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00 

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I O£g I O£b I O£r lo£mul l§~ Metamorphic and volcanic rocks Z ~ 

0£g, quartz-feldspar granulite <(-

O£b, black slate and phyUite, .greenstone E ~ 

O£r, green phyUite, red and green slate Z · 

O£mu, meta-sedimentary and meta-volcanic ~ o 

rocks undivided n:: 0: mo ------?---?--- l: Contact o( 

Solid in mapped areas; dashed where inferrecf.J on lithologic simil.arity, topography, or mag - netic anomalies; queried where inferred on little evidence 

---v.;:uit- Dashed where inferred 

5 0 5 10 15 Ml LES I I I I. I I I I 

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r • · • ·+ ' /. •' n + O£g ,-/~ _, _ _.. O£b 

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FIGURE 168.1.-Simplitl.ed geologic map of west-central Maine, northern New Hampshire, and adjacent Quebec. 

0 

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SHORT PAPERS IN THE GEOLOGIC AND"'HYDROLOGIC SCIENCES, ARTICLES 147-292 C-53 

DEVONIAN ROCKS 

Severn,l lithologic facies have been distinguished 

within the Devonian rocks. Dark-colored argillaceous 

sandstone interbedded with minor gray slate and felsic 

volcanic rocks within the ~{oose River synclinorium 

contains abundant Early Devonian fossils. Slate in 

and adju,cent to the ~{oose River synclinorium also 

contains Early De.vonian fossils, but no fossils have 

been found in the sandy unit within the Frontenac 

synclinorium, which consists predominantly of massive argillaceous sandstone and minor slate and volcanic rock. The western unit · is characterized by 

nrgillaceous and arenaceous limestone, slate, and sandstone, and contains Early Devonian fossils at its base 

in rocks similar to the Silurian rocks described above. 

The slnte unit in the northeastern part of figure 168.1 

is overlain by the sandy facies of both the Frontenac 

nnd Moose River synclinoriums, but the slate and sand 

fncies nre also in part laterally equivalent. In the 

Attenn quadrangle ( B-5) fossiliferous Upper Silurian 

rocks intertongue with the lowermost portion of the 

gray slate. Thus, although the dark-colored slate, 

sandstone, and limestone is probably predominantly 

Early Devonian in age, they may locally be Middle 

Devonian or Late Silurian. 

POST-LOWER DEVONIAN INTRUSIVE ROCKS 

AND METAMORPHISM 

The pre-Upper Silurian, the Silurian, and the Devonian rocks all have undergone regional metamorphism 

of chlorite grade in the northern and western part of 

the area and higher grade to the southeast. Hornblende diorite and gabbro masses intrude the Lower 

Devonian rocks and seem to have been somewhat 

affected by the regional metamorphism. Plutons, predominantly of medium-grained biotite quartz monzonite, but including some more mafic rocks, intrude all 

the metasedimentary units and are surrounded by contact-metamorphic aureoles. Isotopic ages for metamorphic or igneous minerals from several units (Hurley and others, 1959) suggest that the regional metamorphism and the intrusion of the Devonian quartz 

monzonite occurred nearly simultaneously in Middle 

Devonian time. 

MAGNITUDE OF THE TACONIC OROGENY IN 

THE AREA 

In the Spencer Lake (C-5) and Attean (B-5) quadrnngles several lines of evidence indicate that the preUpper Silurian rocks were emergent during much of 

Late Silurian and Early Devonian time. The evidence 

includes observed relief on the surface of the preUpper Silurian rocks, including the presence of possible fossil seacliffs and seastacks, and intertonguing 

of rock composed of large angular blocks of pre-Upper Silurian ·rock debris in Upper Silurian or Lower 

Devonian reefal material with slate of the same age. 

Along the west side of the Boundary Mountain anticlinorium none of the conglomeratic or calcareous 

Upper Silurian units has yet been found and slate of 

probably Early Devonian age rests directly upon the 

pre-Upper Silurian rock. The absence of the Upper 

Silurian rocks could be the result of a major fault or 

of removal by erosion in Early Devonian time. It 

seems more likely, however, that the presence of Upper 

Silurian units with near-shore characteristics on the 

east side of the Boundary Mountain anticlinorium 

represents a coincidence between the locations of the 

folded Upper Silurian shore-line and the present erosion surface, and that the absence of these near-shore 

deposits on the west side results from the onlap of the 

slate fa0iP.s onto the pre-Upper Silurian surface. The 

Upper Silurian near-shore deposits, if originally present, are now below the present erosion surface. 

The distribution of pre-Upper Silurian units is not 

yet known in detail, but likely trends of a number of 

pre-Upper Silurian units are shown on figure 168.1. 

. There appears to be a continuous sequence of these units 

from northwest to southeast across the Boundary ~fountain anticlinorium without major repetition, and the 

trends do not seem to be directly related to the Middle 

De~onian deformation which formed the Moose River 

synclinorium. The relation of these apparently steeply 

dipping contacts to the Silurian and Devonian contacts at the south end of the Moose River synclinorium 

suggests that the Taconic orogeny in this area involved major deformation rather than just a tilting of 

the older rocks. 

Other evidence suggests that the Taconic orogeny 

involved metamorphism of fairly high grade. Relict 

sillimanite, partly altered to white mica, and garnet 

occur at several places in the quartzo-feldspathic 

granulite of the Attean (B-5) and Spencer Lake 

( C-5) quadrangles. These occurrences are apparently 

well away from any intrusive mass and the Middle 

Devonian metamorphism in the Attean quadrangle 

(B-5) is only of chlorite grade. Further work may 

indicate that the Taconic orogeny was a major event 

in this area, involving metamorphism of the sillimanite grade. It should be recognized, however, that. 

the validity of this suggestion depends on the correct-
C-54 GEOLOGICAL SURVEY RESEARCH 19 6 1 

ness of assigning an Ordovician and (or) Cambrian 

age, rather than a Precambrian age, to the pre-Upper 

Silurian granulite. 

REFERENCES 

Billings, M. P., 1956, The Geology of New Hampshire, Part 

II, Bedrock geology: New Hampshire State Planning and 

Development Commission, Concord, N.H., 203 p. 

Boucot, A. J., 1961, Stratigraphy of the Moose River synclinorium, Maine: U.S. Geol. Survey Bull. 1111-E, p. 

153-188. 

Boucot, A. J., Griscom, Andrew, Allingham, J. W., and Dempsey, W. J., 1960, Geologic and aeromagnetic map of northern 

Maine: U.S. Geol. Survey Open File Maps, 5 sheets. 

Hurley, P. M., Boucot, A. J., Albee, A. L., Faul, Henry, 

Pinson, W. H., and Fairbairn, H. W., 1959, Minimum 

age of the Lower Devonian slate near Jackman, Maine: 

Geol. Soc. America Bull., v. 70, p. 947-950. 

Marleau, R. A., 1957, Woburn area, electoral district of 

Frontenac : Quebec Dept. Mines Prog. Rept. 336. 

-- 1958, East Megantic and Armstrong areas, electoral 

districts of Frontenac and Beauce: Quebec Dept. Mines 

Pro'g. Rept. 362. 

169. AXIAL-PLANE FOLDING IN SOUTHEASTERN CONNECTICUT 

By RicHARD GoLDSMITH, Denver, Colo. 

Work done in cooperation with the Oonnectimtt Geological and Natural History Survey 

The bedrock of southeastern Connecticut is a crystalline complex of granitic to granodioritic gneisses· 

and of sedimentary and probably volcanic rocks of 

high (sillimanite) metamorphic grade. Granitic and 

quartz-monzonitic gneisses and granodioritic gneiss 

comprise from 30 to 50 percent of the complex. Biotite-quartz-feldspar gneiss and hornblende-biotitefeldspar gneiss, probably in part metavolcanic rocks, 

comprise about 30 percent. The remainder is quartzite, calc-silicate rock, and pelitic and semi-pelitic 

schist and gneiss. Most of the granitic rocks are concor·dantly to semiconcordantly intercalated among the 

other rocks. No unconformities have been recognized. 

The units are distributed in a complex fold pattern resulting from continuous deformation or more than one 

episode of deformation. 

Certain key units are helpful in tracing the fold pattern of the bedrock sequence. One is an aegirineaugite granitic gneiss, which is in phacolithic bodies 

along a particular horizon of interlayered amphibolite 

and light-colored feldspathic gneiss and granodioritic 

gneiss. ~{apping of this distinctive assemblage and 

the adjacent rocks has revealed the fold pattern indicated on figure 169.1. Note that the trace of the 

axial plane of the syncline in the garnet-mica schist 

and gneiss has been involved in later folding along 

easterly-trending axial planes. In figure 169.2 the 

aegirine-augite granitic gneiss and the horizon in 

which it appears are used to illustrate in three dimensions the type of folding characteristic of the area. 

The overturned folded syncline shown in figures 

169.1 and 169.2 lies in its northwestern part along 

Hunts Brook in the Montville quadrangle and is here 

called the Hunts Brook syncline. It appears to be 

continuous with a syncline of regional significance 

in quadrangles to the west, called by L. Lundgren 

(written communication, 1959) the Chester syncline. 

The fold is interpreted as a syncline rather than an 

anticline on the basis of stratigraphic and structural 

relations in quadrangles to the west and northwest 

mapped by Lundgren and to the north and northwest 

mapped by G. L. Snyder. 1 

Symmetry on opposite sides of the axis of the Hunts 

Brook syncline is not perfect as the aegirine-augite granitic gneiss appears only on one limb. In figure 169.1, 

the granodioritic gneiss complex on the west limb is 

too thin to show at the scale of the map. The biotitequartz-feldspar gneiss unit also is much thinner in 

the west limb than in the east limb. 

The plunge of the overturned Hunts Brook syncline 

is eastward or southeastward in the northwest corner 

of the Montville quadrangle. In the adjacent quadrangles to the west, the plunge of Lundgren's Chester 

syncline is westward and the garnet mica schist and 
41 

SEA 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC. SCIENCES, ARTICLES 147-292 C-55 

-

-

--

NIANTIC 

QUADRANGLE 

I 

SEA LEVEL B 

2000' "' 

\ 

\ 

\ 

\ \ 

'\ \ 

qc 

\ 

-

qc 

0 

- MONTVILLE 

QUADRANGLE 

---.....--

1 MILE 

UNCASVILLE 

~DRANGLE 

---- --

--- -- qc 

'<0 

gdc 

B' 

EXPLANATION 

Garnet-mica 

~ schist and gneiss 

~:::::::[::~:~:::::::::1 Hornblende-biotite-feldspar 

gneiss 

~ 

Granodioritic 

~ gneiss complex 

gdc, gru.nodioritic gneiss mixed with (l:mphibolite nnd mafic-poor gneiss; gra.nodioritic 

gneiss with inclusions of wmphibolite. 

ga, neoirine-nugite (}'l"(l,nitic gneiss 

f~:-~:\~///}1 Biotite-quartz-feldspar gneiss 

Biotite-qu.(l:rtz-feld.9pcP' gneis.~ with minor 

qua.rtz1:te nnd a:mphibolite; a.t top, thin cnlcsilica.te gneiss, b1:otite-gnrnet gneiss, wnd 

.~illinw.nite gneiss 

~~qc~~ Complex of quartz-monzonitic and granitic 

gneiss, quartzite, and metasedimentary 

schist and gneiss 

------ Contact 

Dn.~hed where a.pprox1:mntely /.ocnted 

~- Syncline Anticline 

Trace of axial plane of overturned fold 

with plunges 

3'Y 

Strike and dip of inclined foliation and 

layering 

/ 

Strike of vertical foliation and layering 

)'5 

Strike and plunge of fold axes and mineral 

lineation 

J!...,Iomu~ 169.1.-Geologic map and sections of parts of the Uncasville, Montville, Niantic, and New London quadrangles, Connecticut. 
C-56 GEOLOGiCAL SURVEY RESEARCH 19 61 

FIGU RE 169.2.-Isometric diagram showing folding of the Hunts Brook syncline as marked by the aegirine-augite granitic gneiss 

(stippled) and its corresponding horizon on east and west limbs. 

gneiss, as well as younger rocks, appear again in the 

core of the syncline (Lundgren, written communication, 1959). 

The anticbne to the east of, and corresponding to, 

the Hunts Brook syncline is involved with it in the 

later folding, and the plunge of its arcuate axis swings 

from northwestward to southeastward. The trough 

of the Hunts Brook syncline rises in the northern 

later-formed anticline along line of section B-BI 

(north side of section A-AI). Representation of units 

at depth is schematic. The nose of the old anticline 

lies to the southwest of this younger anticline and is 

partly do,,nfolded in the younger syncline. 

The original trend of the rock units at the time of 

the formation of the Hunts Brook syncline is problematical. It may have been westerly or more northerly according to whether a northwest-trending shear 

couple or purely northeast-southwest compression was 

involved in the later folding. Traces of axial planes 

of the later folds trend west-northwest. Axes of 

minor folds near the Hunts Creek syncline plunge 

relatively steeply to the northeast. The steep attitudes 

of foliation and layering in the larger flexures also indicate fairly steeply plunging axes. This pattern suggests north-south compression, perhaps with an appreciable right-lateral component during the later 

folding. Mineral lineation and fold axes plunge 

gently to moderately southeastward near the secondary 

fold in the Niantic and New London quadrangles, 

probably largely under the influence of the later folding on foliation and layering oriented differently from 

that along the main Hunts Brook syncline. 

The trend of the axial planes of the secondary folds 

is fairly consistent throughout the area of the four 

quadrangles. Plunges of minor fold axes are consistent locally but not regionally. The pattern probably reflects local adaptation to later deformation of 

differently oriented parts of previously formerl folds, 

but it may reflect a more complex history of deformation throughout the area. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-57 

One should not conclude fron-i the map that rocks 

in the I-:Iunts Creek syncline were folded between relatively mn.ssi ve blocks of the complex of quartz-monzonitic and gr.anitic gneiss and metasedimentary rocks 

to the northeast and southwest. Equally complicated 

folding in this complex is revealed by mapping the 

many diverse rock types within it; this folding conforms to the same general pattern as in the rocks along 

the overturned I-Iunts Brook syncline. · 

The thinning and thickening of the rock units indicate considerable rock flowage. The minor drag folds 

on both limbs near the crest of the secondary fold 

involving the aegirine-augite granitic gneiss in the 

Uncnsville quadrnngle indicate flowage of material 

into it. No evidence of cntaclasis exists in this part of 

t:he nrea and the pattern, texture, and mineralogy of 

the rocks indicate deformation at a fairly high temperature, perhaps during or penecontemporaneous 

with mobilization and intrusion of rocks of the. granodioritic gneiss complex. Older igneous rocks in the 

complex of quartz-monzonitic and granitic gneiss and 

metasedimentary rocks may have been recrystallized 

and even remobilized during this time. 

The axial-plane folding may be an expression of 

the behavior of the rocks at depth, perhaps during an 

early phase of deformation that at higher levels, and 

perlutps at a later time, resulted in the generally westward-trending :Honey Hill thrust fault (Lundgren, 

Goldsmith, and Snyder, 1958) about 5 miles to the 

north of the area shown on figure 169.1. The direction 

of movement of the secondary folding of the Hunts 

Brook syncline appears to be consistent with the rightlateral movement inferred on the Honey Hill fault. 

REFERENCE 

Lundgren, L., Jr., Goldsmith, R., and Snyder, G. L., 1958: 

Major thrust fault in southeastern Connecticut [abs.] : 

Geol. Soc. America Bull., v. 69, no. 12, pt. 2, p. 1606. 

170. A FROST-WEDGED BEDROCK LOCALITY IN SOUTHEASTERN MASSACHUSETTS 

By CARL l(oTEFF, Boston, Mass. 

Wm·lc done in cooperation with the llfassaohusetts Department of Publio Works 

A bedrock exposure in southeastern ~{assachusetts 

exhibits unus1.wJly wide joint openings that apparently 

are unique in the area. This exposure is on the western border of the town of Rochester, approximately 10 

miles north of New Bedford and about 1,000 feet 

southwest of Little Quittacas Pond in the Assawompset Pond quadrangle. It is an isolated knob elongated 

in a northwest direction and is about 200 feet long and 

125 :feet wide. The highest part of the knob is about 

25 feet above the surrounding· ground. 

The bedrock in this area was mapped as the Dedham 

granodiorite, of Devonian( n age, by Emerson (1917, 

p. 175-176), who extended the name from the intrusive 

body at the type locality southeastward to the granites 

of the N ttrragansett structural basin. The rock is 

mainly coarse-grained quartz, feldspar, and amphibole, 

and has a weak to strong foliation. 

The main joint set is parallel to the foliation, strikes 

N. 35° E., and dips vertically or steeply southeast. A 

601530 0-61----.5 

secondary joint set is approximately normal to the 

main set and dips 65° to 70° NE. A third joint set, 

dipping gently northeast, is exposed on the sides of the 

knob. The openings (fig. 170.1) are as much as 3 feet 

wide along joints. of the m~iin set, and as much as 1 

foot wide along joints of the secondary set. The observed depth of the openings is as much as 10 feet, but 

the total depth is obscured by soil. The openings along 

joints of the main set are spaced from 1 to 5 feet apart, 

and most of them extend the entire width of the exposure. The openings along the secondary set of 

joints are much more widely spaced and terminate at 

their intersection with the main set. A joint of the 

third set is exposed at only one place about 7 feet below the surface. Here the movement of an overlying 

block along the joint has slightly widened the opening 

of the secondary joint above this point, but has not 

affected the width of the opening along the main 
C-58 GEOLOGICAL SURVEY RESEARCH 19 61 

FIGURE 170.1.-0penings along the main set of joints. Width 

of the block in the center is about 5 feet; secondary joint 

opening in right foreground. 

joint. The openings along the two nearly vertical 

joint sets extend below this third joint. 

It seems clear that all the openings are a result of 

the movement of the blocks along the nearly horizontal 

joints of the third set, and that the movement has been 

caused by frost wedging. Water or water vapor entering these joints would act, upon freezing, as a lubricant and facilitate the lateral movement of the blocks 

forced apart by the pressure of ice forming in the 

nearly vertical joints. H. T. U. Smith ( 1953) has described similar frost-wedging phenomena at the "rock 

cities" near Olean and Salamanca, N. Y., and he believes (oral communication, 1961) that large blocks of 

conglomerate there slid over an underlying shale, although the contact was not exposed. The nearly horizontal joints described here probably served a similar 

function. Yardley ( 1951) has described frost thrusting in the Northwest Territories, Canada, where ice 

in virtually horizontal joints has thrust individual 

blocks upward. At the Little Quittacas Pond locality 

the direction of easiest relief of stress was lateral 

rather than vertical. 

Root wedging does not appear to be a probable cause 

for the joint separations because this process would 

tend to wedge out individual blocks. The extent of 

the openings from one side of the knob to the other, 

their relative number, and their unusual width seem 

to preclude root wedging as a process for their formation. Also, weathering apparently has not contributed 

appreciably to the widening of the openings. Any 

rounding of the individual blocks by chemical or mechanical processes seems to have taken place before, 

and not after, the advance and retreat of the last ice 

sheet. What rounding there is has affected only isolated edges of the blocks, and is not very extensive 

as shown by the angularity of the joint faces (fig. 

170.1). 

The frost wedging at Little Quittacas Pond probably did not take place until the withdrawal of the 

last ice sheet, because any advance of ice over the bedrock knob in its present form, and in its ·exposed and 

isolated position, would have moved the individual 

blocks from their present alinement, even if they were 

not picked up by the ice. It appears more likely that 

the frost ·wedging occurred during a time of perennially frozen ground. Thus, the age of the frost 

wedging is placed as late glacial during the time when 

periglacial conditions existed near the margin of the 

receding ice. 

REFERENCES 

Emerson, B. K., 1917, Geology of Massachusetts and Rhode 

Island: U.S. Geol. Survey Bull. 597, 289 p. 

Smith, H. T. U. , 1953, Periglacial frost wedging in the "rock 

cities" of southwestern New York [abs.] : Geol. Soc. 

America Bull., v. 64, p. 1474. 

Yardley, D. H., 1951, Frost-thrusting in the Northwest Territories: Jour. Geology, v. 59, p. 65-69. 

' 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-59 

171. LATE-GLACIAL MARINE DEPOSITS IN THE SALEM QUADRANGLE, MASSACHUSETTS 

By RoBERT N. 0LDALE, Boston, Mass. 

Worlc done in cooperation with the Massach~ts tts Department of Public Wo1·1cs 

Late-glacia1 marine deposits occur along the northeast coast of Massachusetts. In the Salem quadrangle, 

Massachusetts, these deposits have been mapped along 

the coast and inland along the valleys from sea level 

to altitudes as ·high as 50 feet. Deposits of till, icecontact stratified drift, and outwash are associated 

with marine clay, silt, fine- to medium-grained sand, 

and gravel. The lower part of the marine unit is clay 

interbedded with layers of fine- to medium-grained 

sand in beds that range from a few inches to 5 feet 

in thickness. The upper part is predominantly sand 

with minor amounts of gravel. Adjacent to the coast 

marine sediments 60 feet or more thick fill the valleys; 

A. 

100' 

50' 

SEA LEVEL 

50' 

100' 

they become thinner up the valleys and grade into 

glaciofluvial outv.·ash. The marine deposits are oxidized from blue gray to brown to a depth of 5 feet. 

The marine unit oYerlies till and ice-contact stratified 

drift; the contact is sharp and there is no mixing of 

the deposits. 

Several outwash deposits in the quadrangle are interbedded with and in part overlie the marine unit. 

The upper ends of these outwash deposits terminate 

at ice-contact slopes that mark the position of glacial 

ice during their formation (fig. 171.1). Near the ice 

contact the outwash is coarse-grained sand and gravel, 

but these beds grade down-stream into finer grained 

.S" "" n[ 

C..<! i~ 

loowl 

EXPLANATION 

I Qyd I 

Younger drift and 

recent deposits 

>-

Outwash deposits Glaciomarine deposits ~ z 

II: 

Ice-con tact 

stratified deposits 

~ 

~ 

Till 

---

Contact 

~ 

I cHon tact, 

head of outwash 

"' to( 

:::J 

0 

A.' 

100' 

50' 

SEA LEVEL 

50' 

100' 

FIGURE 171.1.-Generalized map and section showing the contact relations between glaciofluvial and glaciomarine deposits in the 

east-central part of the Salem quadrangle. 
C-60 GEOLOGICAL SURVEY RESEARCH 1 9 61 

deposits. Where in contact with the marine deposits 

the outwash is composed of fine- to coarse-grained 

sand and fine-grained gravel. The contact between 

the glaciofluvial outwash and the marine unit is 

gradational both laterally and vertically. The contact shown on the map, figure 171.1, is arbitrary and 

represents a zone several hundred feet wide. Silty 

clay more than 50 feet thick was found beneath the 

outwash about 1,800 feet northeast of Hunt Memorial 

Hospital in Danvers. About 400 feet north of the intersection of Maple and Burley Streets, Wenham, 

silty clay of possible marine origin is interbedded with 

sand and gravel within 1,000 feet of the ice-contact 

head of outwash. 

The coastline was farther east than at present before 

the formation of the outwash and the marine unit~ as 

shown by ice-contact deposits along the coast that have 

graded upper surfaces at altitudes of 50 feet, and that 

partly extend below the marine unit. Subaerial conditions persisted long enough for ice blocks to melt and 

for collapse topography to develop in the ice-contact 

deposits. Submergence occurred when the glacial ice 

had retreated up the valleys near to the position of the 

ice-contact heads of outwash (fig. 171.1). During and 

after retreat of the ice, meltwater streams deposited 

sand and gravel as outwash between the ice and the 

marine strandline and in gently dipping deltaic deposits 

in the sea. Clay, silt, and fine-grained sand were 

carried sea ward by these meltwater streams and shore 

currents. Flocculation of the silt and clay caused 

them to be deposited with the sana in quiet water 

offshore. Sea-level rose a maximum of about 50 feet 

relative to the land. At some places glacial ice and 

ice-supported drift acted as a barrier to the sea as at 

the ice-contact head of outwash. Emergence of the 

marine unit by isostatic rise of the land1 surface occurred subsequently, after the ice had retreated much 

farther to the north. 

Table 171.1 shows the correlation of surficial deposits in the Salem quadrangle with other nearby 

deposits. The glaciomarine deposits in the Salem 

quadrangle are correlated with the clays near Fresh 

Pond in Cambridge and the late-glacial marine deposits north of the Salem quadrangle in Massachusetts 

(N. P. Cuppels and E. Sammel, oral communications, 

1960), in New Hampshire, and in Maine on the basis 

of similar geographic and stratigraphic relations to 

honmarine glacial drift and because of similar depths 

of oxidation. Marine sediments at Lynn and Boston 

were deposited at or near the end of an earlier glaciation, possibly the one that deposited the older till in 

the Salem quadrangle. The Lynn and Boston clays 

described by Judson ( 1949) are generally oxidized as 

much as five feet deeper than the Salem clays and 

are unconformably overlain by stratified drift that is 

'probably equivalent to the younger till and stratified 

drift of the Salem quadrangle. 

Kaye (Art. 34, Prof. Paper 424-B) has recognized 

multiple glaciomarine clays in the Boston basin and 

has described their relations to other drift units in th~ 

basin. The youngest glaciomarine clay described by 

Kaye is equivalent to the Boston clay. Clays of this 

age have not been found in the Salem quadrangle, 

but . they may be completely buried by younger de-: 

posits. 

TABLE 171.1.-Stratigraphic relations of surficial deposits in the 

Salem quadrangle with deposits in nearby areas 

Massachusetts north of 

Boston, Lynn, and Salem quadrangle, the Salem quadrangle, Cambridge, Mass. Massachusetts New Hampshire, and 

Maine 

Recent alluvium and Recent alluvium Recent alluvium 

marine deposits. and marine and marine 

deposits. deposits. 

--Unconformity- -Unconformity- -· -UnconformityClays near Fresh Late-glacial Late-glacial 

Pond at Cam- marine deposits. marine deposits 

bridge (Chute, (N. P. Cuppels 

1959). and E. Sammel, 

oral communications, 1960; 

Goldthwait, 

1953; Bloom, 

1960). 

Lexington drift of Younger till and Drift underlying 

Judson (1949) at associated the marine 

Cambridge and glaciofluvial deposits along 

Boston (Kaye, deposits. the coast. 

Art. 34, prof. 

paper 424-B. 

--Unconformity 

Bostori clay (Judson, Unit missing or No deposits 

1949). buried beneath described. 

younger 

deposits. 

UnconformityBoston till of Judson Older till found 

(1949). mostly in 

drumlins. 

REFERENCES 

Bloom, A. L., 1960, Late Pleistocene changes of sea level in 

southwestern Maine: Augusta, Maine Geol. Survey, 143 p. 

Chute, N. E., 1959, Glacial geology of the Mystic Lakes-Fresh 

Pond area, Massachusetts: U.S. Geol. Survey Bull. 1061-F, 

p. 187-212. 

Goldthwait, Lawrence, 1~53, Clays of southeastern New Hampshire: New Hampshire State Planning and Devel. Comm., 

Mineral Resource Survey, pt. 15, 15 p. 

Judson, Sheldon, 1949, The Pleistocene stratigraphy of Boston, 

Massachusetts and its relation to the Boylston Street 

Fishweir, in Johnson, Fredrick, ed., The Boylston Street 

Fish weir II: Phillips Acad., R. S. Peabody Found. for 

Archaeology Papers, v. 4, no. 1, p. 7-48. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-61 

172. END MORAINES ON KITTATINNY MOUNTAIN, SUSSEX COUNTY, NEW JERSEY 

By JAMES P. MINARD, Washington, D.C. 

Several end moraines and eskers were discovered in 

a thickly wooded region in an area of about 40 square 

miles on I<:ittatinny Mountain, in northern New J ersey, by the author in 1952 during mapping of Sussex 

County as part of a Statewide engineering soil survey 

(Minard and others, 1954). These deposits first were 

located and mapped on vertical aerial photographs, 

on which they appear as conspicuous ridges. Field 

study since 1952 confirms the presence and extent of 

the deposits. The moraines extend as two belts entirely across the ·mountain; similar deposits lie in the 

valleys on either side of the mountain. Salisbury 

( 1902, p. 276 and 354) in his classic study made 

several references to the heavily wooded nature of 

I<:ittatinny Mountain, but except for noting a slight 

suggestion of morainal topography southeast of MasP,-

ipacong Pond he indicated an absence of recessional 

moraines everywhere on the mountain. 

The end or recessional moraines now can be traced 

almost continuously across Sussex County from west 

to east (.fig. 172.1). The "crevasse filling" of Salisbury at Ogdensburg (Salisbury, 1902, p. 124, 272, and 

414-415) is probably another segment of the previously mapped recessional moraines that extend from 

Culvers Lake nearly to Ogdensburg, and it fills part 

of the gap between these moraines and the one mapped 

by Salisbury (Spencer and others, 1908) one mile 

northeast of Ogdensburg (fig. 172.1). Study of aerial 

photographs of the region east and northeast of Ogdensburg shows several small end moraines in Morris 

and Passaic Counties, between those in Sussex County 

and those in Bergen County to the east. These deposits are smaller and less conspicuous than those in 

Sussex County and are not discussed here. 

Belts of end or recessional moraines are now known 

to extend nearly continuously across northern New 

Jersey; it seems possible that similar moraines may 

extend westwn,rd across the Delaware River into Pennsylvania. The presence of such a continuous prominent recessional moraine, 12 to 30 miles north of the 

main Wisconsin terminal moraine at and south of 

Stanhope, would suggest a static ice front for a considerable length of time, and possibly a major substa<Ye 

f . b 

o the W 1sconsin. 

BEDROCK GEOLOGY 

l(ittatinny Mountain is upderlain by sedimentary 

rocks of Silurian age. The Shawangunk conglomerate, 

a resistant gray quartzitic sandstone and conglomerate, 

forms the high prominent main ridge of Kittatinny 

Mountain which rises abruptly as much as 800 feet 

above I<:ittatinny Valley to the southeast. The main 

crest of the mountain is largely glacier-scoured bedrock. The formation is about 1,600 feet thick, strikes 

nearly northeast, and dips 20° to 50° NW. Lying 

conformably on it is the High Falls formation, about 

1,800 feet thick, composed of basal gray resistant 

quartzite interbedded with and overlain by red and 

green sandstone, siltstone, and shale. Sets of glacial 

striae, clearly evident on surfaces of exposed beds of 

red sandstone, indicate two directions of ice movement 

-one nearly parallel to the northeast strike of the 

formation and the other considerably more westerly. 

Deep, narrow Wallpack-Mill Brook Valley, along the 

northwest side of the mountain, is underlain by·sandstone, shale, and limestone of Late Silurian and Early 

Devonian age. Broad IGttatinny Valley to the southeast is underlain by Martinsburg shale and slate of 

Ordovician age and by J(ittatinny limestone of Cambrian and Ordovician age. Intruded between the 

Sha wangunk and the Martinsburg is a mass of nepheline syenite approximately 2 miles long and 800 to 900 

feet wide ori the ground surface. This rock forms a 

very rough surfaced bench above the valley just north 

of Beemerville. About half a mile east of the north 

end of the syenite is an oval, steep-sided hill, composed of volcanic breccia, surrounded by Martinsburg 

shale. 

DESCRIPTIONS OF THE MORAINES AND ESKERS 

Two belts of end moraines cross the mountain. The 

southern belt extends from a point on the crest of the 

mountain 1.1 miles northeast of Culvers Lake, westward and north '':ard to a point 1.2 miles southeasterly 

from Abertown. The northern belt extends from a 

point on the main crest of the mountain 1.4 miles 

northwest of Beemerville, northward and westward 

nearly to Four Corners. Each belt consists of several 

segments that range from 0.05 mile to 0.75 mile in 

width, from 0.35 mile to nearly 8 miles in length, and 

from. 20 feet to 90 feet in height. The two largest lie 

mostly in a high intermontane valley, occupied by the 

east fork of Flat Brook (Big Flat Brook), between 

the primary and secondary ridges of the mountain. 

Lateral moraines form narrow ridges on and near 

the main crest of the mountain and almost parallel to 

it. Others form curved ridges on the west slope of 

the main ridge and at. its west base. Ground moraine 
C-62 GEOLOGICAL SURVEY RESEARCH 1961 

,----"' 

N 

1 

/ D 

~ 

~ ' 

0 2 4 MILES 

/v 

A~ ~ 

/~~EXPLANATION 

\reviously ~ mapped moraines 

Newly discovered 

~ moraines; 

letters refer to individual 

segments 

? 

'Esker 

Contact 

.p£ ns 

Nepheline syenite 

D 

Devonian rocks 

s 

Silurian rocks 

0£ 

Ordovician and 

Cam brian rocks 

p£ 

I:'recambrian.rocks. 

FIGURE 172.1.-Map of Sussex County, N.J., showing the location of end moraines and eskers on Kittatinny Mountain and their 

relations to moraines in the valleys on either side. Letters in parentheses are explained in text. 

and deposits of stratified drift cover much of the 

bedrock elsewhere. 

The surfaces of the moraines consist of irregular 

hummocks, parallel ridges, and many kettleholes, all in 

sharp contrast to the relatively smooth surface of the 

adjacent ground. The moraine ridges are partly convex, partly transverse, and partly parallel to the general southwestward movement of the ice. The many 

kettleholes range from 10 feet to 300 feet across and 

a.re as much as 40 feet deep. 

The presence in the moraines of boulders of nepheline syenite and (or) fragments from the Martinsburg 

shale, indicates that ice moved westward from Kittatinny Valley up over the mountain, probably as 

overflow tongues from the major ice mass which 

flowed down the broad valley. 

The northern morainal belt consists of 4 separate 

segments which extend across the mountain from an 

altitude of 800 feet on the bottom of the valley on 

the northwest (occupied by Flat Brook and its west 

'r 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-63 

tributary) across the secondary ridge and intermontane valley to the crest of the main ridge (altitude 

more than 1,500 feet, fig. 172.2). A small glacial lake, 

1% miles long, was dammed behind a prominent 

morai"nal ridge (A) in the valley of Big Flat Brook 

(fig. 172.2) . A powP.r-auger hole in the bed of the 

0 1 MILE 

FIGURE 172.2.-Geologic map of part of the northern belt of 

end moraines on Kittatinny Mountain. Glacial lake bed 

(Qua ternary) , diagonal lines ; end moraine (Qua ternary) , 

Qem; nepheline syenite, ns; High Falls formation ( Silurian), Shf; Shnwangunk conglomerate (Silurian), Ssg. 

Letters in parentheses are explained in text. 

former lake penetrated 5 feet of iron-oxide-mottled 

gray silt and clay underlain by at least 35 feet of gray 

sand and gravel. The sand is mostly quartz and the 

gravel a mixture of quartz, quartzite, sandstone, and 

conglomerate pebbles from the High Falls formation 

and Sha wang:unk conglomerate, and shale fragments 

from the l\1artinsburg. 

Morainal segment (C) lies on morainal segment 

(B) at the west base of the main ridge (fig. 172.2). 

The composition of segment (B) suggests that "the 

Sha wangunk conglomerate was the main source, 

whereas segment (C) contains an abundance of rock 

debris from the Martinsburg shale and nepheline syenite. This latter moraine apparently was deposited at 

the end of a lobe that extended westward from the 

glacier in the main valley, through the col in the 

crest of the mountain, and terminated on morainal 

segment (B) . Segment (D) , lying along the crest 

of the main ridge, was deposited at the margin of a 

large glacier in Kittatinny Valley to the southeast. 

Abundant shale fragments from the Martinsburg and, 

particularly, abundant nepheline syenite cobbles and 

boulders in this moraine, were carried as much as 

several hundred feet up the ridge from the valley 

below. 

The southern belt of moraines extends southerly and 

easterly along the lower northwest ridge of the mountain, across the intermontane valley (east tributary of 

Flat Brook), and along the crest of the main ridge. 

Morainal segment (E) was deposited along the front 

and sides of an ice lobe in the intermontane valley. 

Most of the material in it was derived from the underlying High Falls formation and the Sha wangunk 

conglomerate, but some syenite boulders are present. 

Numerous kettleholes, hummocky heaps of rock debris, 

boulder fields, and curved ridges characterize the surface of this distinctive end moraine. Segment (F) 

(fig. 172.1) lies along the crest of the main ridge. It 

was deposited at the margin of the main glacier in 

the valley to the southeast, as is evidenced by abundant fragments from the Martinsburg shale, carried 

up from the valley below. 

Several esker ridges lie on the High Falls formation south of Abertown. The main esker is a sinuous, 

narrow ridge 1% miles long, and as much as 40 feet 

high, extending diagonally down the dip slope of the 

mountain. It is gravelly sand at the base, and contains some well-rounded cobbles of sandstone and 

quartzite, in the upper part. 

The moraines, eskers, and lakebed contain large 

amounts of sand and gravel suitable for construction 

purposes, unsorted material for fill, and resistant 
C-64 GEOLOGICAL SURVEY RESEARCH 19 61 

quartzite slabs suitable for riprap. All these deposits 

store large quantities of water during the fall and 

winter and supply the streams during the spring and 

summer. 

REFERENCES 

Minard, J. P., Holman, W. W., and Jumikis, A. R., 1954, 

Engineering soil survey of New Jersey, Report no. 11, 

Sussex County: Rutgers Univ. Engineering Research 

Bull. 25, 76 p. 

Salisbury, R. D., 1902, The glacial geology of New Jersey: 

New Jersey Geol. Survey, Final Rept. State Geol., v. 5, 

802 p. 

Spencer, A. C., Kummel, H. B., Wolff, J. E., Salisbury, R. D., 

and Palache, Charles, 1908, Description of the Franklin 

Furnace quadrangle [New Jersey] : U.S. Geol. Survey 

Geol. Atlas, Folio 161, 27 p. 

173. REDEFINITION OF THE MOUNT LAUREL SAND (UPPER CRETAC~OUS) IN NEW JERSEY 

By JAMES P. MINARD, JAMES P. OwENS, and RUTH Tonn, Washington, D.C. 

In New Jersey the location of the boundary between . 

the Matawan and Monmouth groups of Late Cretaceous age (correlative with the Taylor and Navarro 

groups of Texas) has long been controversial. · Most 

workers place the boundary between the Wenonah 

formation and Mount Laurel sand. These two formations, however, are shown as a single unit on previous 

maps because of an apparent lithologic similarity. 

Therefore, the contact between the two formations, 

which coincides with the Matawan-Monmouth boundary, has not been mapped but was located paleontologically by Weller (1907, p. 23-24) on the basis· of 

the Belemnitella americana and Terebratula ( Ohoristothyris) plioata zone, and by Stephenson and others 

( 1942, p. 438--439) on the basis of the Ewogyra oostata and E. oanoellata zone. These zones are in the 

upper part of the Mount Laurel sand as defined in this 

report. 

During detailed mapping southeast of Trenton we 

examined this boundary and found that the two formations could be distinguished lithologically. We 

have mapped the Wenonah formation and Mount 

Laurel sand as distinct lithologic units from near 

Walnford, where the aggregate thickness is about 40 

feet, to Springville 21 miles to the southwest, where 

the aggregate thickness is nearly 100 feet. Both. units 

thicken southwestward. 

The entire Mount Laurel sand crops out in a gully 

system 1.1 miles south of Walnford, and its relation 

to the underlying Wenonah and overlying Navesink 

formations can be determined in good exposures. This 

is the same locality cited by Spangler and Peterson as 

locality 662 (1950, p. 35, 38). A composite section at 

this locality is shown on figure 173.1. 

The Wenonah formation here is a dark-gray nonfossiliferous massive fine- to very fine-grained sand· 

and is. mainly well sorted (fig. 173.2). Quartz, mica 

(both green and colorless) , feldspar ( 10 t6 15 percent), and glauconite (greater than 5 percent) are the 

major sand constituents. Sand-sized fragments of 

carbonaceous matter and finely crystalline pyrite are 

locally abundant:. The formation is characterized by 

much colorless and green mica, abundant sand -sized 

carbonaceous fragments, and a uniform texture 

throughout. The Wenonah grades upward into the 

Mount Laurel sand with no perceptible interruption. 

The Mount Laurel sand is a fossiliferous dark-gray 

(reddish-brown where weathered) massive sand that 

coarsens from a medium-fine sand at the base to a 

medium-coarse sand containing gravel at the top (fig. 

173.2). Sorting is not as good as in the underlying 

Wenonah. Quartz and feldspar ( 10 to 15 percent) are 

the major minerals, and glauconite occurs in moderate 

amounts in the lower and upper few feet. Small 

ovoid brown pellets of apatite and other organically 

derived remains, such as shark teeth, are common. 

Coarse carbonaceous matter, mica, and pyrite are characteristically less abundant than in the Wenonah. 

The diagnostic features of the Mount Laurel are its 

relatively coarse texture, gravel at the top, and oc· 

currence of fossils. The contact with the overlying 

Navesink formation is distinct, although this boundary is locally interrupted by numerous cyclindrical 

borings that extend down 1nto the Mount Laurel,. and 

are filled with glauconite derived from the overlying 

Navesink. This feature imparts a mottled appearance 

to the upper part of the formation. The overlying 

Navesink formation is a dark greenish-gray very fost 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES t.f7-292 

ll.. 

::::> 

0 

a:= 

(,!) 

:c 

t-

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z 

0 

::=!! 

.::t:. ---

c: ~ ==- =.--::::::. 

·u; -----

~ "=---=::-== 1'0 - ,._ ,..._ 

z ::::= ,..._ ==- ........._.,.......,.,.,..,..., "'::::...~ 

~ 

---- ,.._.,..,... ............. 

Dark greenish-black medium-grained silty and clayey glauconite sand containing 

~ a thin (6-in.) bed of iron-oxide-coated casts and molds of gastropods and pele· 

cypods at the base. Quartz granules also present in the basal bed. 

i;\:.-.:~: ..... :;t,: ~ 

:: ·..:..:- :'· · .:..;_; :o·: :. : .•: Brown medium· to coarse-grained quartz sand containing glauconite, clay, silt, 

:.~·~:::.-::;::;... ~ ~ quartz granules, and ovoid apatite pellets. Many well preserved gastropod and 

"C 

c: 

1'0 

en 

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....J 

.... 

c: 

::s 

0 

::=!! 

~.:f_~:_;'_:~~.:r~./.~; • pelecypod lmo.esslons a•e In the lowe• 12 Inches. 

Reddish-brown to brownish-gray medium· to coarse-grained quartz sand containing 

::: :; : · :: .":·.'···: ~ some granules and glauconite that decrease in amount downward. A shell bed lli\f \d~h ~..':.~u.•:::h~~~t=~~s ,;:~~;':;;;::,~~~,;:~:,~~.:z:;,~.'ostata and EX<>gwa 

~'1?::4-Y?:~ ~ 

~ ~:: ((/~:-~ ~~·:.:\~-~ 

!?);(:~~ir.i?[·~: Reddish-brown oxidized medium- to coarse-grained quartz sand containing glauconite grains, apatite pellets, a few quartz granules, and some silt and clay. 

.... :. : ..... 

~:~w·r~~ :•same as a-• but contains many molds of~-~-

. .·: .· :. 

f\iii/-1'iY~iii ::: ·: ·;·: :·._:_:: ': :: ~= ~ ': 

~ .. ::. · ....... . 

f,~%:?(d 

Reddish-brown to gray mostly medium-grained quartz sand containing some course 

~ quartz sand, glauconite, and apatite. Sand size decreases downward. Some 

mica flakes are present in the basal part. 

·':""' 1.: ~- ~)·: .'\;: Medium dark-gray fine· to medium-grained micaceous sparingly glauconitic quartz 

• ....... ·lf'N. ~ sand containing a mass of white calcareous pelecypod shells and shell fragments 

_ __ ·. · ."i .' :..r'. h~ ~ (mostly Ostreafalcata) and abundant Foraminifera. 

/(/_·:.;.~·: 6\:· 6 · .. : :_: 

i ~>:::)~.)\: .... o· o· · o ···o· i ~:~:/~ ~-:~~:;·ti. ~ :o·:o:.o:·o·.o 

3: ~.:9.:':9':·~.':.·~·: .; 

Medium-gray to dark-gray fine-grained slightly glauconitic lignitic micaceous quartz 

~ sand becoming finer-grained and more micaceous downward. Contains much 

silt and clay. 

Vertical Scale 

FIGURE 173.1.-Stratigraphic section of the Mount Laurel sand, including the basal part of the Nave· 

sink and upper part of the Wenonah formations, at locality 662 of Spangler and Peterson (1950). 

C-65 
C-66 GEOLOGICAL SURVEY RESEARCH 19 61 

lOOr-----------------------------------------~ 

...... 

z 

UJ 

80 

~60 UJ 

0.. 

UJ 

> 

j:: 

~40 :E 

::;) 

(.,) 

-1 0 2 3 4 5 

GRAIN SIZE (c/>) 

FIGURE 173.2.-Variation in size distribution in the upper 5 

feet of the Wenonah formation (curve 3), and the basal 

and upper 5 feet of the Mount Laurel sand (curves 2 and 

1, respectively). Each curve represents a composite sample 

from about 5 feet of beds. 

siliferous massive clayey glauconite sand. Pyrite, 

quartz, mica, and finely comminuted carbonaceous 

matter are minor constituents. It can readily be distinguished from the underlying l\{ount Laurel on the 

basis of its abundant glauconite, and, locally, by a 

shell bed at its base (fig. 173.1). 

As shown on figure 173.1, the Mount Laurel contains two distinctly different types of shell beds. "The 

lower shell beds are characterized by Ostrea falcata 

whereas the upper beds contain Ewogyra costata and 

Ewogyra cancellata, Gryphaea convewa, Belemnitella 

americana, Ohoristothyris plicata, and unidentified 

species of gastropods. A macrofauna! suite similar to 

that in the Navesink is present in the upper part of 

the Mount Laurel. Previously reported faunal studies 

of the Mount Laurel were restricted to the upper 

Ewogyra beds; consequently the formation was 

grouped with the Navesink as a· single biostratigraphic 

unit (Weller, 1907, p. 103). Spangler and Peterson 

( 1950, p. 38) noted the lower shell beds and placed 

the lowest one at the top of the Wenonah, but apparently made no attempt to identify the fossils. Unfortunately, Ostrea falcata, the macrofossil present in 

the greatest abundance, is a wide-ranging Cretaceous 

form of little value for precise correlation. 

Microfossils in the Ostrea beds (table 173.1) were 

found by Ruth Todd to be mixed, having both Taylor 

(==Matawan) and Navarro (==Monmouth) affinities, 

whereas those in the Ewogyra beds (table 173.2) have 

dominant Navarro affinities. It is concluded that the 

lower beds of the Mount Laurel are a mixed or transitional paleontological zone. Stephenson and others 

( 1942, p. 438-439) noted a similar relation between 

units of Taylor and Navarro ages in Texas . 

TABLE 173.1.-Foraminifera identified from lowest Ostrea falcata 

shell beds 

Foraminifera 

Anomalina cf. A. rubiginosa 

Cushman. 

Arenobulimina americana Cushman, juv. Cibicides compressus Olsson _____ _ 

Cibicides coonensis (Berry) ___ --- _ Citharina sp. (striate) ________ -_ 

Dentalina basiplanata Cushman __ Dentalina gracilis d'Orbigny ____ _ 

Frondicularia glabrans Cushman_ Globulina lacrima Reuss _______ _ 

Guttulina adhaerens (Olszewski) __ Neobulimina spinosa Cushman 

and Parker. 

Nodosaria affinis Reuss _____ - _- _ 

Pyrulina cylindroides (Roemer) __ Robulus pseudo-secans Cushman 

[possibly a synonym of R. 

navarroensis (Plummer)]. 

Vaginulina taylorana Cushman __ 

I Mostly as given in Cushman, 1946. 

Recorded age range • 

Austin, Taylor, and Navarro. 

Mt. Laurel and Hornerstown 

(Paleocene). 

Taylor or Navarro. 

1'a"Yi0~ -~~ci -:N ;.~~;~o.-------

Austin, Taylor, and Navarro. 

Taylor or Navarro. 

Upper Cretaceous and Pale- ocene. Navarro and Paleocene. 

Taylor and Navarro. 

Long-ranging. 

Long-ranging. 

Austin, Taylor, and Navarro. 

Taylor. 

TABLE 173.2.-Foraminifera identified from Exogyra costata 

and Exogyra cancellata shell beds 

Foraminifera 

Anomalina nelsoni Berry _______ _ 

Anomalina cf. A. rubiginosa Cush- man. Arenobulimina americana Cush- man. Bolivina (Loxostomum) gemma 

Cushman. 

Buliminella carseyae plana Cush- . man and Parker. 

Cibicides compressus Olsson ____ _ 

Cibicides coonensis (Berry) _____ _ Dentalina gracilis d'Orbigny ____ _ Dorothia bulletta (Carsey) ______ _ Fissurina spp _________________ _ 

Gaudryina stephensoni Cushman_ 

Globigerina (Rugoglobigerina) ru- gosa Plummer. 

Globigerinella aspera (Ehrenberg)_ 

Globotruncana fornicata Plummer_ 

Guembelina qlobulosa (Ehrenberg)_ Guembelina pulchra Brotzen ____ _ Gyroidina depressa (Alth) ______ _ N eoconorbi na sp __ - ___________ _ 

Nodosaria lonqiscata d'Orbigny- _ N onion ella anasata Cushman __ - _ Planoglobulina carseyae (Plummer). Plectina watersi Cushman _____ - _ Pseudotextularia elegans (Rzehak) _ Pseudouvigerina plummerae Cush- man. Pullenia americana Cushman ___ _ Pulsiphonina prima (Plummer) __ Robulus macrodiscus (Reuss) ___ _ 

Spiroplectammina semicomplanata 

(Carsey). 

1 Mostly as given in Cushman, 1946. 

Recorded age range I 

Taylor and Navarro. 

Austin, Taylor, and Navarro. 

Navarro. 

Navarro . 

Mt. Laurel and Homerstown (Paleocene) . Taylor or Navarro. 

Austin, Taylor, and Navarro. 

Austin, Taylor, and Navarro. 

Austin, Taylor, and Navarro. 

Navarro. 

Upper Cretaceous ·and Pale- ocene. Taylor and Navarro. 

Taylor and Navarro. 

Austin and Taylor. 

Austin, Taylor, and Navarro. 

Long-ranging. 

Navarro. 

Navarro. 

Navarro. 

Austin, Taylor, and Navarro. 

Austin, Taylor, and Navarro. 

Taylor and Navarro. 

Navarro. 

Upper Cretaceous and Pale- ocene. Taylor and Navarro. 
,. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-67 

REFERENCES 

Cushman, J. A., 1946, Upper Cretaceous Foraminifera of the 

Gulf Coastnl region of the United States and adjacent 

areas: U.S. Geol. Survey Prof. Paper 206. 

Spangler, W. B., and Peterson, J. J., 1950, Geology of Atlantic 

Coastal Plain in New Jersey, Delaware, Maryland and 

Virginia: Am. Assoc. Petroleum Geologists Brill., v. 34, 

p, 1-99. 

Stephenson, L. W., King, P. B., Monroe, W. H., and Imlay, 

R. W., 1942, Correlation of the outcropping Cretaceous 

formations of the Atlantic and Gulf Coastal Plain and 

Trans-Pecos, Texas: Geol. Soc. America Bull., v. 53, 

p. 435-448. 

Weller, Stuart, 1907, A report on the Cretaceous paleontology 

of New Jersey: New Jersey Geol. Survey, Paleont. ser., 

v. 4. 

174. THE BREVARD FAULT IN NORTH AND SOUTH CAROLINA 

By JoHN C. REED, Jr., HENRYS. JoHNSoN, Jr., BRucE BRYANT, HENRY BELL III, and "VILLIAM C. OvERSTREET, 

Denver, Colo., Columbia, S.C., and Washington, D.C. 

A belt of rocks of low metamorphic grade extends 

along a pronounced topographic lineament from the 

coastuJ plain in Alabama northward at least 375 miles 

to ~H. Airy, N·. C. (fig. 174.1). This belt has a maximum width of only a few miles. It has been known 

as the Brevard belt and many of the rocks in it have 

been mapped as Brevard schist (l(eith, 1905, 1907; 

Stose and Smith, 1939; Crickmay, 1952). 

The Brevard schist was interpreted by Keith ( 1905, 

1907) as Cambrian rock resting unconformably on 

schist, gneiss, and granite of Precambrian age and 

folded into a narrow syncline. Crickmay (1952) regarded the Brevard schist in Georgia as part of the 

Carolina gneiss, and thought that it was intruded by 

granite gneiss of Precambrian _age. Jonas (1932) 

recognized the rocks of the belt as retrogressively 

metamorphosed and interpreted them as marking a 

major thrust fault of late Paleozoic age which she 

connected with the ~{artie thrust in Pennsylvania. 

Later this fault was called the Brevard overthrust 

(IGng and others, 1944). Hamilton (1957) showed 

that the fingers mapped as Brevard schist by l(eith 

( 1905) west of Old Fort, N. C., are retrogressively 

metamorphosed schists derived from adjacent schist 

a.nd gneiss. The authors believe, as a result of recent 

reconnaissance observations in North and South Carolina, that the Brevard belt is a fault zone. The authors agree with Jonas' interpretation that the low 

metamorphic rank in the belt. results from retrogression. 

Detailed study in the Table Rock and Lenoir quadrangles, North Carolina, has shown that rocks within 

the Brevard belt are polymetamorphic and consist ·of 

phyllonite and blastomylonite (recognized by Stose 

and Stose, 1951) derived from adjacent mica schist, 

gneiss, and granitic rock (Reed and Bryant, 1960). 

In the Table Rock and Lenoir quadrangles and at 

all the other places where we have seen the Brevard 

belt,. the rocks generally strike parallel to the trend of 

the belt and dip from 40° to 60° SE. In a segment 

of the belt west and north of Lenoir, vertical to steep 

westerly dips are 'characteristic. Elongate mineral 

grains and aggregates in almost all the cataclastic 

rocks are nearly horizontal and trend northeasterly. 

We have made a reconnaissance of the Brevard belt 

between northern Georgia and Mt. Airy, N.C. At all 

places visited, the rocks (except for apparently exotic 

lenses of dolomitic limestone) consist of polymetamorphic schist, phyllonite, blastomylonite, and some graphitic phyllonite. One common rock type is "fish 

scale" schist or gneiss containing deformed porphyroclasts of muscovite 1 em in diameter. These porphyroclasts are altered to aggregates of sericite where 

retrogressive metamorphism is most complete. In less 

intensely retrogressively metamorphosed rock, pods of 

pegmatite and relict kyanite and garnet are found. 

The low-grade rocks are derived by intense shearing 

and partial to complete recrystallization of the rocks 

on either side of the Brevard fault. These relations 

are particularly well exposed east of Rosman, N.C., on 
~ 

~ 

ROCKS OF THE BLUE RIDGE BELT 

E=-.:.~1 illffi] 

Whiteside granite Cranberry gneiss Rocks of the Grandfather 

In part mapped as Hender- Mountain window son granite by Keith, 1905 

0 50 MILES 

EXPLANATION 

ROCKS OF THE INNER PIEDMONT BELT 

M:.i?f~i};~ tc~~,J r+.:+1 

~ 

Other rocks of the 

Blue Ridge belt 

Henderson granite Biotite granite gneiss 

---- Contact 

,., .. ~ 

Thrust fault 

Barbs on upper plate 

In part mapped as Whiteside granite by Keith, 1907 

Rocks • of the Poor 

Mountain belt 

a 

Other ro$8 of the 

Inner Piedmont belt 

FIGURE 174.1.-Sketch map of the Brevard belt in North and South CaroliD:a from published geologic maps and reconnaissance observations. 

••', .... 

0 

~ 00 

G'l 

t:rJ 

0 

t"' 

0 

0 

1-1 

(') 

l= 

~ ~ 

< t:rJ 

~ 

~ 

t:rJ 

Ul 

t:rJ 

> 

~ 

~ 

..... 

(0 

0) 

..... 
,. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-69 

U.S. Highway 64. There is a transition westward 

from I-Ienderson granite through sheared Henderson 

granite to blnstomylonite of the Brevard belt. On the 

west side of the belt, layered mica schist and gneiss 

of the Blue Ridge show a transition southeastward 

to phyllonite in the Brevard belt. 

The occurrence of limestone in the Brevard belt has 

been cited as evidence of a unique stratigraphic unit. 

Lenticuhtr beds of marble are more common in Piedmont rocks than is usually supposed (Sloan, 1908; 

Conrad, 1960; Clarke, 1957, 1958, written communication, 1958). These marbles are mostly coarsely crystalline ; grain size of 2 to 5 mm is common and locally 

is as much as 1 em. The marble is found at scattered 

localities in th~ Piedmont, and some localities such as 

those near Marion, N.C., and in the Poor Mountain 

belt near Walhalla, S.C., are almost adjacent to the 

Brevard belt. One limestone inside the belt at Fletcher, N.C., is fine-grained recrystallized white and 

gray dolomite containing phyllitic partings. It closely 

resembles the Shady dolomite in the Grandfather 

Mountain window, where the dolomite was metamorphosed under greenschist facies conditions and displays no evidence of having been at higher grade. 

Limesto11e at Fletcher is highly disordered and most 

likely it is faulted into the adjacent phyllonite rather 

than included as a simple sedimentary lens or an 

infold of a younger formation. 

Mapping in the Grandfather Mountain area has revealed gross differences between the rocks of the Blue 

Ridge and those of the Inner Piedmont. Rocks of 

the Blue Ridge have a higher proportion of mica 

schist and amphibolite, more gneisses of migmatitic 

aspect, granitic rocks of different character and structural habit, and pegmatites of a different composition 

than rocks of the Inner Piedmont. The Henderson 

granite mapped by l{eith ( 1905) northwest of the 

Brevard belt is part of the Cranberry gneiss (Eckelmann and 1\::ulp, 1956), and is markedly different from 

I-Ienderson granite at its type locality southeast of 

the belt. The Cranberry gneiss is a layered gneiss 

containing numerous granitic layers and lenses of contrasting composition, layers of biotite schist, amphibolite, and plagioclase porphyroclast schist, whereas the 

Henderson granite is a relatively uniform augen gneiss 

of quartz monzonite composition. 

Farther south, Whiteside granite at the type locality northwest of the Brevard belt is coarser, more 

contorted, and richer in inclusions and pegmatite 

dikes than the biotite granite gneiss called the Whiteside granite by Keith (1907) southeast of the belt. 

In South Carolina the Poor Mountain zone of Sloan 

( l908) has been GOnsidered a part of the Brevard belt 

( IGng and others, 1944) . One of us (Johnson) has 

found that the rocks in the Poor Mountain zone consist of coarsely crystalline marble associated with 

hornblende gneiss and Henderson granite-rocks typical of the Inner Piedmont. The lithologic units are 

truncated by phyllonite and blastomylonite in the· 

Brevard belt, which il'l this area was called the Chauga 

zone by Sloan. Rocks within the Chauga zone have 

a strong, subhorizontal cataclastic lineation that trends 

toward . the northeast, parallel to the strike of the 

rocks. The lineation 'Yas observed by Clarke (written 

communication, 1958), but he did not recognize its 

cataclastic origin. Mapping by Keith (1907) in the 

Pisgah quadrangle shows different rock types on either 

side of the Brevard schist. 

Overstreet and others (Art. 45, Prof. Paper 424-B) 

conclude that most rocks of the Piedmont of North 

and South Carolina are of probable Paleozoic age except, perhaps, for some rocks of late Precambrian 

age near the base. They find no evidence of earlie~ 

Precambrian rocks in the Piedmont. No Precambrian 

ages have been obtained for minerals from rocks east 

of the Brevard belt (Long, Kulp, and Eckelmann, 

1959; Overstreet and others, Art. 45, Prof. Paper 

424-B) . However, isotopic determinations on zircon 

are lacking. Geologic and mineral age data show that 

much of the rock of the Blue Ridge west of the 

Brevard belt is of earlier Precambrian age and is unconformably overlain by late Precambrian rocks, all 

of which were metamorphosed to medium grade at 

least once during the Paleozoic. 

We conclude that the Brevard belt marks a major 

fault because of the retrogressive metamorphism of 

the rocks in it, the differences in rocks on either side, 

and truncation of the Grandfather Mountain window 

and stratigraphic units in the Poor Mountain area. 

The extension of the belt traced by Jonas (1932) into 

Virginia is uncertain (Brown, 1958; Espenshade, 

1954). We have found no rocks on one side of the 

fault which can be definitely matched with rocks on 

the other, so the direction and amount of displacement 

are unknown. Intense cataclastic lineation in the fault 

zone suggests important lateral movement, whereas 

regional geologic considerations indicate that some 

vertical component was involved. 

In the Grandfather Mountain area the Brevard 

fault truncates the southern edge of the Grandfather 

Mountain window and the fault zone contains unmetamorphosed diabase dikes of Triassic ( ~ ) age, showing 
C-70 GEOLOGICAL SURVEY RESEARCH 19 61 

that the fault was active after large-scale Paleozoic 

thrusting and before Triassic ( ~) igneous activity. 

REFERENCES 

Brown, W. R., 1958, Geology and mineral resources of the 

Lynchburg quadrangle, Virginia: Virginia Div. Mineral 

Resources Bull. 74, 99 p. 

Clarke, J. ,V., 1957, Contact metamorphism in Laurens County, 

South Carolina : South Carolina Div. Geology, Mineral 

Industries Lab. Monthly Bull., v. 1, no. 4, p. 2-7. 

--- 1958, A normal fault in Cherokee County, South Carolina: South Carolina Div. Geology, Mineral Industries 

Lab. Monthly Bull., v. 2, no. 3, p. 20-22. 

Conrad, .S. G., 1960, Crystalline limestones of the Piedmont 

and mountain regions of North Carolina: North Carolina 

Dept. Conserv. Devel. Bull. 74, 56 p. 

Crickmay, G. W., 1952, Geology of the crystalline rocks of 

Georgia: Georgia Geol. Survey Bull. 58, p. 1-54. 

Eckelrnann, F. D., and Kulp, J. L., 1956, The sedimentary 

origin and stratigraphic equivalence of the so-called Cranberry and Henderson granites in western North Carolina: 

Am. Jour. Sci., v. 254, p. 288-315. 

Espenshade, G. H., 1954, Geology and mineral deposits of the 

James River-Roanoke River manganese district, Virginia: 

U.S. Geol. Survey Bull. 1008, 115 p. 

Hamilton, W. B., 1957, Polymetamorphic rocks of the Blue 

Ridge front near Old Fort, North Carolina: Am. Jour. 

Sci., v. 255, p. 568-573. 

Jonas, A. I., 1932, Structure of the metamorphic belt of the 

southern Appalachians: Am. Jour. Sci., 5th ser., v. 24, 

p. 228-243. 

Keith, Arthur, 1905, Description of the Mt. Mitchell quadrangle: U.S. Geol. Survey Geol. Atlas, Folio 124. 

--- 1907, Description of the Pisgah quadrangle [N.- C.-

S. C.] : U.S. Geol. Survey Geol. Atlas, Folio 147. 

King, P. B., and others, 1944, Tectonic map of the United 

States: Am. Assoc. Petroleum Geologists. 

Long, L. E., Kulp, J. L., Eckelmann, F. D., 1959, Chronology 

of major metamorphic events in the southeastern United 

States: Am. Jour. Sci., v. 257, no. 8, p. 585-603. 

Reed, J·. C., Jr., and Bryant, B. H., 1960, A major topographic 

lineament in western North Carolina and its possible 

structural significance, in Short papers in the geological 

sciences: U.S. Geol. Survey Prof. Paper 400-B, p. B195-

B197. 

Sloan, B. E., 1908, Catalogue of the mineral localities of South 

Carolina: South Carolina Geol. Survey, ser. 4, Bull. 2, 

505 p. 

Stose, G. W., and Smith, R. W., 1939, Geologic map of Georgia: 

Georgia Div. Mines, Mining and Geology. 

Stose, G. W., and Stose, ·A. J., 1951, Blue Ridge Front-a fault 

scarp: Geol. Soc. America Bull., v. 62, p. 1371-1373. 

175. ANNUAL MINIMUM STREAMFLOWS IN A PERMEABLE BASIN IN OHIO 

By WILLIAM J. ScHNEIDER, Washington, D.C. 

The magnitude of annual minimum streamflows 

during the summer and fall in permeable basins is 

governed by the extent that ground water is released 

to the streams from storage, and by the precipitation. 

These factors have been related for the Mad River 

drainage basin, which includes 485 square miles near 

Springfield, Ohio. The Mad River basin is described 

by Cross and Bernhagen ( 1949) as follows: 

The Mad River occupies a broad, trough-like valley of preglacial and interglacial origin, and most of its course lies between the morainal ridges deposited by the Miami and Scioto 

lobes of the Wisconsin glacier. The surface material in the 

interlobate areas consists of extensive permeable drift such 

as kames, kame terraces, and end-moraines accompanied by 

high-level outwash in the uplands and valley train in the main 

valleys. At no other place in the state is there such an accumulation of permeable material and as a result the Mad 

River has the highest index of flow of all the streams in 

Ohio. 

Annual· minimum flows for the period 1922 to 1956 

were used for this study. The annual minimum flow 

is defined as the average flow for the minimum seven 

consecutive days of streamflow in the hydrologic year 

ending April 30. ·The seven-day period rather than a 

shorter period is used in order to dampen out or 

minimize any unnatural low flow which might occur 

in a shorter period from temporary storage or other 

causes in the basin. 

Annual minimum flows of the Mad River usually 

occur in the fall coincident with the normal seasonal 

lows of ground-water levels. During the 35 years of 

record, 17 of the annual .minimum flows occurred in 

September and October, 2 in late July, 4 in .August, 

2 in November, 7 in December, and 3 in January and 

February. None occurred from late February to late 

July. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-71 

(/) 

IJ. 

(.) 

z 

~200 

u.. 

:::!: 

::l 

:::!: 

z 

::§ 

_, 

<( 

::l 

~ 100 

<( 90 

80 

70 

BASE FLOW ON APRIL 30, IN CFS 

x-5 

Rp= 120~ :J! 

Rp=lOO·~ ,2 .!:! c: .... ~ 

Rp=80 ~ _g .9- Cll 

Rp=60 ~ ~ O..iij 

> 

"0 

Q) 

c: 

~ .0 

0 

FIGURE 175.1.-Relation of base flow and precipitation to 

annual minimum flows of Mad River near Springfield, Ohio, 

occurring during summer and fall. 

The magnitude of the ground-water supply at the 

beginning of the ground-water depletion season in the 

summer and fall is represented in this study by· the 

base flow of the ~1ad River near Springfield, Ohio, 

on April 30. The measure of precipitation was taken 

as the percent of normal precipitation at Urbana, 

Ohio, for the period beginning May 1 and ending on 

the last date of 7 -day period of annual minimum 

stream flow. · 

Preliminary graphical analyses indicated a difference 

in the relations for summer-fall and for winter ·minimums. Therefore, the final analysis, shown by figure 

175.1, was limited to the 25 annual minimum flows 

that occurred prior to December 1. The relation is 

computed as: 

log Qm=0.284+0.63 log Q,+0.32 R 11 (1) 

where Qm is the annual minimum flow in cfs, ·Q, is 

base flow in cfs on the preceding April 30, and R11 is 

the ratio of precipitation for the period May 1 to date 

of low flow to the normal preCipitation for that period. 

The regression coefficients in equation 1 are statistically significant at the 0.1 percent level; the standard 

error is + 10, -9 percent. 

REFERENCES 

Cross, W·. P., and Bernhagen, R. J., 1949, Ohio stream-flow 

characteristics, Part 1, Flow duration: Ohio Dept. Nat. 

Resources, Div. Water, Bull. 10, 40 p. 

176. CLASSIFICATION OF GLACIAL DEPOSITS IN THE KILLBUCK LOBE, NORTHEAST-CENTRAL OHIO 

By GEORGE W. WHITE, Urbana, Ill. 

Work done in cooperation with the Ohio Department of Natural Resources, Division of Water 

Deposits of the IGllbuck glacial lobe, which occur 

in several counties in northeast-central Ohio in the 

Allegheny plateau (fig. 176.1), can now be divided into 

several rock-stratigraphic units (table 176.1) as has 

been done with the deposits of the Grand River lobe 

in eastern Ohio ("Vhite, 1960) and northwe~tern 

Pennsylvania ( Shepps and others, 1959). 

MILLBROOK TILL 

The Millbrook till is named for the village of Millbrook in southwestern Wayne County, Ohio. The 

following section was measured 1¥1 miles northnortheast of Millbrook in the SE1J.tSE1Jt, sec. 25, Plain 

TABLE 176.1-Glacial deposits of the Killbuck lobe 

Epoch Stage Sub- Unit Material 

stage 

Hiram till Brown clay till 

Pleistocene Wisconsin Cary Hayesville till Brown silty clay till 

Navarre till Yellow-brown sandy till ---- (?) ____ 

Wisconsin 

(?) Olive-brown sandy till; in 

Millbrook till places has weathered zone Illinoian at top 

(?) 
C-72 GEOLOGICAL SURVEY RESEARCH 19 61 

Township, Wayne County, In a steep road bank and 

ditch: 

Quaternary system: 

Pleistocene series: 

Wisconsin stage: 

Cary substage: 

Hayesville till: 

Soil and weathered dark-brown till; sparingly 

pebbly; poorly exposed _______________ _ 

Navarre till: 

Till, yellow-brown, non calcareous ________ _ 

Till, yellowish-brown (10YR 5/6); calcareous; sandy, pebbly; sand, 48 percent; 

silt, 35 percent; clay, 17 percent _______ _ 

Silt, olive-brown, calcareous (ranges from 

1 to 4 feet in thickness) _______________ _ 

Illinoian(?) or Wisconsin(?) stage: 

Millbrook till: 

Till, olive to light olive-brown (2.5Y 4/4-

5/6), with dark stains along partings; 

calcareous; sandy, pebbly; sand, 49 percent; silt, 38 percent; clay, 13 percent __ 

Till, dark-gray (5Y 4/1); hard, platy; sand, 

44 percent; silt, 41 percent; clay, 15 

percent _____________________________ _ 

Bottom of ditch. 

Thickness 

(Ft. in) 

4 0 

1 0 

2 6 

3 0 

3 0 

1 6 

15 0 

The Millbrook till is sandy and pebbly, and is characteristically olive brown. 

The Millbrook till overlies the Paleozoic bedrock. 

At many localities the upper part of the Millbrook 

tiil is leached and severely weathered. 

The Millbrook till extends across most of Wayne, 

the central part of Ashland, northern Holmes, and 

western Stark Counties. Outcrops are common in 

many of the valleys tributary to Killbuck Creek 

northwest, north, and northeast of Wooster, and especially in cuts of the Pennsylvania Railroad 2 to 4 

miles east of Wooster. It is well exposed in strip 

mines in Paint Township, southeastern Wayne 

County, where the overlying till is thin or absent. 

The Millbrook till may be Illinoian or very early 

Wisconsin in age. The latter age has been proposed 

for a till in western Ohio having a burled weathered 

zone (Forsyth, 1957). 

NAVARRE TILL 

The Navarre till is named for the village of N avarre, southwestern Stark County. The following 

section was measured 2 miles south of Navarre and 50 

feet north of the highway bridge in a deep cut of the 

Nickel Plate Road, SW% sec. 16, Bethlehem Township: 

41° 

L 

TUSCARAWA 

30 MILES 

FIGURE 176.1.-Map showing areal extent of rock-stratigraphic 

units in Killbuck glacial lobe, Ohio. (1) Illinoian drift of 

Grand River lobe; (2) Illinoian drift of Scioto lobe; (3) 

Mogadore 'till; ( 4) Kent till of Grand River lobe; ( 5) 

Navarre till ; ( 6) Hayesville till ; ( 7) Hiram till ; ( 8) 

Wisconsin till of Scioto lobe. 

Quaternary system: 

Pleistocene series: 

Wisconsin stage: 

Cary substage: 

Navarre till: 

Loam, dark gray-brown _______________ _ 

Loam, yellow-brown __________________ _ 

Silt loam, brownish-yellow _____________ _ 

Till, much weathered; yellow-brown and 

gray; some manganese stains _________ _ 

Till, noncalcareous; dark yellow-brown __ _ 

Till, calcareous; dark yellow-brown (lOYR 

4/4); sandy, moderately pebbly; irregular horizontal fracture; sand, 46.3 

percent; silt, 37.9 percent; clay, 15.8 

percent------------~--~-------------

Till, calcareous; yellow-brown mixed with 

gray ______________________________ _ 

Till, calcareous; gray (10YR 4/1); sandy, 

moderately pebbly; sand, 53.8 percent; 

silt, 33.0 percent; clay, 13.2 percent ___ _ 

Pennsylvanian system: 

Shale, limestone, coal, and clay _________ _ 

Level of track. 

Thickness 

(Ft in) 

0 7 

0 4 

1 1 

2 0 

2 0 

4 8 

2 0 

5 0 

27 0 

44 6 

" 

,, 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-73 

The Navarre till is sandy to moderately pebbly, and 

contn,ins scattered cobbles and a few boulders. It is 

yellow brown where ox·.dized. The Navarre till unconformably overlies bedrock or the Millbrook till. 

The Navarre till occurs at the surface in westcentral and southwestern Stark County, a very small 

area in extreme southern Summit County, and in a 

belt extending across central Holmes County and 

southern Ashland County. It forms knolls around the 

margin of the IGllbuck lobe in Stark County in the 

prominent Buck Hill end moraine. 

The Navarre till is the same age as the Kent till 

of the Grand River lobe in eastern Ohio (White, 

1960, p. 5) and northwestern Pennsylvania (Shepps 

and others, 1959, p. 31), and is correlative with the 

"early Cary" drift of the Scioto and Miami lobes 

(Goldthwait, 1952, p. 2a, map). 

HA-:YESVILLE TILL 

The Ifayesville till is named from the village o~ 

Hayesville in southern Ashland County. The following section was measured in a road cut and ditch at a 

roa.d corner 1 lj2 miles northeast of the center of 

Hayesville. The locality is at the top of the south 

wall of the valley of Oldtown Run in the center of 

sec. 11, Vermillion Township: 

Quaternary system: 

Pleistocene series: 

Wisconsin stage: 

Cary substage: 

Hayesville till: 

Silt loam, dark gray-brown _____________ _ 

Silt loam, yellowish-brown _____________ _ 

Silty clay loam, coarse, yellow-brown ____ _ 

Silty clay loam (much weathered till), 

mottled gray, brown, and yellow ______ _ 

Till, noncalcareous, weathered, dark-brown 

(10YR 4/3), with black manganese 

stains------------------------------

Till, calcareous, dark-brown; secondary 

calcite splotching ___________________ _ 

Till, calcareous dark-brown, silty, sparingly pebbly; sand, 20.4 percent; silt, 

47.6 percent; clay, 32.0 percent _______ _ 

Bottom of ditch. 

601530 0-61-6 

Thickness 

(Ft in) 

0 7 

0 5 

0 

0 11 

1 4 

1 0 

1 9 

7 0 

In auger holes on the east side of the· road the 

Hayesville till overlies brown gravel, beneath which 

is weathered Millbrook till. The Hayesville till crops 

out in road cuts 1 mile south of Hayesville, for several 

miles along an east-west road 2 miles north of Hayesville, and at a crossroad 2¥2 miles south-southeast of 

Hayesville. 

The Hayesville till is silty, sparingly to very moderately pebbly, and contains a few cobbles and fewer 

boulders. It is dark brown where oxidized, and contrasts with the light yellow-brown or olive-brown 

color of older tills. 

At many places the Hayesville till lies unconformably upon sand and gravel or Na-varre till. Where 

the Navarre till is missing, the Hayesville till overlies the Millbrook till. 

The Hayesville till forms the surface in northwestern Stark County, a small part of southeastern 

Medina, almost all of Wayne', central and southern 

Ashland and northern Holmes Counties, and it extends 

an unknown distance into Richland County. 

In most of the area the Hayesville till is less than 

10 feet thick and at some places it is only 1 or 2 feet 

thick. It is thickest in the northern part of the area. 

The Hayesville till is correlated with the Lavery till 

of the Grand River lobe (White, 1960, p. 6: Shepps 

and others, 1959, p. 38), and with drift of the Scioto 

lobe called "middle Cary" by Goldthwait ( 1952, p. 

2a, map). 

HIRAM TILL 

The Hiram till was named from its type locality in 

the Grand River lobe (White, 1960). It has now been 

traced into the l{illbuck lobe in northwestern Wayne 

and northern Ashland Counties where it has the same 

characteristics as previously described by White ( 1960, 

p. 8). 

REFERENCES 

Forsyth, J. L., 1957, "Early" Wisconsin drift in Ohio [abs.]: 

Geol. Soc. America Bull., v. 68, p. 1728. 

Goldthwait, R. P., 1952, Guidebook for the 1952 field conference of friends of the Pleistocene : Ohio Geol. Survey. 

Shepps, V. C., White, G. W., Droste, J. B., and Sitler, R. F., 

1959, Glacial geology of northwestern Pennsylvania: Pennsylvania Geol. Survey Bull. G-32. 

White, G. W., 1960 Classification of Wisconsin glacial deposits in northeastern Ohio: U.S. Geol. Survey, Bull. 

1121-A, 12 p. 
C-7 4 GEOLOGICAL SURVEY RESEARCH 1 9 61 

177. ROTATIONAL BLOCK OF THE CUMBERLAND OVERTHRUST SHEET IN SOUTHEASTERN KENTUCKY AND 

NORTHEASTERN TENNESSEE 

By KENNETH J. ENGLUND, Washington, D.C. 

The Cumberland overthrust sheet is a northeasttrending .rectangular area approximately 125 miles 

long by 25 miles wide which is located in southwestern Virginia and adjacent parts of Kentucky and 

Tennessee. This sheet has moved to the northwest on 

the Pine Mountain overthrust fault an estimated 2 

miles at its northeast end and about 10 miles at its 

southwest end (Wentworth, 1921, p. 368). The resulting rotation by pivoting on the northeast end of 

the overthrust sheet was confirmed by Butts (1927), 

who discovered fensters in the center of the sheet that 

indicated an intermediate distance of movement of 

about 7 miles. This measurement was later modified 

to about 6 miles by Miller and Fuller (1954, p. 260). 

In addition to the Pine Mountain and associated· 

faults on the periphery of the Cumberland overthrust 

sheet, faults and associated folds have been reported 

at several places within the sheet. The most conspicuous of these is the Rocky Face fault (Ashley and 

Glen, 1906, p. 47-50), which strikes northward across 

the Middlesboro syncline in the west-central part of 

the overthrust sheet (fig. 177.1). This fault has been 

described as having both strike-slip (Rodgers, 1953, 

fig. 5) and vertical displacement (Hauser and others, 

1957, fig. 6). The genetic and structural relations of 

the Rocky Face fault to the entire overthrust sheet 

have received little attention. 

Observations made during detailed mapping of the 

Rocky Face fault confirm previous reports that the 

displacement of the west side of the nearly vertical 

fault plain is predominantly strike-slip to the south 

(fig. 177.1). The direction of displacement is substantiated by the drag of beds. The amount of displacement is from 1 to 2 miles, as indicated by the 

offset of lithologic units in Carboniferous rocks cropping out on opposite sides of the fault. At its south 

end, the Rocky Face fault. intersects a zone of northwestward dipping thrust faults that contains several 

previously unrecognized fault slices involving rocks 

as old as the Chattanooga shale. This fault zone 

strikes southwestward from the Rocky Face fault at 

Cumberland Gap and is herein designated the Doublings thrust-fault zone, named after the creek which 

flows in the valley along the trace of the fault between 

Powell and Cumberland Mountains. The minimum 

displacement on the Doublings thrust-fault zone is a 

little less than 2 miles, as shown on the structure section (fig. 177.2); this me&surement is about the same 

as the amount of strike-slip displacement on the Rocky 

Face fault. Southwestward along the Doublin~s 

thrust-fault zone, beyond the area of detailed mapping 

(fig. 177.1), the fault slices thin and the displacement 

appears to be confined to one fault plane near the base 

of the Chattanooga shale. Considering the amount of 

displacement in d1e area of detailed mapping, the 

Doublings fault probably extends several miles southwestward, possibly changing into a bedding plane 

fault. 

The relations described here between the Rocky 

Face and Doublings faults are similar in many respects to those between the Jacksboro and Pine Mountain faults at the southwest corner of the Cumberland 

overthrust sheet. The Jacksboro fault, like the Rocky 

Face fault, is a strike-slip fault with the northeast 

side displaced to the northwest (fig. 177.1). The 

Jacksboro fault, at its northwest end, also intersects 

a belt of imbricate faults at the trace of the Pine 

Mountain overthrust fault which, like the Doublings 

fault, also converges to a single fault plane to the 

northeast. 

The relative directions of movement on the Jacksboro, Pine ~fountain, Rocky Face, and Doublings 

faults resulted in clockwise rotation of the block 

bounded by these faults relative to the remainder of 

the Cumberland overthrust sheet. This clockwise rotation of the block probably was facilitated by a distribution of movement to the imbricate fault slices at 

the east and west corners of the main block, and it 

explains movement to the southeast along the Doublings thrust-fault zone in an area where the major 

thrusting was to the northwest. 

REFERENCES 

Ashley, G. H., and Glenn, L. C., 1906, Geology and mineral 

resources of part of the Cumberland Gap coal field, Kentucky: U.S. Geol. Survey Prof. Paper 49, 239 p. 

Butts, Charles, 1927, Fensters in the Cumberland overthrust 

block in southwestern Virginia: Virginia Geol. Survey 

Bull. 28, p. 1-12. 

Hauser, R. E., Walker, F. H., and Nelson, V. E., 1957, Itinerary: Some stratigraphic and structural features of the 

Middlesboro basin, Kentucky Geol. Soc. and Appalachian 

Geol. Soc. Ann. Field Conf. Guidebook : 35 p. 

Miller, R. L., and Fuller, J. 0., 1954, Geology and oil resources of the Rose Hill district, the fenster area of the 

Cumberland overthrust block, Lee County, Virginia: Virginia Geol. Survey Bull. 71, 383 p. 

Rodgers, John, 1953, Geologic map of east Tennessee with 

explanatory text: Tennessee Div. Geol. Bull. 58, 168 p. 

Wentworth, C. K., 1921, Russell Fork fault of southwest Virginia: Jour. Geology, v. 29, p. 351-369. 

., 
84 °15' 84°00' 

0 5 MILES 

83°45' 

~ 

-<.. ~\~ 

o-0~ 

-----

0<? 0~, ~<Q r 

<:>o,/ 

/ 

/ 

/}"' 

-?- _1 ........ 

-.--...---.~ "'T'" ""T"" 

Thrust fault, barbs 

on upper plate 

Dashed where approximately located 

~ 

Cross fault, showing 

direction of relative 

movement 

EXPLANATION 

u 

D 

Normal fault 

Dashed where inferred; 

U, upthrown side; D, 

downthrown side 

R 

Reverse fault; 

R, upthrown side 

r 1 

Southwest part of 

Cumberland overthrust sheet 

t: :::J Areas mapped 

in detail 

FIGURE 177.1.-Generalized map of the southwest part of the Cumberland overthrust sheet showing relations of major faults. 

~ ~ 

8 

~ "d 

trl 

~ 

Ul 

z 

~ trl 

0 

trl 

0 

t"' 

0 

0 

..... 

0 

> z 

t) 

~ t) 

~ 

0 

s 

0 

..... 

0 

a 

trl 

~ trl 

_Ul 

> 

~ ~ trl 

Ul 

..... 

""' "" I 

., 

<0 

., 

0 

J;, 

01 
C-76 GEOLOGICAL SURVEY RESEARCH 19 61 

1000' 

SEA LEVEL 

-1000' 

-2000' 

POWELL 

MOUNTAIN 

2000' 

1000' 

SEA LEVEL 

-1000' 

-2000' 

.FIGURE 177.2.-Section showing relation .of the Doublings thrust fault zone to the Pine Mountain overthrust fault. Position of 

section indicated on map. 

178. FOLDS AND FAULTS IN THE EASTERN PART OF THE MARQUETTE IRON RANGE, MICID~AN 

By J. E. GArn, R. E. THADEN, and B. F. JoNEs, Denver, Colo., Columbia, Ky., and Washington, D.C. 

Work done in cooperation with the Geological Survey Division of the Michigan Department of Oonservatior&-

The Marquette iron range, Michigan, is on a westplunging synclinorium composed of middle Precambrian rocks bounded on the north and south by lower 

Precambrian basement rocks (Van Rise and Bayley, 

1897; James, 1958, p. 28-30). Recent detailed mapping near the east end of the range, where the lower 

part of the middle Precambrian section is exposed 

across the nose of the synclinorium, reveals several 

faults not previously known a:nd has modified the interpretation of some folds rna pped in earlier work 

(Van Rise and Leith, 1911, pl. 17, fig.'!). 

These structures are noteworthy because similar patterns of folds and faults may exist in the main ironproducing part of the range a few miles west of the 

area shown in figure 178.1. In particular, it seems 

likely that the Negaunee iron-formation of that area 

has been offset along extensions of the westwardtrending faults shown in figure 178.1, or along other 

faults with similar orientations. The structures also 

indicate the possibility that the Marquette stratigraphic section recurs east of the area. 

The major rock units involved in the folding and 

faulting near the east end of the range are, in seq.uence, the basement of Mona schist and granitoidgneissic rocks overlain in profound unconformity by 

Mesnard quartzite, Kona dolomite, Wewe slate, Ajibik 

quartzite, and Siamo slate (Van Rise and Bayley, 

1897, p. 221-328). 

I~ the trough of the synclinorium in sec. 5, T. 47 

N., R. 25 W., the sinuous contacts of the Kona, Wewe, 

and Ajibik formations indicate rather uniform smallscale folding, whereas eastward from sec. 5 to Lake 

Superior the trough of the synclinorium is occupied 

by several large folds, including an anticline and a 

syncline that plunge westward, and an eastwardplunging syncline. The anticline, with Mona schist 

in its core (mainly in Nlh sees. 2 and 3, T. 47 N., R. 

25 W.), was mapped by Van Rise and Bayley (1897), 

but the fault along its north limb was not recognized. 

Movement along this fault cut out the Mesnard quartzite and much of the l(ona dolomite on the north limb 

of the fo]d and brought basement rocks in the anticline into contact with the Kona dolomite north of the 

fault. The structure now mapped as an east-plunging 

syncline (Nlh sec. 1, T. 47 N., R. 25 W.) was interpreted by Van Rise and Bayley (1897) as a canoeshaped fold, with the east end located west of the lake 

shore. Detailed mapping, however, revealed no evidence of closure at the east end or of a ~est plunge 

of the fold axis west of the lake shore. It is therefore 
T.48N. 

46.30' 

T.47N. - • 

~ ... I • .. 13 ~-

" p£k 

24 

87"30' 

R.25W. 87.22'30" R.24W. 

1s.· -. ' ... 

19 

17 ""' ,""' ,..,., ,.,.. .,.,., pi:g 

20 

28 I 27 

10 

16 15 

21 22 

I 26 

\ 

p(:mo 1'\. 

< 

"Y+ 

"<!> 

p~ 

11 12 

89" 88" 

Geology by J. E. Gair, R. E. Thaden, and B. F. Jones, 1957-60 

1" 0 1 MILE 

FIGURE 178.1.-Map of Precambrian geology near east end of Marquette iron range, Michigan. 

N 

Qlc. I 

~ 

1 

J 

~ 

~ ~ 

...0 

"<!>~ .; 

0 

~ 

Siamo slate 

8 

Ajibikquartzite 

EJ 

Wewe slate 

f!P£k I 

Kona dolomite 

Outcrop areas of exte118ive 

silicification slwum in black 

~t~E!l 

j! ~ 

cE 

J 

Mesnard quartzite 

UNCONFORMITY 

I pCII8 I 

Granitic and gneissic rocks 

I p£mo"l 

Mona schist 

------- Contact 

_o ___ _ 

u Fault 

Dashed where uncerl.ain; U, 

upth.rown Bide; D; dotonth.rown Bide 

~ "' ____.. .. Anticline 

z 

c( 

a: 

m 

~ 

< u 

w 

0:: 

{l 

Sh.owing approximate trace of axial 

plane and bearing.and plunge of aria 

J, ... - t ... Syncline 

Showing approximate trace of axial 

plane and bearing and plunge of aria 

~ 0 

!lj 

t-:3 

"d 

> "d 

i::'j 

!lj 

Ul 

z 

~ i::'j 

C) 

i::'j 

0 

t"4 

0 

C) 

1-4 

(") 

~ t::=' 

~ t::=' 

!lj 

0 

t"4 

0 

0 

1-4 

0 

Ul 

(") 

1-4 

i::'j 

~ i::'j 

_Ul 

> 

!lj 

j 

~ i::'j 

Ul 

...... 

.;:. 

~ 

I 

t.-.:1 

co 

t.-.:1 

0 

I 

--l 

--l 
C-78 GEOLOGICAL SURVEY RESEARCH 19 61 

possible that the syncline is open to the east and may 

portend a major reversal of plunge for the Marquette 

synclinorium. If this interpretation is valid, the middle Precambrian rocks found west of Lake Superior 

a.Iong the Marquette range would recur beneath the 

lake and adjacent land areas that have Paleozoic rocks 

at the surface. 

Fault surfaces are rarely exposed, and for the most 

part the existence and position of the faults are inferred from (a) anomalous thickness changes of formations, (b) juxtaposition of formations normally 

separated by one or more formations, (c) offsets in 

formations or dikes, (d) unusual shear zones or breccias, generally marked by secondary quartz-in conjunction with (a), (b), or (c) -and (e) long straight 

narrow clefts in areas of granitoid-gneissic rocks, 

when such clefts are also in accord with or are alined 

with faults inferred from other criteria. 

Most of the faults mapped near the east end of the 

range trend generally westward, approximately parallel with the synclinorium. The major westwardtrending faults are in or adjacent to the trough of the 

synclinorium, or along the south margin of the synclinorium. The disposition of these faults in relation 

to the synclinoria! structure suggests that the faults 

are related genetically to the folds. Accordingly, the 

deduction is made that movement on the faults was 

mainly dip slip, roughly perpendicular to· the major 

axis of folding. The apparent right lateral offsets 

along the faults therefore indicate that the displacement .on virtually all the westward-trending faults was 

north-side downward. During the downfolding near 

the east end of the Marquette synclinorium the relative uplifting of the basement as a part of the folding 

process. probaby was greater on the south side of the 

synclinorium than on the north side, thereby accounting for the upthrow of blocks south of the faults. The 

faults trending north-northeastward and northwestward in sees. 4, 8, 9, 16, and 17, T. 47 N., R. 25 W., 

formed earlier than the major westward-trending 

faults, and their location along or close to the promi- . 

nent south \Yard bend of the Mesnard. and ICona formations suggests that they were related to the folding 

that produced the change in trend. 

A few miles west of the area shown on figure 178.1, 

near Palmer, displacement along the Volunteer fault 

(Tyler and Twenhofel, 1952, p. 120-121) was southside down. The Volunteer fault trends toward and 

may well be an extension or branch of the fault entering the map area in sec. 24, T. 47 N., R. 26 W. 

Therefore, it appears that the general rule regarding 

relative movement on westward-trending faults at the 

east end of the range does not apply to all faults west 

of the area shown on figure 178.1. 

REFERENCES 

.James, H. L., 1958, Stratigraphy of pre-Keweenawan rocks 

in parts of northern Michigan: U.S. Geol. Survey Prof. 

Paper 314-C, p. 27-44. 

Tyler, S. A., and Twenhofel, W. H., 1952, Sedimentation and 

stratigraphy of the Huronian of Upper Michigan: Am. 

Jour. Sci., v. 250, pt. 1, no. 1, p. 1-27; pt. 2, no. 2, p. 

118-:-151. 

Van Hise, C. R., and Bayley, W. S., 1897, The Marquette ironbearing district of Michigan: U.S. Geol. Survey Mon. 28, 

608 p. 

Van Hise, C. R., and Leith, C. K., 1911, The geology of the 

Lake Superior region: U.S. Geol. Survey Mon. 52, 641 p. 

179. SILICIFICATION OF THE KONO DOLOMITE IN THE EASTERN PART OF THE MARQUETTE IRON 

RANGE, MICHIGAN 

By J. E. GAIR, R. E. THADEN, and B. F. JoNES, Denver, Colo., Columbia, Ky., and Washington, D.C. 

Work done in cootJeration with the Geological Surve11 Division of the Michigan Department of Conse1·vation 

The Precambrian Kona dolomite (equivalent to the 

Randville dolomite in tlie lower part of the Animikie 

series of James, 1958, p. 35) is widely exposed in the 

eastern part of the Marquette iron range, Michigan. 

It conformably overlies the Mesnard quartzite and is 

overlain conformably by the W ewe slate. 

The most comprehensive description of the ICona 

has been given by Van Hise.and Bayley (1897, p. 240-

256). The ICona dolomite consists predominantly of 

dolomite and laminated cherty dolomite, but also locally of interlayered slate and quartzite. Chert layers 

in the laminated cherty dolomite are generally less 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-79 

than lh inch thick, and alternate with dolomite layers 

that are generally less than 2 inches thick. Because 

of the uniform thickness of most individual chert 

layers in the laminated cherty dolomite and their 

smooth and sharply defined interfaces with dolomite, 

we believe that such chert layers are primary rather 

than replacements of dolomite along bedding surfaces. 

Parts of the J(ona dolomite are silicified and parts 

are both brecciated and silicified. Van Rise and 

Bayley (1897) noted this, but they did not map the 

silicified parts of the J(ona. Our recent mapping has 

indicated that they included some silicified and quartzitic pnrts of the J(ona in the Mesnard quartzite. 

The distribution of silicified parts of the Kona is 

shown in figure 178.1 of the previous article. As only 

n.rens of. substantinl exposure are indicnted, the real 

distribution is probably not as "spotty" or discontinuous as the rna p suggests. 

Partiltl silicification of dolomite results in {a) 

cherty layers retnining buff to yellowish streaky zones 

of dolomite; (b) cherty masses along cross joints in 

the carbonate layers of laminated cherty· dolomite, 

commonly merging with the chert laminae; and (c) 

isolated masses of dolomite surrounded by massive 

chert or vein quartz. Occurrences such as (b) and (c) 

indicate postconsolidation replacement of the dolomite. 

Silicified J(ona dolomite most typically consists of 

thick laminated masses of fine-grained quartz (chert). 

The ]aminntions are reddish or bluish black to white, 

depending on varintions in minor amounts of different 

iron oxides from layer to layer. Massive siliceous rock 

consisting of fragments of white chert in a reddishbrown hemntitic cherty matrix apparently resulted 

from postbrecciation silicification of the dolomitic portion of laminated cherty dolomite. Thin sections of 

silicified .dolomite generally show a fine-grained mosaic of cherty quartz with small loose clusters of very 

fine-grained carbonate particles. 

Fine- to coarse-grained white vein quartz in masses 

of irregular shape and trend commonly cuts the 

bnnded chert. One large area of secondary silica in 

the J(ona consists almost entirely of vein quartz, but 

along strike this becomes a mixture of cherty silicified 

J(ona and vein quartz. Although massive vein quartz 

~n the J(ona is generally associated spatially with 

cherty silicified J(ona, it is unknown whether the 

quartz is a product, under differing physico-chemical 

conditions, of essentially the same solutions that produced the cherty silicification, or a product of later 

solutions which brought in new silica or remobilized 

the chert. 

Slate, slate-quartzite, slate-dolomite, and quartzitedolomite in the J(ona have also been silicified. The 

slate has been invaded by lenses, pods, or cross-cutting 

masses of coarse-grained vein quartz; in places it has 

been rather thoroughly impregnated both by coarseand fine-grained quartz and retains only streaky remnants of mica. Alternating layers or lenses of purple, 

locally brecciated, quartzite and reddish-brown chert 

are interpreted by us as silicification of interbedded 

quartzite and dolomite. 

The silicification of dolomite in several localities in 

northern Michigan has been discussed by Leith ( 1925) 

and by Gair and Wier ( 1956, p. 34). Leith pointed 

out a widespread relation between silicification and 

erosion surfaces (unconformities) and concluded that 

such silicification resulted from weathering along erosion surfaces prior to deposition of unconformably 

overlying rocks. Although Leith referred specifically 

to unconformities within the Precambrian stratigraphic section, it seems implicit that his concept also 

included possible silicification along the PrecambrianCambrian unconformity, or on the erosion surface 

representing the Cambrian-Pleistocene interval. 

Most of the silicified Kona in the central and western parts of the area. that is in sees. 5, 8, 17, and 18, T. 

47 N., R. 25 W., and in sees. 12 and 13, T. 47 N., R. 

26 W., may well have developed on the post-Precambrian erosion surface, in accordance with Leith's 

hypothesis. In the eastern part of the area in figure 

178.1 (previous article), however, most silicification 

of the J(ona dolomite or replacement of the dolomite 

by massive vein quartz occurred either close to the 

contact with the subjacent Mesnard quartzite (as in 

sees. 32, 34, 35, T. 48 N., R. 25 ,V., the Nlj2 sec. 1, the 

north west part of sec. 3, the NW1,4 sec. 4, and the 

NE1,4 sec. 9, T. 47 N., R. 25 W.) or along faults where 

the ~{esnard quartzite is displaced from the stratigraphic section (as in SW1,4 sec. 2 and the SE1,4 sec. 

3, T. 47 N., R. 25 W.). From the fault in the SW% 

sec. 2, wedgelike quartz veins, from 1f2 to 3 inches in 

thickness, extend a short distance into the granitic 

basement. In the eastern part of figure 178.1, silicabearing solutions evidently moved along the faults, 

along slippage zones between the Mesnard and the 

J(ona, or along shears in the lower part of the Kona 

that were related to slippage in the J(ona-Mesnard 

contact zone. All of these structures probably formed 

during the major folding at the end of middle Precambrian time. 

We have no firm basis for determining whether the 

silica-bearing solutions moved upward, downward, or 

laterally along the slippage zones or faults. One 

might readily deduce from Leith's conclusions that 
C-80 GEOLOGICAL SURVEY RESEARCH 19 61 

such solutions moved downward from an erosion surface that existed at some distance above the present 

surface, and that silicified material on that surface has 

been eroded aw~y, leaving only the downward extensions of silicified material along faults or slippage 

zones. However, the types of silicification described 

above (particularly the thorough bed-by-bed replacement of thick masses of dolomite, the lenticular knots 

of coarse-grained quartz along foliation in slates of 

the l(ona, as well as the wedgelike quartz veins in the 

basement a few feet from a massive white vein quartz 

replacement of the l(ona) seem to us better explained 

by introduction of silica laterally or from below rather 

than from an overlying erosion surface. 

REFERENCES 

Gair, J. E., and Wier, K. L., 1956, The geology of the Kiernan 

quadrangle, Iron County, Michigan: U.S. Geol. Surv~y 

Bull. 1044, 88 p. 

James, H. L., 1958, Stratigraphy of pre-Keweenawan rocks in 

parts of northern Michigan: U.S. Geol. Survey Prof. Paper 

314-C, p. 27-44. 

Leith, C. K., 1925, Silicification of erosion surfaces: Econ. 

Geology, v. 20, no. 6, p. 513-523. 

Van Hise, C. R., and Bayley, W. S., 1897, The Marquette ironbearing district of Michigan: U.S. Geol. Survey Mon. 28, 

608 p. 

180. THICKNESS TRENDS IN THE HARTSHORNE SANDSTONE AND THE McALESTER FORMATION IN 

NORTHWESTERN ARKANSAS 

By BoYD R. HALEY, Denver, Colo. 

Work done in cooperation with the Arkansas Geological and Conservation Commission 

Geologic information obtained since 1953 from mapping Pennsy 1 vanian · rocks in Arkansas and from 

earlier published and unpublished reports gives fairly 

detailed information on the thickness and source area 

of the Hartshorne sandstone, the thickness and source 

area of the McAlester formation, and the stratigraphic 

relations between these two rock units. 

The Hartshorne sandstone of Pennsylvanian age, 

ranging in thickness from a featheredge to 345 feet, is 

the first continuous sandstone unit beneath the Lower 

Hartshorne coal bed in Arkansas, and it is equivalent 

to the lower sandstone unit of the Hartshorne sandstone in Oklahoma. It unconformably overlies the 

Atoka formation of Pennsylvanian age and· conformably underlies the McAlester formation of Pennsylvanian age. The Hartshorne sandstone in Arkansas 

contains minor amounts of siltstone and shale and, in 

a few places, thin beds of coal. The deepest part of 

the sedimentary basin during the deposition of the 

Hartshorne sandstone extended through Sebastian, 

Franklin, Logan, Yell, and Conway Counties, Ark. 

(fig. 180.1). Sediments were supplied to this basin 

from the north across Franklin County, from the 

northeast across Pope County, from the east across 

Conway County, and from the south ~cross Yell 

County as attested to by the thickness trends shown 

on figure 180.1, and by measurements of the dip direction of crossbeds and other features indicating current 

directions. 

SCOTT 

9 5 10 15 20MILES 

YELL 

EXPLANATIO 

Hartshome sandstone ~ more than 200 ft thick 

Hartshome sandstone ~ from 100 to 200 ft thick illiilll . Hartshome sandstone less than 100 ft thick ...... ·>?00··· ... 

Line showing thickneas of Hartshome sandstone 

originally preaent 

lnterool 100 Jt!$t 

Surface -trace of fault 

FIGURE 180.1.-Distribution and thickness of the Hartshorne 

sandstone in northwestern Arkansas. Formation present 

only in patterned areas. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-81 

The McAlester formation, ranging in thickness from 

500 to 2,000 feet, is predominantly shale, but contains 

subordinate amounts of sandstone and siltstone, a few 

thin beds of limestone, and 8 coal beds. The formation was deposited in a sedimentary basin having two 

troughs. The shallower trough extended across Sebastian ttnd Franklin Counties, and the deeper trough 

extended across Sebastian, Scott, Logan, and Yell 

Counties (fig. 180.2). Sediments were supplied to this 

basin probably from areas to the north and south. In 

southwestern Sebastian County and northern Scott 

County the McAlester formation contains a coal bed 

and a sandstone unit that are equivalent to the Upper 

I-Iartshorne coal bed and the upper sandstone unit of 

the IIartshorne sandstone in Oklahoma. These pinch 

out to the north and east in south-central Sebastian 

County. 

The Lower I-Iartshorne coal bed, near the base of 

the ~fcAlest:er formation, has a depositional history 

that is related to the depositional history of the underlying I-Iartshorne sn.ndstone. In general, where the 

I-Inrtshorne sandstone is thick the coal bed is thin or 

absent, and where the sandstone is thin or absent the 

coal bed is thick (figs. 180.1 and 180.3). This relation 

is particulnrly notable In Franklin, Johnson, Pope, 

-·-·-·-·-·-·-·-·T-·-·-·-·-·-·-· I 

! 

POPE 

EXPLANATION 

i Area underlain by 

~ McAlester formation i .......... 800·······'" 

,.-t 

i 

: 

i 

: 

i 

I 

i 

i 

I Line showing thickneas of McAlester formation 

5 Q 5 10 15 20M ILES ' originally present 

Surface trace of fault 

FIOUBE 180.2.-Distribution and thickness of the McAlester 

formation in northwestern Arkansas. 

SCOTT 

5 0 5 10 15 20MILES 

EXPLANATION 

Coal more than 

~ 

28 inches thick 

Coal from 14 ~ to 28 inches thick 

mnm Coal less than 14 inches thick ......... , ......... . 14-inch thickneas line 

Surface -trace of fault 

FIGURE 180.3.-Distribution and thickness of the Lower Hartshorne coal bed in northwestern Arkansas. 

Yell, and eastern Logan Counties. Hendricks ( 1937) 

suggested that belts of thick and thin coal in a small 

part of west-central Sebastian County, where he had 

detailed control, tend to parallel major structural 

axes. The area of his observations was so small that 

regional relations of coal thickness could not be determined. In some areas the Lower Hartshorne coal 

bed was deposited contemporaneously with sandstone 

beds that are lithologically similar to the sandstone 

beds in the Hartshorne sandstone. These sandstone 

beds are mapped as a part of the Hartshorne sandstone because of their lithologic characteristics, but 

they were deposited during early McAlester time, 

probably by the same streams that had supplied sediments to the Hartshorne sedimentary basin. In many 

areas, the inv~rse thickness relation of the Lower 

Hartshorne coal bed to the Hartshorne sandstone can 

be explained by the continuation or noncontinuation of 

Hartshorne-like sedimentation during early McAlester 

time. 

REFERENCE 

Hendricks, T. A. 1937, Pennsylvanian sedimentation in Arkansas coal field : Am. Assoc. Petroleum Geologists Bull., v. 21, 

'no. 11, p. 1403-1421. 
C-82 GEOLOGICAL SURVEY RESEARCH 19 61 

181. POSSIBLE BENTONITE BEDS IN THE ATOKA FORMATION IN ARKANSAS AND OKLAHOMA 

By SHERWOOD E. FREZON and LEONARD G. ScHULTZ, Denver, Colo. 

The Atoka formation, of Pennsylvanian age, in the 

Arkoma basin of western Arkansas and eastern Oklahoma locally contains as· many as four beds of lightgray or greenish-gray soft generally flaky shale that 

has a soapy or pearly luster. The physical characteristics of this shale contrast sharply with the characteristics of harder darker gray micaceous shale common in the formation. Although data concerning the 

distribution of this atypical shale are incomplete, the 

authors hope that the information presented here will 

call attention to the beds and to their potential usefulness in stratigraphic studies of the Atoka formation. 

Light-colored shale, tentatively identified as bentonite, has been observed in the Atoka formation in samples from 36 wells, and in a bed 2 inches thick at 1 

outcrop (fig. 181.1 and table 181.1). Lithologic descriptions of the bentonite( n beds in selected wells, 

and the stratigraphic interval between these beds and 

the base of the Atoka formation are presented by 

table 181.2. 

Where found in well samples, fragments of lightcolored shale comprise less than 5 percent of the 

individual sample. Inasmuch as the samples generally represent 5- to 10-foot drilled intervals, the 

small amount in most samples suggests that the 

beds of light shale in the wells are comparable in 

thickness to the 2-inch thick bed at the outcrop (loTABLE 181.1.-List of wells and outcrop section shown on 

Map locality number 

(fig. 181.1) 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

figure 181.1 ' 

Well name and location of well or outcrop 

Phillips Petroleum Co. 1 C. W. Mandler, 

SEXSWXSW% sec. 1, T. 6 N., R. 10 E., Hughes 

County, Okla. 

Superior Oil Co. 1 Allred, NW%SEXNE% sec. 18, 

T. 8 N., R. 20 E., Haskell County, Okla. 

Carter Oil Co. 1 C. L. Follansbee, SWXNWXSW% sec. 18, T. 9 N., R. 15 E., Mcintosh County, Okla. 

Carter Oil Co. 1 Graham C-309, NW14SEXNEX sec. 3, T. 9 N., R. 16 K, Mcintosh County, Okla. 

Phillips Petroleum Co. 1 Sammons CSEXNEX sec. 22, T. 9 N., R. 21 E., Haskell County, Okla. 

Arkansas-Oklahoma Gas Co. 1 G. D. Cloud, 

SEXNWXSE% sec. 27, T. 9 N., R. 24 E., LeFlore 

County, Okla. 

Phillips Petroleum Co. 1 Ruby, CNWXSWX sec. 30, 

T. 10 N., R. 16 E., Mcintosh County, Okla. 

Edwin D. Pauley 1 Dyton Bennett CSEXNEX sec. 18, T. 10 N., R. 18 E., Mcintosh County, Okla. 

I.T.I.O. Co. 1 John J. Bl~tke, CSWXNWX sec. 3, T. 

10 N ., R. 21 E., Haskell County, Okla. 

L. A. Chudacaff 1 Tabor, NEXNWXSE% sec. 11, 

T. 11 N., R. 16 E., Mcintosh County, Okla. 

TABLE' 181.1.-List of wells and outcrop section shown on 

figure 181.1-Continued 

Map locality number 

(fig. 181.1) 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

Well name and location of well or outcrop 

Midco Oil Co. 1 Mary Dunagan, SEXSEXNEX sec. 31, T. 11 N., R. 19 E., Muskogee County, Okla. 

Diamond Drilling Co. 1 James Mullen, CNW~ sec. 5, T. 11 N., R. 23 E., Sequoyah County, Okla. 

Arkansas-Oklahoma Gas Co. 1 Binnie Barry, 

CN%SWXNE% sec. 23, T. 11 N., R. 25 E., 

Sequoyah County, Okla. 

Residue Co. 1 Mansfield Gas Co., NW%SE%N W~~ 

sec. 6, T. 4 N., R. 30 W., Scott County, Ark. 

Post Petroleum Co. (Carter) 1 H. E. Turner, 

CSWXSEX sec. 15, T. 6 N., R. 28 W., Logan 

County Ark. 

Gulf Oil 6orp. 1 F. R. Borum, SWI4SWXSWI4 sec. 18, T. 6 N., R. 28 W., Logan County, Ark. 

Blackwell Oil & Gas Co. 1 G. A. Scroggin, 

SWXNWXSEX sec. 14, T. 7 N., R. 16 W., Conway County, Ark. 

ShPll Oil Co~ 1 T.V. Jones, NWXNWXNW~~ sec. 19, 

T. 7 N., R., 21 E., Yell County, Ark. 

Western Natural Gas Co. 1 W. B. Bergkamp, 

S%SEXNWX sec. 1, T. 7 N., R. 30 W., Sebastian 

County, Ark. 

Arkansas-Oklahoma Gas Co. 1 George Bieker, 

CNWXSE% sec. 2, T. 7 N., R. 32 W., Sebastian 

County, Ark. 

Gulf Oil Corp. 1 Tackett, CSWXNE% sec. 2, T. 8 N., 

R. 22 E., Johnson County, Ark. 

Gulf Oil Corp. 1 S. W. Roberts, NEXNWX sec. 33, 

T. 8 N., R. 22 W., Logan County, Ark. 

Western Natural Gas Co. 1 Roy Gray, CSW~~NEX 

sec. 25, T. 8 N., R. 24 W., Logan County1 Ark. 

Gulf Oil Co.rp. 1 Hembree, NWXNW%SW:r4 sec. 13, 

T. 8 N., R. 26 W., Logan County.).. Ark. 

Western Natural Gas Co. 1 Lucy vhapman, NWX 

NEXNWX sec. 14, T. 9 N., R. 12 W., Cleburne 

County, Ark. 

Carter Oil Co. 1 C. T. Williams, W%SE%SEX sec. 1, 

T. 9 N., R. 16 W., Conway County, Ark. 

Cosden Oil Co. 1 Shackleford, NWXSEX sec. 13, T. 

9 N., R. 19 W., Pope County, Ark. 

Gulf Oil Corp. 1 J. J. Bauman, CNEXSWX sec. 13, 

T. 9 N., R. 22 W., Pope County, Ark. 

Gulf Oil Corp. 1 Ragon, CSEXSWX sec. 28, T. 9 N., 

R. 23 W., Logan County, Ark. 

Gulf Oil Corp. 1 Arkansas Real Estate Co., Inc., 

E%NEXNWX sec. 32, T. 9 N., R. 23 W., Logan 

County, Ark. 

Arkansas-Louisiana Gas Co. 1 R. S. Barton, SEX 

SEXNWX sec. 27, T. 9 N., R. 28 W., Franklin 

County, Ark. . Stephens Production Co., Inc., 1 Taylor Landthr1p, 

NWXSEXNWX sec. 22, T. 10 N., R. 23 W., 

Johnson County, Ark. 

C.'1rter Oil Co. 1 Boyer Heirs, SWXSWXNEX sec. 18, T. 10 N., R. 24 W., Johnson County, Ark. 

Le Flore County Gas & Electric Co. 4A Low Gap 

Unit, SEXSWXSE% sec. 6, T. 11 N., R. 23 W., 

Johnson County, Ark. 

Carter Oil Co. 1 Federal Government, CNEXSWX sec. 12, T. 11 N., R. 26 W., Franklin County, Ark. 

Cities Service Co. 1 W. R. Bruce, SWXSEXNWX sec. 4, T. 11 N., R. 32 W., Crawford County, .Ar~. 

West side of State Highway 2, north of the ha~rpm 

turn in NEX sec. 3, T. 3 N., R. 19 E., Latimer 

County, Okla. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-83 

ra1 

-I \ 0 36 r-' 35 I 0 34 ~ 

L I MUSKOGEE )1----- -----1 I 1 JOHNSON I J VAN BUREN ~ __1 \ CRAWFORD l 33 32 L - -1 r------l , SEGUOYAH \ FRANKLIN 0 0 _j 1 ra1 I MCINTOSH 12 \ f . I POPE -~-1 ~ 'L l o10 IF11 )\, o o13 ~t Smith(! o31 I ~ p28 o27 I L~su --J 8 r5'o9 'l_,, .[~ '-_.rj 91 _j--rl24-""~ )((~ 1 

\ coNWAY),-- -----i 3 0~ ~~-v,J cv--- I o20 I f -~.... I o17 

. I 0 ,.r-/

1 

I 05 J o6 II ~o15 LOGAN I-- ~ _j l FAULKNER 

HUGHES l_ .1-"- L 1 o2 II SEBASTIA~_. .,..--r \.J-.7 ) 

.,r- I HASKELL _j 1 .--'1 I ~--'../f 01 ( PITTSBURG r--.IJ:A"TiMER-1 <I~ "f14""--L ____ j YELL / ~ 1 

1 I ,.J LEFLORE ;::aJr:n...-..1 l /- PERRY _ _r- ""\(--J 

I MeAq .... , J ( ~.~ SCO'M' I l ,---..,.~· PULASKI 

I ~~~ _L___ -.I.., L_l ~ 0 - L__ _ --...__ r ,r I ., ittl;R'ock 

0 10 20 30 40 50 MILES ~--~--~--_.--~--~ 

ll'mumc 181.1.-I ... ocntlon of 36 wells and 1 outcrop (X) in Arkansas and Oklahoma having possible bentonite beds in the Atoka 

formation. Numbers refer to wells and outcrop listed in table 181.1; 

TABLl~ 181.2.-Injormation on possible bentonite beds in selected 

wells and in the o~ttcrop section 

Map locality No. 

(fig. 181.1) 

Description or possible bentonite bed(s) 

2 Olive-gmy flaky shale; unidentified clear 

mineml grains and orange, flaky mineral 

(tnica~-----------------------------

3 Olive-gray to light olive-gray, soft shale; 

scattered fine to medium grains of un- identified clear mineraL ______________ _ 

4 Light brownish-gray to pale-yellow brown 

sh_n.le; brow~ mica and unidentified clear mmeral grams _______________________ _ 

Very light gray to yellow-gray flaky shale; 

unidentified clear mineral grains _______ _ 

11 Light-gray soft flaky shale; brown mica ___ _ 

J .. ight-gmy to very light gray flaky shale; 

fine round grains of unidentified clear rnineral ____________________________ _ 

13 Light olive-gray to yellowish-gray flaky 

shale: scattered fine grains of unidenti- fied clear mineraL ___________________ _ 

Light-gray to very light gray dolomitic ~ soapy flaky shale; scattered unidentified 

clear mineral grains __________________ _ 

14 Pale reddish-brown and grayish-yellow 

waxy shale; red pinpoint inclusions ____ _ 

Grayish-orange flaky soapy shale; grayish- red platy inclusions (mica?) ___________ _ 

17 Yellowish-orange shale _________________ _ 

Dusky yellowish-gray flaky dolomitic shale_ 

Light-gray slightly flaky compact shale __ _ Light-gmy compact soapy shale _________ _ 

20 Light-gmy to white shale; some unidentified clear mineral grains ______________ _ 

21 Light-gray waxy flaky shale; fine dolomite 

crystals; trace of dark-gray mica(?) ____ _ 

Distance 

between 

base of bed 

and base of 

Atoka 

formation 

(feet) 

53 

102 

105 

21 

145 

60 

413 

46 

1 6, 777 

1 5, 443 

404 

219 

59 

12 

61 

1, 098 

TABLE 181.2.-lnformation on possible bentonite beds in selected 

wells and in the outcrop section-Continued 

Map locality No. 

(fig. 181.1) 

Description of possible bentonite bed(s) 

Very light gray flaky shale; dolomite 

rhombs, unidentified clear mineral 

grains, and brownish-gray mica _______ _ 

Distance 

between 

base of bed 

and base or Atoka 

formation 

(feet) 

148 

29 Gray granular and flaky shale; unidentified clear mineral aggregates containing 

30 

31 

35 

36 

37 

t Estimated. 

trace of dolomite ____________________ _ 

Light-gray to very light gray shale, very 

slightly dolomitic; trace of unidentified 

clear mineral aggregates; trace of black 

207 

biotite_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 193 

Very light gray to yellowish-gray, granular 

and flaky shale; dolomite rhombs__ _ _ _ _ _ 27 

Yellowish-gray soft flaky shale with 

dolomite rhombs; trace of brown mica; 

trace of black mica __________________ - 568 

Light-gray flaky shale; one piece contains 

1 large grain of unidentified clear mineral_________________________________ 148 

Yellowish-gray soft flaky shale; dolomite 

rhombs and trace of black mica________ 325 

Light-gray soft flaky shale; dolomite 

rhombs______________________________ 15 

Youngest: light-gray hard nonfissile shale; 

trace of very fine mica flakes; breaks 

with rough surface ____________________ --------

Very light gray granular limestone; 

weathers white; iron stains; a single 

irregular bed having maximum thick- ness of~~ inch ________________________ --------

Very light gray, smooth shale: soapy 

luster: weathers to mud; 2 inches thick__ 1 400 

Oldest: light-gray hard nonfissile shale; 

breaks with rough surface _____________ --------
C-84 GEOLOGICAL SURVEY RESEARCH 1961 

cality 37, fig. 181.1). Such small amounts can easily 

be overlooked in sample examination or may be mistaken for pieces of drilling-mud cake. The lightcolored shale readily disintegrates in water and possibly in some samples the small quantity of shale from 

the thin beds is partly or totally removed by waterbase drilling muds and sample washing. The shale 

beds have not been detected on electrical or radioactivity logs. 

X-ray diffraction analyses were made of samples of 

light-colored shale and of darker co~ored shale from 

adjacent beds from locality 37 and from wells 29 and 

30 (fig. 181.1), and the results are shown in table 

181.3. As the 2 wells are only 1 mile apart and the 

light-colored shale beds are about 200 feet above the 

base of the Atoka formation in both wells, the well 

samples probably are from the same bed; the lightcolored shale bed at locality 37 is believed to be a different bed. 

TABLE 181.3.-Mineralogy of some samples of.shale and bentonite(?) 

from the Atoka formation, determined by X-ray diffraction 

(Estimated to nearest 5 percent of total sample; (?), mineral possibly present] 

Locality No. 

(fig. 181.1) 

29 _____ 30 _____ 

37 ___ ~-

29 ____ _ 30 ____ _ 37 ____ _ 

MixedSample Montmoril- layer mont- illite Chlorite Kaolilonite morillonite- nite 

illite 

Darker shale adjacent to or near the bentonite(?) 

b 

b 

a 

b 

a 

a 

c 

--------

-------- 20 

30 

35 25 10 

25 35 10 

15 20 ------ 25 5 ------

Bentonite(?) 

60 ------------ 75 

75 (?) 

10 

10 

10 

5 

30 

20 

5 

Quartz 

20 

20 

35 

35 

10 

5 

20 

Samples of the darker shale contain mixed-layer 

montmorillonite-illite, illite, kaolinite, quartz, and, in 

some samples, montmorillonite and chlorite (table 

181.2) ; the absence of chlorite in the outcrop (loc. 37) 

samples is probably due to its having been destroyed 

during weathering. Samples of the light-colored shale 

are predominantly mixed -layer montmorillonite-illite, 

and contain some kaolinite and quartz; a trace amount 

of illite may be present in one sample from the outcrop. Unlike the mixed-layer clay in the darker shale, 

the mixed-layer clay in the light-colored shale shows 

regular mixed-layering, as indicated by a superorder 

reflection at a spacing of 30 A after glycol treatment 

of the samples. Megascopic examination of the lightcolored bentonitic ( ? ) shale from many wells indicates 

that it contains colored mica-probably biotite-that 

generally is much coarser than the normal detrital 

mica in the other shales of the Atoka. 

Clear-cut shard or other volcanic textures have not 

been observed in samples of the light-colored shale. 

The mineralogy of the light-colored shale beds suggests, but does not prove., that they are of volcanic 

origin. The predominance of a single clay mineral, 

the absence of chlorite, and only a questionable trace 

of illite indicate that the original sediments of these 

beds differed significantly from those of the darker 

shale beds. The light-colored shale beds in the Atoka 

are not composed of montmorillonite, as many typical 

bentonite beds are, but the mixed-layer clay dominant 

in the light-colored shale of the Atoka formation is 

common to some Paleozoic metabentonites (Weaver, 

1953). l(aolinite like that in the light-colored shale 

of the Atoka may form as a result of alteration of 

volcanic ash. 

IJ1complete studies show that some of the lightcolored shale beds in the Atoka formation can be 

correlated over areas of at least 1,200 square miles. 

Their wide areal extent, apparent thinness, and mineralogical and lithological differences as compared to 

adjacent darker shale beds indicate that these lightcolored beds represent brief, abrupt, and relatively 

widespread changes in the type of sediment deposited. 

Such changes are reasonably attributed to ash falls. 

If these beds represent altered volcanic ash, they may 

serve as useful time markers within the Atoka formation. 

REFERENCE 

Weaver, C. E., 1953, Mineralogy and petrology of some Ordovician K-bentonites and related limestones [Pa.] : Geol. 

Soc. America Bull., v. 64, no. 8, p. 921-943. 
SHORT PAPERS IN THE. GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-85 

182. THICKENING OF THE ATOKA FORMATION IN THE CENTRAL PART OF THE ARKANSAS VALLEY, 

NORTHWESTERN ARKANSAS 

By E. A. MEREWETHER, Denver, Colo. 

Worlc done in cooperation with the Arkansas Geological and Conservation Commission 

The Atokn formation of Pennsylvanian age increases in thickness from a featheredge on the Ozark 

uplift in southern Missouri to as much as 20,000 feet 

in the Ouachita Mountains in Arkansas 140 miles to 

the south. This increase in thickness was recognized 

by some of the first geologists concerned with this 

region (Collier, 1907; Croneis, 1930). 

Recent geologic mapping and drilling on the north 

limb of the Arkansas Valley basin in the Arkansas 

Valley give information on some of the details of 

thickening of the Atoka. In a distance of about 28 

miles in a southerly direction, the Atoka formation 

increnses in thickness from about 3,100 feet at the 

Pure Oil Co. Low Gap well 4-A in central Johnson 

County to about 10,750 feet at the Shell Oil Co. T. V. 

Jones well 1 in northern Yell County (fig. 182.1). 

Between these two wells the Atoka can be divided into 

five unnamed units and the average rates of thickening 

for these units range from 1.87 percent per mile to 

7.55 percent per mile. In addition, the percentage of 

shale in the Atoka as shown by table 182.1, increases 

greatly from the Low Gap well to the Jones well. 

The Atoka formation in the central part of the 

Arkansas Valley consists of interbedded shale, siltstone, rmd sandstone; a few thin lenticular beds of coal 

and limestone in the upper part of the formation; and 

a few thin lenticular beds of limestone in the lower 

part. Coal and limestone beds comprise less than 1 

percent of the Atoka and are not included in table 

182.1. 

TABI~E 182.1.-Percentages of sandstone, siltstone, and shale, and 

thickness (in feet) of sandstone in the Atoka formation at six 

localities in northwestern Arkansas 

Atoka formation 

Whole formation Lower three units 

Locality Percentage of- Thick- Percentage of- Thick- ness of ness of 

sandstone sandstone 

Sand- Silt- Shale (feet) Sand- Silt- Shale (feet) stone stone stone stone 

---------------- A.-------- -------- -------- -------- ---------- 45 30 25 804 B--------- 27 34 39 1,222 28 46 26 768 

c.-------- o _________ 20 28 52 1,070 22 34 44 688 26 23 51 1,393 26 31 43 896 E.-------- 12 21 67 877 10 25 65 465 

F •..• ----- 17 19 64 1, 762 13 25 62 951 

The Atoka formation is divided into 5 units by the 

top and base of the formation, and by 4 widespread 

beds withi11 the formation that can be identified in 

drill cuttings, electric logs of drill holes, and at outcrops 

(fig. 182.1). Surface and subsurface stratigraphic 

information has been projected to a line trending 

S. 5° E. across part of the north limb of the Arkansas 

Valley basin. The resulting cross section (fig. 182.1) 

illustrates a thickening of the entire Atoka formation 

in a southerly direction at 'an average rate of 4.67 

percent per mile. 

An isopach map of the Atoka formation in the 

Arkansas Valley indicates that, if the top of the 

Atoka is taken as a horizontal datum, the base of 

the Atoka in the direction of maximum thickening 

closely approximates an exponential curve expressed 

as Y= (1+p)x (E. E. Glick, oral communication, 

1961). In this formula, p is the rate of thickening 

per mile in percent, x is the distance in miles, and Y 

is the ratio of the thickness of a unit to that of a correlative thinner unit. The Atoka formation in this 

area doubles in thickness approximately every 15 miles 

in the direction of maximum thickening. Within the 

Atoka the maximum rate of thickening (7.55 percent 

per mile) is in the unit between the bentonite ( ~) bed 

(Frezon and Schultz, Art. 181) and the sandstone that 

produces gas in the l{noxville gas field, in the lower 

part of the Atoka (fig. 182.1). The minimum rate of 

thickening ( 1.87 percent per mile) is in the lowest 

unit of the formation. The rates of thickening per 

mile for the units delineated on figure 182.1 are evidence that the basin subsided, relative to the shelf, at 

the slowest rate in very early Atoka time, at a maximum rate during early to middle Atoka time, and at 

intermediate rates in late Atoka time. 

The percentages of sandstone and siltstone in the 

Atoka formation (table 182.1) in general decrease to 

the south along the line of the cross section, but the 

total thicknesses of sandstone and siltstone stay nearly 

the same. The percentage and amount of shale in 

general increase in a southerly direction, and most of 

the thickening of the Atoka formation in the area 

along the line of the cross section (fig. 182.1) is a 

result of the increase in the amount of the shale. 
0 

c( (,) (.) 

8.J. .=..... ~ e -Q. u;a. " o,.... oro c·.::: ro..... (.)c 

NORTH Q) " ~ £ ::;: ~ = ro .._ 3: a. -o o ·- o E ::Jo Q)C ~::!!: :!::::J 

e e e 0 o,.... 0 (.) (.) u ..... = ..... = 5=:::: O>.Ot:OQl 

:!::.g,:!:: O:!::tj a:1: a~a~ 

a.,... 

0 Q) U> 

0~ -"E :iro 

c.!' :I: 

Q. 

0 

(.) ..... -Ill C5i 

:!::..0 

::JO 

(.!'0:: 

0 

(.) 

o:;: 

=Q) 

Q) c .s::.o en-, Thickness ~ ....J Ci5 j .:C ;: a ~ (feet) A 8 

0 ..., . ~P of Atoka formation, _ __ ____ __ __ __ C 0 E F 

-uppermost continuoliS"Sandstofie7 ----___ --===-r r ttl I ____ -----i 

1000 

2000 

3000 

4000 

5000 

6000 

7000 

8000 

9000 

10,000 

11,000 

12,000 

-----...., Continuous sandstone, ___ _ 

T 

I I 1 I I 

Correlation lines are 

dashed where inferred ,---l ___ _ 

1 JOHNSON ~-

' 

low Gap 4-A I 

LINE OF SE~TION, l_j 

I 

I landthrip 0 I 0 W~ins I 

Clarksville r- /~ b~auman 

. Higb 

'- ./""'-' ~Who:fon J • Tackett 

•

1 

Hardgrave 

~~oberts 

· I'\ Russellville 

J - 0 

Jones\ 

rr-- ' J YELL 

POPE 

LOGAN 

) 

PART OF NORTHWESTERN ARKANSAS SHOWING 

LOCATION OF LINE OF SECTION AND WELLS 

SHOWN ON CROSS SECTION 

1

."---... (5I ............... .............. "-.... 

'"'"' 

""' 15 MILE~ 

SOUTH 

Thickening per mile 

(percent) 

4.91 

.01 

4.67 

7.55 

1.87 

FIGURE 182.1.-Correlation of s~ratigraphic units in the Atoka formation, Johnson County to Yell County, Ark. Wells projected to line of section. 

0 

I 

00 

~ 

Q 

trl 

0 

t"l 

0 

Q 

1-,-4 

(') 

> t"l 

U2 

q 

::tl 

<: 

trl 

~ 

::tl 

trl 

UJ 

trl 

> ::tl 

~ 

-co 

0) 

...... 

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SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-87 

The pronounced thickening of the Atoka formation 

was probably caused by the rate of generally continuous deposition keeping pace with the rate of subsidence 

jn a basin .. Sandstone and siltstone in the lower and 

middle part of the Atoka represent periodic influxes 

of fine-grained clastic material from a distant northern source into a gently sloping sh'allow largely marine 

basin in which organic-rich shales were accumulating. 

Sediments in the upper part of the Atoka were probably deposited near a shoreline that oscillated across 

the basin, as suggested by the alternation of marine 

shale units, channeling sandstone units, and coal beds. 

REFERENCES 

Collier, A. J., 1907, The Arlmnsas coal field: U.S. Geol. Survey . 

Bull. 326, 158 p. 

Croneis, C. G., 1930, Geology of the Arkansas Paleozoic area, 

with special reference to oil and gas possibilities: Arkansas Geol. Survey Bull. 3, 457 p. 

GEOLOGY AND HYDROLOGY OF WESTERN CONTERMINOUS UNITED STATES 

183. THE QUARTZ DIORITE LINE IN NORTHWESTERN NORTH AMERICA 

By JAl\IES G. MooRE, ARTHUR GRANTZ, and M. C. BLAKE, JR., Menlo Park, Calif. 

Buddington (1927) demonstrated that the granitic 

rocks of southeastern Alaska show a regional zonation 

in composition: they pass progressively from quartz 

diorite on the west, through granodiorite, to quartz 

monzonite on the east. A similar relation has been 

described i.n the western conterminous United States 

(Moore, 1959) where it is possible to delineate a line 

( cn,lled ·the quartz diorite line) roughly parallel to 

the Pacific Coast, which separates a western zone in 

which quartz diorite is the dominant granitic rock 

from an eastern zone in which granodiorite or quartz 

monzonite is the dominant granitic rock. The granitic 

rocks considered are chiefly of Jurassic and Cretaceous 

age, but they include some Tertiary intrusives and possib!"y some Paleozoic ~ntrusives. In the present paper 

the quartz diorite line is extended across Alaska and 

the significance of the regional chemical differences 

that it helps to outline is explored. 

Data regarding the dominant granitic rock type in 

each of approximately 100 mapped areas in Alaska 

nnd Canada (British Columbia and Yukon) are shown 

on figure 183.1. In order to compare the data, the 

same system· is used in classifying the granitic rocks 

of all the mapped areas, even if the author of a published report used a different system. The classification system is the same system . used in the earlier 

compiln.tion of dn.tn. on granitic rocks of the western 

conterminous United Stn.tes (Moore,. 1959). On figure 

183.1 symbols are used for three main groups of 

granitic rocks: (a) quartz diorite, (b) granodiorite, 

and (c) quartz monzonite or granite. 

The granitic rocks of Alaska show an increase in 

the proportion of !(-feldspar relative to plagioclase 

inland from the southern continental margin; this 

chn.nge is very similar to that found in the granitic 

rocks of Californin., Oregon, and Washington. In 

each area the granitic rocks become progressively 

richer in IC and Si, and poorer in N a, ·Fe, and Mg 

inward from the continental margin. 

The qun.rtz diorite line drawn across Alaska (fig. 

183.1) separates a zone adjacent to the southern coast 

in which quartz diorite is the dominant granitic rock 

from a zone to the north where granodiorite, quartz 

monzonite, or granite is the dominant granitic rock. 

The quartz diorite line does not mark an abrupt 

change in composition; and its position is dependent 

on the classification system employed. 

From the latitude of ICetchikan to that of Skagway, 

the line is close to the international boundary between 

Aln.ska and Canada. It trends northwestward from 

Skn.gway on the north side of the St. Elias and 

Wrangell l\iountains. The line reaches its farthest 

north point about 70 miles south of Fairbanks from 

where it curves to the southwest and ultimately passes 

out to sea at Bristol Bay. The line remains north of 

the Aleutian ~slands, mn.ny of which are underlain by 
T LAWRENCE 

68 LAND 

8 

• 

Q 

PRIBILOF 

ISLANDS 

" 

168• 

--{-sa. 

p.\..€.\,)1'\P.~ 

F~($~ (\} 

.77 .77 

ALASKA 

.83 

.81 

.81 

.19 .91 

.87 

.89 .84 

.17 

d 

oc~t\~ 

pt\cJfiC 

93-40 

.83 

.76 .88 .61 

GULF OF ALASKA 

EXPLANATION 

Dominant granitic rock types: 

.30 

Quartz diorite 

18 

• Granodiorite 

.22 

Quartz monzonite or granite 

* Areas with significant amounts of quartz diorite 

present though not dominant 

Quartz diorite line (northern limit of "quartz diorite 

as the dominant granitic rock) 

Numbers refer to references on table 183.1 

.43 

• 51 .51 

50 0 50 100 150 MILES 

o c;:> o't:/ 

~0 0 

ALEUTiAN ISLANDs 020~~.,E.> ~ ~. _5) 

··"' """" -=r""'- 0 

FIGURE 183.1.-Dominant granitic rock types in some mapped areas of Alaska and adjoining parts of Canada . 

. " -.... 

0 

I 

00 

00 

0 

t".J 

0 

t"4 

0 

0 

~· 

t"4 

~ ~ 

< t".J 

~ 

~ 

t".J 

Ul 

t".J 

> 

~ 

n 

~ 

...... 

~ 

0) 

...... 
.,., 

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SHOHT PAPEHS IN THE GEOLOGIC AND HYDHOLOGIC SCIENCES, ARTICLES 147-292 C-89 

quartz diorite, .but is probably south of the Pribilof 

Islands. The line is subparallel to the arcuate pattern 

of the regionnJ structural elements of southern Alaska. 

By combining all the data on the position of the 

qt.uutz diorite line in northwestern North America, 

t-he line can be traced for more than 3,500 miles from 

t-he Gulf of California to Bristol Bay in the Bering 

Sen, (fig. 183.2). The quartz diorite line is approximately parallel to the west coast of North America, 

nnd especially to the inner edge of the continental 

slope. On the average, it is about 150 miles inland 

from the inner edge of the continental slope. 

Two prominent landward embayments are present 

in the trend of the quartz diorite line. In Alaska the 

line curves northward 300 miles from the continental 

slope, and in Oregon and Washington, the line curves 

eastward more than 400 miles. Both ·embayments are 

reflected in more subdued landward curves in the 

t-rend of the edge of the continental shelf. 

Although the embayment in Oregon and Washingt-on is only faintly reflected by the configuration of the 

coast line or of the inner edge of the continental slope, 

it is paralleled more closely by coast lines of the geologic past. The line representing the greatest transgression of seas of early Tertiary age ( d~tted line, fig. 

183.2) is deflected markedly into the embayment in 

'~Tashington and Oregon. Moreover, some evidence 

suggest-s that the· continental slope within this embayment may have been farther east than at present 

during early Tertiary time. Eocene rocks of the 

Olympic Peninsula in northwestern Washington are 

marine throughout; chiefly pillow basalt, thin-bedded 

graywacke, argillite, and red foraminiferal limestone 

with associated manganese deposits. Such an assemblage of rock~, and the absence of shallow-water sedimentary structures in them, suggest deposition in 

deep water, possibly on or beyond the continental 

slope. 

The quartz diorite line is approximately parallel to 

major Mesozoic and Cenozoic tectonic elements, such 

ns elongation of granitic intrusives, foliation of metamorphic rocks, axes of folds, and strike of large faults. 

Major Quaternary volcanoes are alined parallel to, 

and slightly on the seaward side of the line (see fig. 

183.2). 

It is evident from the relations described above and 

shown on figure 183.2 that the quartz diorite line i::; a 

fundamental feature of the western continental margin of North America. It trends approximately 

parallel to the edge of the continent as indicated today 

by its relation to the shore line and to the continental 

slope, and as indicated in the past by its relation to 

early Tertiary shore Jines. The difference in chemical 

1(}01530 0-61-7 

UNITED STATES 

ALASKA 

CANADA 

EXPLANATION 

Quartz diorite line 

Greatest extent of early 

Tertiary marine transgression 

rmrmmn Continental slope 

Dashed line outer edge continental shelf 

• • 

Major Quaternary volcanoes 

100 0 100 200 MILES 

FIGURE 183.2.-The position of the quartz diorite line in 

northwestern North America and its relation to other features of the continental margin. 
C-90 GEOLOGICAL SURVEY RE:SEARCH 1 9 61 

composition of granitic rocks on each side of the line 

is presumably inherited from chemical differences in 

the crust, which existed before the granitic rocks were 

emplaced (Moore, 1959). A possible explanation of 

this difference is that west of the quartz diorite line 

the crust was thinner than in the area east of it and 

composed of a larger percentage of eugeosynclinal 

sediments and volcanic rocks that are relatively rich 

in. sodi urn. The character of the Precambrian rocks 

west of the line is little known because exposures are 

extremely rare. However, the authors believe that 

Precambrian granitic rocks are practically nonexistent 

west of the line. If this is true, then the Mesozoic 

and Cenozoic granitic rocks there are largely in their 

first cycle, that is, they were emplaced in a basement 

containing nc older granitic rock. 

E~st of the quartz diorite line, before emplacement 

of the Mesozoic granitic rocks, the crust was probably . 

thicker and was composed of a larger percentage of 

platform-type sediments as well as great volumes of 

granitic rock. Thus, east of the line the crust was 

relatively rich in potassium relative to sodium. The 

Mesozoic and Cenozoic granitic rocks generated In 

this crust therefore contain a larger proportion of 

potassium feldspar relative to sodium-calcium feldspar than the granitic rocks of the continental border. 

Quartz diorite appears to be the dominant granitic 

rock encircling the entire Pacific basin. A detailed 

search has not been made of the literature to establish 

the position of the line in the southern or western 

Pacific. However, evidence at hand suggests that the 

line passes west of Kamchatka and between Japan 

and !Corea. A similar change in composition of granitic rocks seems to occur slightly north of New 

Guinea, and in northern New Zealand. The quartz 

diorite line probably lies from 200 to 600 miles on 

the outside (landward side) of the andesite line (Marshall, 1911, and Macdonald, 1949), and consequently 

the island arcs of the Pacific border are between the 

andesite line and the quartz diorite line. 

REFERENCES 

Buddington, A. F., 1927, Coast Range intrusives of southeastern Alaska: Jour. Geology, v. 35, p. 224. 

Macdonald, G. A., 1949, Hawaiian petrographic province: Geol. 

Soc. America Bull., v. 60, p. 1541-1596. 

Marshall, Patrick, 1911, Oceania: Handb. der Regionalen 

Geologie, v. 7, no. 2, 36 p. 

Moore, J. G., 1959, The quartz diorite boundary line in the 

western United States: Jour. Geology, v. 67, no. 2, p. 

198-210. 

184. PRODUCTION AND USE OF FRESH WATER FROM THE ASHLEY VALLEY OIL FIELD, UINTAH COUNTY, UTAH 

By R. D. FELTIS and H. D. GoonE, Salt Lake City, Utah 

Work done in cooperation with the Utah State Engineer and the Utah Oil and Gas Conservation Commission 

vVater produced in association with oil from wells 

in the Ashley Valley field, Uintah County, Utah, contains only 500 to 2,000 parts per million (ppm) dissolved solids-much lower than the total , in typical 

oil-field brines. At this relatively low salinity the 

water from the Ashley field is used for irrigation in 

and near the field; whereas typical oil-field brines 

must be disposed of by other means to prevent harm 

to plants and soils. 

The Ashley Valley oil field is on a 300-foot closure 

on the axis of the westward-plunging Section Ridge 

anticline in the north-central Uinta Basin (fig. 184.1). 

Oil is produced from the highly fractured Weber 

sandstone of Pennsylvanian age and the Phosphoria 

formation of Permian age at a depth of about 4,200 

feet. In 1960 the field contained 27 producing wells 

in about 1% square miles. The field· is under sufficient 

hydrostatic pressure to maintain flowing wells. 

The amount of water produced from the oil field 

has increased from 0 in 1948 to more than 18,700,000 

barrels (2,400 acre-feet) in 1960. The maximum water 

yield for an individual well during 1960 was about 

2,920,000 barrels (about 380 acre-feet). Since 1950, 

when the field became fully developed, the oil pro-

'-

.. 

.j, 

I 
o( 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-91 

r----~~~~---,---~R~.2~0~E~·---,,---~~~--~--~~~~--~--~~~~~~--~~~---,.---~R~-~2~5~E~·---, 

I 

I I 

I 

I~- 1 S. 

I 

.-"=-'lJ+./.Jol/;--~~~~~~~~~1~ ., 

EXPLANATION 

,...U 

• 

ms }~~ ~::J Nav&,Jo sandstone .0:: ~ 

1-z c( 

z 

c( 

Weber m sandstone J~~ z Ul z ::J 

w 0 

a.z ffi c( LL 

MissisSippian fZEl and ~~H ~ ~ ~ Pennsylvanian rocks ~ ~ 

undifferentiated ~ w -a. 

::Eo 

z 

c( 

,..-------.,.. 

Contact 

Dashed where approximately located 

Anticline 

Showing trace of axial 

plane and bearing and 

plunge of axis 

Syncline 

Showing trace of axial 

plane and bearing and 

plunge of axis 

---2500-....-... 

Structure contour 

Drawn on fhp of the 

Navajo sandstone 

0 6 MILES 

J T. 

. 2 

s. 

T. 

3 

s. 

IT. 

I s 

I S. 

FIGURE 184.1.-Generali~d geologic map of part of northeastern Utah, showing structure in the vicinity of the Ashley Valley oil 

field (T. 5 S., R 22 E.). Geology in ranges 19E-23E adapted largely from Kinney (1955, pl. 1), that in ranges 24E-25E :in 

part from Goodhue (1957, pl. 1, sheet 1). 

duction has remained between 730,000 and 1,400,000 

barrels per year, although the ratio of water to oil, 

and hence the water production, has increased. In 

1953 the water-to-oil ratio was 1.2 to 1 and by 1960 

the ratio had il1ereased to 13 to 1. Pumps were installed in several wells in 1959 and 1960 to increase 

oil production but their effect on the ratio of waterto-oil production is not known. 

The water-drive of the oil field is probably sustained 

by surface recharge in outcrop areas north and east of 

the field. Possibly the water comes not only from the 

oil-bearing strata but also from a sequence of underlying Pennsylvanian and Mississippian limestones. 

Thomas (1952, p. 12), in describing springs observed 

in Split Mountain Canyon said, "These springs rise 

from cavernous beds near the top of the Madison 
TABLE 184.1.-Chemical analyses of water samples from selected sources in Ashley Valley, Utah. 

Location 

Source of sample Section T.S. R.E. 

- I - ------

Pan American Petroleum 10. NE~SW~SE~ 22 

Pan American Petroleum L SE~SW~NE~ 22 

Pan American Petroleum L NE~SW~SW~ 23 

Equity Oil 7 --------------- SW,USE,UNW~ 23 

Equity Oil 1-9 (composite)_ 23 

Equity Oill'--------------- NE,UNW,USW,U 23 

Hollandsworth 1 ----------- NW~SW~SE~ 23 

Robert Six 1M ----------- SW~SE~SW~ 24 

Pan American Petroleum 2. NW~NW~N.E~ 26 

Pan American Petroleum 3_ NW~NE~NW~ 26 

-

.. 

Irrigation ditch _____________ NE~NE,U 22 

Union Irrigation Co. canal _ SE~SE~NW~ 25 

Oil_-field drainage ditch _____ NE~ 26 

Ashley Creek _______________ j NE.U 31 

NE~ 26 

1 Residue on evaporation at 180° C. 

z Includes 20 ppm COa 

3 Includes 10 ppm COa 

5 

5 

5 

5 

5 

5 

5 

5 

5 

5 

-

5 

5 

5 

3 

'Water from this well is included in the preceding sample 

~Includes 23 ppm COa 

+ -, --;., 

22 

22 

22 

22 

22 

22 

22 

22 

22 

22 

22 

22 

22 

21 

22 

... 

[Analyses by the U.S. Geological Survey and U.S. Bureau of Reclamation] 

Constituents in parts per million (ppm) 

Tern- Specific per a- con due- Na+K ture tance in I Bi- Date collected pH (degrees micro- Sil- Cal- Mag- car- Sui- Cblor- Bo- Ni- Fabren- mhos at ica Iron cium nesi- bon- fate ide ron trate beit) 25° c (Si- (Fe) (Ca) um Sodi- Potas- ate (SO,) (Cl) (B) (NOa) 

0:) (Mg) um sium (HC-

(Na) (K) Oa) 

Selected oil wells 

I Nov. 3,1959 8.1 112 829 19 ·----- 85 27 52 238 227 4.0 ------ 0. 5 

Nov. 4,1960 7.8 115 975 ---- 34 103 28 38 I 20 386 244 104 0.28 3.2 

Nov. 3,1959 7.9 120 1,860 20 .................. 155 38 198 340 519 108 ------ 3. 3 

Nov. 3,1959 8. 5 112 1,330 21 ------ 112 30 158 2 300 379 76 ------ .6 

Nov. 3,1959 8.4 -------- 1,350 19 ------ 116 36 152 3 283 399 86 ------ .0 

Nov. 3,1959 8.6 110 1,590 20 ------ 93 27 253 6 337 362 170 ............ -- .5 

Nov. 3,1959 8.0 -------- 2,560 27 ------ 109 31 547 518 615 372 ------ 2.6 

Nov. 3, 1959 7. 7 -------- 2,340 23 ------ 338 74 163 280 1,120 77 ------ .3 

Nov. 3,1959 8.0 115 2,460· 22 ------ 242 56 261 317 874 162 ............... 4. 1 

Nov. 4,1960 7. 4 120 1,830 20 .05 192 43 171 I 27 270 681 116 .44 .2 

---------

Oil-field drainage and irrigation ditches 

Nov. 4,1960 7. 7 -------- 1,340 18 0.03 128 31 1171 23 256 441 72 0.26 0.0 

Nov. 4,1960 8.0 -------- 2,940 10 .01 293 172 263 9.3 322 1, 590 72 . 57 19 

Nov. 3,1959 7.8 -------- 2,350 17 ------ 208 65 279 249 877 190 ------ 8.3 

I -

Natural surface drainage 

Mar. 14, 1956 ----- -------- 335 ---- ------ 45 13. 1. 8 1.2 6 151 40 3.6 ------ ------ May 24,1956 ----- -------- 102 ---- ------ 15 2.3 1.4 .8 45 13 .4 ------ ------ July 9,1956 ----- -------- 165 ---- ------ 23 4. 3 2.3 .8 89 6. 7 .4 ------ ------ Aug. 7,1956 ----- -------- 195 ---- ------ 27 5.0 1.2 .8 102 6. 7 ------- ------ ------ Sept. 17, 1956 ----- -------- 224 ---- ------ 24 8.2 2.1 .8 120 ------- ------- ------ ------ Mar. 14, 1956 ----- -------- 2,000 ---- -----· 227 117 104 3. 5 7 314 940 28 ------ ------ May 25,1956 ----- -------- 581 ---- ------ 61 26 22 2. 3 8 139 182 5.0 ------ ------ Aug. 7,1956 ----- -------- 5,300 ---- ------ 361 376 567 9.8 9 320 

Sept. 18, 1956 ----- -------- 4, 385 ---- ------ 326 311 427 8. 2 10 306 

3,130 115 ------ ----,-- 2,560 81 ------ ------

6 Includes 10 ppm C Oa 

7 Includes 22 ppm C Oa 

s IncludP.s 2 ppm COa 

9 Includes 3 ppm C Oa 

10 Includes 26 ppm C Oa 

., • y A-; f 

Hardness Per- as CaC03 cent Dis- sodi- solved Non- urn solids Car- car- (sum) bon- bon- ate ate 

~32 324 129 26 

11,060 372 55 17 

1,210 544 265 44 

925 404 158 46 

947 438 206 43 

1,090 344 68 62 

1,960 400 0 75. 

1,930 1,150 920 24 

1, 780 834 574 41 

1,410 656 435 35 

1950 446 236 35 

I 2, 770 1,440 1,170 28 

1, 770 784 580 44 

----- ----

I 197 ------ ------ 2 

175 ------ 6 

1100 ------ 6 

1113 ____ ._~._ 

------ 3 

1141 ------ ------ 5 

11,668 ------ ------ 18 

I 413 ------ ............... 15 

I 5, 500 ------ ------ 33 

4, 584 ------ ------ 31 

. Sodiurn- adsorp. 

tionratio 

-

1. 

3. 

3. 

3. 

5. 

12 

2. 

3. 

2. 

2. 

3. 

4. 

9 

4 

3 

0 

b 

tv 

0 

t:rl 

0 

t"4 

0 

0 

~ t"4 

~ ~ 

< t:rl 

~ 

~ 

t:rl 

[/1 

t:rl 

> 

~ 

~ 

~ 

co 

0) 

~ 
..( 

~-

{ 

( 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIEN·CES, ART~·CLES 147-292 C-93 

limestone, or possibly at the base of the Morgan formation." l-Ie considered these " * * * to be artesian 

springs, dependent on this high outcrop area [in the 

Uinta Mountains (fig. 184.1)] for recharge." 

In the Ashley Valley area these sources of water 

are about 2,000 feet deeper than the bottoms of the 

oil wells. Peterson ( 1957, p. 191) has described normn:l faults of 150 feet displacement that could have 

formed conduits between the Madison and Morgan 

formations, nnd the overlying oil-bearing rocks. 

AnnJyses of water from the Ashley Valley field are 

shown in table 184.1. It is principally a calciumsodium-sulfate water with bicarbonate as an additional important constituent. Few samples of water 

were collected for analysis before 1959, so it is not 

possible to determine whether a secular change has 

occurred in the dissolved solids or in the percent of 

ehemicnJ constituents. 

AltlH~ugh the sodium content of the Ashley Valley 

oil field water might preclude its use for irrigation in 

mttny nreas, this water can be used in Ashley Valley 

because the local soil contains gypsum derived from 

the underlying Mancos shale. Base exchange of sodium ions from the oil-field water with calcium ions 

in the soil prevents deflocculation of the soil and maintains its tilth. 

The water of Ashley Creek (table 184.1) is high in 

calcium, magnesium, and sulfate, presumably leached 

from the gypsum-bearing .soils by irrigation water. 

Thus, the water from the oil field, with its high content of sodium, may be used successfully either mixed 

with the water of Ashley Creek or used directly on 

soil containing gypsum. In some parts of the area the 

oil field waters contain less dissolved solids than water 

from the creek. 

It is possible that irrigation of gypsiferous soils 

with relatively fresh oil-field waters may be found 

practicable in other areas-particularly in the Rocky 

Mountain region, where this combination of conditions 

is more likely to occur or be approached than in most 

other parts of the county. 

- REFERENCES 

Goodhue, Betty, 1957, Geologic map of the Uinta Basin, Utah, 

in Intermountain Assoc. Petroleum Geologists Guidebook 

8th Ann. Field Conf., 1957. 

Kinney, D. M., 1955, Geology of the Uinta River-Brush 

Creek area, Duchesne and Uintah Counties; Utah: U.S. 

Geol. Survey Bull. 1007, 185 p., 6 pls., 13 figs . 

Peterson, V. E., 1957, The Ashley Valley oil field, in Intermountain Assoc. Petroleum Geologists Guidebook 8th Ann. 

Field Conf., 1957, p. · 191-192. 

Thomas, H. E., 1952, Hydrologic reconnaissance of the Green 

River in Utah and Colorado: U.S. Geol. Survey Circ. 129, 

32 p. 
C-94 GEOLOGICAL SURVEY RESEARCH 19 61 

185. RELATION OF THE DEEP AND SHALLOW ARTESIAN AQUIFERS NEAR LYNNDYL, UTAH 

By R. W. MowER, Fillmore, Utah 

Work done in cooperation with ihe Utah· State Engineer 

Ground water occurs in several aquifers in the vicinity of Lynndyl, Utah. There is one shallow 

perched water-table aquifer and at least two artesi~n 

aquifers. The perched aquifer is not related to the 

artesian aquifers and, because it is relatively unimportant, is not . discussed ·here. This investigation 

shows also that the artesian aquifers are not related. 

Well logs indicate that the many alternating beds of 

gravel, sand, and clay form two general aquifer groups 

(shallow and deep artesian aquifers), separated by an 

aquiclude consisting of about 400 to 500 feet of clay, 

silt, sand, and lenses of gravel (fig. 185.1). The upper 

group (shallow artesian aquifer) consists of 200 to 

250 feet of saturated material, about 75 to 150 feet of 

which is sand and gravel. The lower group (deep 

artesian aquifer) consists of about 200 to 300 feet of 

saturated material, about 75 to 135 feet of which is 

sand and gravel. The relation of the shallow and deep 

aquifers to the sand and gravel lenses in the aquiclude 

is not known', although well logs indicate that they 

probably are not related. 

The irrigation wells drilled in the vicinity of Lynndyl during 1951-58 were completed in the shallow artesian aquifer. Water levels in the wells declined 

progressively during that period. In the fall of 1958 

an irrigation well was drilled into the deep· artesian 

aquifer. Limited testing at that time indicated the 

presence of a considerable ground-water reservoir that 

apparently was not related to the shallow artesian 

aquifer. 

Pumping tests and an extensive observation program began in the fall 1959 and continued through 

1960 to determine the relation of the shallow artesian 

aquifer to the deep artesian aquifer and to determine 

if all shallow wells actually were completed in the 

same aquifer. 

The deep artesian well ( C-15-5) 26baa-1 (fig. 185.2) 

was pumped continuously for 27 days during N ovember and December 1959, and water-level measurements 

were made in selected wells completed in the shallow 

aquifer within a radius of 8 miles. Water-level 

measurements for the pumped well and for several 

representative wells are plotted on figure 185.3. These 

hydrographs show no measurable decline of water 

levels in wells completed in the shallow aquifer, 

caused by p'umping the deep well. The slight irregularities in the hydrographs are due chiefly to fluctuating atmospheric pressure. After correcting for 

atmospheric pressure changes and this rising waterlevel trend, a maximum of 0.03 foot of decline remains 

to be accounted for. This amount is within the limits 

of accuracy of the water-level measurements, the 

corrections for atmospheric pressure changes, and data 

plotting. 

Interpretation of the recovery data for the deep well 

indicates that the coefficient of transmissibility (T) in 

the vicinity of the deep aquifer is 57,000 gpd/ft 

(gallons per day per foot). In another deep well 

(C-16-5)19cbd-1, about 6 miles to the southwest of 

(C-15-5) 26baa-1, the coefficient of transmissibility 

was 34,000 gpd/ft. The coefficient of storage (S) 

could not be determined in either test of the two deep 

wells because there were no deep observation wells. 

Tests in the shallow aquifer show an average T of 

300,000 gpd/ft and an average S of 3.3 x 10-4 • A 

consideration of the differences in the material in the 

two· aquifers suggests that the coefficient of storage for 

the deep . aquifer should be less than for the shallow 

aquifer, and for purposes of argument S for the deep 

aquifer is assumed to be about 10-4 • Calculations 

using aquifer constants T equals 57,000 gpd/ft and S 

equals 10-4 suggest that if the observation wells and 

the pumping well (C-15-5)26baa-1 had been completed in the same or connected aquifers, the water 

levels in the observation wells should have declined 17 

to 23 feet after 27 days of pumping. The hydrographs in figure 185.3 show no decline in water levels 

in the observation wells during the period Nov. 24 to 

Dec. 22, when well (C-15-5)26baa-1 was being 

pumped. 
'. 

t 

~· 

;-

~· 

~-

SHORT. PAJ»ERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-95 

(C-14-5) 

35cdc-1 

"

0 0 0 0 II 0 0 0 0 

0 0 0 0 

Gravel 

mil 

Sand 

I:::::=:::J 

~ 

Silt 

D 

Clay 

H~~~t~ Gravel and sand 

Gravel 

~ 

~ and clay 

~f~'·tt;.tt 

~ii:A.1 

(C-15-5) 

13bbc-1 

Gravel, sand, and clay 

Sand, • silt, and clay 

j:

oooooJ 0 0 0 0 

0 D 0 0 

Bar beside log 

represents casing 

perforations 

:.:;.;.:~tP.?~ 0 0 0 0 

0 0 0 0 

-~!f:~~r- 4300 

_r-

~~~ _-- --f--- 4200 ---

-11~4100 

l!...,IOURE 185.1.-Grnphic logs of representative wells. 

A pumping test was made in the shallow aquifer 

during April 1960, using well (C-15-5)2ddc-1 as the 

pumped well. and observing water levels in the other 

shallow wells and in the deep well ( C-15-5) 26baa-1. 

No measurable effect was observed in the deep well 

but within 2 hours measurable effects were observed 

in all the shallow wells within a radius of 31/2 miles. 

'iV ater levels in 16 wells were measured at least 

monthly during 1960. Hydrographs for 5 selecte4 

wells are shown in figure 185.4. The shallow irrigation wells were pumped intermittently during the 1960 

irrigation season, April to September. Water levels 

in the shallow wells reacted to the intermittent pumping, as shown by the fluctuation of the hydrographs 

in figure 185.4. The deep well was turned off purposely for 2 weeks during July to make additional 

measurements of possible interference between it and 

the shallow artesian wells. Again no measurable effects were noted. 

It is concluded that if the deep and the shallow 

aquifers are related, it is to such a small degree that 

interference between them can be considered nil, and 

that the deep aquifer can be developed with no detrimental effect on the shallow aquifer, at least within 

a radius of 8 miles of well (C-15-5)26baa-1. 

0 3 MILES 

FIGURE 185.2.-Map showing locations of selected wells in 

the Lyrindyl area, Utah. 
C-96 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

· November December 

5 10 15 20 25 10 15 20 25 

DEPTH, 

IN FEET 

14 L I c 0 1 10 0 I 0 0 0 I 0 

15 

0 0 (C 15-4~8cbb 1 ~I ~ 

::k I (C-15-4)18daa-l r I· ·I I· ·I ~ 0 0 0 0 0 

146 

I 0 

:::I I (C-15-4 )20dcc-l 

~ I· ·I 0 I 0 

I· 

0 0 

125 I o ·I 1 99- I . I . I 100~ j I (C 

15 5)2ddc 1 ~ . I 0 

r 0 0 0 

101 

:I I (C-15-5)13bbc-l 

0 0 I· 98 I . I I . . I 1 

+10 

0 - .-a.!!! 

10 ~ --- 20 

30 

40 

(C-15-5)26baa-1 

50 

60 

70 

80 

90 

~~ 100 

E'IGURE 185.3.-Hydrographs of selected observation wells, November and Decemb~r, 1959. (Locations of wells shown ·on tigure 

185.2.) 

f. 

4r 

~ 

).. 

"' 
I 

r' 

1 

... 

7· 

J, 

... 

~-

~ 

t 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-97 

DEPTH, 

IN FEET 

~F r ~· ~_j ~ I IF I I 01 -1: 0 

: (C-15-4)8cbb-1 ...0.. o----

::c 10 I. tt I I I;J I .:t/· t--· I 01 ;C-15-4)18daa-1 ~ 0 0 

0 170 

120 I 0 I c oct- -I 0 I I ~ r I ~ ... p 0 g 0 0 

140 : (C-15-4 )20dcc-l 

:~r I:C-15-5)1~b~-1 ~~~~~I ~ ocj~ I 

~---ol I 

01 

-o- 130 0 

+10 

- 0 

10 

20 

30 

~ 

,..._,. ~ I~ II 

I: 

I 40 

50 (C-15-5)26baa-l i 

I 60 

70 

80 

I 

: 90 

100 

110 

\ ! 

\. I.... ..... ' J 

- lo\.. --~ 

l!'wum~ 18G.4.-Hydrogrnphs, dashed where inferred, of selected observation wells, 1960. (Locations of wells shown in figure 

185.2.) 
C-98 GEOLOGICAL SURVEY RESEARCH 19 61 

186. A REINTERPRETATION OF TWO OF G. K. GILBERT'S LAKE BONNEVILLE SECTIONS, UTAH 

By DAVID J. VARNES and RICHARD VAN HoRN, Denver, Colo. 

Unconformities generally are not well displayed 

within the deposits of Pleistocene Lake Bonneville. 

Therefore, the history of the lake, especially its early 

part, must be inferred from isolated fragments of 

positive evidence. Perhaps a dozen or so definitive 

areas of exposures are now known. Some were first 

studied by G. K. Gilbert, and several of these localities are still of prime interest 70 years after his classic 

work. 

Gilbert (1890, p. 188-200, 259-262) based a reconstruction of the principal oscillations of the lake 

largely upon interpretation of the stratigraphic record 

at three critical localities in west-central Utah. These 

are the exposures of lake beds at (a) Leamington, 

where the Sevier River issues westward from the Canyon Range, and at (b) the upper and (c) the lower 

parts of the Old River Bed. The Old River Bed is a 

northwest-sloping valley, 25 to 60 miles northwest of 

Leamington, that once connected the Sevier body of 

Lake Bonneville with the main body. The lake cycles 

inferred from these stratigraphic sections were shown 

schematically in Gilbert's figure 30. 

Reexamination of the Leamington and lower Old 

River Bed localities has led us to conclusions that 

differ somewhat from those of Gilbert. The upper 

Old River 'Bed section is informative but complex, 

and we believe that it deserves detailed study before 

Gilbert's interpretation can either be confirmed or 

revised. 

Dark-colored sandy gravel is exposed sporadically 

for about 8 miles along the east side of the Old River 

Bed from just north of the Shutoff, shown on the 

Coyote Springs, Utah· topographic sheet, northwestward to the southern boundary of the Dugway Proving Ground, Tooele County, Utah. This gravel caps 

remnants of a strath terrace along the valley. Trenching done by us in 1957, and in company with R. B. 

Morrison in 1960, demonstrated the presence of similar 

sandy gravel in place, at the level of the terrace, but 

within the adjacent Lake Bonneville deposits. The 

gravel fills a channel cut in and covered by finegrained beds that Gilbert called Yell ow Clay, and 

which we regard as equivalent to part of the Alpine 

formation. 

The base of the gravel in the Yellow Clay is 4,455 

feet above sea level, where trenched in the NE~SE~ 

sec. 1, T. 10 S., R. 10 W. ·(Table Mountain, Utah 

topographic sheet). It drops to an altitude of 4,420 

feet 3lf2 miles to the northwest, and appears to rise to 

an altitude of about 4,520 feet 4 miles to the southeast. 

The gravel is typically 5 to 15 feet thick, is crossbedded, and contains a few cobbles as much as 4 inches 

in diameter, although more than one-half the material 

is medi urn to coarse sand. The pebbles are mostly of 

volcanic rocks, quartzite, and chert. The sandy gravel 

rests on olive to gray silty clay and grades upward 

into sand. The sand is overlain by silty clay arid 

interbedded silt and sand, on which lies about 5 feet 

of typical White Marl. The base of the ·white Marl 

at the locality of the trench is about at altitude 4,493 

feet and is in many places marked by an unconformity 

and a few inches of pebble and cobble gravel. The 

marl is overlain by 6 or 7 feet of gray silt, overlain 

in turn by 10 to 15 feet of gravelly sand that has been 

reworked into dunes. 

At some places the present Old River Bed lies outside of the older gravel-filled channel. Here the 

gravel within the Yellow Clay is missing, and Gilbert 

evidently recorded his typical lower Old River Bed 

section in one of these areas. He mentions, however, 

that. "In this [the Yell ow Clay] are occasional passages of sand, but these are local and discontinuous" 

(Gilbert, 1890, p. 190). Gilbert's field notes covering 

several visits to the Old River Bed indicate that he 

observed and dug out gravels in the Yellow Clay near 

the upper Old River Bed section, but he interpreted 

the larger bodies downstream as terrace cappings of 

post-White Mar 1 age. 

Stratigraphic studies at and near Leamington disclosed two gravels, rather than one, within the Lake 

Bonneville sediments that were deposited prior to the 

White Marl or its equivalents. (See fig. 186.1). At 

Leamington the thicker and lower wedge, at an altitude of 4,955 feet, is the gravel that Gilbert ( 1890, 

p. 192, fig. 28, unit 3) placed between the Yellow Clay 

and White Marl. We believe that this gravel lies 

wholly within the upper part of the Yellow Clay or 

Alpine formation, and that a similar but thinner and 

higher gravel at altitude 5,002 feet marks the drop 

in the lake between the epochs of the . Yell ow Clay 

nnd the White Marl. The upper gravel at Leamington 

is overlain by a few feet of light-colored diatomaceous 

and calcareous sand that contains a layer of black 

basaltic ash. This is overlain by sand, and the de-

·t 
+ 

. I~ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-99 

5200' w. 

5100' 

sooo' 

4900' 

Gl LBERT (1890) 

Bonneville shoreline --5ii'4.6-f'eel.---

White 

marl 

Alluvial __ _9!,<!_V~.!__ ____ _ 

Yellow cloy 

E. 

THIS PAPER 

Quartzite 

0 100 200, FEET 

I~IOUit~: 186.1.-Ding•·mnmutic sketch of Luke Bonneville deposits adjacent to the mountain front northeast of Leamington, Utah, 

showing the differing interpretations of Gilbert and the authors. Pre-Lake Bonneville deposits are quartzite; ot, old talus; and 

on, old nlluyinl fun. Lithology of luke deposits is indicated by gr, gravel; ss, sand; m, diatomaceous sandy marl; -c;-clay; 

cs, <:lnyey silt; nnd ss-s, interbedded sund and silt. Post-Lake Bonneville young talus and alluvium are shown by yt and- ya. 

Gilbert's nltitude for the Bonneville shoreline is derived by adding his difference in elevation from the railroad at Leamington, determined by spirit level, to th~ modern U.S.C.&G.S. altitude of the rails. 

posits are c~tpped by beach gravel at altitude 5,046 

feet. The ash, which has been found associated with 

White M~trl at many places in the LeamingtonLynndyl-Oak City· area, occurs not only in beach 

deposits but also in the upper part of the basin sediments. "r e believe that the 'Vl1ite Marl and ash were 

deposited during the rise of the lake from the AlpineBonneville recession to the highest or Bonneville level. 

It is not possible to demonstrate conclusively that 

the gravel within the Yellow Clay at the lower 

Old River Bed and the lower of the two gravels at 

Len.mington are equivalent, because exposures are not 

continuous between the two localities.· The general 

sequence of beds is quite similar, although the Leamington section is somewhat coarser owing to its position at the head of a major delta. The gravel in the 

Alpine at Leamington can be trace.d about 3 miles 

westward, away from the shoreline, by a discontinuous 

thin line of well-rounded beach pebbles and cobbles 

within the enclosing beds of silt a.nd clay. 

The Yellow Clay or Alpine formation generally 

comprises more than three-fourths of the Lake Bonneville deposits. The lake apparently had no outlet 

during this long early period. Fluctuations in water 

level in response to imbalance between inflow and 

evapoi:ation were inferred by Gilbert from a study of 

the Intermediate embankments. These fluctuations 

are confirmed by the stratigraphic record in the Leamington-Delta area, which indicates three periods of 

high water prior to the recession between the deposition of Yell ow Clay (or Alpine formation) and White 

Marl. vVe believe that one of the recessions in Alpine 

time, perhaps the fall between the second and third 

high-water stages, may be of a magnitude comparable 

to the Alpine-Bonneville and later· major recessions. 

REFERENCE 

Gilbert, G. K., 1.890, Lake Bonneville: U.S. Geol. Survey Mon. 

1, 438 p . 
C-100 GEOLOGICAL' SURVEY RE'SEARCH 1961 

187. REVISION OF STRATIGRAPHIC NOMENCLATURE OF CAMBRIAN ROCKS, NEVADA TEST SITE AND 

VICINITY, NEVADA 

By HARLEY BARNES and ALLISON ·R. PALMER, Denver, Colo., and Washington, D.C. 

Work done in cooperation with the U.S. Atom·ic Energy Commission 

Re-evaluation of lithologic data and consideration of 

new paleontologic data suggest that stratigraphic 

units in a thick sequence of rocks of Cambrian age 

exposed on the Nevada Test Site (fig. 187.1) have 

been miscorrelated with units in other parts of southern Nevada. Therefore, a revision of the stratigraphic 

nomenclature used by Johnson and Hibbard ( 1957) is 

desirable. Figure 187.2 gives a generalized geologic 

section and a comparison of stratigraphic names. 

WOOD CANYON FORMATION 

The oldest rock known to crop out on the test site 

is a sequence of quartzite and shale. correlated by 

J'ohnson and Hibbard ( 1957, p. 336) with the Stirling 

quartzite of Nolan (1929, p. 463) but in the present 

114° r---------~~--------+---------~42° 

38° 

' ,. 

' 

SP 

SPRING 

N 36° 

' ' '.> 

0 50 100 150 200 MILES 

FIGURE 187.1.-lndex map of Nevada showing Nevada T~st 

Site and· other localities. 

report correlated with the Wood Canyon formation of 

. Nolan (1929, p. 463, 464). Our decision to correlate 

these rocks with the Wood Canyon formation is based 

on a comparison of their lithology with that of the 

corresponding sequence of rocks in the Desert Range, 

45 miles southeast of Banded Mountain, and with the 

lithology of the Stirling quartzite and Wood Canyon 

formation at the type locality in the northwest Spring 

Mountains (fig. 187.1). At its type locality, the 

Stirling includes thick sequences of quartzite containing abundant lenses of pebble and cobble conglomerate; the Wood Canyon at its type locality also 

contains much quartzite but with little conglomeratic 

material, essentially none of cobble size. In addition, 

the Wood Canyon contains more quartzitic sandstone 

and sandy shale than the Stirling. It also contains 

a few thin limestone beds, whereas the Stirling does 

not. The rocks that crop out on the test site 2 miles 

north of Banded Mountain are chiefly quartzite with 

a few lenses of pebble conglomerate, much interbedded 

sandy shale, and a few thin beds of limestone. 

Because of faulting the thickness of the Wood Canyon formation cannot be determined on the test site, 

but a thickness of more than 1,200 feet is exposed. 

Nolan (1929, p. 463, 464) reports 2,ioo feet in the 

northwestern Spring Mountains, and Clark Burchfiel 

(oral communication, 1960) reports 2,200 feet in the 

Specter Range. 

CADIZ, CHAMBLESS, AND LATHAM FORMATIONS 

Above the Wood Canyon formation is a 1,000-foot 

sequence of interbedded shale and limestone with a 

few thin sandstone beds in the lower part. Johnson 

and Hibbard (1957, p. 337-340) correlated the lower 

part of this sequence with the upper part of the Pioche 

shale, the Lyndon limestone, and the Chisholm shale 

of the Pioche district (fig. 187.1); they named the 

next higher 275 feet the Jangle limestone; and they 

placed the top of the sequence, a silty and shaly limestone unit 50 feet thick, in the lower part of their 

newly -defined Yucca Flat formation. 

This sequence is faulted and poorly exposed on the 

test site where it crops out 2 miles east of Banded 

·Mountain, but fossils recently collected from these 

beds indicate that the Chisholm shale, Lyndon lime-
j., 

1 

+ 

<, 

-I 

~-

.1 •. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

GENERALIZED JOHNSON AND HIBBARD, 

AGE THIS PAPER GEOLOGIC 1957 

z 

<{ 

-

0:: 

co 

~ 

<{ 

u 

'-

Q) 

a. 

a. 

::::> 

1-?-

Q) 

-

"0 

"0 

·-

~ 

Formation 

Windfall 

formation 

Dunderberg shale 

Bonanza King 

formation 

Member ~~~~~~~~ SECTION Informal 

subunit 4 

/ I / I 1/ /j 

/ / 

Smoky member / I / I / C-D 1/ I /I 

/4 

/ / 

f------ A 

............ 

Catlin member B 4 4 

4 4 ... . . '1' ····"A···-

+ ·i· ... 

3 D 

---···· .. ·····-

2 c 

······· .......... / L / / _l J I I 

Banded Mountain / / / 

member / / / / 

V/ / / 

1 _L_/ / / v / / / \ 

/ / / / 

J I I 1\ 

------ - -!~-/ / / ·=-~-~-3·=--~/ /..., 

Papoose Lake 

1/ / / /1 ////1 B L _L / / 

L L / 

L ~ / / / / / / / 

/ / 

/ / / / / / / / / / / 

Formation 

Upper Cambrian rocks 

t:: 

ro 

c. 

>Q; c. 

c. 

::::> 

Dunderberg shale 

Yucca Flat 

formation 

EXPLANATION 

Limestone 

Dolomite 

Limestone or dolomite 

Silty limestone 

Shale 

Quartzite or quartzitic 

sandstone 

0 0 0 0 

l

""oool 0 0 0 

oQOC)O 

member Conglomerate 

/ / / 

/ / 

/ 

.......... 

I A 

.......... I J J _l _j Q) .... 

I I I I _j >~ ~ ... ···-··· ... Jangle limestone 1-·f. ~----+ ... +--{" 

Cadiz _ ~~ber ___ j-~--~~-t-~~-~-~>---~J~a~ng~l~e~li~m~e=s~to~n~e--~ formation · · · · · =:::-:::;1 -?-~------~---------f~=-~-r-~==T-==:~~~,-~=~.---C_h_i_sh_o_lm_s_h_a_le __ ~ Chambless limestone 

Latham shale 

Wood Canyon 

formation 

Stirling quartzite (Not exposed in · 

test site area) 

I I I I !_ 

t---- -l. 

. . . .... 

--~--~·-·.·.~-~{ 

·.·.·.·.·.·.·.·.· .) 

Lyndon limestone 

Pioche shale 

Stirling quartzite 

(Not exposed in 

test site area) 

Chert in limestone or dolomite 

C-101 

]j"'muRE 187.2.-Revision of stratigraphic nomenclature of Cambrian rocks in area of Nevada Test Site, southern .Nevada. 
C-102 GEOLOGICAL SURVEY RESEARCH 19 61 

stone, and upper part of the Pioche shale of Johnson 

and Hibbard are older than, and do not correlate with, 

the corresponding units in the Pioche district. Shale 

in the lower part contains the olenellid trilobite Bristolia and is of late Early Cambrian age. It correlates 

with the Latham shale (Hazzard, 1954) in the Providence Mountains, California. This shale, mapped 

as the upper part of the Pioche by Johnson and 

Hibbard, is chronologically equivalent to the lower 

part of the Pioche in the Pioche district. The Lyndon 

limestone of Johnson and Hibbard is miscorrelated 

and as mapped seems to inelude limestone of more 

than one age. A thick lower limestone with abundant 

Girvanella is probably of late Early Cambrian age 

and correlates with the Chambless.limestone (Hazzard, 

op. cit.) and the Combined Metals member of the 

Pioche shale in the Pioche district. A thinner limestone also mapped as Lyndon is of earliest Middle 

Cambrian age. It contains trilobites of the Kochaspis-

~lagiura zone, a fauna found in limestone beds just 

above the Combined Metals member of the Pioche 

shale at Pioche. Both of these limestones are older 

than the Lyndon limestone at Pioche. The overlying 

Chisholm shale of Johnson and Hibbard at the test 

site contains an Albertella zone fauna of early Middle 

Cambrian age which is characteristic of the upper 

part of the Pioche shale at Pioche. Above the Jangle 

lim~stone as mapped by Johnson and Hibbard is a 50-

foot brown-weathering sequence of silty limestone that 

Johnson and Hibbard included in the lower part of 

their Yucca Flat formation. Glossopleura, characteristic of the upper part of the Cadiz formation elsewhere in the region, and of the true Chisholm shale, 

has been found in this brown-weathering silty sequence, which is here included with the Jangle limestone and the underlying "Chisholm shale" in the 

Cadiz formation. The Jangle limestone as mapped 

by Johnson.and Hibbard is recognized as a member of 

the Cadiz formation in the Nevada Test Site. 

The Wood Canyon and overlying Latham shale 

compose a lithologically transitional \Sequence and 

their contact is therefore arbitrary. We suggest the 

contact should separate the lower sequence' of interbedded shale, quartzite, and sandstone from the upper 

sequence of interbedded shale and limestone. Therefore, we place the contact at the top of the highest 

thick quartzite or quartzitic sandstone in the sequence. 

This is the approximate horizon at which Nolan ( 1929, 

p. 463, 464) placed the top· of the Wood Canyon in 

the northwestern Spring Mountains, except that he 

put the uppermost 20-foot bed of quartzite in an 

ove;rlying formation correlated with the Bright Angel 

shale. Because of the transitional nature of the con.: 

tact the upper part of the Wood Canyon formation 

includes some thin beds of limestone and the lower 

part of the overlying Latham shale includes some thin 

beds of sandstone. 

BONANZA KING FORMATION 

Between the Cadiz formation and the Dunderberg 

shale is a carbonate sequence about 5,150 feet thick 

called by tTohnson and Hibbard (1957, p. 340) the 

Yucca Flat formation and here correlated with the 

Bonanza King formation of Hazzard and Mason 

( 1936, p. 234, 235) as redefined by Palmer and Hazzard ( 1956). The Yucca Flat formation on the test 

site and the Bonanza .King formation in the Nopah 

Range (fig. 187.1) are lithologically similar and occupy essentially the same stratigraphic interval. In 

view of this and in view of the fact that the term· 

Bonanza King has priority, we are substituting Bonanza IGng formation for Yucca Flat formation as the 

name for the carbonate sequence on the test site. The 

term Yucca Flat, is therefore, abandoned. 

The Bonanza King formation on the test site consists of limestone and dolomite, parts of which are 

silty and sandy. A persistent brown-weathering siliceous carbonate sequence about 40 feet 'thick occurs 

37"15' 

ol ~ 

I 

I 

!~ 0 5 10 MILES 

CONTOUR INTERVAL 1000 AND 200 FEET 

FIGURE 187.3.-Index map of part of Nevada Test Site showing location of measured sections: 1, 2, Bonanza King formation; 3, Dunderberg shale and Windfall formation; 4, 

Windfall formation. 

t 
' ... 

SHORT PAPERS IN THE GEOLOGIC AND HYDR9LOGIC SCIENCES, ARTICLES 147-292 C-103 

nbou t 2,400 feet below the top of the formation and is 

here used as the lithologic basis for subdividing the 

unit into two members. The lower . member is here 

nnmed the Papoose Lake member (fig. 187.3), after 

the plnya 9 miles east of Banded Mountain, and the 

upper member is named the Banded Mountain member, after the area of its most conspicuous exposure. 

The location of measured sections is shown on figure 

187.3. The brown-weathering siliceous carbonate sequence is included in the Banded Mountain member 

and is believed to be the equivalent of a regional key 

unit that contains the trilobite "Ehmania?" in the 

Desert Rnnge, Spring Mountains, and Nopah Range. 

This key unit is correlated with unit 7A of Hazzard 

(1937, p. 277) in the Nopah Range. Most of the 

Bonanzn ICing formntion is of Middle Cambrian age 

but at least the top 300 feet, and probably the top 

700 feet, is of Late Cambrian age. 

DUNDERBERG SHALE 

The Dunderberg shale was described by Johnson 

and Hibbard (1957, p. 342) as "brown and reddishbrown hard, fissile, nonresistant shale" with interbedded dark-gray fine-grained fossiliferous limestone. 

.It is a distinctive lithologic unit, here 223 feet thick. 

WINDFALL FORMATION 

The rocks between the Dunderberg shale and the 

Pogonip group of Ordovician age are a previously UJlnamed carbonate sequence about 1,785 feet thick. This 

sequence is .here correlated with the Windfall formation .of Nolan, Merriam, and Williams (1956, p. 20) 

in the Eureka district. The formation is divided into 

Catlin and Smoky members. It is described in greater 

detail by Barnes and Byers (Art. 188, this volume). 

REFERENCES 

Hazzard, J. C., 1937, Paleozoic section in the Nopah and 

Resting Springs Mountains, lnyo County, California: California Jour. Mines and Geology, Rept. 33, State Mineralogist, p. 273-339. 

-- 1954, Rocks and structure of the . northern Providence 

Mountains, San Berna:fdino County, California; in Geology 

of southern California: California Div. Mines Bull. 170, 

p. 27-35. 

Hazzard, J. C., and Mason, J. F., 1936, Middle Cambrian 

formations of the Providence and Marble Mountains, California: Geol. Soc. America Bull., v. 47, no. 2, p. 229-240. 

Johnson, M. S., and Hibbard, D. E., 1957, Geology ·of the 

Atomic Energy Commission Nevada Proving Grounds 

area, Nevada: U.S. Geol. Survey Bull. 1021-K, p. 333-384. 

Nolan, T. B., 1929, Notes on the stratigraphy and structure 

of the northwest portion of Spring Mountain, Nevada: 

Am. Jour. Sci., 5th ser., v. 17, p. 461-472. 

Nolan, T. B., Merriam, C. W., and Williams, J. S., 1956, ·The 

stratigraphic section in the vicinity of Eureka, Nevada: 

U.S. Geol. Survey Prof. Pf:tper 276, 77 p. 

Palmer, A. R., and Hazzard, J. C., 1956, Age and correlation 

of Cornfield Springs and Bonanza King formations in 

southeastern California and southern Nevada: Am. Assoc. 

Petroleum Geologists Bull., v. 40, no. 10, p. 2494-2499. 

188. WINDFALL FORMATION (UPPER CAMBRIAN) OF NEVADA TEST SITE AND VICINITY, NEVADA 

By HARLEY BARNES and F. M. BYERS, Jn., -Denver, Colo. · 

Work done in cooperation with the U.S. Atomic Energy Commission 

l'he sequence of carbonate rocks lying between the 

Dunderberg shale and the Goodwin limestone on the 

Nev.acia Test Site (fig. 187.1 of ·Barnes. ~nd. Palmer, 

Art. 187) is correlated with the Windfall .formation 

that wns originally described by Nolan, Merriam, and 

Williams (1956,, p. 19-22) for the Eureka ·district. 

These_ rocks crop out in the Smoky Hills north of 

Yucca Flat, on Teapot Ridge.and Paiute Ridge east 

of Yucca Flat,. in the: Specter Range in the southern 

part of the test .site, and -:at Bare Mountain west of the 

site. Johnson and Hibbard (1957, p. 343) referred 

to these beds on the test site as unnamed Upper 

Gambrian rocks and assigned to them an estimated 

thickness of 2,660 feet. ~{ore recent detailed measurements, however, show a total thickness of about 1,785 

feet (fig. 188.1) . 
C-104 GEOLOGICAL SURVEY RESEARCH 1 9 61 

/ / / 

L .... / ~ . 

/ ,@D/ 

FEET Top of section 

-e--~ / / 

ca: ~ A:~ 

. . . / 

/ / 

.. / 

1800 i='=i=R ((G oodwin 

li mestone) 

L L / ~ /r / 

:c-:: 

<;::=D ® 

l @) 

~I . I (§) 

= . . i.._ .. 1 .... • ... .... - ~ .. 1700 

-I I 

I @ 

., I .) 

I / 

/ / / -/ 

/ / 

1600 / A:n / 

= / / 

/ / 

/ ., 

• .. ... -- -. --- v / / I / C> / •/ 

/ / / 

/ S::=::> 

/ ccs::y A 

/ / ~ 

/ /@:) 

1500 / / 

~ep / I 

Shale 

Nodules and lenses 

Chiefly siliceous carbonate, 

some chert 

Q) 

..0 

E 

Q) 

E 

>. 

~ 

0 

E 

(/) 

1400 / / / 

~ / / 

/@/.:.. @)/} 

• 

/. / 

/ / /1 

L / / 

1300 

" 

/ 

/ / 

/ / 

L / / 

/ / 

/ / / / 

1200 ~~/ J 

1/ /@/ / c:§7 / ~·v-~-L-

/ / 

/ / 

/ / / / / / 

/ 

/ / 

/ / / / / 

Silty limestone 

Nodules and lenses 

Chiefly chert, some 

siliceous carbonate 

Q) 

..0 

E 

Q) 

E 

>. 

~ 

0 

E 

(/), 

1100 

ty-·· 7 ·y 

/ / / 

L L / ~ 

/ /CS2>/ 

~-~ 

f/ / / 

/ / / 

L / L 

1000 .... 

L L / 

-

/ / 

/ / 

/ / 

/ / / / 

/ / 

900 /"' / L / 

v / / / / / / / / 

/// 

/ / 

L~ / 

// / / 

.... / 

/ / --- // 

ftv/ 

/ .. / 800 

L / /1 ... / / 

/ / /1 

/s9)/1 

/A A:=J / 

/ / .... 

/&/y£ 

Q) 

..0 

E 

Q) 

E 

>. 

~ 

0 

E 

(/) 

600 

500 

400 

.EXPLANATION 

EE8 

Limestone 

~ Dolomite 

-

-

-

Q) 

Cl) 

0 

.. 

~ 

-==> .... ·,~c ~... ·~~ 

1"'-:L_-=~e, 

~ ... ·-r·--r-\ 

~_!_.EXT 

.Ai I I 

"'I J .... I..-~ 

I I I 

I I• I 

C> 

"=> -===- c::> 

P. {:=-! ~II 

<== 1-==r-" ' ~ 

. ..... .. .. .. <::» .. ... .. .. .. .. 

I I <?>-

c:r- -=~ 

r.& .... .. . .... - lJ I I I ... ........... - .... 

.. I I I I 

1•.1 I .. I ... .. lJ I I ... I-I .... .. I I I .. .. ... ..... ..... ... 

-.;::~ 

11'::'1 ~ <?J 

300 I i I=¥ --!. 

3541-CO 

-

I I I II 

-._,_,_ "'i=· .. r=, ... ;-:-=r T{... ... .. 

200 --=':-::r_··· -,- ._, Q) Q) 

..0 ..0 

E E Q) Q) 

E E 

c 

--¥.~ ::: .... ···~···.~-·.,-'-

-::=-~-. 

~:"'::.c.:1.~ 

100 B 

~ 

,::r:--.. ~-· 

~:;~ 

3540-CO 

c 

Ill· 

u 

3539-CO 

.••. -- · 3538-CO 

••. ...L-··~·-· . ...1-:1 

:o .,. _..,. 1 ~;:, 3537-CO 

0 ~ --- ~~~~(Dunderberg shale) 

......, ""V\/ 

Base of section 

Wavy or nodular 

bedding 

~ 

~ - 3540-CO 

Large stromatolites Small stromatolites, 

"Girvanella" 

Covered Probabw lithology shown 

Horizon and number 

of USGS fossil collection 

FIGURE 188.1.-Section of Windfall formation, Nevada Test Site; Catlin member measured on Teapot Ridge (loc. 3, fig. 187.3, 

Art. 187), Smoky member measured on Paiute Ridge (loc. 4, fig. 187.3, Art. 187). 

The lower part of the Windfall formation at the 

test site is about 715 feet thick ~nd is considered to be 

the Catlin member because of its lithologic similarity 

to the type Catlin, which is about 250 feet thick at 

Eureka. At Eureka the Catlin is characterized by 

thin-bedded platy and sandy limestone alternating 

with ledge-forming thicker bedded limestone, and by 

an abundance of thin-bedded chert in the lower part 

(Nolan, Merriam, and Williams, 1956, p. 20). At 

the test site the Catlin is characterized by very thin 

bedded flaggy-splitting limestone and dolomite intercalated with laminae of silty limestone and dolomite, 

and very thin beds of chert (fig. 188.1). 

The upper part of the Windfall formation at the 

test site is distinctly different from the upper part in 

the Eureka district. At Eureka the upper part is 400 

t 
' . 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-105 

feet thick and has been named the Bullwhacker member (Nolan, :Merriam, and 'Villiams, 1956, p. 21). It 

is composed of slope-forming, thin-bedded platy or 

shaly limestone that weathers to a distinctive yellowish-btu color. 

At the test site the upper part of the Windfall formn.tion is a cliff- and ledge-forming carbonate about 

1,070 feet thick that weathers to several shades of 

gray. Because of these differences it seems best to 

adopt tt new name that will distinguish these beds 

from the Bullwhacker member of the Eureka district. 

Accordingly, the upper part of the vVindfall formation on the test site is here named the Smoky member 

after the Smoky Hills at the north end of Yucca Flat 

(fig. 187.3, Art. 187). The member is well exposed in 

the Smoky I-Iills and on Paiute Ridge. In contrast 

with the underlying Catlin, the Smoky member is 

characterized by thick~r beds that tend to split into 

blocks and massive fragments, and by less abundant 

chert that occurs as scattered nodules. The base of 

the Smoky member is placed where the unusually high 

concentration of chert lenses and siliceous carbonate 

concretions in the thin beds of the Catlin are overlain 

by thick- to thin-bedded dolomite and limestone with 

only scattered nodules of chert. Dolomite is pre.-

dominant in the Smoky member, but a stratigraphic 

sequence may be dolomite at one locality and limestone 

at another. On Paiute Ridge the lower 920 feet is 

chiefly dolomite and the upper 150 feet is cliff-forming 

massive-splitting very thick bedded limestone with 

smaller amounts of slope-forming, thin-bedded limestone. Cross-lamination of beds occurs locally 

throughout the member. Predominant colors of ·the 

Smoky member are various shades of gray, and outcrops in many places are marked by conspicuous broad 

contrasting bands of very light and dark gray from 

20 to several hw1dred feet wide. 

Large and small stromatolites are conspicuous in the 

Smoky member. Individual algal "heads" 1 to 2 feet 

wide and 2 to 4 feet high are crowded together in 

thick-bedded strata throughout the member, as well as 

in the overlying Goodwin limestone. The "heads" 

are irregular but generally concentric ovoids that are 

outlined in various shades of gray. "Girvanella" 1 to 

2 inches in diameter occur in sequences of thin-bedded 

strata 6 inches to 3 feet thick, especially in the upper 

part of the member, where they are conspicuously 

e1~1bossed by weathering. 

The contact of the 'Vindfall formation with the 

overlying Goodwin limestone is gradational and is 

determined primarily on the basis of color. The basal 

6010.SO 0-61.--8 

beds of the Goodwin limestone are laminated to thin 

bedded and weather to a characteristic pale yellowish 

brown or light brown, but the uppermost beds of the 

'Vindfall formation weather gray. This contrast in 

color is readily mappable both in the field and on 

aerial photographs. 

~19st of the Windfall formation in the test site area 

is thought to be of Late Cambrian age. A. R. Palmer 

(written communication, 1960) has determined that 

collections 3537 -CO and 3538-CO, 3 and 22 feet respectively, above the base of the Windfall (fig. 188.1 

and : table 188.1), contain trilobites of the lower 

Elvinia zone of Franconia age. Collection 3539-CO, 

TABLE 188.1.-Fossils ide'ntifted tr01n localities 3 and 4 (fig. 

18"1.3, Art. 187), Neva.da. Test Site 

[Collections D733-CO from west side or Paiute Ridge identified by R. J. Ross, Jr.; 

collections 3537-CO to 3542-CO from northeast side or Teapot Ridge identified by 

A. R. Palmer] 

D733-CO (about 200 feet above base of Goodw1n limestone): 

X enostegium cf. X. franklinense Ross 

Symphysurina? sp. 

Parabellefontia cf. P. concinna Hintze 

3542-CO (about 350 feet above base of W1ndfall formation): 

Richardsonella sp. 

Loganellus sp. · Drumaspis sp. 

I dahoia? sp. 

Homagnostus sp. 

Pseudagnostus sp. 

3541-CO (about 260 feet above base of W1ndfall formation): 

Homagnostus sp. 

Loganellus? sp. 

PstUdagnostu .'! cf. P. convergens Palmer 

Hungaia sp. 

Richardsonella sp. 

Lotagnostus sp. 

Prosaukia? sp. 

354Q-CO (about 150 feet above base of Windfall formation): 

Idahoia sp. 

Richardsonllla sp. 

Lo(lanellus sp. 

Wilbernia? sp. 

Pseudagnostus sp. 

3539-CO (63 feet above base of W1ndfall formation): 

Irvingella major Ulrich and Resser 

Elvinia roe.men' (Shumard) 

Pterocephalia sanctisabae Roemer 

Hc,magnostus sp. 

Pseudagnostus sp. 

3538-CO (22 feet above base of W1ndfall formation): 

irvingella angustilimbatus Kobayashi 

Pterocephalia sanctisabae Roemer 

Elvinia? sp. 

Homagnostus sp. 

Pseudagnotus sp. 

3537-CO (3 feet above base of W1ndfall formation): 

Dokimocephalus pernasutus (Walcott) 

I rvingella angusttlimbatus Kobayashi 

Elvinia roemeri (Shumard) 

Pseudagnostus sp. 

Homagnostus sp. 
C-106 GEOLOGICAL SURVEY RESEARCH 1 9 61 

63 feet above the base, contains trilobites of the upper 

Elvinia zone. Collections 3540-CO, 3541-CO, and 

3542-CO ( 150, 260, and 350 feet above base) contain 

a related fauna from the Ptychaspis-Prosaukia zone 

of late Franconia age. Comparable faunas are' found 

in the Catlin member in its type area at Eureka, 

Nevada (Nolan, Merriam, and Williams, 1956, p. 22) . 

No identifiable fossils have been found between this 

fauna and one about 200 feet above the base of the 

Goodwin limestone, where R. J. Ross, Jr. (written 

communication, 1960) identified a fauna equivalent 

to the zone "B" fauna in the Pogonip-Garden City 

sequence, which is of earliest Ordovician age. The 

Cambrian -Ordovician boundary in the rock sequence 

at the Nevada Test Site is therefore at an unknown 

position between these two points, which are about 

1,600 feet apart stratigraphically. 

REFERENCES 

Johnson, M. S., and Hibbard, D. E., 1957, Geology of the 

Atomic Energy Commission Nevada Proving Grounas area, 

Nevada:· U.S. Qeol. Survey Bull. 1021-K, p. 333-384. 

Nolan, T. B., Merriai:n, C. W., and Williams, J. S., 1956, The 

stratigraphic section in the vicinity of Eureka, Nevada: 

U.S. Geol. Survey Prof. Paper 276, 77 p. 

189. REVISED SUBDIVISION OF ORDOVICIAN SYSTEM AT THE NEVADA TEST SITE AND VICINITY, N~VADA 

By F. M. BYERs, JR., HARLEY BARNEs, F. G. PooLE, and R. J. Ross, JR., Denver, Colo. 

Work done in cooperation with the U.S. Atomic Energy Oommission 

Mapping of Ordovician rocks in the Papoose Lake 

and Frenchman Lake quadrangles at the Nevada Test 

Site (fig. 189.1) has shown that the lithologic units 

mapped by ,Johnson and Hibbard (1957, pl. 32) are 

not in sufficient detail for hydrologic and geophysical 

studies in Yucca and Frenchman Valleys. They 

divided rocks of the Ordovician system into the Pogonip group at the base, over lain in turn by the Eureka 

quartzite and "dolomite of middle Paleozoic age, undifferentiated." The last named unit also included 

Silurian and probably Lower Devonian rocks. We 

propose to subdivide the Pogonip group in the vicinity 

of the test site into the three formations defined by 

Nolan, Merriam, and Williams (1956, p. 25-29) in 

the vicinity of Eureka, Nev. (inset, fig. 189.1): the 

Good win limestone, the Ninemile formation, and the 

Antelope Valley limestone. The subdivision is based · 

on the close similarity in lithology and faunal content 

between these formations in the two areas. Johnson 

and Hibbard (1957, p. 352) correlated the lower part 

of the "dolomite of middle Pale9zoic age, undifferentiated" with the Ely Springs dolomite of Late Ordovician age (Westgate and Knopf, 1932, p. 15-16) in 

the vicinity of Pioche, Nev. (inset,, fig. 189.1), but they 

made no attempt to locate the Ordovician-Silurian 

boundary. It is now possible on the basis of additional fossils to locate the Ordovician-Silurian boundary within a stratigraphic interval of 190 feet. The 

new subdivisions of Ordovician rocks at the Nevada 

Test Site are given on table 189.1. 

The Antelope Valley limestone of the Pogonip 

group is here further subdivided into. the Paiute 

Ridge, Ranger Mountains, and Aysees members named 

from exposures at Paiute Ridge, Ranger Mountains, 

a.nd Aysees Peak, respectively (fig. 189.1). The 

stratigraphic descrip~ions and thicknesses are mostly 

from a well-exposed section at Aysees Peak (loc. 2, 

fig. 189.1). The three members are exposed at all 

type localities and show only minor lithologic variation from o!le lo~ali.ty to another. Correlation of these 

members .with the informal lettered units of Joh:r:tson 

and Hibbard (1957, p. 345-349) is shown in table 

189.1. 

The contact between the Cambrian and Ordovician 

systems is placed about 175 feet stratigraphically 

+-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-107 

TARLE 189.1-Generalized strat.igraphic chart of Ordovician system at the Nevada Test Site and vicinity. 

[Locality or measured 5011t1on Includes Initials or persons who measured sections: FMB, F. M. Byers, Jr.; HB, Harley Barnes; and FGP, F. G. Poole. Fauna Identified by R. J. Ross, Jr., except where footnoted. Informal unit designations as used by Johnson and Hibbard (1957, p. 33)] 

New member In- Lithology (sequence conformable Thickness Locality of 

System or series Formation name formal except where noted) (feet) Fauna measured section unltt (fig. 189.1) 

--- Dolomite, olive-gray; 50-foot Halysites or Ranger thick massive yellowish- Cystihalysites.a Moungray bed in middle of unit; tains 

upper part of unit thin and (loc. 4, poorly bedded; a few shaly 2 205 FMB). partings, lenticular chert, 

and silicified horn corals near top; lower part thick 

Silurian E bedded, faintly mottled. 

Dolomite and chert, ratio Favosites(?) sp., 80:20, very thin to thin Dissepimented horn 

bedded; slope forming, but coral cf. Pilophyllum 

otherwise similar to unit 2 60 sp., N ondissepi- below. Corals collected 20 mented horn coral 

ft below top of unit. cf. Rhegmaphyllum 

sp., massive 

--?----? stromatoporoid. 4 

Dolomite and chert, ratio 

70:30; dolomite is medium 

Dinorthis sp. 

dark gray, weathers olive 

E 

gray; chert is medium light 

gray to pale . yellowish 170 

brown, weathers orange and 

brown, very thin bedded to 

thin bedded; cliff forming. 

Brachiopods (Dinorthis sp.) 

20 ft above base. 

Dolomite, light olive gray, 

largely massive; slabby ~o 

D 

blocky splitting prominent 

in upper part; small vuggy 275 

cavities, some lined with 

coarsely crystalline dolomite; cliff forming. --- Upper Ordo- Ely Springs Dolomite, olive-black; bedded 

vician dolomite olive-gray chert especially c abundant in lower 20 ft; 115 

very thin bedded in lower 

20 ft grading upward to 

thin bedded; cliff forming. 

Dolomite, light olive gray; Favosites sp., 

silty in lower 25 ft; very A ustinella sp., 

thin bedded to thin bedded; Holtedahlina sp., 

B slope forming. Relations 160±20 Thaerodonta sp., 

with unit above obscured Sowerbyella? sp., 

by minor faulting. Leptaena sp., 

Zygospira? sp. 

Dolomite, olive-gray, slightly StreptelaSlnatoid 

darker in upper part; sparse coral· 4, · lenticular very thin bedded '' Lambeophyllum'' A chert·; indistinctly thin 105 sp.4 

bedded in lower part grading upward to thick bedded 

with rare sand grains;' slope forming. 

Quartzite, orange, red, and 

--?--

brown in lower 171 ft; 

mostly white and sandy in 

upper 132 ft; fine grained; 300 

mostly thick bedded; cross- bedded in basal 20 ft; forms 

ledges and low cliffs. 

See footnotes at end of table. 
C-108 GEOLOGICAL SURVEY RESEARCH 19 61 

TABLE 189.1-Generalized stratigraphic chart of Ordovician system at the Nevada Test Site and vicinity-Continued 

New member InSystem or series Formation name formal 

unit 1 

Lithology (sequence conformable 

except where noted) 

Thickness· 

(feet) Fauna Locality of 

measured ser.tlon 

(fig.189.1) 

---·------1--------1------------l-...:.._------------------------.,.---------------

Middle Or-

·dovician 

Middle and 

Lower 

Ordovician 

Eureka 

quartzite 

Antelope 

Valley 

limestone 

(Pogo nip 

group) 

Ninemile 

formation 

(Pogonip 

group) 

See footnotes at end of tabl~. 

Aysees 

member 

Ranger 

Mountains 

member 

Paiute 

Ridge 

member 

I 

H 

G 

F 

and 

E 

D 

Limestone; dolomitic in upper 

part; olive gray, mottled 

and weathered in shades of 

orange and brown; very 

thin bedded, flaggy splitting; ledge forming. 

Quartzite, light-gray; weath- ers brown; very fine grained 

V alcourea cf. V. plana, 

Sowerbyella? sp., 

35 Bronteopsis sp., Lonchodomas sp., Homotelus? sp., Unidentified ostracods. 

to fine grained, indistinctly 60 

thin bedded; ledge and 

cliff forming. 

Limestone, medium-gray to 

dark-gray; weathers me- dium light gray and light 

olive gray to yellowish gray; 

contains thin-bedded sili- ceous and laminated silty · limestone that weathers 

shades of orange and brown; 

two pink ledges in lower 

middle; laminated to thin 

bedded; forms varicolored 

stairstep slope. Fossilifer- ous. . 

Limestone, medium-gray to 

dark-gray, thick bedded to 

very thick bedded; upper 

contact gradational and intertonguing, possibly through a large stratigraphic interval; cliff forming. Gastropods and Receptaculites 

abundant in upper part. 

Silty limestone, olive-gray, 

mottled yellow and red 

along silty layers; dominantly very thin bedded; 

thin-bedded brachiopodbearing limestone in upper 

50ft; ledge forming. Abundantly fossiliferous. 

Limestone, gray; laminae and 

etched irregular network of 

silty limestone that weath- ers brown; etched network 

forms "chicken-wire" pattern; thin to thick bedded; 

cliff forming. Many straightconed cephalapods. 

Claystone and limestone (ratio 80: 20) .interstratified; 

claystone is light olive to 

greenish gray, fissile weathering; limestone is gray, 

nodular, very thin bedded 

becoming thin bedded and more abundant in uppermost 50 to 100 ft; forms 

gentle slope, largely cov- ered. 

440 

330 

215 

"Lichenaria" sp.4, 

Eojletcheria sp.4, Orthambonites paucicostata, A nomalorthis 

oklahomensis, Desmorthis? cf. D. neva- densis. 

Palliseria robusta, Receptaculites sp. 

Orthambonites eucharis, 

Orthidiella 2 spp., 

Ingria cloudi, Ectenonotus cf. E. conne- maricus, Paracybeloides? sp., Bathyurellus feitleri, Remopleurides? sp.,· 

Illaenus sp., Carolinnites sp., Trinodus 

sp., Leperditia sp. 

Orthambonites cf. 0. 

subalata, Lachnos370 toma latucelsum, 

Kirk ella decliuita, 

Goniotellina or Bathyurus sp. 

Archaeorthis elongata, 

H esperonomia cf. H. 

antelopensis, Pseudocybele cf. P. nasuta, 

Kirk ella cf. K. decli335 vita, K. cf. K. vigilans, Trinodus sp., 

Pseudomera? sp., 

Lachnostoma cf. L. 

latucelsum, Asaphellus? cf. A. eudocia. 

Ranger 

Mountains 

(loc. 3, 

HB, FGP, 

FMB). 

Aysees 

Peak 

(loc. 2, 

HB, FGP, 

FMB). 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-109 

TARLE 189.1-Generalized stratigraphic chart of Ordovician System at the Nevada Test Site and vicinity--Continued 

System or series 

Lower 

Ordovician 

Formation 

Goodwin 

limestone 

(Pogonip 

group) 

New member 1 In- name formal 

unit 1 

c 

B 

A 

Lithology (sequence conformable 

except where noted) 

Limestone, medium light gray 

to light olive gray; upper 50 

ft weathers olive gray to 

brown; nodular chert in 

lower part becoming sparse 

Thickness 

(feet) 

upward; limestone-pebble 5 415+ 

conglomerate common, es- pecially in upper part; 

thin bedded; silty laminae common in basal and upper 

50 ft; ledge-forming. 

Silty limestone, medium light 

gray with abundant grayish-yellow silty partings; 

laminated to very thinbedded; limestone plates 

weather out on gray-yellow 

slope; gradational and apparently intertonguing con- tacts above and below; 

forms swale. Fossiliferous. 

Limestone, light olive gray; 

brownish-weathering siU- ceous limestone laminae; 

about 200 to 300 ft above 

base is very th.in bedded 

silty fossiliferous limestone; 

cherty near base; thin bedded; lower contact placed at 

base of brownish-weathering thin-bedded olive-gray 

limestone; ledge forming. 

85 

405 

Fauna 

Ampyx sp., Protopresbynileus sp., Lannacus? sf', Pseudoclelandia. sp. 

Nanorthis? sp. 

Xenostegium cf. X. 

franklinensis, Parabellefontia cf. P. con- cinna, Symphysurina 

sp. 

----?-----l·-----------l------------l------l---------------------------·l-------·1---------------------l 

Upper 

Cambrittn 

Windfall 6 

formation 

(upper 

part) 

Smoky 6 

member 

(upper 

part) 

7 A 

Limestone, mainly light gray 

in lower part grading upward to medium gray and 

medium dark gray; dolomitic in lower 35 ft; mainly 

thick bedded to massive; 

upper part contains com- mon very thin layers of 

lenticular chert and large 

ovoid algal structures; con- spicuous "Gitvanella" beds 

in middle of unit; cliffforming. 

2 175 

Locality or measured section (ft~r. 189.1) 

Aysees Peak 

(loc. 2) 

and 

Paiute 

Ridge 

(loc. 1) 

(HB 

FMB). 

Paiute 

Ridge 

(loc. 1, 

HB, 

FMB). 

----------------~--------~~---~----------------l--------l------------------·1------------

Approximate total thickness of Ordovician rocks 

1 Informal units or Johnson and Hibbard (1957). 2 Footage not Included In total thickness or rocks or Ordovician age. 3 Holen Duncan in Johnson and Hibbard (1957, p. 352). • Corals identified by W. A. Oliver, Jr. (written communication, 1961). 

3, 800 

~ Faulted; estimated 500 feet. o See Barnes and Byers, Art. 188. 1 Pogonlp unit A or Johnson and Hibbard (1957, p. 346) extends about 175feet below contact of Goodwin limestone and Windfall formation as shown In table. 
C-110 GEOLOGICAL SURVEY RESEARCH 1 9 61 

116°00' higher than that defined by Johnson and Hibbard 

( 1957, p. 346). This contact is mapped at a color 

change within a 40-foot thick transitional sequence. 

The basal beds of the Ordovician Good win limestone 

are laminated to thin bedded and weather to a char-

,· acteristic pale ·yellowish brown or light brown, but 

the uppermost beds of the Cambrian Windfall forma3roo· tion weather gray (Art. 188). Thin lenticular chert 

is common both above and below the contact as herein 

defined. 

The top of the Ordovician system is placed tentatively at a seemingly minor lithologic break 170 feet 

above the base of Johnson's and Hibbard's (1957, p. 

',,J 351) unit E, "dolomite of middle Paleozoic age, unL...---:I""T'~-----1 differentiated" or about 830 feet above the top of the 

~ Eureka quartzite. The exclusively Middle and Late 

0 5 10 MILES 

FIGURE 189.1.-Map of Frenchman Lake and southern onethird of Papoose Lake 15-minute quadrangles, Nevada Test 

Site and vicinity, showing location of stratigraphic sections 

of Ordovician rocks ( ta:ble 189.1). 

Ordovician brachiopod genus Dinorthis occurs 20 feet 

above the base of unitE, within a 170-foot thick cliffforming dolomite and chert sequence. Corals of unquestioned Silurian age (W. A. Oliver, oral communication) occur 210 feet above the base of unit E (865 

feet above the top of the Eureka quartzite) or about 

190 feet above the stratigraphic position of the Ordovician Dinorthis. Therefore, the Ordovician-Silurian 

boundary must lie within this 190-foot-thick interval. 

REFERENCES 

Johnson, M. S., and Hibbard, D. E., 1957, Geology of the 

Atomic Energy Commission Nevada ·Proving Grounds 

area, Nevada: U.S. Geol. Survey Bull. 1021-K, p. 333-384. 

Nolan, T. B., Merriam, C. W., and Williams, J. S., 1956, T~~ 

stratigraphic section in the vicinity of Eureka, Nevada: 

U.S. Geol. Survey Prof. Paper 276, 77 p. 

Westgate, L. G., and Knopf, Adolf, 1932, Geology and ore deposits of the Pioche 'district, Nevada: U.S. Geol. Survey 

Prof. Paper 171, 79 p. 

190. LITHOLOGIC CHARACTER OF THE DIAMOND PEAK FORMATION (MISSISSIPPIAN) AT THE TYPE LOCALITY, 

EUREKA AND WHITE PINE COUNTIES, NEVADA 

By DAVID 1\.. BREW, Menlo Park, Calif. 

The type locality of the "Diamond Peak quartzite" 

was established by Arnold Hague ( 1880, p. 34; 1882, 

p. 28 ; 1883, p. 252-253; and 1892, p. 85 and 158) in a 

series of reports dealing with the geology of the 

Eureka mining .district. He described the formation 

on the .slopes of Diamond Peak as follows ( 1883, p. 

268) : "* * * conglomerates firmly cemented together 

lie next to the argillaceous shales of the White Pine 

· epoch, but quickly give place to a more massive, uniformly vitreous quartzite, with a characteristic grayish-brown color, and breaking with an irregular flinty 

fracture. Near the summit the beds pass into thinly 

t 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-111 

laminated green and brown schists and shales." In 

1892 Hague expanded this description slightly, noting 

( p. 85) that "Intercalated black cherty bands, * * * 

occur near the middle portion of the horizon." He 

also stntes (p. 158) that the upper shale unit was about 

500 feet thick whereas the lower 2,500 feet consisted 

of "Dark gray quartzites, compact conglomerates, with 

interbedded layers of jasper and siliceous grits. Near 

the base narrow belts of blue limestone * * * ." 

This concept of the Diamond Peak formation as an 

n.lmost wholly coarse clastic unit has persisted, although Dott (1955, p. 2233, 2265-2266) and Nolan and 

others (19~6, p. 56-61) called attention to the occur-

. renee of significant amounts of shale and siltstone in 

the lower part of the formation. 

Recent mapping has shown that the Diamond Peak 

formation on the southern and eastern slopes of Diamond Peak is cut by numerous high-angle faults and at 

least one large low-angle thrust fault (Brew, Art. 191, 

fig. 191.1), and that some of the formation is absent. 

l\{npping elsewhere in the Eureka quadrangle, and 

study of apparently complete and relatively undisturbed exposures of the Diamond Peak formation on 

the northwestern slope of Diamond Peak in sees. 7 and 

18 (unsurveyed), T. 20 N., R. 55 E. (between lat 

39°36' N. and. ]at 39~37' N. and between long 

115°48'30" W. and long 115°50' W.) show that the 

amount of conglomerate and silicified sandstone is 

small relative to other rock types. Only about 12 percent of the formation is conglomerate, 20 percent is 

sandstone and silicified sandstone, 61(2 percent limestone, 5% percent limestone phenoplast conglomerate, 

9% percent claystone, and 45 percent siltstone. 

In the newly studied section about 3,525 feet of 

strata, divided informally into eight map units, are 

assigned to the Diamond Peak formation (fig. 190.1). 

These units have been mapped on all the slopes of 

Diamond Peak and throughout the Eureka quadran.-

gle. The map units vary in thickness and character 

from place to place and probably are not regionally 

persistent. 

Conformably underlying the Diamond Peak formation are laminated and very thin bedded medium-gray 

to medium dark-gray siltstone, clayey siltstone, claystone, and fine-grained sandstone that weather olive 

gray and light olive gray and belong to a relatively 

eoarse facies of the Chainman shale, also of l\1:ississi ppian age. Lenses and beds of conglomerate occur 

l!"'IOURJ£ 190.1.-Generalized columnar section of the Diamond 

Penk formation in the vicinity of Diamond Peak, showing 

approximate thickness and dom~nant lithologic types for 

8 units, A to H. 

en 

::J 

0 

0:: ~ lJ.J a: u. a.. 

in z en 

0 ~ CD ~ 

0:: 

<{ 

{.) 

c 

0 

:;:; 

oaoooooo 

~f 

~i~ ~" :~-'1._~~0~~~ 'b~>''1.'~it 

~~:..?tfis;l.=-

~~~ 

im:'Si§.~-

-~~~-

- - f - f ~f ;_. . .:.. . ..:..:-~ 

- - -/ 

ro .................. . E t 

.E 

.:.. . ...:. _...:.-::. 

.:.. . ...:... . ..:.._-=:_ 

.:.. . ...:... --=- . ...: § 

:-...:...-:-_:-:-=-=-

~~~f ~------==- f 

UNIT 

H 

G 

F 

E 

D 

c 

B 

A 

APPROXIMATE 

THICKNESS, 

IN FEET 

220 

250 

315 

570 

380 

240 

1,270 

280 

EXPLANATION 

~ Siltstone 

[2] 

Sandstone 

0 

Claystone 

B 

Conglomerate 

Limestone 

~ 

~ Cherty 

limestone 

g~~ Limestone 

phenoplast 

conglomerate 

f 

Fossil 

collection 

FEET 

0 

100 

500 

3,525 • Total thickness 

Diamond Peak formation 
C-112 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

in the Chainman, but are much more common in the 

overlying basal unit of the Diamond Peak formation. 

Unit A, at the base of the Diamond Peak formation, 

is characterized by interstratified thick-bedded and 

very thick bedded gray-weathering chert, quartzite, 

and limestone-pebble and cobble conglomerate; siltstone similar to that of the underlying Chainman 

shale; claystone; and thin-bedded gray, brownweathering, fine- to medium-grained silicified sandstone. The unit is about 280 feet thick, forms prominent ledges, and, although discontinuous in detail, 

has been traced throughout the area north of Diamond 

Peak. 

Unit B consists of about 1,270 feet of slope-forming 

thin to very thin bedded siltstone interbedded with 

silicified sandstone, claystone, and minor lenticular 

conglomerate. In general, the unit closely resembles 

the Chainman shale, but forms steeper slopes. 

Unit C has at the base a prominent ledge of very 

thick bedded chert and quartzite cobble and pebble 

conglomerate that weathers gray and brownish-gray. 

This bed is overlain by steep slope forming very thin 

bedded siltstone, claystone, and sandstone. The upper 

one-third of unit C contains some conglomerate and 

very thin bedded gray limestone beds that become 

more numerous upward. The unit is about 240 feet 

thick. 

Unit D is a resistant cliff- and ledge-forming sequence of thick and very thick bedded gray and bluegray limestone interstratified with limy gray and 

brown sandstone, olive-gray claystone and siltstone, 

and gray and brown chert and quartzite cobble and 

pebble conglomerate. This unit also includes some 

limestone phenoplast conglomerate, an unusual rock 

consisting of irregularly shaped nodule-like fragments 

of gray limestone ranging from 0.5 to 10.0 em in maximum ~iameter in a matrix that commonly is siltstone. 

The relative proportion of matrix and phenoplasts 

varies considerably both vertically and laterally. The 

limestone fragments are interpreted as intraformational in origin and are believed to have been plastic 

at the time of. deposition with the siltstone. Unit D 

is about 380 feet thick. 

Unit E is about 570 feet thick and consists of alternating beds of siltstone, sandstone, conglomerate, 

claystone, limestone, and limestone phenoplast conglomerate that form steep slopes and scattered resistant ledges. Limestone and siltstone diminish upward, 

and sandstone and conglomerate are prominent in the 

upper half of the unit. 

Unit F is characterized by distinctive alternating 

purple and green siltstone and claystone, pale-green 

silicified sandstone, pale-green chert-cobble conglomerate, and purple, green, and gray limestone phenoplast conglomerate. The unit is about 315 feet 

. thick and probably is the base of the upper shaly part 

of the Diamond Peak forma.tion noted in previous reports. 

The lower half of unit G contains thick-bedded dark 

chert-pebble and cobble conglomerate and subsidiary 

interstratified siltstone, silicified sandstone, and limestone phenoplast conglomerate and it forms ledges; 

the upper half is poorly exposed and probably consists mainly ·of siltstone. The unit is about 250 feet 

thick. 

Unit H is 220 feet thick and represents the beginning of deposition of the thin- to thick-bedded bluegray limestone that characterizes the conforma~ly 

overlying Ely limestone of Pennsylvanian age. The 

transition to the Ely occurs by the alternation of thick 

bedded blue-gray noncherty limestones with silicified 

sandstone, limestone phenoplast conglomerate, conglomerate, and minor siltstone. 

The upper contact of the Diamond Peak formation 

is placed about at the base of the lowest sequence of 

cherty blue-gray limestone. Limestone abruptly becomes the dominant lithologic type at about this horizon, although siltstone, silicified siltstone, and conglomerate of the Diamond Peak type occur in minor 

amounts through a thickness of about another 140 

feet at the base of the Ely. 

REFERENCES 

Dott, R. H., Jr., 1955, Pennsylvanian stratigraphy of Elko and 

northern Diamond Ranges, northeastern Nevada: Am. 

Assoc. Petroleum Geologists Bull., v. 34, no. 11, p. 2211-

2305. 

Hague, Arnold, 1880, Preliminary report on field-work in the 

Eureka district: U.S. Geol. Survey, 1st Ann. Rept., p. 

32-35. 

-- 1882, Administrative report of Mr. Arnold Hague: 

U.S. Geol. Survey, 2d Ann. Rept., p. 21-34. 

-- 1883, Abstract of report on the geology of the Eureka 

district, Nevada: U.S. Geol. Survey, 3d Ann. Rept., p. 

237-290. 

-- 1892, Geology of the Eureka district, Nevada: U.S. 

Geol. Survey Mon. 20, 419 p. 

Nolan, T. B., Merriam, C. W., and Williams, J. S., 1956, The 

stratigraphic section in the vicinity of Eureka, Nevada: · 

U.S. Geol. Survey Prof. Paper 276, 77 p. 

t 
"'' 

·-

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-113 

191. RELATION OF CHAINMAN SHALE TO BOLD BLUFF THRUST FAULT, SOUTHERN DIAMOND MOUNTAINS, 

EUREKA AND WHITE PINE COUNTIES, NEVADA 

By DAVID A. BREw, Menlo Park, Calif. 

The Bold Bluff thrust fault extends from near Poison Spring north of Newark Summit northeastward 

to the base of the range at a point north of the mouth 

of Sadler Canyon (fig. l91.1). The existence of this 

39° 

35' 

0 

APJ!RO>:.IMATC M[AN 

DCCliNo\TtON. 1961 

1 MILE 

thrust within the Carboniferous strata of the southern Diamond ~1ountains had long been suspected by 

T. B. Nolan (oral communication, 1956) and it has 

been delineated 1n recent detailed mapping·. 

116°00' 115°45' 39°45' 

39° 

35' 

• 

~EUREKA 

Phillipsburg '~ 

mine } 

z ""' ~t~ z :::> 

lf < 8(~ z ~ E: 

~~ 

\ 

\ 

I 

'Diamond 

D. Peak 

I '·.s-<!1 ) C'$~i<?'~$,. o,......_ 

I Bold 

LD. Bluff 

Newark Summit J ~'Poison Spring 

(3 5 D. It:~ Newark Mtn 

~J 

116°00' 0 5 MILES 39°30' 

115°45' 

MAP OF EUREKA QUADRANGLE. NEVADA. SHOWING LOCATION 

OF GEOLOGIC MAP AND PLACES REFERRED TO IN TEXT 

<AFTER NOLAN AND OTHERS, 1956) 

EXPLANATION 

Contact 

Danhed where approximn.tely located 

_0 u ______ _ 

Fault 

Dn.shed where approximatel·y loca.ted; dotfed where concea.led. U, upthroum side; 

0, downthrown side 

__.__._..A... ..A.. 

Thrust fault 

Dashed where approximutely locnted; sawteeth on upper plate 

17 

......... 

Strike and dip of beds 

FIOUI~E 191.1.-Generalized geologic map of part of the southern Diamond Mountains, Eureka quadrangle, Nevada. Formations 

exposed within the map area are: MDp, Pilot shale of Devonian and Mississippian age ; Me, Chainman shale of Mississippian age; Mdp, Diamond Peak formation of Late Mississippian age; Pe, Ely limestone of Pennsylvanian age; Per, Carbon 

Ridge formation of Permian age; TK, undifferentiated Newark Canyon formation of Cretaceous age and megabreccias of 

•rertiary( ?) age; and Qal, alluvium and colluvium of Quaternary age. Inset map shows other localities outside of the map 

area. 
C-114 GEOLOGICAL SURVEY RESEARCH 1 9 61 

In the locality where it has been recognized, th~ 

thrust has brought siltstone, sandstone, conglomerate, 

a.nd limestone of the Diamond Peak formation of 

Late Mississippian age over correlative siltstone and 

sandstone and also over highly deformed very dark 

claystone and siltstone ("black shales") of the Chainman shale of Mississippian age. 

The thrust surface dips in general less than 10° to 

the west, but is locally horizontal and near Sadler 

Canyon dips about 13° north. The main thrust surface is not exposed but was located by the mapping of 

lithologic units within both the Chainman shale and 

Diamond Peak formation. Extensive slickensided 

surfaces, minor thrusts, and overturned folds in the 

lower part of the upper plate indicate that the relative 

1 'h miles east of Phillipsburg mine 

FEET~ 

········· 

3750~ 

~·:··o~o··· 

~ 

~..:..,:.:::..:,.:..·.·. 

.2...o .. o...:...:..·_·..:_· 

oo·oc;·o 

-~r-= ... · !--:-: .. 

~a::~-:7.:.;. 

Diamond Peak 

formation 

North, east, and southeast of 

Black Point 

~~FEET 

ooooooo 

....... 

3500 

... 

~~~:r.; 

-------- .......... 

. . 

.. ······· --· 

4000 ~.:.::.:~~:..; 

r=:::=:.: 

115-.250 

360 

675 

1/ / 

7 7 7 

Chainman shale 

Joana limestone 

Pilot shale 

Devils Gate 

lime~tone 

·-·--

.. -.. -~ 

~':.· ..... : .... : .. ··· 

_ ... ·-· .. 

·-·--

11400 

265 

750 

movement of the upper plate was toward the southeast. 

In the lower plate of the thrust are exposed ( although not all are within the boundaries of fig. 191.1) 

the Nevada formation and Devils Gate limestone 

(Devonian) ; the Pilot shale (Devonian and Mississippian) ; the Joana limestone, · Chainman shale, and 

the lower part of the Diamond Peak formation 

(Mississippian). In the upper plate within the map 

area are exposed the upper part of the Chainman 

shale; a complete section of the Diamond Peak formation; the Ely limestone (Pennsylvanian); the Carbon 

Ridge formation (Permian) ; and younger units. To 

the north of the map area, but within the upper plate 

of the thrust, are exposed the Lone Mountain dolomite 

f.. 

Newark Min-Bold Bluff 

tectonic thickening) 

Joana limestone 

Pilot shale 

EXPLANATION 

Dolomite 

Limestone 

Shaly limestone 

joooooool 

Conglomerate 

Claystone 

Sandstone 

1-~-~-1 -----

-·-·-

Siltstone 

Fr+r+r+J 

Cherty limestone 

Sandy limestone 

FEET 

3000 

2000 

1000 

Hayes Canyon 

member 

Meister member 

} 

Devils Gate 

limestone 0 

Bay State dolomite / 

/ c member 0 

~ 

§ Woodpecker lime-

.e 

:: // 635 

410 Q)o/ . 450? 1-7-'-r---'-r--1 

/ 

Bay State 

dolomite member 

Woodpecker lime . 

stone member 

Sentinel Min 

dolomite member 

1 """ 500 

:::/ 400? ~ii~ 7 

Sentinel Mtn 

.., dolomite member 

t Oxyoke Canyon 

.::: ·:··;·/:·>~ .~ z sandstone member 

Beacon Peak 

dolomite member ....... ~ ... ........ ---------

r ...... ; .. 

FIGURE 191.2.-Thickness and lithologic character of Devonian ·and Mississippian sections in the upper and lower plates of the 

Bold Bluff thrust fault. (Modified in ,Part from Nolan and others, 1956.) 

·+ 
•, 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-115 

(Silurian) and all of the formations noted previously 

ns occurring in the lower plate of the thrust. Nolan 

and others ( 1956) have discussed the stratigraphy of 

n l l these rocks. 

Ali formn,tions involved in the Bold Bluff thrust 

thn.t. n.re exposed in both plates show contrast in thickness, but the contrasts in thickness and lithologic character of the Chainman shale are the most striking 

(fig. 191.2). These differences were first commented 

on by Nolan ttnd others (1956, p. 57-58). Possibly 

some of the variations in thickness are due to unrecognized low-angle fau~ting, folding, or both. 

The difference in thickness of the Chainman shale, 

as shown on figure 191.2, is approximate because the 

Tollhouse Canyon section in the lower plate was obtained in an area of intense deformation and, as Nolan 

and others (1956, p. 57) point out, probably is tectonically thickened. In general, this "black shale" 

variety of Chainnian, where known from less deformed exposures to the south of the area of figure 

191.1 (Nolan and others, 1956, p. 57-58), is markedly 

thinner than in the Newark Summit area. 

The thicker Chainman shale of the upper plate is 

exposed only 1lj2 miles west of the thinner section below the Bold Bluff thrust (fig. 191.1). 

The Chainman shale and Diamond Peak formation 

of the upper plate of the Bold Bluff thrust have been 

differentiated on the basis of the relative proportions 

of conglomerate, sandstone, and siltstone, and· by th~ 

presence of discontinuous, but . nevertheless stratigraphically restricted, lithologic units. Nolan, Merriam, and Williams (1956, p. 57) did not separate the 

formations where they occur in the upper plate. 

The contrast in lithologi.c character of the Chainman 

shale above and below the Bold Bluff thrust fault is 

as striking as the contrast in thickness described earlier. The Chainman of the upper plate consists of 

about 2 percent chert and quartzite pebble and cobble 

conglomerate, 24 percent brown and gray sandstone, 

39 percent olive-gray and brown-weathering gray siltstone, and 35 percent dark-gray siltstone and claystone, which is lithologically similar to the Chainman 

of the lower plate. Any one section of the Chainman 

of the upper plate shows variations from these averages, with conglomerate most likely to be mi.ssing. 

Sandstone everywhere makes up at least 15 percent 

of the section and siltstone predominates over claystone in every section. 

The Chainman shale of the lower plate of the Bold 

Bluff thrust, as exposed in the vicinity of Newark 

Summit, consists of about 90 percent pyritiferous claystone and clayey siltstone, with claystone dominant, 

and about 10 percent sandstone and conglomerate. 

The characteristic claystone and siltstone .are uniformly medium dark gray to grayish black and 

weather to form distinctive angular brownish pencillike fragments as much as 8 inches long and an inch 

in maximum diameter. 

The contrast in lithologic character and thickness of 

the Chainman shale above and below the Bold Bluff 

thrust fault indicates that a somewhat coarser facies, 

deposited near the source· area, has been thrust over a 

finer grained facies and suggests further that the 

coarser grained facies was originally significantly 

thicker than the more easterly, finer grained· facies. 

Recognition of this shortening may assist in explaining some of the differences that exist between other 

formations that are present in both plates of the thrust. 

REFERENCE 

Nolan, T. B., Merriam, C. W., and Williams, J. S., 1956, The 

stratigraphic section in the vicinity of Eureka, Nevada: 

U.S. Geol. Survey Prof. Paper 276, 77 p. 
C-116 GEOLOGICAL SURVEY RESEARCH 1961 

192. MAJOR WESTWARD THRUSTING OF POST-MIDDLE TRIASSIC AGE IN NORTHWESTERN NEVADA 

By RoNALD WILLDEN, Menlo Park, Calif. 

Work done in cooperation with the Nevada Bureau ot Mines 

A .major thrust fault, here called the Quinn River 

thrust, on which the upper·-plate rocks have been displaced westward at least 40 miles has been recognized 

at the south end of the Kings River Range in Humboldt County, Nev. (fig. 192.1). The fault is well 

exposed and is marked by a thick brecciated zone 

above the thrust plane. The upper-plate rocks are 

nonmetamorphosed limestone and fine-grained clastic 

rocks of Permian and Triassic age, which are lithologically quite different from rocks of the same age 

in the surrounding area. Th~ lower-plate rocks are 

part of the mildly metamorphosed Happy Creek volcanic series of Permian or older age that is widely exposed in western Humboldt County. 

Most of the ICings River Range is made up of middle Tertiary volcanic rocks, but pre-middle Tertiary 

intrusive rocks are exposed beneath. the volcanics at 

the north end of the range and Permian and Triassic 

rocks are exposed on a low hill west of the range at 

its south end (fig. 192.2). Three of the four pr~­

Tertiary units recognized at the south end of the 

Kings River Range are in the upper plate of the 

Quinn River thrust. These upper-plate rocks include 

an unnamed fossiliferous limestone formation of Early 

Permian age about 1,000 feet thick. The limestone 

is overlain by about 400 feet of unfossiliferous mudstone, chert, and graywacke; this is in turn overlain 

by the Quinn River formation, which consists of silty 

shale with thin chert and carbonate beds and scattered 

thin gypsum beds. The Quinn Ri:ver formation has 

an exposed thickness of about 600 feet and contains 

Middle Triassic pelecypods and ammonites. 

Permian and, to a lesser extent, Triassic rocks in 

nearby areas are quite different from those in the 

Kings River Range (fig. 192.3, p. C-119). In the Jackson Mountains, Permian fossils have been collected fr9m 

a siliceous recrystallized limestone in a thick sequence 

of interbedded graywacke, intermediate and mafic 

volcanic rocks, silty and· cherty phyllite, pebble conglomerate, and some silty and sandy limestone. This 

sequence rests conformably on the Happy Creek volcanic series and grades upward into a thick unit, of 

probable Late Triassic age, consisting of phyllite and 

thin recrystallized chert and carbonate beds. In the 

Pine Forest Range a carbonate-clastic unit about 

1,000 feet thick rests on the Happy Creek volcanic 

series. Fossils found in the lowermost limestone of 

this unit include lsastraea-like colonial hexacorals and 

radially ribbed carditoid pelecypods that indicate an 

early ~{esozoic age (N. J. Silberling, written communication, 1956). This carbonate-clastic unit is 

overlain by a sequence of dark phyllite with abundant 

interbedded fine-grained quartzite. Rocks of Late 

Permian age, con~isting of volcanic sediments with 

varying amounts of limestone, have recently been reported from Black Rock at the south end of the Black 

Rock Range by Gianella and Larson (1960). 

Permian rocks are not exposed in the Trout Creek 

Mountains, the Slumbering Hills, and the Santa Rosa 

Range. The Triassic rocks in these ranges consist of 

phyllite, slate, and fine-grained quartzite, with some 

thin limestone beds. 

Several formations of Permian age or partly of 

Permian age, which are essentially contemporaneous 

but have widely different lithologies, have been recognized in southeastern Humboldt County. These formations have been involved in repeated periods of deformation which are not yet completely understood. 

Thrust faults separate .most of these formations from 

older and younger units, and their original sites of 

deposition can only be guessed, but all these Permian 

formations with the exception of the l{oipato formation, which is probably at least in part younger than 

Permian (Roberts and others, 1958; Wallace and 

others, 1959) are completely lacking in volcanic material, just as are the Permian rocks of the upper plate 

in the Kings River Range. The Osgood Mountains 

section (fig. 192.3) illustrates the heterogeneity of the 

southeastern Humboldt County Permian formations. 

All the pre-Cretaceous rocks in Humboldt County 

west of the line shown on figure 192.1 as the eastern 

limit of regional metamorphism have been metamorphosed to the greenschist facies or higher, except 

those on the upper plate of the Quinn River thrust. 

The volcanic rocks and the Jurassic diorite intrusives 

contain abundant chlorite, clinozoisite, epidote, and 

albite or sodic oligoclase. The shales have been converted to phyllites and slate with secondary cleavage 

that cuts across the bedding. In contrast, the shales 

of the Quinn River formation are not phyllitic and 

they lack secondary cleavage. The pebbles in the 

Permian and Triassic conglomerates in the western 

part of Humboldt ~ounty, particularly those in the 

+ 

.I 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-117 

10 0 

'""""" 

EXPLANATION 

D 

Quaternary deposits 

D . 

. Quaternary and Tertiary rocks 

Early Tertiary and late Mesozoic intrusive rocks 

Mesozoic rocks 

Paleozoic 

-rocks 

.---.-~--.---.--. -~42° . ·. . . • . I 

30 MILES I 

Contact 

High angle fault 

Dushed where i·IJ!erred; boU 

on downt.hr~wn. side 

Thrust 

' ' fault . Barbs on upper plnte 

Eastern limit of regional metamorphism 

. \ 

I 

. ~ \ 

I 

., 

., 

. \ 

.I 

., 

'I 

>l 

., 

. :\ 

\ 

I 

~41° ·I 

' I 

\ 

I 

\ 

I 

Fioun.E 192.1.-Generalized geology of HumboldF County, Nevada, showing location of area shown on figure 192.2 at south end of 

Kings River Range. 
C-118 GEOLOGICAL SURVEY RESEARCH 19 61 

Base enlarged from 

AMS Vya Sheet 

Geology by Ronald 

Willden, 1956 

EXPLANATION 

Younger··~ii~,~·~ium and ~ lake (]@ sed1ments I a: >-

Quinn R~~Lation } ~ r:;;z:l ~ ~ ~ Older alluvium 0 

I1IPJ!TTI ~ J ::;;zVl ~Cl~ Unnamed chert, mudston ~ ..:~ 

and graywacke a.. 1- Dissecte~vial fans} 1;: 

~ ..: 

Volcanic rocks ~ Includes some interbedded w 

sedimentary rocks 1-

Unnamed ~ limestone }.a..~ :::: .. 

~ }::;:: a: 

Happy ~volcanic ~ ~ g ser1es ~ o 

5000' 

ContactDaslwd wlwre approxima.tely located 

Quin; RTve; tt:'ru:t fault 

Barbs on upper plate 

_AO 

Strike and dip of beds 

Symbols witlwut numbers taken from 

aerial photographs 

4000' 

3000'~~~~~~~-~~~~~------------------L 

0 3 MILES 

FIGURE 192.2.-Geology of the south end of the Kings River Range: 

Jackson Mountains, have been flattened and stretched; 

whereas the conglomerates in the unnamed limestone 

unit in the IGngs River Range are not deformed. At 

the IGngs River Range locality, the limestones are 

not recrystallized, and they contain fairly well preserved fossils-in contrast to· their usual recrystallized 

unfossiliferous condition elsewhere in western Humboldt County. 

The lithologic similarities of the Permian rocks in 

the l{ings River Range to those in southeastern Humboldt County-in particular the absenc_e of volcanic 

material in the two areas and the absence of metamorphic effects in the Kings River Range rocks-indicate that rocks on the upper plate of the Quinn 

River thrust have been displaced westward at least 

40 miles and possibly as much as 50 miles. The volcanic material and degree of ;metamorphism in the 

Permian section to the west iri northern California 

seem to preclude the possibility that the displacement 

on the thrust has been from west to east. 

The age of the thrusting can be fixed as · younger 

than the regional metamorphism, which is younger 

than the intrusion of some diorites of probable Jurassic age in the Jackson Mountains, and older than the 

nonmetamorphosed King Lear formation of Early 

Cretaceous age · (Willden, 1958). The Quinn River 

thrust probably developed as one phase of the orogenic 

episode that produced the mountainous terrane which 

was eroded to form the Cretaceous sediments of the 

King Lear formation. 

Muller ( 1949) has postulated westward overthrusting of substantial magnitude-on the order of tens of 

miles-involving Upper Triassic rocks in the Sonoma 

Range one-degree quadrangle. Later Muller, Ferguson, and Roberts (1951) assigned this thrusting to a 

Jurassic orogeny. The Quinn River thrust is probably 

of the same age and has about the same direction and 

amount of displacement as. postulated by these workers for some thrusts in the Sonoma Range. 

REF'ERENCES 

Ferguson, H. G., Muller, S. W., and Roberts, R. J., 1951, 

Geologic map of the Winnemucca quadrangle, Nevada: 

U.S. Geol. Survey Geol. Quad. Map GQ-11. 

Gianella, V. P., and Larson, E. R., 1960, Marine Permian ~t 

Black Rock, Nevada [abs.] : Geol.. Soc. America Bull., 

v. 71, p. 2061. 

Muller, S. W., 1949, Sedimentary facies and geologic structures in the Basin and Range province, in Longwell, C. R., 

chm., Sedimentary facies in geologic history (symposium) : 

Geol. Soc. ·America Mem. 39, 171 p. 

Muller, S. W., Ferguson, H. G., and Roberts, R. J., 1951, 

Geology of the Mount Tobin quadrangle, Nevada: U.S. 

Geol. Survey Geol. Quad. Map GQ-7. 
FEET 

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10,000 

5000. 

0 

-----------------/"'/"' 

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Happy Creek volcanic 

series 

BASE NOT EXPOSED 

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// 

HUMBOLDT COUNTY 

0104 

2 o3 6 0 0 

Positions of sections 

1. Pine Forest Range (Willden, in press) 

2, 3. Jackson Mountains (Willden, in press) 

4. Kings River Range (this repo.rt and Willden, 

in press) 

s·. East Range (ferguson, Muller, and Roberts, 

1951; modified by Roberts and others, 1958) 

6. Osgood Mountains (P. E. Hotz and Ronald 

Willden, unpublished data) 

5 

Raspberry formation 

r=- 7 Sequence broken 

Winnemucca formation 

Grass Valley formation 

Natchez Pass formation 

Prida formation 

Angular unconformity 

Koipato formation 

Unconformity(?) 

lnskip formation 

BASE NOT EXPOSED 

EXPLANATION 

g 

limastone 

~ Dolomite 

~ Shale 

~ Phyllite 

L~·::::;:;:_:;:J 

Quartzite ~nd sa~dstone 

r;::;·:.~~, Conglomerate 

~ Chert 

I~ I Mafic volcanic rocks 

I~== I Silicic volcanic rocks 

6 FEET 

[00 

Battle formation 

FIGURE 192.3.-Suggested correlation of the Permian and Triassic rocks of the Kings River Range with those in nearby areas. 

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C-120 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

Roberts, R. .J., Hotz, P. E., Gilluly, James,. and Ferguson, 

H. G., 1958, Paleozoic rocks of northccentral Nevada: 

Am. Assoc. Petroleum Geologists Bull., v. 42, p. 2813-

2857. 

Wallace, R. E., Silberling, N. J., Irwin, "r· P., and Tatlock, 

D. B., 1959, Preliminary geologic map of the Buffalo 

Mountain quadrangle, Nevada: U.S. Geol. Survey Min. 

Inv. Field Studies Map MF-220. 

Willden, Ronald, 1958, Cretaceous and Tertiary orogeny in 

Jackson Mountains, Humboldt County, Nevada: Am. 

Assoc. Petroleum Geologists Bull., v. 42, p. 2378-2398. 

--in press, Geology of Humboldt County, Nevada: Nevada 

Bur. Mines Bull. 59. 

193. GEOLOGY OF THE MOUNT WHEELER MINE AREA, WHITE PINE COUNTY, NEVADA 

By DoNALD H. WHITEBREAD and DoNALD E. LEE, Menlo Park, Calif. 

Work done in cooperation with the Nevada Bureau of Mines 

The occurrence of the beryllium minerals phenacite, 

bertrandite, and beryl at the Mount vVheeler mine in 

the Snake Range, White Pine County, Nev., has been 

described by Stager (1960). During the past year 

there have been additional discoveries of beryllium 

minerals and fluorite more than a mile north of the 

mine. This paper presents information on the areal 

geology, irith particular emphasis on the limestone 

that is host to the beryllium minerals. 

The area is underlain by the Prospect Mountain 

quartzite, Pioche shale, and Pole Canyon limestone, 

all of Cambrian age, which are folded into a broad 

anticline that plunges gently to the south; a quartz 

monzonite stock is exposed about three miles north 

of the Mount Wheeler mine (fig. 193.1). 

The distribution and lithology of the Pioche shale 

are of particular interest because the known deposits 

of phenacite and bertrandite are in a limestone unit, 

locally known as the "Wheeler limestone," in the lower 

part of the Pioche. At the Mount Wheeler mine the 

bery Ilium is localized along quartz veinlets in the 

"Wheeler limestone" (Stager, 1960, p. 71). The deposit of phenacite, bertrandite, and beryl a mile north 

of the mine and several deposits of fluorite also are in 

this limestone. 

The Pioche shale is chiefly yellowish brown to dark 

greenish gray, micaceous silty shale with minor limestone and quartzite in the lower part; fine-grained 

calcareous quartzite and interbed~ and lenses of limestone make up the upper one-fourth of the formation. 

The Pioche is 450 feet thick on the north side of Pole 

Canyon and 330 feet thick on the south side of Dry 

Canyon; both sections are poorly exposed, and probably both are cut by faults. The contact between the 

Pioche shale and the underlying Prospect Mountain 

quartzite is gradational through a sequence of alternating quartzite and shale; the contact is mapped at the 

top of the uppermost light gray, resistant quartzite. 

Because of lateral variations in lithology, however, 

the contact may not be everywhere at the same 

horizon. ' 

The "'Vheeler limestone" unit of the Pioche shale is 

medium gray to dark bluish gray, thin- to thickbedded limestone; ·some beds are bioclastic, and in 

places there are beds of sandy .limestone. The limestone is commonly recrystallized, as at the portal of 

the ·Mount Wheeler mine, where it is light gray, 

coarsely crystalline marble. The limestone ranges in 

thickness from 8 feet to about 25 feet, and Stager 

( 1960, p. 70) states that it is as much as 50 feet thick 

in the :Mount ~1eeler mine. Near the mine the 

"vVheeler limestone" is about 45 to 65 feet above the 

.base of the Pioche, about 1 mile west of the mine it 

is 27 feet above the base, and in several places it is less 

than 20 feet above the base. An excellent exposure of 

the basal part of the Pioche on the crest of the range 

shows 11 feet of sandy limestone with irregularly interbedded shale about 10 feet above the base, and several beds and lenses of limestone and sandy limestone 

as much as 4 feet thick over an interval of 70 feet 

above the base. The variations described above raise 

the possibility that the "Wheeler limestone" as 
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EXPLANATION 

0 Alluvium and 

colluvium 

Glacial ~ dep<isits 

~~~~~~tigm:;;!!W.1 Quartz monzonite 

m 

li 

t! 

}~ ., 

------ Contact 

Dcuhed where approximatel11 

located 

--"Fs;t-- Dcuhed where approximatel11 

located 

--+--

Anticline 

Showing t?·ace of axial plane 

and direction of plunge. 

Dashed where approximately located 

~ 

Pole Canyon limestone Strike and dip of beds 

~m111 Geology by D. H. Whitebread, A. B. Griggs, 

and W. B. Rogers 

1 0 .1 2 MILES 

Pioche 

-

shale 

H~HH Prospect Mountain 

quartzite 

z 

~ 

r:r: 

m 

~ 

<t 

u 

-~ 

Shaft 

'}-' 

Ad it 

X 

Prospect 

Crest of the range 

APPROXIMATE MEAN 

DECLINATION, !961 

FIGURE 193.1.-Simplified geologic map of the area in the vicinity of the Mount Wheeler mine; Snake ~ange, White Pine County, Nev. 

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C-122 GEOLOGICAL SURVEY RESEARCH 19 61 

mapped may not be a continuous unit, hut actually 

may consist of discrete lenses of limestone that may 

differ slightly in stratigraphic position, but that all 

occur within about a 70-foot zone above the base of 

the Pioche. A lateral change in the "Wheeler limestone" may be indicated along the adit of the Mount 

'Vheeler mine, where Stager ( 1960, p. 70) reported 

that the limestone is almost completely silicified be-, 

yond 3,800 feet east of the portal. A thin section of 

one sample of this "silicified" rock shmvs it is finegrained micaceous quartzite. The field relations have 

not been observed by the writers because poor ventilation prevented access to that part of the mine. 

A possible source o:f the beryllium is the quartz 

monzonite stock, which is exposed as a westwardtrending band 1 to 3 miles wide (fig. 193.1). On the 

west side o:f the range it intrudes the Prospect Mountain quartzite, but to the east it intrudes the Prospect 

~1ountain, Pioche, and the lower part of the Pole 

Canyon formations. Cross sections based on surface 

maps indicate that the intrusive may extend. to the 

south roughly concordant to the bedding in the overlying sedimentary rocks, and, if so, the intrusive may 

be on the order of 1,000 feet below the Mount Wheeler 

mine. No direct relation is apparent, however, between the mineralization of the limestone and the 

proximity of the intrusive. Throughout most of the 

area contact minerals are absent :from the "Wheeler 

limestone"; but on the crest o:f the range, where the 

limestone is about 1,500 :feet horizontally from the 

intrusive, light-green amphibole and light-green pyroxene are developed locally, and scheelite is disseminated in some beds. Quartz veinlets in recrystallized 

lim~stone probably will serve as the most useful guide 

to additional mineral deposits in the "Wheeler limestmi.e." Prospecting in outcrop areas o:f this limestone 

is hindered, however, by the rubble that characteristically covers slopes underlain by the Pioche shale. 

T~e search for beryllium minerals has been mainly 

confined to the "Wheeler limestone," but the possibility o:f beryllium minerals in other rocks should not be 

overlooked. Limestone apparently is the most favorable host rock for the beryllium minerals, as well as 

for the fluorite and scheelite. • Perhaps the "Wheeler 

limestone" is a good host rock because, being the lowest 

limestone in the stratigraphic section, it would be the 

first to be encountered by ascending mineralizing solutions. Prospecting might be rewarding in younger 

limestones, particularly where the Wheeler is absent.• 

REFERENCE 

Stager, H. K., 1960, A n~w beryllium deposit at the Mount 

Wheeler mine, White Pine County, Nevada, in Short 

papers in the geological sciences: U.S. Geol. Survey Prof. 

Paper 400-B, p. B70-B71. 

194. TRITIUM-AGE OF GROUND WATER AT THE NEVADA TEST SITE, NYE COUNTY, NEVADA 

By ALFRED CLEBSCH, JR., Washington, D.C. 

Work done in cooperation with the U.S. Atomic Energy Commission 

Estimates o:f the residence time of water in an 

aquifer are important to several problems in hydrology, particularly to questions concerning the movement o:f medium- and long-lived fission products in 

ground water. Methods o:f estimatin·g the residence 

time by utilizing the natural distribution and radioactive decay rate of tritium, and increases in the tritium concentrations resulting from the testing of hydrogen bombs have been described by Libby (1953), 

Kaufman and Libby ( 1954), von Buttlar and Libby 

(1955), and von Buttlar and Wendt (1958). 

Tritium in the ground water from the Nevada Test 

Site and vicinity suggests a much shorter residence 

time for water in perched aquifers than for water in 

the main aquifer. Analyses of water samples collected 

in 1958 and 1959 from a tunnel, a spring, and five 

wells (fig. 194.1) are reported in table 194.1. The 

samples from the t:unnel and the spring are from 

perched aquifers. 

. In estimating the residence time for the water (underground or in the aquifer) , an average pre-hydrogen bomb tritium concentration of greater than 8 

,. 
.... 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 

116°15' 

37°1~~+-------------------~~7n~ 

NEVADA 

I 

t'\.. 

J 

Base adapted from Army · 

Map Service V502 · 

. o.__..~-_2..___.3_4..__...J 

l!"'IGuuE 194.1.--Map of the Nevada Test Site and vicinity showing tunnel, wells, and springs sampled for 

tritium analysis, and inferred directions of ground-water movement. Shaded areas are higher than 6,000 

feet nbove sea level. Hachures indicate steep slopes. 

C-123 
C-124 GEOLOGICAL SURVEY RESEARCH 1 9 61 

TABLE 194.1.-Tritiu.m.analyses of water samples from the Nevada 

Test Site and vicinity 

[Analyses by L. L. Thatcher, U.S. Geological Survey; analyses completed June 28, 1960] 

ConcanSample location Aquifer Date of tration 

Estimated 

residence 

time a 

(years) 

sampling (T units) I 

Well a _______________ Oak Spring formation ___ . 8- 7-58 <0.5 >50 Do _____ ------ _________ do___________________ 4-21-59 <.5 >50 

Well5A______________ Alluvium __ ------------- 2-26-59 <.5 >50 Well5C ___________________ do___________________ 2-26-59 <.5 >50 

Well J 11------------- Oak Spring formation___ 8- 7-58 <.5 >50 Do ____________________ do ____________ ------_ 4-21-59 <.5 >50 

Well15S/49-14aaL ___ Alluvium_______________ 1-28-59 <.5 >50 

Whiterock Spring____ Oak Spring formation___ 8- 7-58 34 < 6 >0.8 Tunnel U12e.05 ___________ do___________________ 9-12-58 36 < 6 >0.8 

t One tritium unit equals 1 atom of tritium per 1QIS atoms of protium. 2 Based on an average pre-1952 tritium concentration in precipitation of >8 <35 

T units. 

T-units (tritium units; one T-unit equals 1 atoni of 

tritium per 1018 atoms of protium) and less than 35 

T-units is assumed, based on analyses of Chicago precipitation by Kaufman and Libby · (1954) and von 

Buttlar and Libby . ( 1955). The only pre-hydrogen 

bomb tritum analyses of precipitation available are 

those made at Chicago. 

The tritium analyses (table 194.1) indicate that 

water in the aquifers. tapped by supply wells on the 

Nevada Test Site and one nearby off-site well had an 

apparent residence time of more than 50 years. If 

the natural tritium level was higher than 8 T -units, 

water from all the wells sampled would be older than 

indicated in table 194.1. On the other hand, water in 

perched aquifers in the high areas has been recharged 

since 1952, as indicated by the tritium samples from 

Whiterock Spring and tunnel U12e.05 (site of the 

Blanca explosion of October 30, 1958). 

Since the fall of 1952 the tritium content of atmospheric water has been highly vari~ble as a result of 

hydrogen-bomb tests. The first increase in tritium concentration due to bomb testing resulted in a concentration of tritium in precipitation of 66-+-1 T-units at 

Chicago on November 18, 1952. In the periods MarchJuly 1954 and March-September 1956, tritium in Chic.ago rainfall exceeded about 100 T -units and between 

December 18, 1957, and July 29, 1958, the tritium level 

in Chicago rain and snow (and presumably in Nevada 

precipitation) ranged from a minimum of 54.0 T-units 

to a maximum of 2160.0 T-units (Barrett· and Huebner, 1960).. Between these "peaks" the tritium level 

decreased considerably, sometimes to less than 10 

T-units. 

Many different mixtures of old water with water 

that entered the aquifer since 1952 might result in the 

tritium concentration shown by the samples of perched 

water, but if the aquifers had been recharged significantly during one of the "peaks," the tritium concentration should have been higher. 

The above interpretations are somewhat tentative 

because they are based almost entirely on the tritium 

concentration in Chicago precipitation, and there may 

have been geographic variations that would invalidate 

the interpretations (C. W. Carlston, U.S. Geol. Survey, written communication, January 16, 1961). Geographic variations seem unlikely, however, in view 

of the general agreement found by von Buttlar and 

Wendt ( 1958) between their analytical data for precipitation in New Mexico, and the analytical data for 

precipitation in Chicago. 

Underground nuclear tests in Rainier Mesa (fig. 

194.1) produced strontium-90 that has been taken 

. .into solution by perched ground water ( Clebsch and 

Barker, 1960). It is important to know whether the 

contaminated water is likely to reach wells that are 

utilized for water supplies and what the concentration 

of' contaminants might be when the ground water 

reaches the wells. This requires a know ledge of the 

rates and directions of ground-water movement, both 

of which are poorly known at present. The tritiumage interpretations, however, provide a basis for estimating the minimum time required for movementand certain inferences can be drawn about the directions of movement. 

One may infer that the Rainier· Mesa-Shoshone 

Mountain highland is an area of ground-water replenishment, inasmuch as orographic effects should 

re!;mlt in appreciably greater precipitation on the 

mountains than that measured in the adjacent valleys 

and closed basins. In 1960 the .precipitation was 8-9 

inches on Rftinier Mesa and 4-5 inches in Yucca 

Valley and Jackass Flats. One may also infer that 

much. of the perched water ultimately reaches the 

main aquifer, because of the scarcity and small discharge of nearby springs and virtual absence of vegetation dependent upon ground water. The natural 

discharge area for this hydrologic system probably 

is the Ash Meadows-Death Valley· Junction area south 

of Lathrop Wells (Clebsch, 1960). A generalized interpretation of the probable flow pattern is shown on 

figure ·194.1. . 

If perched water contaminated with strontium-90 

moves to one of the wells sampled, 40 years or more 

will be required for travel. In this time, the strontium-90 activity would have been reduced to about 35 

percent of its concentration at the site of the explosion 

by radioactive decay alone. Physical and chemical 

+ 
.. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-125 

processes such as diffusion, dispersion, and ion exchange should further reduce the concentration of 

activity, possibly by several orders of magnitude. 

REFERENCES 

Barrett, E. W., and Huebner, Leonid, 1960, Atmospheric tritium analysis: Chicago Univ., Tech. Progress Rept. No. 2, 

Contrnct AT (11-1)-636, Feb. 16. 

Clebsch, Alfred, Jr., 1960, Ground water in the Oak Spring 

formation and hydrologic effects of underground nuclear 

explosions at the Nevada Test Site: U.S. Geol. Survey 

'l'EI 759, 29 p. (Available fro)ll Office of Tech. Services, 

U.S. Dept. Commerce, Was~ington 25, D.C.) 

Clebsch, Alfred, Jr., and Barker, F. B., 1960, Analyses of 

ground water from Rainier Mesa, Nevada Test Site, Nye 

County, Nevada: U.S. Geol. Survey TEl 763 (open-file 

rept.) 22 p. · 

Kaufman, Sheldon, and Libby, W. F., 1954, The natural distribution of tritium: Phys. Rev., v. 93, no. 6, p. 1337-1344, 

March 15. 

Libby, W. F., 1953, The potential usefulness of natural tritium: [U.S.] Natl. Acad. Sci. Proc., v. 39, p. 245-247. 

von Buttlar, Haro, and Libby, W. F., 1955, Natural distribution of cosmic-ray produced tritium II: Inorg. Nucl. Chern. 

Jour., v. 1, no. 1, p. 75-91. 

von Buttlar, Haro, and Wendt, Immo, 1958, Ground-water 

studies in New Mexico using tritium as a tracer: Am. 

Geophys. Union Trans., v. 39, no. 4, p. 660-668. 

195. PROPOSED CLASSIFICATION OF GROUND-WATER PROVINCES, HYDROLOGIC UNITS, AND\CHEMICAL 

TYPES OF GROUND WATER IN THE UPPER COLORADO RIVER BASIN.. . 

By DAviD A.. PHOENix, Salt Lake City, Utah 

In 1958, the Geological Survey st~rted the Upper 

Colorado River hydrologic studies project to gather 

and analyze information about the water resources 

of the upper basin in order to provide a basis for 

intelligent planning of future water developments in 

the basin. 

~T ork on the phases of the project concerned with 

ground water has resulted in (a) the division of the 

upper basin into 6 ground-water provinces; (b) a 

broad grouping of the rocks into 7 hydrologic units, 

each defined in terms of its potential ground-water 

yield; n.nd (c) a classification of ground waters from 

springs, and from wells mostly less than 1,500 feet 

deep, by their content of dissolved solids. 

The six ground-water provinces (fig. 19.5.1) recognized in the upper basin facilitate descriptions of the 

occurrence and chemical character of the ground 

wn.ter. The provinces, which differ from those of 

~1einzer (1923, p. 309-310), are based mainly upon 

the geology, and are separated in most places by 

ground-wnter divides. Four of the provinces, the 

Green River-Washakie, the Uinta-Piceance, the San 

Juan, and the Black Mesa are large structural basins 

in which the general occurrence and quality of ground 

water are similar and relatively uniform. Permeable 

beds receive ground-water recharge in the peripheral 

areas of these provinces and contain mineralized 

ground water under artesian pressure in the central 

areas. In the Canyon Lands province the strata are 

more complexly folded and locally are intruded by 

igneous rocks. In the Rocky Mountain province, 

granite, metamorphic, and volcanic rocks yield small 

supplies of excellent water, largely from joints. The 

sedimentary rocks in this province yield water to 

springs along the outcrops and to wells near the outcrops. 

The water-bearing rocks in the upper basin, including the consolidated rocks in almost -200 formations 

and the alluvium along the flood plains and stream 

terraces, can be grouped into seven major units according to their geologic and hydrologic properties. 

Unit 1, the alluvium which is found in all the provinces, is recharged during periods of high stream flow, 

and during the irrigation season much of this water 

returns to the streams laden with sodium, chloride, and 

sulfate, and in some areas nitrate. Three of the seyen 

hydrologic units, units 2, 3, and 5, consist chiefly of 

thick deposits of shale and siltstone, which cover about 

70 percent of the region to great depths. They yield 

but little water and serve mainly to confine artesian 

water in underlying aquifers. In some places shallow 

wells in these units yield small amounts of water for 

livestock, but the water generally is highly mineralized except near recharge areas. The sandstone of 
C-126 GEOLOGICAL SURVEY RESEARCH 19 61 

0 

Idaho Falls 

IDAHO WYOMING 

..... 

·······~os· ::: 

·· ...... _ .... .. 

INDEX TO GROUND-WATER PROVINCES 

OCheyenne 

0 

Salt Lake City COLORADO 

UTAH Denver 

0 

Santa FeO 

NEW MEXICO 

ARIZONA 0 ?5 50 75 100 .125 MILES 

EXPLANATION 

Fluvial deposits beneath and 

bordering stream terraces 

and flood plains 

40-400 feet thick 

Lacustrine deposits of shale 

Maximum thickness about 7,000feet 

Marine deposits of sandstone 

and shale 

Maximum thickness about 

12,000feet 

Mostly continental •deposits of 

quartzose sandstone 

Maximum thickness about 3,500feet 

Continental and marine 

deposits of shale 

Maximum thickness about 1,500feet 

Mostly marine deposits of 

limestone and shale 

Maximum thickness about 8,000 feet 

in southwestern Colorado and 

southeastern Utah 

Igneous and metamorphic 

rocks undifferentiated 

Drainage divide 

Ground-water divide 

Shown whete not coincident with 

drainage divide 

FIGURE 195.1.-Maps showing ground-water provinces and major hydrologic units in the Upper Colorado River Basin. 

. .I 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-127 

unit 4 yields "'a.ter to flowing artesian wells in many 

parts of the Canyon Lands, Black Mesa, San Juan and 

Ui nbt-P:iceance provinces. The water generally is of 

good quality within n, few miles of the recharge areas, 

but at greater distance from the outcrop the water 

locnJly is too highly mineralized for most uses. Over 

.large n,rens, particularly in the Canyon Lands province, the sandstones are deeply dissected and much or 

all of the water is clrained out. The oldest sedimentary rocks in the region, in unit 6, comprise aquifers 

that differ gren,t]y from place to place. In parts of 

the Canyon J....~ands province where the rocks contain 

suJine minerllils they yield only brine; but in the Rocky 

l\1:ounta:in and Black l\1esa p·rovinces, where limestone 

or sandstone is the dominant rock, they locally yield 

supplies of wnter suitnble for domestic, stock, and 

municipal neeqs. · Unit 7, composed of igneous and 

metamorphic rocks, is restricted mostly to mountainous areas in all the provinces. In places where they 

are weathered or jointed, these rocks yield small supplies of excellent water; elsewhere they are generally 

unproductive. 

The rocks of the Rocky l\1ountain province contribute water of excellent quality to the streams. The 

rocks in most other provinces, particularly those including shales of .marine origin, contribute consider-. 

able amounts of dissolved solids to the streams. Thus, 

during periods of low streamflow, when the flow of the 

Colorado River and :its tributaries consists almost 

wholly of ground-water discharge, the water becomes 

progressively harder and more concentrated in dissolved solids toward the mouth of the upper basin. 

The water-bearing strata in each of the hydrologic 

units yield water that differs chemically from place to 

place, depending upon the source of supply, distance, 

and rate of ground-water movement, and the mineralogy of the aquifers. However, a study of about 1,000 

analyses of ground water indicates that the waters 

in all the units are characterized by the dominance of 

one cation and one anion, and the sequence of chemical 

types is almost the same for all seven units. In order 

of increasing concentration of dissolved solids the 

dominant ions are : less than 300 ppm (parts per mi 1-

lion) of dissolved solids, calcium and bicarbonate; 

300-700 ppm, sodium and bicarbonate; 700-3,500 ppm, 

sodium and sulfate; and more than 3,500 ppm, sodium 

and chloride. Bicarbonate also is present in waters 

having total concentrations up to about 5,500 ppm, but 

is not a major constituent, and sulfate also is present 

in waters having total concentrations up to 10,000 

ppm. This progressive increase of total dissolved 

solids in the water results in chemical changes that 

ultimately make the water unfit for use. 

The aquifers in the Upper Colorado River Basin 

are not highly productive, so the larger cities and 

towns must rely on surface-water supplies. However, 

the limited supplies of ground water are of considerable value for domestic and stock supplies and small 

industrial or town needs, and additional supplies can 

be developed in many places where supplies of surface 

"·ater are not available. 

REFERENCE 

Meinzer, 0. E., 1923, The occurrence of ground water in the 

United States, with a discussion of principles: U.S. Geol. 

Survey ·water-Supply Paper 489, 321 p. 

196. METAMORPHISM AND STRUCTURAL HISTORY OF THE COAL CREEK AREA, FRONT RANGE, COLORADO 

By JonN D. WELLS, DouGLAS M. SHEJUDAN, and ARDEN L. ALBEE, Denver, Colo .. , and Pasadena, Calif. · 

Three periods of deformntion and metamorphism 

during Precambrian time, one of which ~vas accompained by igneous intrusion, produced the quartzite, 

schist, n,nd gneiss of the Coal Creek area (fig. 196.1). 

A simplified geologic map of the Coal Creek area 

(fig. 106.2) shows the major lithologic groups. The 

metasedimentary rock units· included in table 196.1 

are combined into groups, as shown in the explanation 

of figure 196.2, that have similar gross lithologic features. The igneous rocks are grouped as one unit. 

Rocks are grouped into the cataclastic rock unit where 

cataclasis is so extreme that the original unit cannot 

be recognized. 

The quartzite and schist in quartzite occur in the 

central and northern parts of the area and outline the 

northeast-plunging Coal Creek syncline. South of 
C-128 GEOLOGICAL SURVEY RESEARCH 1 9 61 

Longmont& 

BOULDER 

10 10 MILES 

FIGURE 196.1.-Index map showing location of the Coal Creek 

area, Colo. 

this qua1tzite and schist mass is a succession including 

biotite-quartz-plagioclase gneiss, microcline-quartzplagioclase-biotite gneiss, lime silicate rocks, amphibolite, and schist typical of the Idaho Springs formation. 

The igneous rocks consist almost exclusively of two 

units : a part of the Boulder Creek batholith and a 

·younger quartz monzonite. These are present southeast and north west of the Coal Creek syncline. Very 

small amounts o.f pegmatite, aplite, and hornblendite 

and associated ·hornblende diorite are present, but 

these are not significant in this discussion and will not 

be considered further. 

The rocks of the Boulder Creek batholith are me- · 

diulll grained and gray, ranging in composition from 

quartz monzonite to quartz diorite, and consisting essentially of quartz, -feldspar, and biotite. The quartz 

monzonite unit is_ fine grained and tan, ranging in 

composition from granite to granodiorite, and consisting essentially of quartz, feldspar, biotite, and muscovite. The quartz monzonite contains inclusions of 

the Boulder Creek rocks and, therefore, is younger. 

These rocks, however, are intimately mixed with irregular mutual contacts and interdiki11g relations, and 

both units have about the same structural history. 

These factors indicate that these rocks are closely associated in time and origin. 

The igneous and metasedimentary rocks have been 

granulated in varying degrees of intensity in the 

northeast-trending cataclastic zone (fig. 196.2), which 

is as much as 1.5 miles wide. This cataclastic zone 

is considered to be part of the Idaho Spri11gs-Ralston 

shear zone (Tweto and Sims, 1960) .. 

Upturned Paleozoic and Mesozoic sedimentary rocks 

flank the area on the east side. The northwest-trending faults show Laramide movement. 

The earliest recognized period of Precambrian deformation was plastic folding which formed mineral 

lineations that plunge predominantly south-southwest. 

These lineations are in the metasedimentary rocks but 

not in the igneous rocks. The second recognized period was plastic folding that (a) warped the southsouthwest plung~ng mineral alinements, (b) formed 

the Coal Creek syncline which plunges east-northeast 

and minor folds that locally plunge west-southwest, 

and (c) formed mineral lineations in the metasedimentary and igneous rocks that plunge nearly south. 

The intrusion of the igneous rocks accompanied the 

second period of folding. These rocks cut the folded 

quartzite and schist and engulfed large bodies of 

them; Boulder Creek rocks intruded the Coal Creek 

syncline and formed a phacolith. The igneous rocks 

were deformed by pervasive, minor cataclasis, possibly 

as a result of differential movement near the quartzite 

contact and were folded to a minor extent. The 

parallelism of the nearly south-plunging mineral 

a.linements in the metasedimentary and igneous rocks 

indicates that alinements in both rocks were formed 

by the same deformation. 

The third period of deformation formed the cataclastic zone south of the axis of the Coal Creek syncline. The foliation formed by this deformation cuts 

layering in the metasedimentary rocks and earlier 

forme.d foliation in the igneous rocks. This deformation obilterated all preexisting structures in some areas 

and modified structures in others. 

Metamorphism of the Coal Creek area is believed to 

be closely related to the structural and intrusive history. The metamorphic rocks fall into three categories that are correlative with the three periods of structural deformation : (a) rocks containing mineral assemblages of high -grade regional metamorphism 

formed during the first two periods of deformation; 

(b) rocks containing new high-grade mineral assemblages· in part superimposed on earlier assemblages, 

suggesting fluctuations in pressure, temperature, and 

other variables during a complex history of folding 

and intrqsion; and (c) rocks in which the earlier highgrade mineral assemblages were modified textur~lly 

and structurally by cataclasis, and variably recrystallize~ but with only minor retrogression. 

+ 
,-

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

EXPLANATION 

Rocks of the Boulder Creek 

batholith and quartz monzonite 

Cataclastic rocks 

Schist in quartzite, and interlayered biotite-quartz-plagioclase gneiss and quartzmica schist 

Quartzite 

Qmirtz-mica schist 

Amphibolite and lime 

· silicate rocks 

Microcline-quartz-plagioclasebiotite gneiss and interlayered rocks 

0 

z 

<( 

0:: 

Ill 

~ 

<( 

u 

w 

0:: 

a.. 

~ 

Contact 

Fault 

---+-t-~ Anticline 

Showing direction of plunge 

Syncline 

Showing direction of plunge 

2 3 MILES 

FIGURE 196.2.-Simplified geologic map of the Coal Creek area. 

N 

C-129 
C-130 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

l\1ost of the mineral suites of the Coal Creek area 

are typical of the gneiss and schist of the Idaho 

Springs formation and are common and widespread 

in the east-central Front Range. These mineral suites 

and the relatively uncommon suites from the quartzite 

and schist in the Coal Creek area are shown in table 

196.1, which lists the significant minerals in each metasedimentary rock type followed by notes on their 

paragenetic relations. 

The common mineral suite of muscovite with sillimanite (category 1) is correlative with the lower 

sillimanite zone (Heald, 1950, and Thompson, 1957) 

TA~LE 196.1.-Sttites of significant minerals in each metasedimentm·y rock type with notes on paragenesis 

[Note: Quartz is present in all specimens except amphibolite] 

Microline-quartz-plagioclase-biotite gneiss and interlayered 

rocks : Microcline, plagioclase (oligoclase), biotite, epidote. 

(hornblende, garnet-from Ralston Buttes quadrangle) 

Amphibolite and lime silicate rocks : 

Hornblende, plagioclase (andesine), epidote, clinopyroxene, 

calcite. (garnet, cummingtonite, tremolite, microcline, 

scapolite, vesuvianite-from Ralston Buttes quadrangle) 

Quartz-mica schist : 

Muscovite, biotite, plagioclase (oligoclase), sillimanite, 

garnet (mostly almandine), andalusite, microcline. 

Sillimanite needles in microline and muscovite. 

Sillimanite needles replacing biotite. 

Fine-grained muscovite replacing ·sillimanite glomeroporphyroblasts. 

Biotite and muscovite pseudomorphous after staurolite. 

Sillimanite, instead of andalusite, common south of 

Coal Creek area. 

Interlayered biotite-quartz-plagioclase gneiss and quartz-mica 

schist: 

Muscovite, biotite, plagioclase (oligoclase), microcline, 

sillimanite, andalusite. 

Sillimanite needles in muscovite and microcline. 

Quartzite: 

Muscovite, andalusite, plagioclase, microcline (detrital), 

sillimanite, biotite. 

Muscovite replacing biotite in specimen with andalusite. 

Sillimanite replacing muscovite a fraction of a millimeter from andalusite. 

Schist in quartzsite: 

Muscovite, biotite, plagioclase (oligoclase), cordierite, 

andalusite, garnet (spessartite and almandine), staurolite. 

Andalusite, younger; poikilitically includes staurolite 

and some biotite and muscovite; almandine garnet 

nearby. 

Cordierite about same age as andalusite, both of 

which are younger than early folding inasmuch as 

cordierite poikilitically includes folds. 

Transverse orientation of biotite. 

Lime silicate-quartz rock in schist in quartzite (in bodies too 

small to be sho"•n on figure 196.2) : 

Epidote, plagioclase (oligoclase-andesine) , microcline, 

tremolite, garnet. 

while the local occurrence of the critical assemblage 

sillimanite with microcline (category 1) indicates that 

the highest metamorphic grade reached is correlative 

to the higher sillimanite zone. Inasmuch as sillimanite is both replaced by and replaces micas, multiple generations of these minerals must have occurred. 

The earliest crystallization of sillimanite cannot be 

determined with certainity, but it must have occurred 

as early as the second and possibly the first deformation. During the second deformation andalusite and 

cordierite (category 2) crystallized poikiloblastically. 

Poikilitic inclusions of staurolite (category 1), as well 

as opaque minerals, quartz, and muscovite that outline 

microfolds, are probably relicts of the first deformation. It seems "likely that the andalusite and cordierite were formed at the time that the igneous rocks 

were intruded. The position of andalusite relative to 

sillimanite and kyanite (Thompson, 1955, fig. 3, p. 

97) suggests that this period was characterized by 

relatively lower pressure· and (or) relatively lower 

temperature than during metamorphism when sillimanitic schist was formed. 

There seems to be some spatial relation between the 

distribution of andalusite, sillimanite, and quartz 

monzonite. Andalusite is abundant in the quartzite 

and schist along Coal Creek, where both the quartz 

monzonite and the Boulder Creek rocks are abundant, 

but sillimanite rather than andalusite is found where 

only Boulder Creek rocks are exposed farther south 

in the Ralston Buttes quadrangle. 

Despite this spatial relation, these rocks are not true 

contact metamorphic rocks; no typical contact metamorphism is noted at the igneous contacts. Only a 

thin micaceous selvage is formed along the contact 

with the quartzite and no effect is seen in other rock 

types. The various "contact" and "regional" suites 

are interlayered, and they extend over rather large 

areas. We suggest that the observed mineralogic 

differences are caused by different metamorphic environments, probably related to the syntectonic Intrusive activity. 

The late Precambrian cataclastic deformation mechanically deformed part of the metasedimentary and 

igneous rocks. The cataclasis reduced the grain size 

and changed th~ texture ; some rocks were recrystallized (category 3). Late poikilitic muscovite crystallized with biotite and a few needles of sillimanite. 

Potassic feldspar became more perthitic and all feldspars became less well-twinned than before. Late 

microcline filled small fractures. Only minor retrogression accompanied cataclasis, more muscovite was 

formed and, locally, chlorite replaced biotite. 

t 

'(. 

,II 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC' SCIENCES, ARTICLES 14 7-2 9·2 C-131 

REFERENCES 

Heald, l\f. 'l'., 1950, Structure and petrology of the Lovewell 

l\1ountnin qundrnngle, New Hampshire: Geol. Soc. America 

Bull., v. 61, p. 43-89. 

'l'hompson, J. B., Jr., 1955, The thermodynamic basis for the 

mineral facies concept: Am. Jour ·sci., v. 253, no. 2, p. 

65-103. 

--- 1957,· The graphical analysis of mineral assemblages 

in pelitic schists : Am. Mineralogist, v. 42, p. 842-858. 

Tweto, Ogden, and Sims, P. K., 1960, Relation of the Colorado 

Mineral Belt to Precambrian structure, in Short papers 

in the geological sciences: U.S. Geol. Survey Prof. Paper 

400-B, p. B8-B9. 

197. EARLY AND LATE GROWTH OF THE GYPSUM VALLEY SALT ANTICLINE, SAN MIGUEL COUNTY, COLORADO 

By E. R. LANDIS, E. M. SHOEl\IAKER, and D. P. ELSTON, Denver, Colo., and ~{enlo Park, Calif. 

Work (lone "in cooperation with the Division of Research, U.S. Atomic Energy Commission 

The Gypsum Valley salt anticline, in southwestern 

Colorado is one of the major salt anticlines of the 

Paradox basin (fig. 197.1). Detailed structural, stratigraphic, and paleontologic investigations in southm"tstern Gypsum Valley indicate that the earliest stages . . . 

C]I? 

Salt core of anticline 10 0 10 MILES 

·of growth of the salt structure occurred in Middle 

Pennsylvanian (Des ~{oines) time, and that the latest 

stages of growth appear to have occurred in Late 

Cretaceous (upper Carlile and Niobrara) time. Unconformable relations between the leached cap of the 

c=J 

Outcrop area of 

Cretaceous rocks 

Area shown 

~ 

on figure 197.2 

2-l 

Location of meas~red sections 

Outcrop area of pre-Cretaceous rocks 

1 0 1 MILES 

FIGURE 197.1.-Index maps of salt anticline region, Utah and Colorado, and the Gypsum Gap quadrangle, Colorado. 
C-132 

500 

GEOLOGICAL 

CONTOUR . AL 20 FEET INTERV 

SURVEY RESEARCH 1 9 6 1 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-2.92 

1! l 

B 

'Alluvium 

Residual gypsiferous mantle 

B 

Gravel deposits 

UNCONFORMITY 

Mesaverde formation 

Mancos shale 

UNCONFORMITY 

B 

Burro Canyon(?) formation 

EXPLANATION 

>-

0:: 

<( 

z 

0:: 

w 

1-

<( 

:::> 

0 

(/) 

:::> 

0· 

w 

u 

<( 

1-

w 

0:: 

u 

Salt Wash sandstone member of Morrison formation 

Entrada sandstone 

UNCONFORMITY 

Chinle formation 

UNCONFORMITY 

Cutler formation 

UNCONFORMITY 

Rico formation 

Numbers on map refer to units 

shoum on figure ·t97.3 

Hermosa formation 

Phu, upper member. NumberR 

on map refer to units shown. 

Ph p 1, upper part of exposed 

Paradox member. 

IPhp2, middle part of exposed 

Paradox member; claystone 

is dotted; brecciated dolomite 

and limestone is in black. 

Php3, lowest part of exposed 

Paradox member; claystone 

is dotted 

u 

H 

1-

z 

H 11. 

z 

~ 

z 

<( 

> 

J 

>-

(/) 

z 

z 

w 

11. 

(f) 

5· 

0:: 

w 

ll. z' 

0 

m 

0:: 

<( 

u 

~-------.. _ 

Contact 

Dashed where approximately 

located; dotted where concealed 

~---..... . 

Fault 

Dashed where approximately 

located; dotted where concealed. U, upthrown side; 

D, downthrown side 

------+----------. 

Anticline 

Dotted where concealed 

---------+-------· .. Syncline 

Dotted where concealed 

35 

..L 

Strike and dip of beds 

Approximate strike and dip direction of contorted beds 

c 

Prospect 

Explanation for figure 197.2. 

C-133 
C-134 · GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

A A' 

7000' 7000' 

6500' 

6000' 

FIGURE 197.3.-Section A-A' across part of southeastern Gypsum Valley. Symbols explained on map (fig. 197.2) 

and measured sections (fig. 197.4). 

salt-bearing Paradox member and the limestone-bearing upper member of the Hermosa formation of Middie Pennsylvanian age indicate that growth of the 

Paradox Valley and Gypsum Valley anticlines began 

prior to the end of deposition of the Hermosa formation (Elston and Landis, 1960; Elston and Shoemaker, 

1960). The salt anticlines apparently grew gradually 

during l\{iddle and L~tte Pennsylvanian, and Permian 

time, and a thick sequence of "post-salt" Paleozoic 

rocks was deposited adjacent to the salt structures. 

The Gypsum Valley anticline is underlain by a thick 

elongate northwest-trending salt core, about 2 to 3 

miles wide, more than 25 miles long, and more than 

10,000 feet thick. The salt core, and an overlying 

leached cap that crops out on the valley floor, are rocks 

of the Paradox member of the Hermosa formation of 

l\{iddle Pennsylvanian age (Bass, 1944; Cater, 1955a). 

Deep drill holes have penetrated about 4,000 feet of 

"post-salt" Paleozoic rocks beneath the south flank of 

the anticline, and about 8,500 feet of "post-salt" 

Paleozoic rocks beneath the north flank. These rocks 

thin and pinch out against the salt structure, and 

Mesozoic strata directly overlie the leached cap of the 

salt core. 

Although structurally .complex in detail, the leached 

cap in southeast Gypsum Valley is structurally simple 

in gross view; the units of the Pa'i·adox are folded into 

a broad anticlinal flexure upon which smaller folds 

are superimposed. Rocks of the Paradox member directly underlying the upper member of the Hermosa 

in southeast Gypsum Valley (figs. 197.2 and 197.3) 

have been traced for a distance of about 1 mile to the 

northwest, across the crest of the anticline, where the 

lower two of the three exposed map units of the Paradox are overlain unconformably by the Salt Wash 

member of the Morrison formation of Jurassic age. 

The relations here indicate that no great extrusion of 

the caprock occurred during growth of the salt structure, although leaching of salt from the anticlinal core 

has resulted in the development of internally disrupted units interbedded in gypsum. Similary, a 

gross simplicity of the cores also exists in Paradox 

Valley (rna pped by Elston) and in Sin bad Valley 

(rna pped by Shoemaker) . . 

In southeast Gypsum Valley, the lowest exposed 

unit (fig. 197.2) of the Paradox member consists 

dominantly of gypsum with discontinuous dark-gray 

claystone beds, the middle unit (fig. 197.2) consists of 

interbedded gypsum and greenish-gray to dark-gray 

claystone, and some dark-gray limestone and dolomite beds at the top, and the upper unit (fig. 197.2) 

consists of light-gray to yellowish-gray dolomite, darkto light-gray claystone and siltstone, and subordinate 

sandstone. The upper unit, which generally is transitional into the upper member of the Hermosa :formation, locally appears to be separated from it by 

an unconformity that possibly is equivalent to unconformities mapped beneath the upper member in 

northwest Gypsum Valley (Elston and Landis, 1960), 

and in Paradox Valley. Fossils indicate a late Middle Pennsylvanian (Des Moines) age for the upper 

member of the Hermosa formation and for most of 

the overlying Rico formation on the south flank of 

the Gypsum Valley anticline (Hunt's Hole section, 

fig. 197.4 and table 197.1) ; the remainder of the Rico 

formation is Late Pennsylvanian in age. The Hunt's 

Hole section (fig. 197.4) correlates lithologically with 

the section in the map area (fig. 197.2) where the 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-2.92 C-135 

faunn are generally sparse and are not critically diagnostic of age. 

Growth of the salt structure is. recorded by the 

pinchout of rock units of late Paleozoic to Late 

Jurassic age against the salt structure. Locally, in 

southeast Gypsum Valley, rocks of Late Jurassic and 

Early Cretaceous age, and some rocks of Late Cretaceous age, also appear to thin and pinch out over the 

salt structure. In and adjacent to the map area (fig. 

197.2) the Mancos shale of Late Cretaceous age overlies rocks ranging in age from Middle Pennsylvanian 

to Early Cretaceous. Near Gypsum Valley the Mancos is about 3,000 feet thick (Stokes and Phoenix, 

1948; Cater 1955a), but in the mapped area (fig. 

197.2) the maximum exposed thickness is about 200 

feet. The contact of the Mancos with older rocks is 

generally poorly exposed, but where seen it seems to 

be depositional. The Mesaverde formation of Late 

Cretaceous age, which conformably overlies the Mancos, crops out in the eastern part of the area mapped, 

and extends 6 miles to the southeast in an asymmetrically down warped area (Vogel, 1960). The authors interpret this feature to be a syncline formed 

by subsidence over the salt core of the Gypsum Valley anticline. This feature appears to be similar to 

the Coke Ovens syncline that overlies the southeast 

end of the Paradox Valley salt structure (Cater, 1955b; 

Shoemaker and others, 1958). The southern margin 

of the salt core of the Gypsum Valley structure a-pparently is delimited in the southeast part of the 

TAl~I.J~ 197.1.-Fossils collected from Hunt's I-lole measured 

section, southeastern Gypsum Valley, Colo. 

[Fossils ldcntlflcd by E. L. Yochclson, aided by David Delo, Jr., I. G. Sohn; L. G 

Hcnbcst, and Helen Duncan] 

U.S. Ocolog- lcal Survey locality 

19130-PC 

19129-PC 

Fossils Age assigned to diag- nostic fossils 

Linoprod'uct'ltS meniscus 

and Condra. 

Neospirifer cf. N. latus 

n.nd Condrn. 

Dunbar} . Early Late 

Dunbar Pennsylvanian. 

Juresania? sp. indet. 

"Dictyoclostus" cf. "D" san us (Girty). 

Composita subtilita (Hall) 

Crinoid stems 

Compos£ta subtil-ita (Hall) 

Phricodothyris perplexa 

(McChesney). 

Terabratuloid? indet. 

hermoAllorisma cf. A. terminale (Hall) 

Bairdia spp. 

Rectobairdia sp. 

Barlandia perparva Plummer 

Osagia sp. 

Calcitornellids 

Apterrinella? sp. 

Spiroloculina sp. 

Clim.acammina sp. 

Tetrataxis sp. 

TABLE 197.1.-Fossils collected from Hunt's Hole measured 

section, southeastern Gypsum Valley, Colo.-Continued 

U.S. Geolog- ical Survey locality 

19129-PC 

19128-PC 

19127-PC 

19126-PC 

Fossils 

Bradyina magna Roth and 

Skinner. 

Millerella sp. 

Fusulina lonsdalensis Dunbar 

and Henbest. 

"Dictyoclostus" hermosa nus (Girty). 

Composita subtilita (Hall) 

Phricodothy.ris sp. indet. 

Algae? 

Crinoid stems and plates 

Incrusting bryozoan 

Rhomboporoid bryozoan 

Linoproductid brachiopod 

Composita sp. 

Nuculana? sp. indet. 

Perm_ophorus? sp. indet. 

Allorisma sp. indet. 

Small pelecypods indet. 

Bellerophontacean indet. 

"Strobeus" sp. indet. 

Gastropod with spirallirae indet. 

Horn coral indet. 

Crinoid stems 

Rhomboporoid bryozoan 

Ramose and incrusting bryo- zoans. Meekella striqtocostata (Cox) 

Derbyia cf. D. crassa (M and H.) 

Linoproductus ~eniscus Dunbar 

and Condra. 11 Dictyoclostus" hermosanus 

(Girty). 

Juresania nebrascensis (Owen) 

Composita subtilita (Hall) 

Neospirifer sp. indet. 

Nuculana sp. indet. 

Permophorus? sp. indet. 

Septimyalina? sp. indet. 

Aviculopecten cf. A. occidentalis 

(Shumard). 

Bellerophon sp. indet. 

N eritacean? indet. 

High-spired gastropod indet. 

19125-PC Plant scraps indet. 

Sansabella sp. 

19124-PC Crinoid stems 

Echinoid debris 

Prismopora triangulata (White) 

Com.posita sp. 

Crurithyris sp. 

Spiriferoid brachiopod (fragment). 

Pectenoid pelecypod (fragment) 

19123-PC Linoproductus sp. indet. 

Cancrinella? sp~· indet. 11 Dictyoclostus'' her100sanus 

(Girty). 

Neospirifer? sp. indet. Con~posita subtilita (Hall) 

Spirifer cf. S. boonensis Swallow 

Allorisma? sp. indet. 

Fasciculopecten cf. F. knighti 

Newell. 

Myalinid pelecypod indet. 

M etoptoma sp. indet. 

Age assigned to diag- nostic fossils 

Late Middle 

Pennsylvanian. 

Middle Pennsylvanian. 

Middle Pennsylvanian. 

Middle Pennsylvanian. 

Late Paleozoic. 

Middle Pennsylvanian. 

Middle Pennsylvanian. 
C-136 GEOLOGICAL SURVEY RESEARCH 19 61 

map area by thin wedges of Mesozoic strata against 

which the Mancos was deposited. · 

Fossils collected from the lowermost Mancos,. where 

it rests directly on the Paradox in the northeastern 

part of the ·:map area, were identified as Niobrara m 

2 

Hunts Hole 

SALT WASH MEMBER . ·.·: 

OF MORRISON · 

FORMATION 

(JURASSIC) Y 

-. 

EXPLANATION 

c::::::z=::z=J 

Dolomite 

. o:::::::cJ 

Limestone 

·c:::cz=o Dolomitic limestone 

cz::::c::z::J 

. Limy dolomite 

-~ 

· '' Siltstone 

1- I 

Claystone 

1-fV'>-1 

Clayey siltstone 

., .. ·r"" I 

Sil!y claystone 

: 

~ 

Sandstone 

~ 

.- Silty 

· 

~ 

. Clayey 

. 'r::=::::::::=J 

: -'sand~-· 

~ 

Dolomitic 

~­

Limy 

c::=:e::=J 

Feldspathic 

-~ 

Conglomeratic 

~ 

Micaceous 

;~ 

Cherty 

c:==J 

Covered 

ES:9==::J 

Partly covered 

19136 

Fossil collection 

FEET 

L 'Refers to map subdiVISIOns 20verlies near-vertical beds~~ the Hermo~a formation 

FIGURE 197.4.-Measured sections in eastern; part of Gypsum 

Valley, Colo. Location of sections shown. on. index map of 

Gypsum Gap quadrangle (fig. 197.1). 

age (W. A. Cobban, oral communication, 1960). In 

the valley floor, about 1,000 feet north of the :r:nap 

area, fossils of late Carlile age (W. A. Cobban, oral 

communication, 1959) were collected from near the 

base of the Mancos. The Mancos and -underlying 

Upper Cretaceous Dakota sandstone, which crop out 

in the valley floor- within 500 feet of the north edge 

of the area mapped, are downfaulted relative- to the 

Pa~adox member, and also apparently are downfaulted 

relative to the· Mancos (fig. 197.2). 

Stokes and Phoenix· (1948) show the Mancos in the 

mapped area: (fig. 197.2)· in sedimentary contact with 

Pal~zoic rocks. The authors coricur with this inter.:. 

pr~tation. The overall distribution of the Mancos 

and Mesaverde relative to the salt structure appears to 

be best explained· by· a· pinchout of pre-Mancos Cretaceous rocks and a thinning of the Mancos on the salt 

structure. -· Faunal evidence suggests that the core of 

the Gypsum Valley salt structure in southeast Gypsum 

Valley was not completely buried U!ltil Niobrara time. 

.. REFER~NCES 

Bass, N. W., 1944, Paleozoic stratigraphy as revealed by deep 

wells in parts of southwestern_ Colorado, northweste.rn New 

Mexico, northea!3t~rn. · Arizona, and southeastern Utah: 

U.S. Geol. Survey on·_a,nd, Gas InT. Prelim. -Chart 7, with 

accompanying text. · 

Cater, F. W., Jr.,· 1955a, Geology of the Gypsum Gap quad-

- rangle, Colorado: U.S. 'Geoi. Survey Geol. Quad. Map 

GQ-59. , ~: . 

-_ -- 1955b, Geology of· the Naturita NW quadrangle, Colo-

. rado: U.S. Geol. Survey Geol. Quad. Map GQ-65. -

Elston, D. P., and Landis, E: R., 1960, Pre-Cutler uncon~ormities and early growth of the _Ps,tra_dox Valley and Gypsum 

Valley salt anticlines, Colorado, in Short papers in the 

geological sciences:. U.S. Geol: Survey Prof. Paper ·400-B, 

art. 118, p. B261-B265. 

Elston, D. P., and Shoemaker, E. M., 1960, Late Paleozoic and 

early Mesozoic structural history of the Uncompahgre 

fl:ont, in Four O~rners Geol. Soc. Guidebook Field Conf. 

No. 3, Geology of the Paradox basin fold and fault belt, 

1960 : p. 4 7-55. . 

Shoemaker, E. M., Case, -J. E., and Elston, D. P., 1958, Salt 

anticlines of the Paradox basin, in Intermountain Assoc. 

Petroleum Geologists Guidebook, 9th .Ann .. Field Conf., 

Guidebook to the Geology of the Paradox basin, 1958 : 

p. 39-59. 

Stokes, .W. L., and Phoenix, D. A., 1948, Geology of the EgnarGypsum Valley area, San Miguel and M<~mtrose Counties, 

Colorado: U.S. Geol. Survey Oil and Gas Inv. Prelim. 

Map 93. 

Vogel, J. D., 1960, Geology and ore deposits of the Klondike 

Ridge area, Colorado: U.S. Geol. Survey open-file report, 

205 p. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 1 4 7-2.9 2 C-137 

198. EMPLACEMENT OF THE WILSON PEAK STOCK AND ASSOCIATED INTRUSIVE ROCKS, 

SAN MIGUEL MOUNTAINS, COLORADO 

By CALVIN S. BROMFIELD, Denver, Colo. 

During the Tertiary period, probably in post-Oligocene time, the Wilson Peak stock and the Black Face 

and Ames intrusives were emplaced in the Upper Cretaceous and Tertiary sedimentary rocks and overlying 

Tertiary volcanic rocks in the San Miguel .Mountains, 

the westernmost prong of the San Juan Mountain region of southwest Colorado (fig. 198.1). The Wilson 

Peak stock underlies an area of about 5 square miles 

and is exposed through a vertical distance of over 

4,000 feet. It is a composite stock composed of microgranogabbro, medium-grained granodiorite, and porphyritic quartz monzonite, intruded in that ord~r. The 

Black Face intrusive, southeast of the stock, is a 

smaller, westward trending mass. The Ames intrusive, east of the stock, is connected with the stock by 

a narrow discordant west-trending arm. The Ames 

and Black Face intrusives are both identical seriate 

porphyritic granodiorite, an.d probably are exposures 

of a single saucer-shaped mass. These igneous .bodies 

were all emplaced at relatively shallow depths; in the 

terminology of Buddington (1959, p. 677) they are 

epizonal intrusives. No accurate figure can be given 

for the cover of rocks originally present above the existing level of exposure, but perhaps not more than 

5,000 feet of volcanic and sedimentary rocks were 

present, and probably much less. 

Where not disturbed by intrusions, the Mancos shale 

of Late Cretaceous age, and the Telluride conglomerate and the overlying volcanic series, both of Tertiary age, are generally flat-lying with only minor 

undulations superposed on a gentle southerly to southwesterly rise of strata toward the Rico dome, which 

is approximately 10 miles to the southwest. The intrusion of the Wilson stock and the associated Black 

Face and Ames intrusive rocks produced two contrasting effects on the nearly flat-lying strata, depending on the' mode of emplacement. The Black Face 

and Ames intrusives apparently made room for themselves primarily by forceful doming of their roof 

rocks and by pushing aside strata; the later Wilson 

Peak stock was emplaced, at least in its final stage, 

primarily by piecemeal stoping, and adjacent flat-lying 

strata were not appreciably disturbed. 

Pnrt:s of the sedimentary roof rocks are still preserved on the Black Face intrusive (fig. 198.1, section A-A'). Along the north side of the intrusive the 

601.030 0-61-10 

contact of the igneous and sedimentary rocks dips 

north and is essentially concordant. Along the south 

side, however, the strata have been crowded aside, and 

near the edge of the intrusive they are commonly 

vertical to overturned, and probably are locally faulted. 

Strata on the south side of the intrusive probably were 

first stretched and faulted, and later crumpled as the 

magma expanded laterally and vertically. 

A belt of folded strata connects the west end of the 0 

Black Face intrusive with the Wilson Peak stock. 

Sedimentary rocks in this belt are sharply bent into 

an asymmetric anticline that is locally overturned to 

the southwest and probably faulted (fig. 198.1, section B-B'). The axial trace of the fold describes a 

roughly crescent-shaped arc open to the northeast. At 

its west end, the fold is transected by the Wilson Peak 

stock; eastward, the fold is continuous with the fold · 

occupied by the Black Face intrusive. The fold was 

probably formed by a buried extension of the Black 

Face intrusive as shown by· the structural relations, 

and the presence of several dikes and small irregular 

intrusives of the Black Face type which cut the anticline and in part are parallel to it. 

The Ames intrusive, near· the Wilson Peak stock, 

is a discordant body adjacent to which the strata 

are domed and crumpled .. The intn1sive grades 

northeastward into a sill 600 to 800 feet thick that 

made room for itself by separating the adjacent rocks. 

The Ames and Black Face intrusive rocks probably · 

connect in subsurface. 

The Wilson Peak stock is inferred to be younger 

than the Black Face and Ames intrusive rocks because 

the stock truncates at approximately right angles the 

belt of rocks structurally deformed by the Black Face 

intrusive, and because east-northeast trending dikes 

that cut the deformed belt do not cut the stock (fig. 

198.1). Some evidence suggests that these dikes may 

be essentially contemporaneous with the stock. 

The Wilson Peak stock, in contrast to the Black 

Face and Ames intrusive rocks, appears to have been 

emplaced, at least in its final phase, by a process of 

.Piecemeal stoping. Some doming may have occurred 

1iear the northeast edge· of the stock during intrusion 

of an early granogabbro, but if this mode of emplace· 

ment was widespread the evidence has been obliterated 
EXPLANATION 

D 

Sedimentary and volcanic rocks 

II 

Intrusive rocks 

-------...... 

Contact 

u o---

Fault 

Dashed where inferred. U, upthroum side; 

D, downthrown.side 

----t 

Anticline 

Dashed where inferred. Where shown on Black Face 

intrusive rocks it indicates structure ·in overlying 

rocks now largely eroded away 

-t+--

Overturned anticline 

---+ Syncline 

Dashed where inferred 

_...20 

Strike and dip of beds 

+0 

Strike and dip of vertical beds 

0 1 2 MILES 

-P--

Overturned beds 

--13000--

Structure contour 

Drawn on base of Telluride conglomerate. Omitted 

to east where datum plane largely absent through 

erosion; structure is indicated by other map symbols. 

Contour interval 200 feet 

---Dike 

B 

5 

--1_ 

N 

. Ames 

A / .... ...--Mancos shale A'12,

000, 

~:~::~: B' 

14,000' 

13,000' 

C' 

14,000' 

13,000' 

12,000' 

FIGURE 198.1.-Generalized structure map and sections of the Wilson Peak stock area, San Miguel Mountains, Colo. 

't" -'.. ...... ~' ., 

Q 

I 

~ 

~ 

00 

0 

tzj 

0 

~ 

0 

0 

~ ~ 

U1 

q 

:::0 

< tzj 

~ 

:::0 

tzj 

U1 

tzj 

> 

:::0 

n 

~ 

.... 

co 

0) 

+ 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-2.92 C-139 

during the final intrusion. Several lines of evidence 

suggest piecemeal stoping was the important intrusive 

mec.hanism. Along much of the stock contact the flatlying strata are esse:r;ttially undisturbed and the relation of the sedimentary rocks to the stock indicates 

that a considerable volume of country rock has disappeared (fig. 198.1, section 0-0'). In plan the outline of the stock is irregular (fig. 198.1). The contacts of the stock with the country rocks are sharp, 

essentin.lly vertical, irregular in detail, and discordant. 

In addition, piecemeal stoping is strongly suggested 

by irregular apophyses, dikes, and sills which may 

. have acted as levers to pry off blocks of country rocks; 

by reentrants of the stock along bedding planes and 

fracture surfaces in the country rocks, resulting at 

places in a steplike pattern of outcrop both laterally 

and vertically; and by the presence locally of angular 

inclusions of wall rock near the contacts. These 

features are observed through a vertical interval of at 

least 2,000 feet. 

REFERENCE 

Buddington, A. F., 1959, Granite emplacement with special 

reference to North America: Geol. Soc. America Bull., 

v. 70, no. 6, p. 671-747. 

199. STREAM DIRECTIONS IN TRIASSIC ROCKS OF THE COLORADO PLATEAU 

By F. G. PooLE, Denver, Colo. 

Work (/,one in cooperation with the U.S. Atomic Energy Commission 

The cross-stratified fluvial units ·of Triassic age are 

here grouped into four major stratigraphic units. 

These units are: Moenkopi formation of Early and 

Middle ( ~) Triassic age; lower part of Chinle formation of Late Triassic age; upper part of Chinle 

formation of Late Triassic age; and Kayenta formation and upper part of the underlying Moenave formation of Late Triassic ( ~) age.1 

These units are interpreted as fluvial because in 

their lithology and sedimentary structures they are 

physically similar to modern stream deposits. Two 

major types of cross-strata sets are recognized in fluvial units· on the Colorado Plateau-trough and planar 

(Mcl(ee and Weir, 1953). Nearly all cross-strata 

measurements used to determine the directions of 

stream flow shown on figure 199.1 were made on 

trough sets. The direction of dip was measured at the 

closed end of the trough set. At each locality 50 to 

150 of these measurements were taken within a particular stratigraphic unit and averaged to obtain a 

resultant stream-flow direction. Each arrow shown 

on figure 199.1 represents the resultant dip direction 

of cross-strata in one or more subunits in the four 

major stratigraphic units at a particular locality. No 

correlation or stratigraphic position of these subunits 

1 The Kayenta formation is now cont'lldered as Late Triassic( 7) in 

age (Lewis, Irwin, and Wilson, In press). 

is implied within the four major stratigraphic units. 

The resultant dip orientations indicate that drainage 

trends are closely related to the positions of major 

Triassic highlands and that the regional drainage 

direction shifted from dominantly northwest to dominantly southwest during Triassic time in response to 

shifting areas of uplift and subsidence. 

MOENKOPI FORMATION 

The fluvial part of the Moenkopi consists of reddish 

. sandstone, siltstone, and local conglomerate that are 

believed to represent deposits on alluvial plains and 

tidal flats. 

Cross-strata dip orientation measurements were made 

in the "lower massive sandstone" of McKee (1954), 

Holbrook member, and a sandstone in Arizona; a 

ledge-forming sandstone in southeastern Utah; the 

conglomeratic Ali Baba member in west-central Colorado and east-central Utah; and conglomeratic units 

in west-central New Mexico and east-central Arizona 

(fig. 199.1A). The averages o£ these measurements 

indicate that the streams that deposited the fluvial 

sediments of the Moenkopi :formation flowed most 

commonly northwestward and less commonly toward 

the north, west, and northeast (fig. 199.1A). 

The Mogollon and Uncompahgre highlands were 

probably the principal source areas for the. Moenkopi 
C-140 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

I 

I 

1. 

I 

~---- ------------------ JlALT LAKE crTXo~ _ 

/

1

. 1 \~RONT RANGE 

' I ' I\ HIGHLAND I / /-----{__ _____ /- tr \ I ODENVER 

I UTAH \ \ ..... l ....... '""• '·· ... \ I 

i ~ ~ \ ... ~ .... oa;:~.J··········· CO~ORADO 

, B I ·, G~y1 _ "'ty, 1 

I / 8 8 I . '""1\'o GJ?~ \ 

I / ,-I I 

~--+--- ----~-- :.-----------------;--~ 

:--------~ 

I 

I 

I 

I 

I 

I . ----l 

SALT LAKE CITY t=A----- __ ,,, .•• ::-.:;FRO~; -;~GE I 0 -A 'A ! § HIGHLAND I :,A \ ~ I I ····-..... ~ DENVER I 

UTAH : Grand \ C·O·-i 0 o 0 

"'- jJu~ctio~-·''''"'\., A ......... ~ RAD I "-e\ ' { c,. ......... \ 

I ............ 8 B 1 \ 1-C! f I \ ----,~ ' \_ 1z0-t, ! 

! -- ~~,\ '~ ~B E \ (;11-~~1-G> I '- -co_/~c.l""" I F\\ .. 1-<>;p~~ I L)t:'""--soo~~ \ , / F ·····-•• , ~ -----.--~ 

-.;-i4--~s..,_s: "'c-t---===~~~~/-- ~ t co/) ·c~1H?Iup·ts __,-1 oSANTA FE' I 

1

: ,/{;i A ···;~.:.ctJOn ~~;~~J> 

I

I,.,&-' i' c t I I ...., \ ,' 0 I 1 \ ~ -rc I ' 

\ 

I 

,) 

) 

I 

I 

) 

........ 

' --~1oooi ~{\~ .,1 1 

..... I--.......... Flagstafb \ I CHI' CH /J ./LLM II ·' ' ~ '•.,, CG H ~ 

\ 

0

Gdzt····ARIZONA CDH c~ H NEW MEXICO I 

, ~ 01\' ""· · · ....... cH-I E. Basal sandstone and conglomer~te of 

~ OSANTA FE I 

Flagstaff : 

t 

0 F 'E I l' ,_EI 

ARIZONA i 'iE \: MEXICO 

NEW 

............................ ~·PiioEiN'i'x"""""""'"'""'' .... ~ .............................................. , 

I 

I 

I 

I 

) .... ,, Dolores formation 

/ PHOEN;~·-................. F. Lower part of Dolores formation 

~ ... I G. u~:,~~e~~n ~:;;: ;:~~~;~~:~dh~~~~ 

MOGOLLON I 

I 

I 

I 

HIGHLAND 

A. Ali Baba member 

......._ 1 B. Ledge-forming sandstone 

I 

j 

'' ......._ I ~--- C. Lower massive sandstone ' , ______ ..___ _ _ D. Undifferentiated sandstone 

E. Holbrook member 

F. Undifferentiated conglomerate 

A MOENKOPI FORMATION 

-1 i-f'i(i'H""""...... formation ( ll..,qtvo'"·· H. Sonsela sandstone bed of Petrified 

A. Basal sandstone and conglomerate of Forest member 

Chinle formation (Gartra grit of I I. Agua Zarca sandstone member 

Thomas and Krueger, 1946) 1 _ J. Basal sandstone of Chinle formation 

~: ~:n:!':~ ::::~=~ ._-_I :: ~~e:: s~:::o~:~~~~!ne of Dockum 

D. Undifferentiated sandstone of Petri- group 

fled Forest member M. Middle sandstone of Chinle formation 

B LOWER PART OF CHINLE FORMATION 

:--------, 

I 

,--------

1 

I I 

I 

I 

I ---------

0SALTUKE CITY T---------

UTAH 

I 

I 

I -,---' 

I 

i 

I 

I I. 

0

FJagstaff 

ARIZONA 

NEW MEXIGQ 

C UPPER PART OF CHINLE FORMATION D KAYENTA FORMATION AND UPPER PART OF MOENAVE FORMATION · 

~ 

Approximate limit of deposition 

Barb.9 on .9ide of non deposition or erosion 

EXPLANATION 

1

ooo-----

Isopach line 

Dashed where inferred. Interval 500 feet 

Generalized direction - of streamflow 

FIGURE 199.1.-Stream directions during deposition of Triassic rocks, Colorado Plateau. 

-· 

~ 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-141 

sediments on the Colorado Plateau although some 

sediments were derived f:r;om the Front Range highlat;d. In addition to the flow direction of streams, 

further evidence that the source areas for Moenkopi 

sediments were northeast, east, and southeast of the 

formation is that the average grain size of the rock 

is progressively smaller and cross stratification is less 

common to the west and north. Regional stratigraphic relations of the units studied indicate that the 

fluvial sandstones derived from the Uncompahgre and 

Front Range highlands are older than those derived 

from the Mogollon highland. 

LOWER PART OF CHINLE FORMATION 

The lower part of the Chinle formation consists of 

variegated bentonitic claystone, siltstone, clayey sandstone, and persistent sandstone and conglomerate beds 

that have physical characteristics of stream channel 

nnd flood plain deposits. 

The members and units studied in this part of the 

:formation are given on figure 199.1B. Cross-strata 

dip directions indicate that the streams that deposited 

t.he sediments in the members and units studied 

flowed mainly north, northwest, and west (fig. 199.1B). 

The Mogollon highland was probably the main source 

nrea for lower Chinle sediments; the Uncompahgre 

and Front Range highlands contributed a minor 

amount of detritus. Sedi.ments of the lower part of 

the Chinle become coarser southward toward the Mogollon highland and eastward toward the Uncompahgre and Front Range highlands. 

UPPER PART OF CHINLE FORMATION 

The upper part of the Chinle formation consists of 

red sandstone and siltstone, and subordinate gray conglomerate and limestone that are believed to represent 

fluvial, flood-plain, deltaic, and lacustrine deposits. 

It includes the Owl Rock and Church Rock members 

of the Chinle in southeastern Utah and northeastern 

Arizona, the red siltstone part of the Chinle. in northwest Colorado, and the upper part of the Dolores 

formntion of southwestern Colorado. The Owl Rock 

member, ~vhich is predominantly limestone and structureless siltstone, was not studied. 

Cross-strata dip directions in sandstone units of the 

upper part of the Chinle indicate that the sediment 

was derived from positive areas adjacent to the depo-

-sitional bnsin (fig. 199.10). The red siltstone and 

sandstone in the upper part of the Chinle were probably derived largely from older sedimentary rocks 

exposed on and adjacent to the Uncompa.hgre and 

Front Range highlands. Cross-strata orientations in 

the upper part of the Dolores formation of southwest 

Colorado, and a local sandstone bed, the Black Ledge, 

of the Church Rock member in southeast Utah, indicate a source in the lTncompahgre highland. An additional minor source to the west of the west margin 

of the upper part of the Chinle is suggested by dip 

orientations in the I-Iite · bed, a local unit· in the 

Church Rock member of southeast Utah: 

KAYENTA FORMATION AND UPPER PART OF THE 

MOENAVE FORMATION 

The l{ayenta formation consists primarily of red-. 

brown sandstone, siltstone, and claystone that have 

physical characteristics typical of fluvial and flood 

plain deposits. The Springdale sandstone member of 

the underlying Moenave formation is included with 

the l{ayenta in this report because it is similar in 

lithology and depositional environment. R. F. Wilson (oral communication, 1961) believes that the 

Springdale sandstone member is laterally equivalent 

to most_ of the l{ayenta formation of northeastern 

Arizona. 

Cross-strata orientations indicate that the regional 

drainage in l{ayenta and Springdale time was mainly 

to the west and southwest (fig. 199.1D). The Kayenta sediments were probably derived mainly from 

older sedimentary rocks uplifted along the east margin 

of the formation. Sediments of the Kayenta formation, in general, decrease in coarseness southwestward 

from western Colorado. 

REFERENCES 

Lewis, G. E., Irwin, J. H., and Wilson, R. F., in press, Changes 

in age assignment for the Glen Canyon group (T•·iassic und 

Jurassic) on the Colorado Plateau: Geol. Soc. America 

Bull. 

McKee, E. D., 1954, Stratigraphy and histo•·y of the Moenkopi 

formation of Triassic age: Geol. Soc. America l\Iem. m, 

183 p. 

McKee, E. D., and Weir, G. W., 1953, Terminology fo•· stt·atification and cross-stratification in sedimentary rocks: Geol. 

Soc. America Bull., v. 64, no. 4, p. 381-389. 

Thomas, H. D., and Krueger, 1.\L L., 1946, Late Paleozoic an(l 

early Mesozoic stmtig•·aphy of the Uinta Mountains, Utah: 

Am. Assoc. Petroleum Geologists Bull., v. 30, no. 8, p. 125fl1293. 
C-142 GEOLOGICAL SURVEY RESEARCH 19 61 

200. SODA RHYOLITE (PANTELLERITE?) FROM LAKE COUNTY, OREGON 

By GEoRGE W. ·wALKER, Menlo Park, Calif. 

Reconnaissance mapping has disclosed several widely 

separated masses of sodium-rich volcanic rocks of 

middle to late Cenozoic age in south-central Oregon, 

a region characterized by large volumes of calcic-alkalic volcanic rocks. The most extensive exposures 

of these rocks are on the flanks of Hart Mountain 

(sees, 1, 9, ~nd 12, T. 36 S., R. 25 E.) in southeastern 

Lake County; other masses of sodium-rich rocks, exposed in the upper drainage of Deep Creek (sec. 2, T . 

41 S., R. 21 E.) southeast of Crane Mountain, Lake 

County, probably are extensions of the silicic intrusive and extrusive volcanic rocks of the High Grade 

A 

district of California (Hill, 1915; Gay and Aune, 

1958). 

The sodium-rich volcanic rocks occur both as nearsurface intrusive masses as much as a mile long and 

several hundreds of feet wide and as restricted thick 

flows that emanated from the intrusive centers. All 

of these rocks are porphyritic, the phenocrysts being 

enclosed in a fine-grained holocrystalline groundmass 

(fig. 200.1) ; commonly the flows are strongly flow 

banded and locally autobrecciated suggesting a magma 

of high viscosity. 

t · 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-143 

Analyses of two samples of these sodium-rich rocks 

are presented in table 200.1. Sample 1 was collected 

from a large intrusive at the west base of Hart 

Mountain and sample 2 from a brecciated flow on the 

east flank of the mountain. The alkali content of 

these rocks, totaling about 10.5 percent, is higher than 

normal for rhyolite, and the ratio of N a20 to K20 is 

approximately 6 to 5. In both rocks analyzed the 

content of Al20 3, CaO, and MgO is noticeably low. 

Both samples are characterized by a slight molar ex-

. cess of Al 20 3 + Fe203 over N a20 + K20. Standard 

minerals of the norm, which for both specimens includes quartz, orthoclase, albite, acmite, and diopside, 

also are presented in table 200.1. Even though the 

groundmass of both samples is too fine grained to perB 

mit accurate and complete modal analyses, an approximate modal analysis has been made of sample 1 

(table 200.1) using a standard point count method 

( Chayes, 1949). 

The sodium-rich rocks of Hart Mountain contain 

many phenocrysts of alkali feldspar (4V(-) =4 7° ± 2°), 

fewer phenocrysts of a pleochroic green diopsidic pyroxene (variable 2V(+)=65°±5°; n11 ""'1.77) with slightly 

darker green reaction rims, and scattered rare phenocrysts of quartz and oxyhornblende in a fine-grained 

groundmass. The groundmass consists of anhedral 

grains of quartz and alkali feldspar, small prisms and 

shreds of acmite (na""'1.76; n-r""'l.80; XA.c=0°-5°), a 

pleochroic blue amphibole (riebeckite?, n11""' 1.69; XA.c 

=4 °), a pleochroic brown mineral (n11 ""' 1. 76; ZA.c ""'43°) 

FIGURE 200.1.-Photomicrographs of thin sections of soda rhyolite intrusive, A, and flow-banded and auto brecciated flow, B. Phenocrysts of anorthoclase (anc) and diopsidic pyroxene (py) in fine-grained groundmass of quartz and alkali feldspar (light colored 

minerals) and acmite, riebeckite?, aen igmatite-rhiinite?, and magnetite (dark colored minerals). 
C-144 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TABLE 200.1.-Rapid rock analyses (in weight percent), calculated norms, and an approximate mode of two samples of soda 

rhyolite from Hart Mountain, Lake County, Oreg. 

[Analysts: P. L. D. Elmore, I. H. Barlow, S. D. Botts, Gillison Chloe, U.S. Geological Survey] 

Sample ..... _____ ----- __ -- _______________ ------______ 1 2 

Field number.-------------------------------------- GWW-3--{)0 GWW-4-60 

Si02--------------------------------

Al20a----- -- ------._----- ------- ---- - Fe2

0 3 ______________________________ _ 

FeO _______________________________ _ 

~g~~~============================= K20 ~a 0----------------------~-------- __________________ : ____________ _ H2o _______________________________ _ Ti02 

______________________________ _ 

P205-------------------------

~no ______________________________ -·------_ 

Total ________________________ _ C02 

_______________________________ _ 

Norm• 

Quartz ____________________________ _ Orthoclase _________________________ _ Albite _____________________________ _ ~cmite ____________________________ _ Diopside ___________________________ _ 

~~~~~~~~~~======================= Total ________________________ _ 

Approximate mode 2 

68. 6 

13. 5 

3. 1 

1.8 

0 03 

. 52 

5.8 

4. 7 

1.0 

. 37 

. 03 

0 17 

99. 6 

<.05 

16. 6 

27. 8 

43. 0 

5. 5 

2. 2 

1. 1 

1.6 

.8 

98. 6 

Phenocrysts a ______________________________________ _ 

Anorthoclase_______________________________ 32. 0 

Diopsidic pyroxene__________________________ 3. 0 

Oxyhornblende--~-------------------------- . 2 

~r~~~eJ~~;8::===================================== Quartz and alkali feldspar_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 48. 0 

Riebeckite?, acmite, and aenigmatite-rhonite? _ _ 14. 0 

Orange-brown alteration mineraL __ ·________ _ _ _ . 4 

• Calculated by C.I.P.W. system. 

69. 4 

13. 2 

3. 2 

1.8 

. 05 

0 30 

5. 8 

4. 6 

1.0 

. 35 

. 05 

. 18 

99. 9 

<. 05 

18. 2 

27. 2 

42. 0 

6. 5 

1.2 

1. •7 

1.4 

.8 

99. 0 

35. 2 

2.0 

62. 4 

2 Based on a 350-point traverse in each of three thin sections, sample 1. Color 

index 20. 3 A few crystals of qu·artz present 1n some sections. 

probably transitional in the rhonite-aenigmatite series, 

magnetite, and an unidentified orange-brown alteration 

mineral. 

The alkali feldspar phenocrysts commonly are 

faintly zoned and exhibit either fuie grid-twinning or 

poorly developed simple twinning. A cryptoperthitic 

intergrowth of the albite and orthoclase components 

in this alkali feldspar is suggested by the complex diffraction pattern obtained from the phenocrysts (fig. 

200.2A). To simplify the diffraction pattern and allow an .. estimate of composition, the phenocrysts were 

heated in a muffie furnace for 6 hours at 1,000°C to 

homogenize the albite-orthoclase components into one 

feldspar. A diffraction pattern of the homogenized 

feldspar (fig. 200.2B) is similar to the pattern (fig. 

200.20) given for a high temperature synthetic alkali 

feldspar whose composition is Ab 710r29 (Donnay and 

Donnay, 1952, fig. 4). The normative feldspar shows 

about Abs0 0r4o which suggests that this compositional 

estimate is the right order of magnitude. The moderately large .axial angle ( 47°+2°) of the natural 

feldspar is comparable to those given by Tuttle (1952, 

table 1) and by Carmichael (1960, table 3, spec. 3112F) 

for anorthoclase of compositions ranging from about 

Ab1sOr23 to Abs30r3s. An X-ray diffraction pattern 

of the light fraction (sp gr <2.88+) of the groundmass suggests that the groundmass feldspar also is 

anorthoclase. 

Some mineralogic differences exist between the sodium-rich rocks exposed on Hart Mountain and those 

southeast of Crane Mountain. Sanadine, as phenocrysts, is an important constituent of the rocks near 

Crane Mountain. Also, quartz (as phenocrysts and 

crystal· fragments), oxyhornblende, and aenigmatite 

or rhonite are more abundant, whereas diopsidic pyroxene and acmite are rare or lacking. 

According to the classification of Rittman (1952), 

these volcanic rocks chemically are soda rhyolite, close 

to his alkali rhyolite. They have many chemical and 

mineralogical characteristics in common with varieties of pantellerite (Washington, 1913), but contain 

slightly less N azO + K 20, less Fez03 + FeO + Ti02, 

and more Al203 than those on the island of Pantelleria. 

· The geologic occurrence of these rocks as intrusive 

and flow units within large andesitic and basaltic volcanic piles suggests that they are late volcanic differentiates. As yet, no data are available as to the 

characteristics of the parent magma or the type of 

pre-Tertiary bedrock intruded; consequently, there is 

no evidence either for or against sodium enrichment 

of the magma by contamination. 

REFERENCES 

Carmichael, I. S. E., 1960, The feldspar phenocrysts ()f sorue 

Tertiary acid glasses: Mineralog. Mag., v. 32, p. 587-608. 

Chayes, Felix, 1949, A simple point counter for thin section 

analysis : Am. Mineralogist, v. 34, p. 1-11. 

Donnay, Gabrielle, and Donnay, .J. D. H., 1952, The symmetry 

change in the high-temperature alkali-feldspar series: Am. 

.Jour. Sci., Bowen Volume, pt. 1, p. 115-132. 

Gay, T. E., .Jr., and Aune, Q. A., 1958, Geologic map of Cali- . 

fornia, Alturas Sheet: California Div. Mines. 

Hill, .J. l\:l., 1915, Some mining districts in northeastern California and northwestern Nevada: U.S. Geol. Survey Bull. 

594, 200 p. 

Rittman, A., 1952, Nomenclature of volcanic rocks: Volcanol. 

Bull., ser. 2, v. 12, p. 75-102. 

Tuttle, 0. F., 1952, Optical studies on alkali feldspars: Am. 

.Jour. Sci., Bowen Volume, pt. 2, p. 553-567. 

Washington, H. S., 1913, The volcanoes and rocks of PantelIeria, Part II: Am . .Jour. Sci., v. 21, p. 683-713. 

.• 
A. 

B. 

C. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

------------- --

' . Natlkal feldspar 

-------------- ----- --- -- ------------

,. 

Homogenized feldspar 

1000" C., 6 hrs 

Na71 K29 A/Si3 08 

(From Donnay and Donnay, 1952) 

C-145 

-------------- ---------- -- --- -- -------------- -- -- -- --------------

13° 15" 20" 25° 30° 35° 40° 

FIGURE 200.2.-Powder diffraction patterns. A, Unmodified natural feldspar phenocrysts; B, homogenized feldspar phenocrysts; 

and C, high-temperature synthetic alkali feldspar. 
C-146 GEOLOGICAL SURVEY RE·SEARCH 1 9 61 

201. PREHNITE-PUMPELLYITE METAGRAYWACKE FACIES OF UPPER TRIASSIC ROCKS, 

ALDRICH MOUNTAINS, OREGON 

By C. ERviN BROWN, Washington, D.C. 

In east-central Oregon a thick sequence of Upper 

Triassic rocks, briefly described by Thayer and Brown 

(1960), contain authigenic mineral assemblages characteristic of the prehnite-pumpellyite metagraywacke 

facies and the laumontite stage of the zeolite facies of 

Coombs (1960). The lithology and authigenic alteration are similar to those of a sequence of rocks in 

Southland, New ZeaJand, in which the lower grade 

mineral facies were first recognized (Coombs, 1954). 

The rocks in Oregon, which make up most of the 

Aldrich Mountains, have a composite· thickness of 

40,000 to 50,000 feet and comprise conglomerate, graywacke, shale, siltstone, tuffaceous graywacke, andesitic 

tuff, rhyolitic vitric tuff, and basaltic lava. These are 

unconformably overlain by as much as 14,000 feet of 

similar .Jurassic rocks present south of this area (Lupher, 1941). 

IntraJormational unconformities, differences in 

trends of folds, and faults that cut only the older 

rocks of the sequence show that deformation recurred 

during deposition. _Eastward thickening of younger 

units in the sequence indicates successive eastward 

shifts of the basin of deposition. Absence of foliation 

suggests that the strongly folded sedimentary rocks 

were only partly indurated and possibly well lubricated by connate water during folding and deep burial. 

Many of the rock types contain large amounts of 

authigenic chlorite, albite," and quartz, and also minor 

quantities o£ sphene, epidote, and rutile that possibly 

are not. authigenic. Authigenic pumpellyite, prehnite, 

and laumontite occur chiefly in volcanic rocks or rocks 

rich in volcanic debris. 

Albite is the most abundant detrital plagioclase 

throughout the stratigraphic section. Although some 

fragments are obviously from albitic rocks, I believe 

most of them were albitized in places. Albite also 

forms fine-grained mosaics of twinned laths intergrown 

with quartz that replace the matrix of tuffaceous graywackes and tuffs. In one specimen of bedded vitric 

tuff~ the shard structure is well preserved despite complete recrystallization of the glass to a felt of intergrown albite laths and quartz. Albitic plagioclase 

too fine for microscopic identification also has been 

indicated in. devitrified tuffs by X-ray diffraction. 

Authig(mic quartz likewise occurs throughout the 

stratigraphic section, both intergrown with albite as 

a devitrification product and as cryptocrystalline clots 

associated with laumontite. Greenstones near the base 

of the section contain secondary quartz; and pillow 

basalts about 4 miles southwest of Canyon City are 

veined by quartz, pumpellyite, and calcite. Finegrained quartz veinlets are numerous in siliceous mudstone and chert in the lower part of the sequence. 

Chlorite is most abundant as an alteration product 

of basic volcanic fr~gments in graywackes and basaltic lithic tuffs. It forms much of the yellowish:-green. 

cryptocrystalline matrix in graywacke, tuff, and green-· 

stone. In places chlorite forms flaky spherulitic aggregates, some of which show an anomalous blue interference color. 

Prehnite occurs most commonly as wispy patches in 

tuffaceous rocks, but also forms idioblastic prisms 

as much as 0.5 mm long in mudstone and siltstone and 

veins in shattered rock near early faults. The )Vispy 

patches are as much as 10 mm in diameter and 

weather to light-gray spots . 

. Pumpellyite has been found mainly in bas~ltic lavas 

in the lower part of the stratigraphic section and in 

the pillow lavas southwest of Canyon City. It occurs 

with chlorite in amygdules and also forms veinlets 

with calcite and quartz. Pumpellyite also occurs in 

coarse lithic tuffs. 

Authigenic laumontite occurs as spots in siltstones 

of Jurassic age south of the Aldrich Mountains and 

almost completely replaces some rhyolitic or dacitic 

vitric tuffs of Triassic age. Laumontitized tuff is 

present in 2-inch layers in the upper part of the sec-· 

tion and in beds as much as 10 feet thick in the lower 

part. Irregular optically continuous patches as much 

as 5 mm across generally include several hundred relict 

shard forms. Laumontite. has replaced interstitial 

material in dacitic volcanic breccia and In a conglomerate near the base of the section. 

Celadonite occurs as thin green bands, mainly in 

tuffaceous rocks that constitute most of the peaks of 

the Aldrich 1\fountains. In thin section this mineral is 

seen as irregular blue-green pleochroic blebs localized 

in layers. Celadonite is also present in greenstones 

near the base of the sequence and in finely cross-bedded 

tuffaceous siltstones near its top. 

Epidote, sphene, and rutile are found throughout 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-147 

the section as extremely .fine grains or granular aggregates. Commonly, these cannot be distinguished 

one from n.nother nor can their authigenic origin be 

established because of the small grain size. 

The assemblages of authigenic minerals in the Alrlrieh Mountains are characteristic of rocks in the zeolitic fneies, named by Fyfe and others (1958) as a 

result of Coombs' study in New Zealand (1954). This 

:facies is charncf"erized by authige.nic zeolites, albite, 

adularia, and quartz, all stable at low temperature in 

an aqueous environment. Coombs and others (1959) 

studied other occurrences reported in the literature 

and interpret·ecl the zeolitie facies according to results 

of hydrothermal syntheses. They found that the stability of some zeolites is affected by the availability 

of free silica and consequently redefined it as a zeo1 ite mineral facies, an n.ssemblage formed under physicn.l conclitions that produce quartz-heulandite;--quartzn,nalcime, or quartz-laumontite. Analcime and heulandite are indicative of a lower grade stage and 

laumontite of a higher grade. A non-zeolitic transition zone between the zeolite facies and the greenschist, facies wa,s also recognized and was named the 

prehnite-pumpellyite metagraywacke facies by Coombs 

(1!.>60). This mineral facies is characterized by 

prehn ite or pumpellyite, generally with quartz, albite, 

n.nd chlorite. l\{ost of the altered rocks of the Aldrich 

Mountains are in this facies. 

The zeolitic alteration :in the rocks of Southland, 

New Zealand, is attributed to elevated temperature and 

pressure related to deep burial (Coombs, 1954). The 

authigenic minerals :in the Aldrich Mountains rocks do 

not span enough of the lower grade mineral facies to 

determine whether depth of burial was significant in 

controlling the mineral associations that app.ear in 

various parts of the section. Detrital plagioclase does 

seem to be more completely albitized in the lower 

units than in the upper; laumontite occurs in the upper 

part of the Triassic sequence and in basal Jurassic 

rocks, but it is also present in the lower part of the 

Triassic section. These older rocks may not have been 

deeply buried, however, because of the eastward shift 

of the basin of deposition. 

The rocks under consideration are thicker and more 

intensely folded than those in New Zealand, and consequently were probably plunged into an environment 

where temperature and pressure were above th~ stability range of the more hydrated zeolites. The generally selective occurrence of laumontite in silicic 

vitric tuffs, prehnite in tuffaceous rocks, and pumpellyite in basaltic lavas indicates the influence of original 

rock composition on the authigenic mineral assemblage. 

REFERENCES 

Coombs, D. S., 1954, The nature and alteration of some Tt·iassic 

sediments from Southland, New Zealand: Royal Soc. New 

Zealand Trans., v. 82, p. 65-109. 

--l9GO, Lower grade mineral facies in New Zealand: 

Internat. Geol. Cong., 21st, Copenhagen 1960, sec. 13, pt. 13, 

p. 339-351. 

Coombs, D. S., Ellis, A . .J., Fyfe, ,V. S., and Taylor, A. l\:1., 

1959, The zeolite facies, with comments on the interpretation of hydrothermal syntheses: Geochim. et Cosmochim. 

Acta, v. 17, p. 53-107. 

Fyfe, W. S., Turner, F .. J., and Verhoogen, .John, 1958, Metamorphic reactions and. metamorphic facies: Geol. Soc. 

America Mem. 73, 259 p. 

Lupher, R. L., 1941, .Tm·assic stratigmphy of central O•·egon: 

Geol. Soc. America Bull., v. 52, p. 219-270. 

Thayer, T. P., and Brown, C. E., 1960, Upper Triassic graywackes ancl associated rocks in the Aldrich 1\lonntains, 

Oregon, in Short papers in the geological sciences: U.S. 

Geol. Survey Prof. Paper 400-B, p. B30Q-B302. 
C-148 GEOLOGICAL SURVEY RE·SEARCH 19 61 

202. COMPUTATION OF THE TOTAL FLOW OF THE COLUMBIA RIVER AT THE MOUTH 

By HoLLIS M. 0REM, Portland, Oreg. 

Gaging the flow of Columbia River is not feasible 

in the tidal reach, which extends from the mouth 145 

miles upstream to Bonneville Dam. Therefore, requests· for information on the· total flow at the mouth 

can be answered only by estimating flow from the ungaged areas and adding these estimates to the gaged 

flows. Such requests are of two kinds, those for estimates of monthly discharge ~or previous years and 

those for estimates made currently within a few days 

after the end of each calendar month. This paper 

describes the way both kinds of estimates are made. 

The first step in estimating the monthly discharge 

for previous years is to estimate the annual inflows 

for the period 1943 to 1957 from the various ungaged 

areas downstream from all stream-gaging stations on 

the basis of a map showing average annual runoff. 

This map was developed by Harry Hulsing and Nick 

Kallio (written communication, 1961) from an isohyetal chart furnished by the Corps of Engineers 

and from Geological Survey runoff data. The amount 

of annual flow from each ungaged area is estimated 

from the gaged flow of a nearby area and from the 

ratio of runoffs, as defined by the map, for the two 

areas. The annual flows so obtained are then distributed by calendar months on the basis of the distribution of flows from gaged areas having similar elevation, exposure, and position. The estimated average 

runoff from ungaged areas for the period 1943 to 

1957 is 5.0 percent of the estimated total flow of Columbia River at the mouth. Figure 202.1 shows the 

drainage area of Columbia River below The Dalles 

and the locations of gaging stations. 

Monthly runoff measured at gaging stations for 

which reports are available a few days after each 

month are added to the runoff estimated for ungaged 

areas to give the total estimated monthly runoff. 

Estimates of current monthly inflow below The Dalles 

include estimates for three main reaches of the Columbia River as follows: 

Inflow reach 

Columbia River from The Dailes to Vancouver 

Willamette River at mouth 

(adjusted for change in storage) 

Columbia River below Willamette River (adjusted for 

change in storage) 

Measured runoff 

Wind River near Carson plus 

Hood River near Hood River 

Willamette River at Salem 

(adjusted for change in storage) 

Lewis River at Ariel (adjusted 

for change in storage) and 

Cowlitz River at Castle Rqc~~ 

A preliminary value of the monthly flow of Columbia 

River at the mouth is obtained by adding the estimates 

for the three inflow reaches to the measured flows at 

the following stations: 

Drainage area (square 

Gaging station records available each mo~th 

miles) 

Index area Total area 

Columbia River at The Dalles _____________ -------- 237,000 Klickitat River near Pitt _________________ 1, 290 -------- Hood River near Hood River (includes con- duit) _________________________________ 329 -------- Wind River near Carson __________________ 225 -------- Willamette River at Salem ________________ 7, 280 -------- Cowlitz River at Castle Rock _____________ 2,238 -------- Lewis River at ArieL _____________________ 731 --------

Subtotal of areas below The Dalles __ 12,093 21,000 

Columbia River at the mouth _____________ -------- 258.000 

The preliminary value is corrected for precipitation 

on 400 square miles of river, slough, pond, and island 

a.rea below The Dalles and below Salem, and for 

evaporation from the same area. All of the precipitation which falls on water surfaces is assumed to become 

runoff. Evaporation is taken as 2.0 feet per year 

(U.S. Weather Bureau, 1959.). and is distributed among 

the months according to the average pattern for 

Seattle (U.S. Weather Bureau, 1950). 

For months when the flows at The Dalles and at 

Salem are changing, a correction for time-of-travel is 

applied to the estimates of flow at the mouth. 

Finally, the estimated mean flow at the mouth is 

adjusted, without consideration of time lag~ for aggregate storage change in 8 major power reservoirs 

on the Columbia River, 5 reservoirs in the vVillamette 

River basin, and 3 reservoirs in the Lewis River basin, 

and for the pumped diversion at Grand Coulee. 

Data on the mean fl0w of record and the adjusted 

flow at the mouth of the Columbia River is published 

monthly in the Pacific Northwest 'Vater Resources 

Summary.1 

REFERENCES 

U.S. Weather Bureau, 1950, Mean monthly and annual evaporation from free water surface for the United States, 

Alaska, Hawaii, and West Indies: U.S. Weather Bur. 

Tech. Paper 13. 

-- 1959, Evaporation maps for the United States: U.S. 

Weather Bur. Tech. Paper 37. 

1 Summary prepared by U.S. Geological Survey Current Records 

Center, Portland, Ore., and released by the U.S. Geological Survey in 

collabo~ation with the Canada Department of Northern Affairs and 

Natural Resources Water Resources Division. 

FIGURE 202.1.-Map of lower Columbia River basin showing location of gaging stations. 

\ 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-14Q 

0 

N 

r 

WASHINGTON 

EXPLANATION 

0 

Gaging station used for making 

estimates for previous years 

• Gaging station used also for 

making estimates currently 

~ ··~ · . . 

;· OREGON 

Dam 

Basin divide 

0 25 50 MILES 

Drainage divide 
C-150 GEOLOGICAL SURVEY RESEARCH 19 61 

203. DEFORMED BASALTIC CAPROCK AS AN AQUIFER AT COW VALLEY, OREGON 

By BRuCE L. FoxwoRTHY, Portland, Oreg. 

Work done in cooperation with the office of the Oregon State Engineer 

In parts of the Basin and Range province (Fenneman, 1931), and to a lesser extent in the flanking 

mountains and plateaus, a layer of lava caps older 

rocks exposed on the slopes of buttes, mountains, and 

plateaus. At places, the effectiveness of these caprocks as aquifers is greater than has been commonly 

appreciated. Much of the caprock lava is massive in 

appearance and creates the illusion of impenetrability, 

but sp.rinkage joints, vesicular zones, and local breccia 

layers may give it considerable permeability. In parts 

of the area of their occurrence, the lava beds have 

been deformed so that they extend below the level of 

the water table, where they may constitute a permeable reservoir for ground water. 

B~altic caprock of this type is the main aquifer for 

the irrigation wells in Cow Valley, a small upland 

basin in Malheur County, in the semiarid part of Oregon (fig. 203.1). Studies being made in that area 

(Brown and Newcomb, 1956) indicates that this type 

of aquifer may be fairly common in that region and 

in regions of similar geologic setting. 

In the northern part of the lower Malheur River 

basin, and in adjacent drainage basins northwest of 

Ontario, Oreg. (fig. 203.1), a widespread layer of 

basaltic lava caps sedimentary rocks of Pliocene and 

· Pleistocene age, and sedimentary, metamorphic, and 

granitic rocks of l\1esozoic(?) age. The lava ranges 

from about 10 to 300 feet in thickness, and it caps the 

older rocks in upland areas north and south of Cow 

Valley. Folding and faulting in the Cow Valley area· 

Columbia Plateaus province 

E G 0 

Basin and Range province -.....,' ......._ 

'-.....,_ 

' \ 

' 

FIGURE 203.1.-Cow Valley in relation to major physiographic 

provinces in Oregon. 

44o~·s N 

4000' 

3600'c__ __ _L_ _________________ _J 

FIGURE 203.2.-Diagrammatic section across Cow Valley, Oreg., 

showing the position of the caprock lava where_ it constitutes 

the major aquifer. 

have lowered it to and below the present valley floor. 

"Vithin the valley it overlies relatively impervious 

sedimentary and partly metamorphosed rocks, and is 

overlain by alluvium and colluvium. The maximum 

thickness of the alluvium is about 300 feet near the 

Genter of the valley floor. Figure 203.2 shows the 

general stratigraphic relations and position of the 

water table within the valley. 

The first test wells for irrigation in the valley obtained water from the alluvium, but problems of sand 

entering the wells and excessive dra wdown of water 

level during pumping caused later wells to be drilled 

deeper into the underlying basalt. The· basalt affords 

much greater yields and sand-free water; consequently, 

it has been tapped by the latest 14 of the 18 irrigation wells in the area. 

The lava consists principally of joined massive basalt in ·which layers of rubbly breccia are interspersed. 

Drillers' ~ogs show that toward the south side of the 

valley the bottom part of the lava zone consists of red 

sandy and scoriaceous tuff. Other tuff layers are intercalated in the lava. The maximum thickness of 

basalt penetrated thus far is 314 feet; however, where 

it was penetrated completely by one well it had a 

thickness of only 45 feet. 

The \Yells that tap the basalt have an average 

pumping yield of about 1,100 gpm (gallons per minute) and less than 100·· feet of drawdown. Aquif~r 

tests on some of those wells indicate coefficients of 

transmissibility ranging from about 85,000 to 300,000 

gpd/ft (gallons per day per foot). The ground water in the la.va rock and in the overlying alluvium is 

a hydraulically continuous body. Pumping from a 

well that taps either aquifer eventually causes some 

lowering of ground-water level's throughout the reservoir. 
SHORT PAPERS IN THE GEOLOGI·C AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-151 

The great demand for ground \Yater in the valley, 

,\·hich lacks other dependable supplies for irrigation, 

resulted in a progressive lowering of ground-water 

levels during the period 1951-60, and led to studies 

to determine the average annual recharge to the 

ground-water body. Data now available indicate that 

the recharge may be only about 5,000 acre-feet per 

yen.r for the entire drainage bnsin, which covers about 

60 square miles. The estimated recharge is about t'Yothirds of the annual pumpage during recent years. 

Chemical analyses of ground water from the alluvium and from the lava indicate that the waters from 

the two aquifers are similar in character and are of 

generally good quality for most uses. 

REFERENCES 

Brown, S. G., an'd Newcomb, R. C., 1956, The ground-water 

resources of Cow Valley near Ironside, Malheur County, 

Oregon: U.S. Geol. Survey open-file rept. 

Fenneman, N. M., 1931, Physiography of Western United 

States: New York, McGraw-Hill Book Co., Inc., 534 p. 

204. FACIES DISTRIBUTION AND HYDROLOGY OF INTERMONTANE BASIN FILL, SAFFORD BASIN, ARIZONA 

By EDWARD S. DAVIDSON, Tucson, Ariz. 

Work dO?w in coopm·ation with the Un·iversity of Arizona 

The Safford basin includes about 1,350 square miles 

in southeastern Arizona (fig. 204.1). Reconnaissance 

mapping in this area shows that the extent of permeable gravels may have been significantly overestimated. 

Previous descriptions of the basin sediments have been 

made by G. J(. Gilbert ( 1875), Schwennesen ( 1919, 

1921), and J(nechtel (19:38). 

The Safford basin is a northwest-trending depression lying between the Gila and 'Vhitlock l\{ountains 

to the northeast and the Pinaleno and Santa Teresa 

Mountains and l\{ount Turnbull to the southwest. 

Peaks in the mountains to the northeast average.about 

5,500 feet in altitude, and those to the southwest range 

from 10,000 feet in the Pinaleno Mountains to 7,000 

feet in the Santa Teresa l\{ountains and at Mount 

Turnbull. The central part of the basin has an altit-ude of about 2,800 feet. The Gila River drains the 

basin, entering from the east and leaving to the west 

at Coolidge Dam. 

The basin is a. typical basin-and-range downfaulted 

sediment-filled trough lying between the uplifted 

ranges .. The maximum displacement and thickness of 

sediment are not known, but a well near Pima (fig. 

204.1) was drilled to a depth of more than :3,700 feet 

without reaching bedrock. 

The mountains to the northeast are composed of 

mafic lava flows, agglomerate, and tuff; those to the 

southwest consist of granite and assorted metamorphic 

and indurated sedimentary rocks, including granitic 

gneiss, limestone, and conglomerate. 

Sediments in the basin are classified in this report 

as (a) terrace gravel and alluvium, (b) deformed conglomerate or gravel, and (c) basin fill. The basin fill 

unconformably overlies the deformed conglomerate or 

gravel beds and is erosionally overlain by the terrace 

gravels a1i:d alluvium. The terrace gravels and alluvium are not ·distinguished on figure 204.1. 

Terrace gravels and alluvium were deposited by the 

Gila and its tributaries. The terrace gravels mantle 

slope~ extending from the mountain fronts to the 

present stream flood plain. The alluvium fills valleys 

of the present streams. 

The deformed conglomerate or gravel beds crop out 

in a closely limited area, and are apparently derived 

from local sources. The beds are moderately to firmly 

cemented and moderately folded and faulted. These 

rocks are exposed only on the basin margins; a finer 

grained facies may occur in the central part of the 

basin, but this is not yet definitely known. The deformation of the beds probably occulTed during a major pulse of block faulting preceding deposition of 

the unconformably overlying basin-fill sediments. 

The basin-fill sediments are thick extensive deposits 

of flat-lying unconsolidated sediment forming the bl.llk 
C-152 GEOLOGICAL SURVEY RESEARCH 1961 

EX PLANA l'ION 

I !l~J d:1~~1 } g,gra.vel and grit s, silt and sctnd 

c , clay 

!,Limestone' 

U NCONFO RMITY 

Deformed conglomerate or gravel 

Igneous and metamorphic rocks 

...---?--- Contact 

Dashed where indtifiniU>, 

q~ten'ed where lloub(fuf 

u 

Fault, showing relative movement 

U, upthrown Bide; D, downthrown Bide 

ARIZONA 

Safford 

N 

• 

I 0 10 

\"' '~ 

. ~ 

> 

n ··~ 

.'I 

15 MILES 

·--.. 

Geology by E S Davld<;.on 

FIGURE 204.1.- Geologic map of the Safford basin, Arizona, showing distribution of basin-fill deposits. 

of fill in the basin. They range in age from Pliocene 

to middle Pleistocene (Knechtel, 1938; Wood, 1960; 

Lance, 1960). Four principal types of basin-fill sediments can be distinguished: (a) gravel and gritspread out from the mountains basin ward, but deposited 

in substantial amounts only where large streams entered the basin; (b) silt and sand-deposited over 

much of the basin by running water, probably in 

poorly, defined stream courses ; (c) green and black 

clay-probably deposited mainly in marshes or 

swamps; and (d) limestone-deposited in fresh-\Yater 

lakes. Tuff and diatomite beds and lava flows are 

interbedded in the sediments and in most areas provide the only convenient means of correlating units 

from place to place. 

The distribution of the several facies of the basin 

fill and their sedimentary structures suggest that the 

sediments were deposited by streams heading m the 

mountains and converging in two low areas represented by extensive limestone and clay facies. Thus, 

at the time of deposition of the basin-fill sediments, 

the drainage was largely centripetal, and not throughgoing as at present. 

Fanlike gravel beds did not coalesce to form the 

continuous gravelly basin edge seen in many generalized maps of western basins. The gravel deposits are 

notably small and sporadic northeast of Safford, at 

the Whitlock Mountains, and along the edge of the 

Pinaleno Mountains. Most individual gravel beds do 

not extend basin ward in tongues; instead they grade 

rather abruptly basinward to silt and fine sand. At 

some places, particularly north of Fort Thomas to 

north of Pima, the gravels appear to be relatively 

thin, and may represent only a thin mantle of gravel 
~.· 

... 

SHORT PAPERS IN THE GEOLQGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-153 

on a bedrock surface. North of the Pinaleno l\1ountains, gravel in the :fans is ,·ery poorly sorted, and 

t·he fans contain considerable clay. 

The basinward edge of. the gravel facies is not more 

thn n 2 or 8 miles from the older rocks along the basin 

margin except in a few places "·here the gravels extend 6 to 8 miles inward from the point where the 

streams of Tertinxy and Quaternary age entered the 

basin. One o:f these places is a well-known locality, 

the site o:f Gilbert's ( 1875) type section of the Gila 

conglomer:t.t"e, where the present Gila River enters the 

Safford bnsin. A sitnilar .large stream entered the 

basin :from the south; its mouth is about 10 miles 

southeast o:f Coolidge Dam. 

Ground water in basin-fill sediments similar to those 

described is recharged primarily by runoff from rain 

and snowmelt in adjacent mountains. The most effective channehnty for this recharge is the coarsegravel :facies that occurs near the margin of the basin. This gravel margin is not everywhere present, 

nor .is it everywhere highly permeable; thus, 'Yater 

wells drilled in the marginal areas may not everywhere be good producers. l\1oreover, a thin mantle 

of gravel over bedrock, clay-rich gravel, silt, or other 

fine sediment "·here gravel normally is expected, and 

a shorter basinward extension of gravel than is commonly expected, all reduce the effective recharge to 

the basin-fill sediments. 

REFERENCES 

Gilbert, G. K., 1875, Report on the geology of portions of 

Nevada, Utah, California, and Arizona : U.S. Geog. and 

Geol. Surveys W. 100th Meridian Rept., v. 3, p. 17-187. 

Knechtel, M. M., 1938, Geology and ground-water resources of 

the valley· of the Gila River and San Simon Creek, Graham 

County, Arizona: U.S. Geol. Survey Water-Supply Paper 

796-F, p. 181-222. 

Lance, J. F., 1960, Stratigraphic and structural position of. 

Cenozoic fossil localities in Arizona : Arizona Geol. Soc. 

Digest, v. 3, p. 155-159. 

Schwennesen, A. T., 1919, Ground water in San Simon Valley, 

Arizona and ~ew Mexico: U.S. Geol. Survey Water-Supply 

Paper 425-A, p. 1-35. 

-- 1921, Geology and water resources of the Gila and San 

Carlos Valleys in the San Carlos Indian Reservation, Arizona: U.S. Geol. Survey Water-Supply Paper 450-A, p. 1-27. 

Wood, P. A., 1960, Paleontological investigations in the 111 

Ranch area:· Arizona Geol. Soc. Digest, v. 3, p. 141-l4R . 

205. MIOCENE AND PLIOCENE HISTORY OF CENTRAL ARIZONA 

By F. I{ TwENTER, Phoenix, Ariz. 

The ~iogollon Him separates the Basin and Range 

province :from the Colorado Plateaus province in cent".t·al Arizona. Southwest of the ~iogollon Rim, Cenozoic roeks fill rnany basins and valleys, some of which 

are indicated on figure 205.1. The geological history 

o:f this region is shown diagrammatically on figure 

20:>.a, and is summarized below. 

A thick series of volcnn ic rocks, chiefly tuffaceous 

sediment·s, pyroclastic deposits, and basaltic lavas, occur throughout much of the Basin and Range proyinee, and part of the Colorado Plateaus province ~n 

central Arizona. Volcanic rocks in one area may not 

be stTiet'ly correlative with those in another; however, 

the rnajor period of Cenozoic volc~mic activity in centTa l Arizona probably started in l\1iocene time and 

lnst·ecl t·o early Pliocene time. 

601530 0-61--11 

Basaltic lavas, and pyroclastic and tuffaceous rocks 

' underlain by conglomerate, are called the I-Iickey formation in the Black Hills (Anderson and Creasey, 

1958). Volcanic rocks in the Hickey can be traced 

into, and correlated wit]}, other volcanic rocks in surrounding areas, and most tuffaceous sediments, pyroclastic rocks, and basaltic lavas in the basins, valleys, 

and intervening mountains of central Arizona are believed to be equivalent to the Hickey. 

The volcanic rocks of the Hickey, and the eq u ivalent volcanics accumulated during a period of recurrent diastrophism. Gradual tilting of large fault 

blocks produced low-lying· areas in "·hich tuffaceous 

sediments and pyroclastics were deposited. In Rock 

Springs VnJley, Bloody Basin, Seven Springs Basin, 

lower Verde Valley, and Sunfto"~er Basin, tuffaceous 
C-154 GEOLOGICAL SURVEY RESEARCH; 19 61 

FIGURE 205.1.-Index map of Arizona. Section A-A' shown on 

figure 205.3. 1, Verde Valley; 2, Chino Valley; 3, Lonesome 

Vall~y; 4, Skull Valley; 5, Peeples Valley; 6, Walnut Grove 

Basin; 7, Rock Springs Valley; 8, Bloody Basin; 9, Seven 

Springs Basin; 10, Lower Verde Valley; 11, Sunflower Basin; .12, Tonto Basin; and 13, Phoenix area. The solid line 

separates the physiographic provinces, the dashed line separates th"e Mountain Region on the north from the Desert · 

Region on the south. 

and pyroclastic rocks equivalent to the Hickey make 

up the major- part of the Cenozoic rocks. 

In Verde Valley, volcanic rocks equivalent to the 

Hickey overlie erosional remnants composed chiefly of 

conglomerate and lesser amounts of sandstone, mudstone, and limestone; these rocks are referred to here 

as Dry Beaver Creek rocks. Included 'vith the Dry 

Beaver Creek rocks are the oldest alluvial materials 

of Mahard ( 1949) , the Cenozoic sediments of Mears 

(1950), and the type A gravels of Price (1950). The 

Dry Beaver Creek rocks are exposed at altitudes 

ranging from about 3,500 to 6,500 feet and were probably laid down during a continuous cycle of deposition. 

After development of the ancestral Mogollon Rim 

and excavation of a deep, broad valley in the area 

now occupied by Lonesome, Chino, and Verde Valleys, 

Dry Beaver Creek rocks were deposited in the Verde 

Valley area until the accumulated materials were 

more than 3,000 feet thick. Later erosion removed 

most of the Dry ·Beaver Creek rocks; only remnants 

remained when Hickey-equivalent volcanic deposits accumulated~ Similar geologic events may have occurred in much. of Arizona's Basin and Range provInce. 

In Verde Valley, Chino Valley, Lonesome Valley, 

Tonto Basin, Walnut Grove Basin, Peeples Valley, 

and Skull Valley, ·volcanic rocks equivalent to the 

Hickey are overlain by lacustrine and fluviatile rocks 

that in their lower parts appear to interfinger with or 

conformably overlie the volcanics; in their upper parts 

the lacustrine and fluviatile rocks unconformably overlie tilted Hickey equivalents (fig. 205.2). No major 

break in deposition occurred between the deposition 

of the volcanic materials and ·the lacustrine and :fluvia,tile rocks. 

Fossiliferous lacustrine and fluviatile rocks in Tonto 

and Walnut Grove Basins interfinger with or conformably overlie volcanic rocks equivalent to the 

Hickey. Fossils in the upper part of beds in the 

Tonto Basin are "no older than· lower Pliocene and 

possibly as young as middle Pliocene" ( J. F. Lance, 

oral communication, 1960). In Walnut Grove Basin, 

the upp~r member of Hook's Milk Creek formation, 1 

which overlies· tuffaceous rocks equivalent to volcanic 

rocks in the Hickey formation, contains "* * * diagnostic fossils of lower Pliocene age" (Lance, 1960, 

p. 156). These fossils indicate that deposition of the 

lacustrine and fluviatile rocks that overlie volcanic 

rocks equivalent to the Hickey formation began in 

lower Pliocene time, and that the Hickey formation 

and equivalent volcanic rocks accumulated in Miocene 

and earliest Pliocene time. They indicate, also, that 

the Dry Beaver Creek rocks are no younger than 

Lacustrine and fluviatile rocks I ........................... . ········ 

I ! .<··· ....................... ··:·.·.·.· ..... ·.: 

Volcan;ci~ rocks 

FIGURE 205.2.-Diagrammatic section of typical basin or valley, 

showing relation of volcanic rocks (equivalent to the Hickey 

formation) to lacustrine and fluviatile rocks. Black line in 

volcanic rocks and dotted lines in lacustrine and fluviatile 

rocks are hypothetical marker beds. 

1 Hook, D. L., 1956, Late Cenozoic stratigraphy and structure of 

part of the Walnut Grove Basin, Yavapai County, Arizona: Unpub. 

M.A. thesis, Arizona Unh·. 

... 

"" I 
A 

I 

..... 

~· 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, A.RTICLES 147-292 

Basin and Range Province 

I 

Desert region I Mountain region 

I 

A. early Pliocene to early Pleistocene 

B. late Miocene to early Pliocene 

C. middle Miocene(?) 

D . . early Miocene(?) 

E. pre-Miocene(?) 

EXPLANATION 

Colorado Plateaus Province 

C-155 

A' 

Pliocene lacustrine and fluviatile rocks Paleozoic rocks in Colorado Plateaus Province and mountain region 

Hickey formation 

-

and equivalent rocks 

Dry Beaver Creek rocks and 

~ other time-correlative sediments fBl . Mesozoic and younger rocks in Colorado Plateaus Province 

~ Chiefly Precambrian rocks in Colorado Plateaus 

Province and mountain region 

Except as indicated, comprises all rocks deposited 

prior to Hickey time in desert region 

ll'IOURI': 205.3.-Diagrnmmatic sections showing relations of rocks along section A-A', figure 205.1. 
C-156 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

Mi_ocene, and that the Mogollon Rim is Miocene or 

older. 

Recurrent structural movement during and following deposition of the Hickey and equivalent rocks elevated the Colorado Plateaus and produced the present mountain ranges of the Basin and Range province. 

Thereafter, the uplifted areas were eroded and the 

basins .alluviated. 

Deposits correlative with ~he fossil-bearing rocks in 

Walnut Grove arid Tonto Basins are covered by !titer 

deposits in much of the desert region, especially in 

the Phom}.ix area; however, tilted blocks of rocks 

equivalent to the Hickey protrude above the alluviated 

desert floor locally. 

REFERENCES 

Anderson, C. A., and Creasey, S. C., 1958, Geology and ore 

deposits of the Jero·me area, Yavapai County, Arizona: 

U.S. Geol. Survey Prof. Paper 308, 185 p. 

Jenkins, 0. P., 1923, Verde River lake beds near Clarkdale, 

Arizo~a: Am. Jour. Sci., 5th ser., v. 5, no. 25, p. 65-81. 

Lance, J. F., 1960, Stratigraphic and structural position of 

Cenozoic fossil localities in Arizona : Arizona Geol. Soc. 

Digest, v. 3, p. 155-159. 

Mahard, R. H., 1949, Late Cenozoic ehronology of the Upper 

Verde Valley, Arizona: Denison Univ., Sci. Lab. Bull., v. 41, 

art. 7, p. 97-127. 

Mears, Brainerd, Jr., 1950, Cenozoic geomorphic history of the 

Oak Creek Canyon region, Arizona [Abs.] : Geol. Soc. 

America Bull., v. 61, no. 12, pt. 2, p. 1557. 

Price, W. E., Jr., 1950, Cenozoic gravels on the rim of Sycamore Canyon, Arizona: Geol. Soe. America Bull., v. 61, 

no. 5, p. 501-508. 

206. CORRELATION OF PERMIAN ROCKS IN NORTHEASTERN ARIZONA AND ADJOINING PARTS OF 

NEW MEXICO AND UTAH 

By CHARLES B. READ and A. A. WANEK, Albuquerque, N. Mex., and Menlo Park, Calif. 

The Permian rocks that crop out in .the Monument 

Valley upwarp and Defiance uplift, Arizona and Utah, 

the Mogollon Rim, Arizona, and the Zuni ~1ountains 

of New Mexico, have been studied by one or both of 

us at various times during the last 15 years. This 

report is a resume of our present. opinions regarding 

the correlation of these. strata and will be supplemented 

at a later date by a more detailed account. The accompanying index map, figure 206.1, shows the location of all the areas discussed except the ~1ogollon 

Rim, which lies south of the map in Arizona at a latitude of approximately 34°15' N. 

The Zuni uplift in New Mexico is an oval eroded 

dome locally complicated by faults. Permian rocks 

are exposed widely in the central part of the dome 

and rest directly on rocks of Precambrian age, or on 

marine rocks that may be of Pennsylvanian or Permian age. The stratigraphic sequence in the Zuni uplift is shown in table 206.1, column 1 (Read, 1950). 

The ~1ogollon Rim is an east-trending escarpment 

in central Arizona. It has been studied by I-Iudd1e 

and Dobrovolny ( 1945) and by one of us in the vicinity of Carrizo Creek and the canyon of Salt River. 

The stratigraphic sequence is shown in table 206.1, 

column 2. 

The Defiance uplift is an asymmetrical anticline 

that trends north along the New Mexico-Arizona line 

from about the latitude of Gallup almost to the Four 

Corners. Permian rocks as shown in table 206.1, columns 3 and 4, rest on Precambrian rocks in the southern and central parts of the uplift, but elsewhere the 

base of the section has not been observed (Read, 

1950). 

The Monument Valley upwarp is a major structural feature in the central part of the Colorado Phtteau province and lies athwart the Arizona-lJtah 

boundary line. In this area, rocks of Permian age 

rest conformably on strata assigned to tlie Rico and 

Hermosa formations. The stratigraphic sequence in 

the ~1onument Valley upwarp is shown in table 206.1~ 

columns 5 and 6 (Baker and Reeside, 1929; Baker, 

1936). 

FIGURE 206.1.-Index map of parts of Arizona, New Mexico, 

and Utah showing locations of the Zuni uplift, Defiance uplift, 

and Monument Valley. Arrows indicate the dominant direction of inclination of crossbedding in (M) Meseta Blanca member of the Yeso formation; (G) Glorieta sandstone; (LD) lower 

member of the De Chelly sandstone; (UD) upper member of 

the De Chelly sandstone; (C) Cedar Mesa sandstone member 

of the Cutler formation; and (CO) Coconino sandstone. 
... 

36" 

35" 

SHOR'l~ PAPERS IN 'l'HE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

uo· 

I 

I 

109" 

C-157 

~ J~ ~ I ~Z: uot ~-~ ~ ·.'f . ~~-\ 00+ XC ~ .UDX .: ~~ I 4 ~ ~1~~---.:£~";;"1/{ _J,. ____ ··~ UTAH 

1 

COLORADO 

N 

) ~ urt"'--./· c<"""'t r·· . ---ARWNA · --·-------- . ~9p -J.1f" UD ·.~ I 

__ j I _.· ~ I 

Kayenta 

0 

I ~. \~ I i ·~ r-- : ~ 

I

I \t I r· 

S A N J ... U A N i A P (A C H E (J 

I

I ) UO ,.~.~~ 1 

·. Lo/~ · 

I t"'~~~Ap I tJ··~ ... 

A v A J 0 I ... i LO ~ '~, ;t I ; 

I ) ) ~<?, \~UY·---------~---

1 ( ; ll)~ • •• 

0 I ( \ LO~v ~ Keams Canyon ! ganado /oo ~~Ft Defmnee ~ - -1 t~G.t MC KINLEY 

I /J /.. ~·ll ~ ,._r-···'--"'(··· 

) f ~UD I . . ~- · .. 1 ~ l~ i ~~_r-··· Gallup 

I :s~~ :7 v 

I

I )~#/'1. r<'& 

v,c:,< '\-, G 

I ~O.ofl~~· ... : /~ ~~ 

I -~ I ~inslow • I /. 

\cot. I~~··· ... ~ ~· )/ /oo ..j.. ···~ Holbrook .. /'-··~! ico "-. ... ~· 

co 

10 0 
:!: 

UJ 

1-

(/) 

>-

(/) 

(.) a:: - UJ cncG 

cnzz 

~<::l a:: 0 1- >-

z 

~ 

:!: 

a:: 

UJ 

a.. 

z;:: 

<~ 

-z Z< 

<- >:!: ...Ja:: 

>UJ 

en a.. zo 

~z a..< 

c: 

11 Cl) 

>-

TABLE 206. I.-Nomenclature and correlation of Permian sequences in parts of New Mexico, Arizona, and Utah 

(Equivalence is not necessarily implied in the "Triassic and younger" and "Pennsylvanian and Permian?" brackets where formations or members are placed opposite] 

Zuni uplift, 

New Mexico 

Shinarump member 

of Chinle formation 

Glorieta 

sandstone 

San Ysidro member 

Meseta Blanca 

sandstone member 

Abo formation 

I 

I 

c: 

0 

:;::; 

111 

E 

.E 

"i; 

c. 

:I 

(/) 

I 

I 

I 

2 

Mogollon Rim, 

Arizona 

Various Mesozoic and 

Cenozoic formations 

Coconino 

sandstone 

Upper 

member 

Middle 

member 

Lower 

member 

(Beds of Pennsylvanian 

age may be included in 

the Supai formation) 

Naco formation 

(Pennsylvanian) 

Cl) 

c: 

~ "0 

c: 

::l 

~ 

16 Cl) 

c 

I 

3 4 

Defiance uplift, Arizona 

Southern part 

Shinarump member 

of Chinle formation 

Upper 

member 

Supai formation 

Cl) 

c: 

.s 

Ill 

"0 

c: 

111 

Ill 

~ 

"'i 

.r:. 

(.) 

Cl) 

c 

I 

Northern part 

Shinarump member 

of Chinle formation 

Upper 

member 

Lower member 

Supai formation 

·. ~ 

c: 

0 

:;::; 

111 

E 

2 

Cl) 

;; 

:I 

(.) 

I 

5 6 

Monument Valley, Utah_ and Arizona 

Eastern part 

Moenkopi formation 

Hoskinnini tongue 

De Chelly 

sandstone 

member 

Organ Rock 

tongue 

Halgaito 

I tongue 

Rico formation 

(May contain beds of 

both Permian(?) and 

Pennsylvanian ages) 

~ 

Hermosa formation 

(Pennsylvanian) 

c: 

0 

:;::; 

111 

E 

2 

Cl) 

;; 

:I 

(.) 

Western part 

Moenkopi formation 

• Hoskinnini tongue 

De Chelly 

sandstone 

member 

Organ Rock 

tongue 

Cedar Mesa 

sandstone member 

Halgaito 

tongue 

Rico formation 

(May contain beds of 

both Permian(?) and 

Pennsylvanian ages) 

Hermosa formation 

(Pennsylvanian) 

~~ 

0 

I 

1-l 

c.n 

00 

0 

trl 

0 

t'4 

0 

0 

H 

~ t'4 

(/1 

q 

l:tl 

< trl 

~ 

l:tl 

t:r-1 

Ul 

trl 

> l:tl 

~ 

.... 

co 

0) 

.... 
I 

' SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCEs,· ARTICLES 147-292 C-159 

'I'he general correlation of the Permian strata based 

on both physical and paleontologic data as interpreted 

by the writers is also shown in table 206.1. ~T e are 

of the opinion that the Abo· formation of the Zuni 

Mountains correlates with the lower member of the 

Supai formation along the Mogollon Rim in the vicin-

.ity of Carrizo Creek. rhe lower part of the Supai 

formation in the Defiance uplift~ and part or all of 

the finJgaito tongue of the Cutler formation in Monument Valley, also seem to be eqt1ivalent to the Abo 

formation. 

The Yeso f01zmation in the Zuni uplift consists of 

the Meseta Blanca and the San Ysidro members and 

is equivalent to the middle and upper members of the 

Supai in the M:ogollon Rim. Equivalent strata in the 

Defiance uplift are the upper part of the Supai and 

the lower member of the De Chelly sandstone. The 

Gedar :Mesa sandstone ·member of the Cutler formation in l\1onument Valley is believed to be the approximate correlative of the l\1esettt Blanca sandstone member of the Yeso formation; the Organ Rock 

tongue seems to correlate with the S~tn Ysidro member of the Yeso formation, and with the upper part 

of the Supai formation and the lower member of the 

De Chelly sandstone. · 

The Glorieta sandstone and the San And~·es limestone are correlated on paleontological evidence with 

the Coconino sandstone and l(aibab limestone, respectively, of the Mogollon Rim. The upper member of 

the De Chelly sandstone in the Defiance uplift is correlated with the Glorieta sandstone and the Coconino 

sandstone. Except for one report of its occurrence 

in the subsurface south of Fort Defiance, Ariz., the 

l(aib~tb limestone is believed to be absent from the 

uplift (Pei.rce, 1958). 

The l.lpper member of the De Chelly sandstone in 

the Defiance uplift seems to correlate with the De 

Chelly sandstone member of the Cutler formation in 

l\1onument VaJley. 

The I:Ioskinnini tongue of the Cutler formation, as 

defined by Baker (1936) and Baker and Reeside 

( 1929), is of uncertain age. Physical evidence suggests that it may be a part of the Moenkopi formation and it is so shown in table 206.1. 

Of interest in connection with the correlation of 

' the Permin.n strata are the dominant directions of the 

foreset beds in the thick tangentially crossbedded 

sandstones that are present in all the areas examined. 

These are shown in figure 206.1. (See also· Reiche, 

1938.) The dominant directions were determined by 

mea.suring 100 or more directions of maximum inclination of crossbedding at places shown on the map, 

a.nd plotting these in 5° and 10° classes. 

Two preferred directions of inclination were observed, one trending southeast and east, and the other 

south and southwest. The southeast-east directions 

of inclination are characteristic of the Meseta Blanca 

sandstone in the Zuni Mountains, the lower member of the De Chelley sandstone in the Defiance up-

. lift, and· the Cedar l\1esa sandstone member of the 

Cutler in l\1onument Valley. Observations on the direction· of inclination of foreset beds in the middle 

member of the Supai formation on the l\1ogollon Rim 

have not been made. 

South to southwest directions of inclination are 

characteristic of the Glorieta sandstone in the Zuni 

uplift, the upper member .of the De Chelly sandstone 

in the Defi~nce uplift~ 'ai1d the De Chelly member of 

the Cutler formation in Monument Valley. In the 

area of Holbrook and 'Vinslow, Ariz., south to south-

. west directions ·of inclination of foreset beds were 

observed in the Coconino sandstone. Observations 

have not been made at more southerly places. 

These thick tangentially crossbedded sandstones 

have been referr~d to by some as having been ¢I.eposited under aeolian conditions (Opdyke and Runcorn, 1960). Others have ascribed their origin to 

beach and nearshore marine. environments, thus interpreting them as transgressive sandstones (Read 

and others, 1945; Read, 1950). At the present time 

we prefer this interpretation. 

'Vhether the rocks were deposited in aeolian or in 

transgressive beach and bar environments, there is 

evidence that the wind or the water, or both, moved 

toward the south and southeast during transportation and deposition of the sediments of the lower group 

of sandstones. The sediments of the upper group of 

sandstones were transported by wind or water, or both, 

moving to the south and south west. 

Explanation of these changes in directions of currents as indicated by the direction of crossbedding is 

conjectural. They may be related, however, to differences in direction of marine transgression. 

REFERENCES 

Baker, A. A., 1936, Geology of the Monument Valley-Navajo 

Mountain region, San Juan County, Utah: U.S. Geol. 

Survey Bull. 865, p. 24-40. 

Baker, A. A., and Reeside, .J. B., .Jr., 1929, Correlation of the 

Permian of southern Utah, northern Arizona, and southwestern Colorado: Am. Assoc. Petroleum Geologists Bull., 

v. 1~, no. 11, p. 1413-1449. 

Huddle, J. W., and Dobrovolny, Ernest, 1945, Late Paleozoic 

stratigraphy and oil and gas possibilities of central and 

northeastern Arizona: U.S. Geol. Survey Oil and Gas Inv. 

Prelim. Chart 10. 
C-160 GEOLOGICAL SURVEY RESEARCH 1 9 61 

Opdyke, N. D., and Runcorn, S. K., 1960, Wind direction ih 

the western United States in the late Paleozoic: Geol. Soc. 

America Bull., v. 71, p. 959-971. 

Peirce, H. W., 1958, Permian sedimentary rocks of the Black 

Mesa basin area, in New Mexico Geol. Soc. Guidebook of 

the Black Mesa basin, 9th Field Conf.: p. 82-87. 

Read, C. B., 1950, Stratigraphy of the outcropping Permian 

rocks around the San Juan Basin, in New Mexico Geol. 

Soc. Guidebook of the San Juan Basin, New· Mexico and 

Colorado : p. 62-66. 

Read, C. B., Wilpolt, R. H., Andrews, D. A., and others, 1945, 

Geologic map and stratigraphic sections of Permian and 

Pennsylvanian rocks of parts of San Miguel, Santa Fe, 

Sandoval, Bernalillo, Torrance, and Valencia Counties, 

north-central New Mexico: U.S. Geol. Survey Oil and Gas 

Inv. Map OM-21. 

Reiche, Parry, 1938, An analysis of cross-lamination; the 

Coconino sandstone: Jour. Geology, v. 46, no. 7, p. 905-

932, 6 figs. incl. index maps. 

207. TROY QUARTZITE (YOUNGER PRECAMBRIAN) AND BOLSA AND ABRIGO FORMATIONS (CAMBRIAN), 

NORTHERN GALHJRO MOUNTAINS, SOUTHEASTERN ARIZONA. 

By MEDORA H .. KRIEGER, Menlo Park, Calif. 

Recent detailed mapping in the northern end of the 

Galiuro Mountains, Pinal County, Ariz., has solved 

some problems that have long puzzled stratigraphers. 

Many geologists have considered the Troy quartzite to 

be correlative with the Cambrian Bolsa quartzite and 

Abrigo limestone farther south. Thick diabase sills 

in the area have been variously considered to be postPennsylvanian to pre-Troy in age. Mapping in the 

Holy Joe Peak quadrangle (fig. 207.1) in southern Arizona has proved that rocks formerly called Troy quartzite include units of Precambrian and Cambrian age and 

that these 1mits are separated by a major unconformity. 

The older of these two units, to which the name Troy 

is here restricted, rests disconformably on the Dripping Spring quartzite of the Precambrian Apache 

group and has been extensively injected by diabase 

also of Precambrian age. The Cambrian beds compo~e the Bolsa and overlying Abrigo formations; the 

Bolsa rests from place to ·place on the Apache group, 

on Troy, and on deeply weathered diabase. 

Ransome ( 1915, p. 384-385) named the Troy quartzite and used the name at Ray and in the Sierre Ancha; 

he included it in the Apache group, which he considered to be Cambrian in age. He found that the 

upper part locally contains shaly and silty sandstone. 

Cambrian fossils had already been discov6red in similar beds farther east (Campbell, 1904). Diabase sills 

were considered to be post-Paleozoic by Ransome ( 1903, 

p. 86). Darton (1925, p. 36) recognized that-

* * * the "Troy" in most places includes in its upper part or 

is overlain by a much younger sandstone, doubtless equivalent 

to the Tapeats and Bolsa-Abrigo beds. 

Darton ( 1925, p. 34 and 254) found that the Troy locally rests with sedimentary contact on diabase and 

concluded that small diabase dikes in younger Paleozoic limestones are not of the same age as the large 

diabase sills. Stoyanow ( 1936, p. 4 72-481) extended 

the name Troy southward to the Santa Catalina Mountains, where it conformably underlies the Abrigo. 

Farther south the Abrigo overlies the Bolsa quartzite. Stoyanow placed the Apache group, minus the 

Troy, in the Precambrian. Shride (1958 and oral 

communications) recognized the pre-diabase and Precambrian age of the Troy in the Sierra Ancha and 

concluded that it was separated from Catnbrian sedimentary rocks farther south by a long time interval; 

the two formations, however, had not been definitely 

recognized in contact until the present study. · 

In the Holy Joe Peak quadrangle Cambrian rocks 

rest at most places on the Dripping Spring quartzite 

of the Apache group or on diabase, but in local areas 

Cambrian rocks rest on the Troy quartzite, which has 

been preserved in grabens and intruded by diabase in 

the same manner as the Apache. The best exposures 

are in the Zapata Mountain-Holy Joe Peak area (fig. 

.207.1), where as much as 700 feet of the formation 

is preserved. The Troy, which is mainly conglomerate and sandstone in a lower member and quartzite 

in an upper member, is overlain by about 700 feet of 

Cambrian sandstone, shale, and mudstone, consisting 

of two cliff-forming units alternating with two slopeforming units (fig. 207.2, top). The lower, cliff-forming 

unit is the Bolsa quartzite; the upper three units are 

assigned to the Abrigo formation, which here contains 

carbonate beds at the top. 
SHORT PAPERS IN 'l'HE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

EXPLANATION 

Sedimentary and 

volcanic rocks 

Elocabrosa 

limestone 

Martin 

limestone 

A brigo and Bolsa 

formations 

tp~db I Diabase 

Troy quartzite 

pCtu, upper member; 

p£tl, lo~r member 

!{Dripping Spring ~ quartzite 

< I' I 

~~~g \ 

Granitic rocks 

C- 161 

>-

"' <( 

;::: 

"' w 

.... 

a.. a.. ~}8 "' w iJi !::: <Jl z 

~ :::E ~ <( 

u z 

~ 

z 

0 

> 

w 

0 

z 

<( 

ii' 

"' :::E 

<( 

u 

z 

<( 

ii' 

"' :::E 

<( 

:.l 

"' a.. 

Post-diabase or post-Paleozoic fault 

110'45' 110'30' 

---- _:;:..,...:.:=------.,.-------='- 33' 

'\ 

'\ 

INDEX MAP OF SOUTHEASTERN ARIZONA 

'\, \ '\'\L_ ____ _._ ______ __j 32'45' 

HOLY JOE PEAK QUADRANGLE 

SHOWING LOCATION OF 

DETAILED GEOLOGIC MAP 

Index map of the qu&drangle shows in black the outcrops of Cambrian formations. Troy quartzite only 

locally underlies the Cambrian rocks on Zapata and 

Brandenburg Mountains and west of the San Pedro 

The index map of southeastern Arizona shows location of areas cited and the area (stippled) within which both the younger Precambrian Troy and the 

Cambrian formations are known to occur; north 

of the area only Troy remains: south of it only 

Cambrian formations are present 

FIGURE 207.1.-Geologic map of the Zapata Mountain-Holy Joe Peak area. 
C-162 GEOLOGICAL SURVEY RESEARCH 19 61 

ZAPATA MOUNTAIN 

BRANDENBURG MOUNTAIN 

FIGURE 207.2.-Sketches of Zapata and Brandenburg Mountains, from photographs; viewed from the southwest. pCds, Dripping 

Spring quartzite; pCtl, lower member of Troy quartzite; pCtu, upper member of Troy quartzite; pCdb, diabase; £b, Bolsa 

quartzite; £a, Abrigo formation; Dm, Martin limestone; Me, Escabrosa limestone; Tsv, sedimentary and volcanic rocks. 

In the Holy Joe Peak quadrangle the Troy shows 

no significant lateral variations and is readily distinguished from the Bolsa and Abrigo by differences in 

color, composition, and bedding, and by the relations 

to diabase. The lower member of the Troy is generally dark brownish gray, the upper member is white 

or light gray; the Cambrian rocks are pale or light 

brown. Channeling and very irregular bedding (fig. 

207 .3A) are characteristic of the Troy, especially in 

the lower member, which is probably of terrestrial 

origin; bedding in the overlying Cambrian rocks is 

much more regular (fig. 207.3B). Wherever the base 

of the Troy is exposed, it includes conglomerate, light 

bluish-gray sandstone, and arkosic conglomerate; conglomerates in the basal part of the Bolsa locally re:. 

semble conglomerate in the basal Troy, but the other 

lithologies are lacking. The Troy and Bolsa formations are unfossiliferous, but the Abrigo contains 

abundant phosphatic linguloid brachiopods, scolithus 

tubes, and burrows or tracks on the bedding planes. A 

generalized stratigraphic section of the Troy, Bolsa, 

and Abrigo formations is given in table 207.1. 

The Cambrian and underlying Precambrian rocks 

are virtually concordant in dip, and the relief on the 

erosion surface at the contact is generally low. At 

Brandenburg Mountain, however, much of the Cambrian pinches out against monadnocks of the Troy 

(fig. 207 .2, bottom). The Troy is assigned to the Precambrian because of the long time interval that probably is represented by its complete removal from large 

areas, and by deep weathering of the diabase prior 

to deposition of the Bolsa. Isotope analyses of ura-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-163 

nium- and thorium-bearing minerals in differentiates 

in diabase in the Sierra Ancha indicate a minimum 

age of about 1,200 million years (Silver, 1960) for the 

diabase. 

Stratigraphic sections between the Little Dragoon 

Mountains and the Sierra Ancha show that the Cambrian rocks become thinner and the Abrigo becomes 

progressively more sandy northward; hence, the term 

Abrigo formation seems more appropriate than Abrigo 

limestone in and north of the Santa Catalina Mountains. Cambrian stratigraphic units in the Santa Catalina Mountains and in the Holy Joe Peak quadTABLE 207.1.-Generalized stratigr1

aphic section ot T1·oy, Bolsa, 

and Ab1·igo torrnations 

Abrigo formation: 

Thickness 

(feet) 

Upper slope-forming unit. Sandstone, shale, mudstone, 

and quartzite; some cliff-forming; tracks and trails 

common; brown quartzite and sandstone that contain phosphatic linguloid brachiopods at base of 

upper 100 feet, overlain by interbedded sandstone, 

glauconitic beds, intraformational conglomerate, and 

minor amounts of carbonate; dolomite and limestone that contain silicified Billingsella brachiopods 

near top ----------------------------------------- 248 

Upper cliff-forming unit. Sandstone and quartzite, 

similar to Bolsa quartzite, but thicker bedded and 

contain scolithus tubes and horizontal markings ____ 126 

Lower slope-forming unit. Sandstone, shale, mudstone, 

and thin interbedded quartzite; contains abundant 

fragments of phosphatic linguloid brachiopods especially in lower part, and vertical scolithus tubes and 

horizontal tt·acks or burrows higher up ___________ 155 

1'otal Abrigo formation ------------------------- 529 

Bolsa quartzite: 

Cliff-forming, unfossiliferous, even-grained, evenly 

bedded sandstone and quartzite, locally crossbedded, 

thinly bedded and very thinly laminated at top; 

purplish pebble- to small boulder-conglomerate, as 

much as 25 feet thick, at base where it rests on 

diabase, but absent where it rests on. Troy ___ _____ 158 

Total Cambrian -------------------------------- 687 

Troy quartzite: 

Upper member. Quartzite and some sandstone, mostly 

cliff-forming, white, quite pure, locally slightly 

arkosic (white feldspar or clay from feldspar), in 

part pebbly (quartz pebbles), thicker bedded than 

lower unit and irregularly bedded; base is white 

quartzite about 6' thick with 6" quartz-pebble conglomerate beds ---------------------------------- 523 

Lower member. Sandstone, conglomerate, a few beds 

of quartzite, and thin silty layers; mostly cliff-forming; dark brownish-gra~ -weathering; thin and very 

irregulat· bedding, abundant channelling; two conglomerate beds and intervening light bluish-gray 

sandstone at base; abundant large pink fragments 

of feldspar and quartz porphyry in upper conglomerate; light-colored quartzite beds more abundant uP:. 

ward -------------------------------------------- 208 

Total Troy quartzite ______ 7 _________________ ____ 731 

rangle are similar to and are correlative with the 

Bolsa and Abrigo farther to the south. Near PoYerty 

Flat on the Gila River, and near Superior, undifferentiated Cambrian beds rest on the Troy quartzite; near 

Globe Cambrian rocks rest on the Apache group. No 

Cambrian rocks have been recognized in the Sierra 

Ancha "·here sandstone of Devonian age fills deep 

channels in the Troy quartzite. The Troy in that 

area includes three members; the lowest pinches out 

soutlwmrd. The middle member is primarily a sandstone that has large-scale crossbedding and thus differs lithologically from the lowest member in the 

A 

B 

FIGUHE 207.3.-Contnlsting bedding features in the 1'roy and 

Bolsa quartzites. A, Details of channeling and very irregulat· bedding in lower member of 'rroy quartzite. B, Thin 

regular bedding in top of Bolsa quartzite. 
C--164 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

Holy Joe Peak area, but the two units can be correlated as shown by progressive changes between the 

two areas. 

REFERENCES 

Campbell, M. R., 1904, The Deer Creek coal field, Arizona: 

U.S. Geol. Survey Bull. 225, p. 240-258. 

Darton, N. H., 1925, A resume of Arizona geology: Ariz. Bur. 

Mines Bull. 119, 298 p. 

Ransome, F. L., 1903, GeoJogy of the Globe copper district, 

Arizona: U.S. Geol. Survey Prof. Paper 12, 168 p. 

Ransome, F. L., 1915, The Paleozoic section of the Ray quadrangle, Arizona: Washington Acad. Sci. Jour., v. 5, p. 380-

388. 

Shride, A. F., 1958, Younger Precambrian geology in southeastern Arizona [abs.] : Geol. Soc. America Bull., v. 69, 

p. 1744. 

Silver, L. T., 1960, Age determinations on Precambrian diabase 

differentiates in the Sierra Ancha, Gila County, Arizona 

[abs.] : Geol. Soc. America BulL, v. 71, p. 1973-1974. 

Stoyanow, A. A., 1936, Corre~ation of Arizona PaJeozoic formations: Geol. Soc. America Bu11., v. 47, p. 459-540. 

208. TRAP-DOOR INTRUSION OF THE CAMERON 'CREEK LACCOLITH, NEAR SILVER CITY, NEW MEXICO 

By WALDEN P. PRATT and WILLIAM R. JoNES, Denver, Colo. 

The Silver City region of southwestern New Mexico contains a variety of intrusive igneous massesdikes, sills, laccoliths, and stocks-in a terrane characterized also by a complex pattern of normal faults 

(Art. 150). Recent mapping in the Hurley vVest 

quadrangle, on the southern edge of the Silver City 

region, has revealed details of intrusion of the Cameron Creek laccolith, once regarded as a stock (Paige, 

1916) but now known to have a concordant roof and 

floor. The laccolith made room for itself by lifting 

its roof like a trap-door; the fault that represents the 

open side of the "trap-door" was then stoped out by 

the magma and is no longer exposed. Interpretation 

of the development of the laccolith and the structures around it, which involve two periods of faulting 

earlier than the laccolith, is facilitated by the presence of segments of an older sill that postdated the 

first period of faulting but predated ~he second. ·The 

present distribution of formations and the shape of 

the laceolith are shown on the geologic map (fig. 

208.1) and cross. sections (fig. 208.2). Our interpretation of the stages of development is shown on figure 208.3 as suceessive maps; somewhat generalized, 

at the level of the present ground surface. This interpretation is summarized as follows: 

1. Pre-Late Cretaeeous til6ng and normal faulting of 

the Oswaldo formation, with dominantly rightlateral apparent offset. Erosion to an irregular 

surface, followed by deposition of the Beartooth 

quartzite in Late(?) Cretaeeous time and the 

Colorado formation in Late Cretaceous time (fig. 

208.3A). · 

2. Emplacement of Chino Quarry sill within the Oswaldo formation, at different distanees above the 

base because of the earlier faulting. Roof rocks 

are raised uniformly. Southernmost of earlier 

faults is locus of feeder ehannel (fig. 208.3B) . 

3. Minor folding of Oswaldo and Beartooth formations, and renewed faulting, with left-lateral apparent offset. Major movement is on Indian Village fault, which splits westward into two (or 

more) faults, southernmost of which is later to 

coincide with part of Cameron Creek fault (fig. 

208.30). 

4. Intrusion of· Cameron Creek laccolith along surface indicated by dotted line in figure 208.30. 

Room for laccolith is created by vertical uplift 

of roof rocks along a new fault, the Cameron 

Creek fault (which represents the open side of 

the "trap-door"), so that the entire block north 

of fault is apparently offset to east (fig. 208.3D). 

(Hinge of "trap-door" is represented by point 

where laccolith wedges out to north-now concealed under Gila conglomerate.) Laccolith magma then partly engulfs rocks south of fault so 

that western part of fault now appears stoped. 

Rocks within Indian Village fault zone-Lake 

Valley limestone, Oswaldo formation, and Chino 

Q.uarry sill-are severely faulted by drag along 

Cameron Creek fault (fig. 208.3D). 
•· 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-165 

Gila conglomerate 

Dikes 

Camer·on 

~ 

~ 

Creek laccolith 

Biot·ite-quaTtz lntite 

,>-

1-0:: 

<t:ct: 

=>z 

Oo:: w 

EXPLANATION 

Chino Quarry sill 

H1:ot·ite lnt:ite 

Colorado formation 

kY~~/l Beartooth quartzite 

Abo formation 

(f) 

::::> 

0 

w 

u 

<t: 

1-

w 

0:: 

u 

Syrena formation 

Pob£a.~Xfj Oswaldo formation 

z 

~ 

z 

<t: 

> --' 

>-

(f) 

z 

z 

w 

!Pob, bnsal ,q/w.le ·mem.be1· a.. 

~ ~ }~£ i~ Lake Valley limestone ~ 

}r Percha shale 0 

(f) 

::::> 

0 

0:: 

w 

LL. 

z 

0 

en 

0:: 

<t: 

u 

+ 

0.5 MILES 

~--.. 

Contact, showing dip 

Dot.ted wheTe concealed 

,__-?---... Fault 

Dashed whe·re a.p]n·o~:inw.t.el'JI 

loca.ted; shO'I·t. dashed where 

inde}1>wite O'l' ?>nfeTred; dut.terl 

wheTe concealed; cru.en:erl 

where en:.~tence ·is u:nce·rtu:1:n 

Postulated pre-intrusion 

position of fault 

-2_0 

Strike and dip of beds 

FIGURE 208.1.-Geologic map of part of Hurley West quadrangle, Grant County, N. Mex. 
C-166 GEOLOGICAL SURVEY RESEARCH 1 9 61 

A 

Qal 

TKc 

B 

TKc 

Qal 

c 

A' 

6000' 

5000' 

C' 

6000' 

5000' 

FwURE 208.2.-Cross sections through Cameron Creek laccolith. (Compare fig. 208.1.) 

5. Erosion; deposition of Gila conglomerate; later erosion to present surface (fig. 208.1). 

Evidence that the Chino Quarry fault preceded, and 

in part limited, emplacement of the Cameron Creek 

laccolith, is found in the fault zone in the NE!J.t,SElJ.t 

sec. 27, T. 18 S., R. 13 W., where the laccolith intrudes the rock of the fault zone. The presence in 

the fault zone of dark-green latite like that of the 

Chino Quarry sill suggests that the original fault 

acted as a feeder for the sill-as it did later for the 

Cameron Creek laccolith. According to this interpretation, renewed movement on the fault after emplacement of the sill (fig. 208.30) deformed the feeder 

dike and left the isolated remnants now exposed. 

The geologic age of the faults and the intrusive 

rocks is known only as post-middle Late Cretaceous 

and pre-late Miocene( n; within these limits they can 

be dated only with respect to each other and therefore 

cannot be correlated certainly with any specific epoch 

of the Tertiary. 

REFERENCE 

Paige, Sidney, 1916, Description of the Silver City quadrangle, 

New Mexico: U.S. Geol. Survey Geol. Atlas, Folio 199. 

) 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

.:....Horizon of intrusion 

of Chino Quarry sill 

f Horizon of intrusion o~ 

\,::.~eron Creek laccohth 

··· •.. \ .. 

A 

c 

B 

D 

0 1 MILE 

C-167 

Fwum~ 208.3.-lnferred history of deformation in the vicinity of the Cameron Creek laccolith, shown as successive maps at level 

of present ground surface (compu.re fig. 208.1.) TKc, Cameron Creek laccolith; TKq, Chino Quarry sill; Kc, Colorado formation; 

Kb, Beartooth quu.rtzite; Po, Oswu.ldo formation; Pob, basal shale member of Oswaldo formation; Ml, Lake Valley limestone; 

feeder dikes shown in solid black. Large arrows in D s~1ggest relative uplift of roof by intrusion of laccolith. 
C-168 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

209. MIDDLE AND UPPER TERTIARY ROCKS OF SOUTHEASTERN WYOMING AND ADJOINING AREAS 

By N. M. DENSON u,nd M. H. BERGENDAHL, Denver, Colo. 

Tuffaceous continental deposits of middle and late 

Tertiary age unconformably overlie the truncated edges 

of older rocks in western Nebraska, sou.theastern 

'Vyoming, and ·northeastern Colorado. The thickness 

of these Tertiary rocks ranges from about 600 feet 

in the "·estern and southern parts of the area to about 

1,900 feet in the northeastern pa:rt. In general, the 

younger rocks are coarser grained than the older ones 

-the Oligocene rocks are chiefly· claystone and siltstone; the l\iiocene rocks, very fine grained sandstone; 

and the Pliocene rocks, medium- to coarse-grained 

sandstone and conglomerate. Lenticular beds of bentonite and fresh water limestone occur locally. 

Middle and upper Tertiary rocks contain large quantities of volcanic ash. 'Vhere they are underlain by 

arkosic and carbonaceous rocks, suitable reducing conditions may exist for the precipitation and concentration of uranium leached from the ash by ground 

water. Northwest of the I-Iartville uplift, in southeastern "ryoming, small deposits of uranium occur 

along gravity faults of small displacement in the Arikaree formation of l\iiocene age .. 

The· data from numerous test wells for oil and gas, 

and from are~l mapping are adequate to determine 

structure and thicknesses of the rocks, and the general 

configuration of the erosion surface upon which they 

were deposited. . 

The writers iu·e··indebted to Laura. ,V. McGrew for 

information on the Fort Laramie-"Theatla.nd area and 

for sa.mple logs of several wells. R. F. Gantnier, 

.J. A. Thomas, and T. S. Sterrett made size analyses 

and prepared slides and thin sections of the Tertiary 

rocks for petrographic studies. · 

8trati,qra7)hy.-The. · stratigra.phic succe$sion and 

nomenclature for the middle and upper Tertiary rocks 

in western Nebraska, southeastern "ryoming, and 

northeastern Colorado have been described bY. Lugn 

(1939), McGrew (1953), and Galbreath (1953). In 

this report only the names of the chief rock units are 

used, without reference to the subordinate units recognized by the foregoing authors. In the region shown 

in figures 209.1 and 209.3, the Tertiary rocks are assigned to the 1Vhite River formation of Oligocene 

age, the Arikaree formation of Miocene age, and the 

Ogallala formation 1 of Pliocene age. These units can 

·t The lower part of the Ogallala at a' few places· is rep.orted to contain vertebrate fo~sils •Wl)i~h some· paleontologists regard as late Mio- cene in age. 

be recognized and mapped over wide areas and are 

particularly useful for regional studies. 

Figure 209.1 shows the areal distribution of the 

Tertiary rocks and their present total thickness as 

determined from electric, gamma ray, and sample logs. 

Paleogeogra,phy and geologic history.-As indicated 

by the schematic diagram, figure 209.2, erosion followed uplift at the close of the Oligocene and again 

at the end of the l\iiocene and removed much of the 

Tertiary sequence in the southwestern part of the 

region. The Ogallala in the southwestern part of the 

area rests on the bevelled edges of the 'White River 

and Arikaree formations. Northward and northeastward the ~ite River thickens from about 300 feet 

to 850 feet, and the Arikaree from a feather edge to 

about 600 feet. Both units are reported to contain 

younger beds in areas to the northeast than they do in 

areas to the southwest. 

Figure 209.3 shows the reconstructed thickness of 

the 'Vhite River formation immediately preceding 

deposition of the Arikaree or Ogallala formations. 

As shown on this map the White River formation generally increases in thickness toward the northeast. 

Local areas of greater thickness probably represent 

topographic lows or vall~ys formed by a pre-Oligocene 

drainage system. In some areas the present-day 

streams are parallel· to valleys developed on the land 

surface at the beginning of Oligocene time, although 

in other areas the present-day and ancient valleys 

trend in different directions. Stream piracy, perhaps 

preceded by regional uplift in post-Pliocene time, is 

suggested by a change in the trend of present-day 

Horse and Bear Creeks. The upper reaches of these 

streams are alined with two conspicu~ms pre-Oligocene 

topographic lows in Scottsbluff. and Banner Counties, 

Nebr. (fig. 209.3). These topographic lows at one 

time ma.y have formed the lower courses of Horse and 

B·ear Creeks; the two streams now turn abruptly north 

at their "elbow of capture" in southeastern Goshen 

County, 'i'\Tyo., and flow north and northeastward 

through Goshen Hole to the North Platte River. 

Possible source of sediments.-The surface upon 

which the Oligocene rocks were deposited now slopes 

·northeastward from an elevation of about 6,600 feet 

in northeastern Larimer County, Colo., to about 3,600 

feet in northwestern Nebraska. This is partly the 

re$ult of tilting subsequent to deposition of the White 

+{iv~r formation. A southwesterly source for the sediments comprising the Oligocene and Miocene rocks 
\. 

i .. 

SHOH'l' PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C·-169 

103 ° 30' 

,--,;----::-------::-T---,r----r-----,-------"T""--,...,---------- 43 ·oo· 

CONVERSE 

0 SIOUX o o 

o KIMBALI:e 

WELD 

EXPLANATION 

Pliocene, Miocene, and Oligocene 

rocks 

Stippled where rocks nre more than 

1,100/eet thick 

D 

Mesozoic and Paleozoic rocks 

Thickness measurement 

F-rom electric log of selected 

d·rill hole 

_;_-----tSOO 

Isopach line 

Showing combined thickness of Plio· 

cene, Miocene, nnd 0/.igocene rocks. 

Intervnl 1,00 feet 

0 16 MILES 

40°30'~~-~~~~---~~-----~-----K~----~-~--~-------~40°30' 

105°30' 103°30' 

FwuRJ~ 209.1.-lVI'ap showing combined thickness of Oligocene, Miocene, and Pliocene rocks in test wells in southeastern Wyoming 

and adjoining areas . 

. oo15ao 0-61--12 
C-170 GEOLOGICAL SURVEY RESEARCH 1 9 61 

A 

I SOUTH DAKOTA 

1"---

WYOMI~G I ~ 

I NEBRASKA 

-- ~ --1 COLORADO I 

A' 

FwuRE 209.2.-Schematic diagram showing stratigraphic relations of middle and upper Tertiary rocks from east side of Laramie 

Range northeastward to the Nebraska panhandle. 

is suggested in areas away from the major uplifts 

by the following: (a) direction of crossbedding observed over large areas in the Arikaree formation 

indicate transportation and deposition by northeasterly flowing stream, (b) northeasterly axial trends 

of "pi py" conGretions in Miocene rocks {Schultz, 

1941, p. 74, 77) indicate northeasterly" direction of 

flow of underground water shortly after or contemporaneous· with deposition, and (c) a small but general increase in the average percentage of heavy 

minerals occurs in the Oligocene rocks towards the 

southwest (table 209.1). 

Petrography of Oligocene rocks.-The average of 

·size analyses of about 100 samples from 10 measured 

sections of ·the White River formation in the region 

(table 209.1) indicate that these rocks are remarkably uniform in grain size over wide areas and contain relatively insignificant amounts of locally derived materials. To the unaided eye most of the 

samples appear similar in color, texture, and composition, but preliminary studies of thin sections show 

considerable variation in component minerals. In 

general, these rocks consist of 65 to 85 percent silt 

and 5 to 25 percent very fine grained sand embedded 

in a matrix of clay-size particles. The silt and very 

fine grained. sand fractions cons1st of glass shards 

and angular to subrounded fragments of quartz, 

potassium feldspar (microcline and orthoclase), plagioclase, and, small amounts of detrital minerals. The 

clay-size fraction consists of montmorillonitic clay, 

clay-size carbonate flakes, and fine volcanic ash. 

Shards are present in nearly every sample and comprise from less than 10 percent to at least 50 percent 

of the rock. The glassy components of some samples are partially devitrified, showing feeble birefringence. Samples in which many of the shards 

are devitrified also are marked by a relatively large 

content of montmorillonitic clay. It is inferred that 

TABLE 209.1.-Average grain size distribution, calcium carbonate content, and heavy mineral content for grab samples of Oligocene rocks 

(White River formation) from southeastern Wyoming and some adjacent areas 

[vfg, very fine grained; fg, fine grained] 

Average grain-size distribution of insoluble 

Locality Thickness Num- light fraction, in per- Average 

I ocation of strati- ber cent Average pen·en tagc No. Locality County State graphic of percent of heavy on map unit sam- CaCOa minerals 

(tlg.209.3) sampled, pies Sand in vfg 

in feet Clay Silt ----- sand 

Sec. T.N. R.W. vfg fg 

--- --------- ---------------------

1 Young Woman Creek_ N% 35 ___ 35 64 Niobrara ___ Wyo _____ 300 11 14 64 20 2 30 0. 06 

2 Monroe Canyon ______ SE}~ 17 __ 33 56 Sioux ______ Nebr _____ 200 8 16 80 4 ---- 20 . 06 

3 Slater _______________ SE% 19 __ 22 66 Platte ______ Wyo _____ 190 10 8 66 26 ---- 24 .11 

4 Bear Mountain _______ S% 17 ____ 20 62 Goshen _____ Wyo _____ 235 11 14 80 6 ---- 22 . 20 

5 Eagles Nest __________ 22,26 ____ 21 58 Scottsbluff __ Nebr _____ 200 8 13 81 6 ---- 23 . 09 

6 Scottsbluff ___________ N%12 ___ 21 56 Scottsbluff __ Nebr _____ 280 12 8 86 6 ---- 21 . 08 

7 Horse Creek _________ E% 32 ___ 17 69 Laramie ____ Wyo _____ 300 11 16 70 13 1 24 . 16 

8 Terry Ranch _________ 27, 34 ___ - 12 69 Larimer ____ Colo _____ 280 11 17 68 14 1 31 . 18 

9 Chalk Bluffs _________ 8, 17----- 11 65 Weld ______ ___ do _____ 225 9 13 6·3 23 1 23 . 12 

10 Stony Buttes _________ 2, 3 ___ --- 11 55 Logan ______ ___ do _____ 300 11 12 67 20 1 23 . 06 
I_ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-171 

103°30' 

ro---..-----"""'ft1r-r--..,-~--;;----::::------~--...~--------- -- 43 ooo· 

CONVERSE 

0 

:WELD 

EXPLANATION 

Upper and 

1/w.l 

~ middle Tertiary rocks 

Stippled where formation is more 

than 700 feet thick 

D 

Mesozoic and Paleozoic rocks 

Precambrian rocks 

Thickness measurement 

From electric log of selected drill 

hole. In some areas thickness 

reconstructed from field and well 

data 

----900 

Isopach line 

Showing thickness of White River 

formation. Interval 200 feet 

0 

x® 

Sample locality 

See table 

...__ _____ __, 16 MILES 

~~~~~~------~~------------------~--~--~~~=c~==~~~==~~~40°30' 

103°30' 

FIGURE 209.3.-Map of southeastern Wyoming and fLdjoining areas showing thickness of White River formation (Oligocene). 
C-172 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

both devitrification and formation of montmorillonitic clay in these rocks are produced by post-depositional alteration. 

The dominant heavy 'minerals in these rocks are 

hornblende (both blue-green sodic and red-brown 

basaltic varieties) and biotite, and lesser amounts 

of zircon, garnet, rutile, epidote, orthopyroxene, and 

gold. Most of this assemblage indicates a mixed 

igneous and metamorphic terrane as a source for the 

detrital portion of these ~·ocks; the dominant basaltic 

hornblende and possibly the biotite suggest a volcanic source for some of the heavy minerals compatible with the large amount of volcanic matter in 

the light fraction. 

No pattern, either stratigraphic or areal, has yet 

been recognized in the petrographic variations among 

these samplss. The distribution of gold, for example, is not related to the position of the present mountain front. It occurs in greatest amounts in the 

Slater, Young vVoman Creek, and Stony Buttes sections, far east of all present known sources of gold. 

The significance of this is not completely understood 

at present, but it may be related to a drainage system developed during Qligocene time. 

REFERENCES 

Galbreath, E. C., 1953, A contribution to the Tertiary geology 

and paleontology of northeastern Colorado: Kansas Univ. 

Paleont. Contrib., art. 4, 120 p. 

Lugn, A. L., 1939, Classification of the Tertiary system in 

Nebraska: Geol. Soc. America Bull., v. 50, p. 1245-1276. 

McGrew, P. 0., 1953, Tertiary deposits of southeastern Wyomi,ng, in Wyoming Geol. Assoc. Guidebook 8th Ann. Ji'ield 

Con f., ·Laramie Basin, Wyoming, and North Park, Colorado, 1953: p. 61-(14. 

Schultz, C. B., 1941, The pipy concretions of the Arikaree: 

Nebraska State Mus. Bull., v. 2, no. 8, p. 69-82. 

210. CLAYS IN THE INYAN KARA GROUP (CRETACEOUS), BLACK HILLS, WYOMING AND SOUTH DAKOTA 

By LEONARD G. Scnuvrz and WILLIAM J. MAPEL, Denver, Colo. 

The Inyan l{ara group of Early Cretaceous age 

consists of the Lakota and overlying Fall River formations, and crops out on the flanks of the Black 

Hills in vVyoming and South Dakota. About 110 

samples of Inyan l{ara rocks, taken from 5 outcrop 

sections and from the cores of 2 drill holes, were 

analyzed for their clay minerals to provide information that might be useful in subdividing and correlating stratigraphic units, and in interpreting the 

history of deposition. The rocks sampled are mostly 

siltstone, claystone, and shale. They represent most 

parts of the Fall River formation, but only the upper 

part of the Lakota except for a section at Cabin 

Creek. The stratigraphic relations of the Inyan 

Kara group are summarized in table 210.1 and the 

lithology of the formations and composition of the 

clays at the sample localities are shown on figure 

210.1. 

STRATIGRAPHIC RELATIONS 

The Lakota formation is a nonmarine deposit laid 

down in swampy areas and on flood pl~lins of streams 

m an area of low relief. The Fall River formation 

·is probably a marginal marine deposit laid down on 

tidal flats, in coastal swamps, or in marine deltas 

('Vaage, 1959, p. 63-64). An unconformity separates 

the two formations everywhere in the Black Hills. 

Stream channels outlined by Brobst (1956, p. 103-105) 

and the dip directions of cross beds suggest that sediments in both formations were supplied from the 

southeast. · 

Claystone and siltstone in a unit several feet thick 

at the top of tl1e Lakota formation generally are 

mottled shades of gray, purple, red, and yellow, and 

the rocks contain numerous ferruginous· spherules 

commonly about 1 mm in diameter. Fresh spherules 

are reported by 'Vaage (1959, p. 55) to consist of 

siderite. Ferruginous spherules are also found in a 

mottled zone below a thin tongue of variegated mudsto1le that crops out near the middle of the Fall River 

formation at Angostura Reservoir and elsewhere on 

the east side of the Black Hills. Although the significance of the siderite is equivocal, similar siderite 

spherules in some other areas have been interpreted 

• '
c 

0 

:;:; 

<II 

E 

.£ 

~ ii 

iii 

u... 

a. 

:::l I 

e 

t:IO 

~ <II 

::.c 

c 

<II 

>. 

c 

- I 

c 

0 

:;:; 

<II 

E 

.£ 

<II 

0 

~ 

<II 

....J 

cl 

c/ 

:=~ 

-. 

State Highway 111 

Sec. 20 

T. 54 N., R. 62 W. 

M_!?l!_T~---l~~ WYOMING 0< 

Government Canyon~ "'o 

I 

Rapid City 

0 20 40 60 MILES 

OUTCROPS OF THE INYAN KARA 

GROUP AND SAMPLE LOCALITIES 

c 

0 

~ 

E 

~ 

c 

g 

·.::: 

0 

~ 

,~ r 

Angostura Reservoir 

Center sec. 20 

T. 8 S., R. 6 E. 

Donkey Creek cores 

NWlf• sec. 5 and NWlf• sec. 16 

T. 49 N., R. 68 W. 

FEET LITHOLOGY 

0 

50 

100 

Siltstone 

Shale or 

claystone 

Marl 

Covered 

MAJOR 

~ 

UNCONFORMITY 

MINERAL ABUNDANCE 

EXPLANATION 

MINERALS 

~ 

Well-crystallized kaolinite 

~ 

Intermediate kaolinite 

~ Poorly crystallized kaolinite 

111111111118 

Chlorite 

cl, trace amount 

c:::J 

i, traJ!Ii~:;,ount 

Mixed-layer ~ clay 

Illite dominant 

~ 

Mixed-layer clay Montmorillonite dominant 

Montmorillonite 

-

~ 

Quartz 

@E) 

Feldspar 

f, trace amount 

I:LKJ 

Calcite 

d 

d, t9J'J~~J~~t;unt s Ferruginous spherules 

FIGURE 210.1.-Principal minerals in samples from the Inyan Kara group, Black Hills. 

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C-174 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 . 

TABLE 210.1.-Generalized description of the Inyan Kara group and adjacent formations, Black Hills 

Age Group and formation Thickness Description 

(feet) 

20Q-260 Fissile black shale; a few ferruginous concretions;. thin siltstone seams Skull Creek shale (thins in the lower part; rare marine fossils. 

rn southeastward) 

::::s 

0 

Q) 

<:,) 

«! 0.. 120-160 Interbedded brown-weathering sandstone, light- to dark-gray siltstone, +=> ::::s Q) 0 Fall River formation (thickens and dark-gray silty shale; locally carbonaceous. Thin tongue of 

'"' '"' southeastward) 0 bl) variegated mudstone about the middle of the formation in the 

>. «! eastern part of the Black Hills; nonmarine pelecypods locally at 

"i:: «! '"' the base; contains more sandstone to the southeast. «! ~ --Uncon.f ormity ~ 

= 100-550 Light-gray locally conglomeratic sandstone, and variegated claystone «! 

>.. Lakota formation (thickens and sandy claystone; local lenses of coal and carbonaceous shale 

~ = southeastward) in the lower part; nonmarine fossils. 

<:,) 100± Greenish-gray and grayish-red claystone and ·marl; a few thin beds Q)·oo 

~~ Morrison formation .of grayish-white sandstone; nonmarine fossils. 

~~ ~ 

as a product of a long period of subaerial leaching 

and oxidation (Waage, 1959, p. 56-57). 

CLAY MINERALS 

Abundance of clay minerals in samples studied 

during this investigation is estimated to the nearest 

5 percent on the basis of X-ray diffraction intensities. The clay minerals include kaolinite, illite, 

n1ontmorillonite, mixed-layer clays, and trace amounts 

of chlorite. "\Veil-crystallized, intermediate, and 

poorly crystallized kaolinite and two types of mixedlayer clay have been distinguished-one mixed-layer 

clay has illite and the other has montmorillonite as 

the dominant layer. Nonclay minerals, consisting 

mainly of qu~rtz and minor amounts of feldspar, 

make up from 20 to 90 percent and average about 

50 percent of individual samples. 

The Lakota and Fall River formations have the 

same clay minerals but in different proportions. Illite . 

was found in nearly all of the Fall River samples, 

but was found in less than half of the Lakota samples. This distr1bution of illite may indicate conversion of some mixed-layer clay to illite in brackish 

or marine waters of the Fall River sea, or it might 

indicate local destruction of illite by weathering 

during deposition of the Lakota. 

Montmorillonite is locally abundant in the Lakota 

formation, and the montmorillonitic variety of mixedlayer clay is fairly common in both formations. The 

montmorillonitic variety of mixed-layer clay appears 

to be slightly more prevalent at the northernmost 

outcrops of both formations, but this mineralogic distribution is less marked in the Lakota than in the 

Fall River. The occurrence of montmorillonitic clays 

suggests contamination by volcanic material, and possible additional evidence of volcanism during depositon of the Inyan ICara group is found in the local 

occurrence of trace amounts of apatite in euhedral 

crystals and some biotite in heavy-mineral concentrates from the Fall River formation (W. A. 

Chisholm, written communication, 1957). 

The most consistent variation in the distribution of 

clay minerals is the abundance of poorly crystallized 

kaolinite at several localities in the mottled unit at 

the top of the Lakota formation. At Government 

Canyon and Cabin Creek, poorly crystallized kaolinite 

is the only clay mineral present in this interval. In 

the Donkey Creek cores, kaolinite is the only clay 

mineral present, but it is a well-crystallized variety. 

At Angostura Reservoir, clay in the uppermost Lakota sample (which is about 5 feet stra~igraphically 

below the top of the formation) contains only a small 

amomi.t of kaolinite; however, the kaolinite zone may 

be present in the overlying part of the Lakota, or 

it may have been eroded away before deposition of 

the Fall River formation. At Angostura Reservoir 

a fairly large amount of poorly crystallized kaolinite 

occurs in a sample from the mottled zone near the 

middle of the Fall River formation. 

In all samples from the mottled zones of both formations, chlorite and feldspar-minerals that are relatively easily destroyed by weathering-are absent. 

Concentrations of kaolinite associated with ferruginous material, and the absence of chlorite and feld-

. 

r 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-175 

spar, are consistent with an interpretation of the 

mottled zones at the top of the Lakota and in the 

Fall River formations as zones that have undergone 

severe weathering; they perhaps represent ancient 

soils. The poor crystallization in most of the kaolinite 

in these . zones might indicate degradation of the 

clay during soil leaching. 

REFERENCES 

Brobst, D. A., 1956, Channel sandstone, southern Black Hills, 

·in Geologic investigations of radioactive deposits-Semial)nual progress report, June 1 to Nov. 30, 1956: U.S. Geol. 

Survey .'.rEI-640, p. 102-108, issued by U.S. Atomic Energy 

Corum. Tech. Inf. Service, Oak Ridge, Tenn. 

Waage, K. 1\f., 1959, Stratigraphy of the Inyan Kara group 

in the Black Hills: U.S. Geol. Survey Bull. 1081-B, p. 11-87. 

~· 

211. COBERN MOUNTAIN OVERTHRUST, LEWIS AND CLARK COUNTY, MONTANA 

By RoBERT G1~0RGE SCI-IJ\UDT and PETER Zunovrc, 'Vashington, D.C. 

The Cobern Mountain overthrust is in western 

1\{ontana, in the southeastern part of Lewis and Clark 

County, near the towns of Wolf Creek and Craig 

(fig. 211.1). The ·fault extends from the Dearborn 

River southeastward for many miles along the western margin of the Adel l\{ountain volcanic field, 

which forms the northern end of the Big Belt Range, 

and was partly mapped by Lyons (1944, pl. 1) in 

a reconnaissance study of this area. In the course 

o:f: detailed geologic mapping in 1960, we traced this 

fault northward from the :Missouri River, recognized 

that it has a large displacement and the characteristics of an overthrust, and named it after Cobern 

1\{ountain, a prominent peak approximately 6 miles 

north of Craig. 

The overthrust lies in the eastern part of the socnJled Disturbed Belt, a zone of intensely folded and 

faulted rocks that extends along the eastern front 

of the Northern Rocky l\{ountaiJiS in western 1\{onbtna and southern Alberta. The Disturbed Belt includes rocks of :Mississippian, Jurassic, and Cretaceous age in· the at;e~l. sho,Yn in figure 211.1. (See 

Lyons, 1944, pl. 1.) The 'tr~we of the overthrust is 

within rocks of Late Cretaceous age. The sequence 

of Upper Cretaceous strata in the general vicinity of 

the fault is as follows: 

Upper Cretaceous : 

Adel Mountain volcanics of Lyons (1944) 

St. Mary Hiver formation (lowermost part) 

Two Medicine formation 

Virgelle sandstone 

Telegraph Creek formation 

Colot·ndo group : 

Mal"ins River shale. 

Along the fault, older rocks are thrust northeastward upon younger rocks, and the fault plane cuts 

upward gradually across the stratigraphic section. 

North of the l\1issouri River, the fault brings rocks 

of the Two l\1edicine formation, rocks assigned to 

the St. Mary River formation, and overlying rocks 

at the base of the Adel Mountain volcanics over 

yomiger rocks of the Adel Mountain volcanics. At 

the l\1issouri River, where erosion has exposed the 

fault plane at a deeper stratigraphic level, the Virgelle sandstone forms the hanging wall of the fault. 

South of the l\1issouri River, as shown by Lyons 

(1944, pl. 1), the fault brings rocks of the Two 

l\1edicine formation over the Adel Mountain volcanics. 

In places, north of the l\1issouri River, the overthrust is deformed. Along the upper part of Dog 

Creek and in the vicinity of Cobern Mountain, the 

fault plane is folded into an anticline and syncline 

and its trace is. very sinuous. In this region, the 

dip of the fault plane ranges from near horizontal 

to 50° and the net slip along the fault is more than 

2 miles. Cobern l\1ountain, which forms part of the 

overthrust block, and a small klippe to the south of 

Cobern l\1ountain (fig. 211.1) lie along the axis of 

the syncline. Other klippen, too small to show on 

the accompanying map, occur along the axis of the 

anticline on hill tops adjacent to Dog Creek. West 

of Cobern ·Mountain, the trace of the overthrust is 

offset by a high-angle fault. At its northern limit, 

the plane of the overthrust steepens and the fault 

trace passes into rocks of the Two Medicine formation. Beneath the Cobern Mountain overthrust, rocks 

of the Adel Mountain volcanics are intensely crushed 
C-176 

112°7'30" 

4 7° 15' 

T. 

16 

N. 

0 

GEOLOGICAL SURVEY RESEARCH 1 9 61 

R. 2 W. 

EXPLANATION 

Adel Mountain volcanics of 

Lyons (1944) 

Rocks older than Adel Mountain 

volcanics; principally Two Medicine 

formation 

Cobern Mountain 

~ overthrust 

Saw-teeth on 'Upper plate 

~ u 

High-angle fault A-.c.....,L..~"---,4-+-,~-T-'1"--7''-+-'7"-7._,.,~'--7':_....., U, upthrown l'lide; D, downthrown side 

2 3 4 SMILES 

FIGURE 211.1.-Map showing geologic relations along northern trace of Cobern Mountain overthrust, Montana. 
'-

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-177 

and fractured as a result of .the thrust movement. 

The zone of crushing and fracturing in the footwall 

is as much as 200 feet thick. The rocks in the ha,"nging wall of the fault, principally sedimentary rocks 

of the Two ~1edicine formation, are greatly deformed 

by drag folding and shearing, but they are not so 

.intensely crushed as the volcanic rocks in the footwall. T'he zone of deformation above the fault is as 

much as 300 feet thick. The structural interpreta- · 

tion presented above differs considerably from that 

of Lyons ( 1D44, pl. 1; p. 453). 

At severnJ places within the overthrust sheet, pyroclastic breccias in the lower part of the Adel l\1ounh1.in volcanics lie unconformably on beds of sandstone 

and mudstone that contain abundant shells of the 

oyster Ost1•ea glab1·a (identified by vV. A. Cobban of 

the U.S. Geological Survey), and a similar relation 

is found in the block beneath the fault north of the 

Dearborn River. These beds are confined to the 

northwest niargin of the Adel Mountain volcanic field. 

The principal occurrences of Ostrea glabra are shown 

in fi~ure 211.1 According to Cobban (oral communication), this oyster also occurs in the Horsethief 

sandstone of Late Cretaceous age; and the species 

seems to be restricted to that horizon in this part of 

l\1ontana although it has a known range throughout 

l\1ontana time. The Horsethief sandstone occurs 

north of the area shown in fig. 211.1; there it rests 

conformably on the Two Medicine formation and 

underlies the St. l\{ary River forination. The beds 

of sandstone and mudstone beneath the Adel 1\{ountain volcanics are therefore believed to be of Horsethief age, although they are assigned to the lowermost 

part of the St. l\{ary River formation on the basis 

of lithology. Elsewhere the Adel l\{ountain volcanics rest on a surface eroded across the Two Medicine formation, the Virgelle sandstone, and the upper 

part of the Colorado group, and plant fossils indicate that the volcanics are o£ Late Cretaceous age 

(Lyons, pl. 1; p. 465). From these relationships it. 

follows that the Adel l\{ountain volcanics are of latest 

Cretaceous age and equivalent to part of the St. Mary 

River formation. 

REFERENCE 

Lyons, J. B., 1944, Igneous rocks of the northem Big Belt 

Range, Montana: Geol. Soc. America Bull., v. 55, no. 4, 

p. 445-472. 

212. A REDEFINITION AND RESTRICTION OF THE TERM CHALLIS VOLCANICS 

By CLYDE P. Ross, Denver, Colo; 

Early in my work in south-central Idaho the masses 

of Tertiary volcanic rocks there were grouped as the 

Challis volcanics (Ross, C. P., 1927, p. 79; 1934, 

p. 4()) in a definition that was necessarily broad. The 

rocks with which I was immediately concerned are 

widespread in the region that is centered around 

Challis, so that name was applied to them. They 

were then re~arded as of Oligocene or, at the youngest·, early 1\fioeene age. Only the readily recognizable 

Snake River basalt and Columbia. River basalt were 

excluded from the formation. 

LaJer studies have. demonstrated that, as expected, 

t·he Challis volcanics of the region around Challis 

are a coherent', thick, and widespread (fig. 212.1) 

unit'. There are some volcanic and sedimentary rocks 

in distant part's of south-central Idaho that are now 

recognized as so different from the Challis volcanics 

that they should be excluded from that formation. 

Ftirthermore, confusion has arisen as to the relation 

of certain sedimentary beds in the Challis volcanics 

to the formation as a whole. 

I here propose that the term Challis volcanics be 

restricted to dominantly volcanic strata of early Tertiary age within the part of central Idaho north of 

the Snake River Plain and south of the westwardflowing segment of the Salmon River (near lat 

45°30'). Tuff and sedimentary beds intercalated with 

the lava flows are included in the formation. Essentially, this restricted definition limits use of the name 

to the rocks so designated on figure 212.1, although, 

of course, future mapping will produce modifications 

and extensions in detail. 
~ 

'7 

117. 116. us· 10 0 10 20 30 

jJ 

~l l 

I 

I 

I 

]j .. Q... ~ Silicic volcanic rocks 

!1 

~ : 

£j l ~~ 

a~ 

1!~ 

~j 

"'~ 

~~ "" 

:::, 

___, 

EXPLANATION 

[ill] . t8J Basalt of the Snake Older alluvium and River Plain other sediments that underlie Re· 

cent alluvium and 

lake beds 

II Columbia River basalt and 

associated sedimentary rocks 

~ 

~ 

Challis volcanics with intercalated 

tuff and sedimentary rocks 

llllllil!m 

lll!\IWilll 

Beaverhead formation 

Unpatterned areas are underlain 

by younger and older rocks 

not pertinent to this report 

Contact 

Fault 

~l. Aro ap \ ... 

'·! 

INDEX MAP OF IDAHO 

>-

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>-

a: 

;::: " 

a: 

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0 

"' u 

" t;; 

a: 

u 

FIGURE 212.1.-Map of south-central Idaho showing distribution of Tertiary volcanic and related strata. Geology taken from geologic map of Idaho by C. P. 

Ross and J. D. Forrester, 1947, with numerous modifications based on unpublished maps by C. P. Ross, H. E. Malde, and C. M. Marshall. 

0 

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,_. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-179 

The Challis volcanics consis~ mainly ·of flows and 

flow breccias of a wide range of composition, but 

sedimentary rocks (in part with little or no contained 

volcan·ic matter) and tuff are locally present. In 

phtces members of the formation have been distinguished. These include, among others, the Yankee 

Fork rhyolite, the Germer tuffaceous member, and 

v•trious clastic units near the town of Salmon. The 

lttst are being studied and subdivided by Anderson 

( 1956, p. 28-30; 1957, p. 16-1.8; 1959, p. 25-28)' 

who believes tlutt the various .members are separated 

by unconformities. I-Iowever, neither the unconformities 

discussed by Anderson nor those recognized earlier 

(Ross, 1937, p. 49) are believed to have regional significance. They record inter;uptions in eruption and 

deposition such as are to be expected in volcanic 

strata with intercnlated sediments. 

The Challis volcnnics represent the lower part of 

the Tertiary deposits of south-central Idaho. The 

formation was originally regarded as possibly or 

probably of Oligocene age and not younger than 

early l\1:iocei1e (Ross, 1937; p. 65-68; Brown, 1937, 

p. 164). R. W. Brown (written communication, 1956) 

has revisited plant fossil localities near Salmon and 

near 1\{onumental Creek. The deposits near Monumental Creek were originally thought by Ashlee (Carpenter, 1932, p. 59) to be Oligocene and by Brown 

(1937, p. 164-165) to be early 1\{iocene in age. Brown 

now says that they "could well be late Oligocene." 

I-Ie found little in common between collections from 

near 1\{onumentaJ Creek and those from the Germer 

tuffaceous member near Challis, although he regar~ed 

both as components of the Challis volcanics. He 

now regards the rocks near Salmon, including the 

youngest of Anderson's units (1956, p. 28-30), as 

Oligocene and those near Challis as Eocene. His 

revision of opinion as to the beds west of Challis is 

based on leaves determined as Ficws densifolia that 

resemble some from Yellowstone National Park regarded as of Eocene age. My collections made in 

1.959 nen,r Salmon are regarded by J. A. Wolfe (written communications, 1959 and 1960) as of Oligocene 

age. lie also reported my collections made in 1960 

west of Challis as Oligocene, but the new collections 

add nothing to the information previously available 

for either the Salmon or the Challis area. These collections do not include Fimts densifolia and have little 

bearing on the possibility of an Eocene age for the 

rocks west of Challis. Thus, the Challis volcanics, 

as here restricted, may range in age from Eocene 

into, at the most, early l\1:iocene. Probably most of 

the formation is Oligocene. 

Late Tertiary strata within and on the borders of 

the mountains of the eastern part of south-central 

Idaho have long been known but available details are 

scanty. These strata include volcanic rocks and some 

sedimentary beds, exposed fairly continuously from 

the western part of the Centennial Range past Bannack Pass to the southern end of the hills bordering 

Birch Creek. Other scattered exposures are known 

at the southern tip of the Lemhi Range and along 

slopes northwest of Birch Creek. Available data 

(Scholten and others, 1955, p. 369-379, 376-377; Ross, 

1961), including a reconnaissance in 1960, suggest 

that large parts of these rocks may be Pliocene and 

possibly younger. Clastic beds on both sides of the 

divide between Lemhi River and Birch Creek may 

also 'be Pliocene. Sedimentary beds in Bannock Pass 

may be of late Miocene age (Scholten and others, 

1955, p. 369-370). The possibility that some volcanic and sedimentary rocks in the eastern part of 

south-central Idaho are as old as middle Miocene 

cannot be excluded on present evidence. If any exist, 

they do not belong to the Challis volcanics as redefined. 

The Beaverhead formation in the southeastern part 

of the Beaverhead Mountains (Scholten and others, 

1955, p. 368) is nonvolcanic. Much of it is conglomerate sufficiently like that locally present in the Challis volcanics so that confusion is possible. Conceivably future work may show that some beds now 

mapped as Beaverhead are equivalent to basal conglomerate in the Challis volcanics. 

The intermontane valleys contain large a_mounts of 

poorly consolidated somewhat deformed coarse alluvial material, including the Donkey fanglomerate in 

the upper drainage basin of the Pahsimeroi River 

(Ross, 1947, p. 1122-1124). These are Pliocene and 

younger. All of the varied strata commented upon 

above are younger than (and different from) the 

Challis volcanics of the areas around Challis and 

Salmon. 

In the western part of south -central Idaho the 

Challis volcanics are not known and the Tertiary 

strata differ from those cited above. Most are 

younger. From near Carey westward near the northern border of the Snake River Plain there are silicic 

rocks broadly similar to those mentioned above. Lack 

of definite age criteria introduces some uncertainty 

but all the post-Oligocene silicic rocks in this area 

would now be excluded from the Cha.llis volcanics. 

The western part of south-central Idaho contains extensive exposures of the ·Columbia River basalt and 

of associated sedimentary rocks and some strata that 
C-180 GEOLOGICAL SURVEY . RESEARCH 19 61 

may be younger. All of these are obviously different 

from the Challis volcanics as here defined. Suggested 

ages for the rocks in western areas range from early 

Miocene to late Pliocene and Pleistocene with the more 

recent assignments favoring the later age. (H. A. 

P-owers and H. E. Malde, written communications, 

1961). 

REFERENCES 

Anderson, A .. L., 195G, Geology and mineral resources of the 

Salmon quadrangle, Lemhi County, Idaho: Idaho Bur. 

1\lines and Geology Pamph. lOG. 

--- 1957, Geology and mineral resources of the Baker quadrangle, Lemhi County, Idaho: Idaho· Bur. Mines !and Geology Pamph. 112. 

--- 1959, Geology and mineral resourees of the North Fork 

quadrangle, Lemhi County, Idaho:· Idaho Bur. Mines and 

Geology Pamph. 118. 

Brown, R. W., 1937, Additions to some fossil floras of the 

westem United States: U.S. Geol. Survey Pt·of. Paper 

186-.J, p. 1G3-20G. 

Carpenter, .T. T., 1932, A tentative correlation of northwestern 

Tertiary strata: Northwest Sci., v. G, no. 2, p. 54-55. 

Hoss, C. P., 1927, Ore deposits in Tertiary lava in the Salmon 

Hivet· Mountains, Idaho: Idaho Bur. Mines and Geology 

Pamph. 25. 

--- 1934, Geology and ore deposits of the Casto quadrangle, 

Idaho: U.S. Geol. Survey Bull. 854. 

--- 1937, Geology and ore deposits of the Bayhorse region, 

Custet· County, Idaho: U.S. Geol. Survey Bnll. 877. 

--- 1947, Geology of the Borah Peak quadrangle, Idaho: 

Geol. Soe. America Bull., v. 58, no. 12, pt. 1, p. 1085-1160. 

--- 19G1, Geology of the southern part of the Lemhi Hange, 

Idaho: U.S. Geol. Survey Bull. 1081-F. 

Scholten, Hobert, Keenmon, K. A., and Kupsch, ,V. 0., 1955, 

Geology of the Lima region, southwestern Montana and 

adjacent Idaho: Geol. Soc. America Bull., v. 66, no. 4, 

p. 345-404. 

r' 

I 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-181 

213. UPPER PALEOZOIC ROCKS IN THE DEEP CREEK MOUNTAINS, IDAHO 

By Wn.~,RED J. CARR and DoNALD E. TRIMBLE, Denver, Colo. 

'l\1ore thn.n 11,000 feet of Mississippian, Pennsylvanian, and lower Permian rocks ar-e exposed in the 

Deep Creek l\1ountains 25 miles southwest of Pocatello, Idn.ho (fig. 213.1). Parts of t~is stratigraphic 

sequence n.re correlated with the Lodgepole limestone, 

Great Blue limestone, l\1anning Canyon shale, and 

Oquirrh formn,tion. The last three names, first applied by Gilluly (1932) in the Oquirrh Range, Utah, 

and the Lodgepole limestone of Montana and Utah 

luwe not previously been used in Idaho by the Geological Survey. Fine-grained clastic beds and thinbedded cherty limestone lie below the Great Blue 

and above the Lodgepole in the Deep Creek section; 

these rocks are here named the Deep Creek formation. 

·upper Paleozoic rocks in the Deep Creek Mountn.ins compa.re closely with equivalent rocks to the 

sout·h (fig. 213.1), but, with one exception noted later, 

they n.re generally unlike upper Paleozoic rocks in 

southeastern Idaho to the north and east. The Brazer 

limestone (l\1ississippian) and Wells formation 

(Pennsylva,nian) of southeastern Idaho are not separated by shale equivalent to the Manning Canyon 

shale of Late l\1ississippian and earliest Pennsylvanian 

age. l\1oreover, the Brazer in some areas includes 

rocks of Pennsylvanian, Early Mississippian, and 

Permian age, whereas the· age of the Great Blue is 

Late l\1ississippian. Restriction of the name Brazer 

has been suggested by Sando, Dutro, and Gere (1959), 

who showed that the type Brazer is a dolomite of 

] imited geographic .distribution. The Oquirrh formation, nJthough partly equivalent to the Wells, is 

thicker n,nd less sandy. 

Lowermost l\1ississippian rocks in the Deep Creek 

l\1ountains (fig. 213.1) are limestone and dolomite 

assigned t'o the Lodgepole limestone. These carbonate 

rocks contain fossils of Early Mississippian age. 

The Deep Creek formation .is here named from 

the mountains where it is typically exposed. In the 

type section (measured in S1V1/4NE1/4 sec. 35, T. 

9 S., R. 31 E.), and elsewhere in the region, the formnJ.ion is divisible into two mappable members; a 

lower siHstone, and an upper limestone. The lower 

member, 750 feet thick, consist mainly of light-gray 

to brown or black siltstone that weathers brown to 

purplish and is interbedded with subordinate amounts 

of silty limestone and shale. The upper member, 1,500 

:feet thick, is gray to blue-gray, mostly thin- to 

medium-bedded limestone that contains much dark 

chet~t, and locally is silty, platy, and weathers purplish. The lower contact of the formation is the base 

of the first shale or siltstone above the Lodgepole 

limestone; the upper contact, no~mally gradational, 

is· placed at the change from thin-bedded cherty limestone to the more massive ledges of the Great Blue 

limestone. 

Fossils are rare in the Deep Creek formation and 

the present age assignment· i.s based mostly on the 

stratigraphic position oi the formation between fossilbearing beds in the Lodgepole and Great Blue limestones. From near th~ top of the Deep Creek, J. T. 

Dutro and 1V. J. Sando (written communication, 

1961) have identified the coral Rhopalolasma, and 

brachiopods that "show some similarities· :with forms 

that occur in the Moorefield shale (early Late l\1ississi ppian) of the Mid -Continent region." They conelude that "although the ·age of the Deep Creek formation is uncertain, it may include beds of both late 

·osage and early Meramec age." J. T. Dutro (written communication, 1960) also identified Leiorhynchus 

cf. L. carboniferwm Girty from the lower member on 

Paps Mountain near American Falls, Idaho. He 

stated that "this species ir:;; common in the Chainman 

shale (l\1eramec equivalents) in Utah." On Bannock 

Peak, 5 miles east of the measured section, the Deep 

Creek is present in the upper plate of a. thrust fault, 

and there part of the lower member resembles the 

Chainman shale of western Utah and eastern Nevada. 

Sadlick and Schaeffer ( 1959, p. 1786) believe that 

the Chainman of northwestern Utah ranges in age 

from l\1iddle l\1ississippian to Early Pennsylvanian. 

The Deep Creek formation (fig. 213.1) is also approximately equivalent to the Humbug formation and 

possibly the Deseret limestone in Utah, to parts of 

the Milligen formation in central Idaho, and to the 

lower part of the Br~zer limestone as it has been 

used in central and southeastern Idaho. In the 

l\1ackay quadrangle, Idaho (Ross, 1960) ·an unnamed 

formation (fig. 213.1) that intertongues with the Milligen, Brazer, and 1Vood River formations, locally resembles the lower member of the Deep Creek, and at 

Timbered Dome, west of Arco, (Skipp, Art. 236) 

the rocks exposed are remarkably similar to the Deep 

Creek formation. LeiorhynchU8 carbonijeru1n Girty 

has been reported by· C. P. Ross (written communi-
C-182 GEOLOGICAL SURVEY RESEARCH 19 61 

1 

Mackay Quadrangle, 

Idaho 

Diagrammatic composite 

(Ross, written communication; 

Ross, 1960) 

c 

0 

:;:; 

(II 

·§ 

~ 

·T·I-f"r-

~· .. :.:7-;:.l l 

P-ri-::1 

~ 

I I '1 1 

~ .·:.-:::.'1 I 

2 

Soda Springs, Idaho 

(Armstrong, 1953) 

.... 

Cll 

> 1:+.¥1 I I A A I 4 l..a I• 

~--.·.'I Ill I ::~.·.·.' .... ·-§: 0:: tu·.CL' I ,'.'•I: :I:: ·I::. J'. ov 

1-1000 

'-2000 

3 

Deep Creek Mountains, Idaho 

i·~.. .. . 

·I· I· 1·1· 

" g I AlA lg 

·1··1·'· 1·-J 

"' " I I l I 

I I I i 

·1 ·J ·I · .1 

fl ·I· I ·I· c 

0 

:;:; 

(II 

E 

~ 

'E 

·:; 

·j_ •. l• . . J·-·_1 g 

·I· I· I· I ,, .. l.o.·l ·"1. •.• , ..... ·.·. ,·.-: ,.-.. :.: 1: 

II I· I I .• .A A • \4 

I I I _l 

II· I · I · l 

Dry Lake-Sardine Canyon, 

Utah 

(Williams, 1958; Nygreen, 1958; 

Williams and Yolton, 1945) 

:~~ .:;-_: ·.'_j_'.'-~· 

·,o·.: .. L:.·.A', · .. 1. . ." .• 

~ :.· : .. :·. · ......... ·.::: · . .:..: ."':·:f.:-:··. '.::L: 

... , .... ,·.A'""' 

5 

Oquirrh Range, Utah 

(Gilluly, 1932; Nygreen, 1958) 

~":"' ....... ~·.,·-~···-4-A 

.:··r-~1'/~f>r _: 

11 r" 1 TAl ·~ .. ·.·-L·,·.·~ ... 

~-~·:·~' .. ··::::.:·.:·:· I> • 

~ ..... ..J.... .'-J...•, 

........ ·.·.'..",'·'·'·"· 

::T.·T·-1· ... ·1 

_L. ~·. ~. 

.. ·· · .. :.··.·. 

II · 1·""1·"'1 · ·:-<-. •' ... J...': ~-

.. •'A , o.. . 

~:::·~.-,;::.~·· ... · .. ··. -:·,...·.·.·..L·;.· 

I ·1"'1. I"' · .......... · .. ·.·.·.·.·.: 

.... " "" 

• , .A ·A 

Cll 

c 

0· 

ti 

Cll 

~ 

FIGURE 213.1.-Tentative correlation of upper Paleozoic section, Deep Creek Mountains, Idaho, with selected upper Paleozoic 

sections in Idaho and Utah. Interfingering of formations shown diagrammatically for the Mackay quadrangle, Idaho. See 

explanation on facing page. 

,. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-183 

cation, 1961) from Upper Mississippian rocks in that 

n,rea. 

The Upper ~fississippian Great Blue limestone of 

the Deep Creek ~fountains (fig. 213.1) is like the type 

Great Blue, even to the presence of a medial shale 

zone at the same position above the base of the formation in both sections. The Great Blue in the Deep 

Creek ~fountains contains fossils of probable late 

l\1ertunec age near the base. 

The l\fanning C~tnyon shale of Mississippian and 

Pennsylvanian age is divisible into 3 distinct mem-

\MONTANA- I 

---~ '\ 

I 

I 

\ 

IDAHO 

~~--UTAH-

~~ 

I 

I 

0 

- . . . 

. ' 

. . . 

Siltstone and 

mudstone 

Sandstone 

or quartzite 

Phosphatic shale 

and phosphate rock 

. 

. 

Calcareous sandstone 

or siltstone 

50 100 150 200 MILES 

EXPLANATION 

Bedded chert 

Limestone 

Sandy or silty 

limestone 

Dolomite 

Sandy or silty 

dolomite 

Dolomitic limestone 

Shale or argillite 

A 

.A 

A 

Cherty limestone 

~ 

~ 

Cherty dolomite 

Calcareous shale or argillite 

--?--

Correlation line Correlation line 

fairly well controlled exact position uncertain 

Explanation for figure 213.1. 

hers (fig. 213.1) in the Deep Creek Mountains. A · 

similar tripartite Manning Canyon shale is suggested 

by 'Villiams' and· Yolton's (1945, p. 1145) section 

southwest of Logan, Utah (fig. 213.1). We examined 

this section and believe that, despite uncertainties 

caused by faulting, vVilliams' units 3, 4, and 5 correspond to our members of the Manning Canyon. 

Thick shales that probably correlate with the Manning Canyon shale or Milligen formation occur in the 

Sublett and Black Pine Ranges southwest of the Deep 

Creek l\fountains; however, much more work is needed 

to determine the relations of Mississippian and Pennsylvanian shales in southern Idaho. 

Probably more than 8,000 feet of rocks assigned 

to the Oquirrh formation overlie the Manning Canyon 

shale in the Deep Creek Mountains; a minimum of 

nearly 5,000 feet of Oquirrh, including rocks of Lower 

Permian age perhaps 600 feet thick, has been measured. Four units of the Oquirrh have been mapped 

in the Deep Creek Mountains but it is unlikely that 

these units can be mapped. in adjacent areas. 

Fusulinids from the Oquirrh formation in the Deep 

Creek Mountains, identified by R. C. Douglass, include assemblages of probable Atoka, Des Moines, 

Missouri, Virgil, and Wolfcamp age. E. L. Yochel-

. son (written communication, 1960) recognized Omphalotrochus from the Permian part of the section. 

No equivalents of the Park City or Phosphoria formations have been found, although rocks of this 

age are present (Cheney and others, 1956) in the 

Sublett Range 20 miles southwest. of the section described here. Youngquist and Haegele ( 1955) described Pennsylvanian and Permian rocks in the 

Sublett Range that are about the same age as upper 

Paleozoic rocks in ·the Deep Creek Mountains but 

are different in lithology. 

REFERENCES 

Armstrong, F. C., 1953, Generalized composite stratigraphic 

section for the Soda Springs quadrangle and adjacent 

areas in southeastern Idaho, in Intermountain Assoc. of 

Petroleum Geologists, Guide to the geology of northern 

Utah and southeastern Idaho, 4th Ann. Field Conf., 1953: 

pl. in pocket. 

Cheney, T. 1\I., McKelvey, V. E., and Gere, W. C., 1956, 

Fusulinid-bearing rocks in Sublett Range, southern Idaho 

-a discussion: Am. Assoc. Petroleum Geologists Bull., 

v. 40, no. 7, p. 1716-1719. 

Gilluly, James, 1932, Geology and ore ueposits of the Stockton 

and Fairfield quadrangles, Utah: U.S. Geol. Survey Prof. 

Paper 173, 171 p . 

Nygreen, P. W., 1958, The Oquirrh formation, stratigraphy of 

the lower portion in the type section and near Logan, 

Utah : Utah Geol. and Mineralog. Survey Bull. 61, 67 p. 

Ross, C. P., 1960, Diverse interfingering Carboniferous strata 

in the Mackay quadrangle, Idaho, ·in U.S. Geological Survey, Short papers in the geological sciences: U.S. Geol. 

Survey Prof. Paper 400-B, p. B232-B233. 
C-184 GEOLOGICAL SURVEY RESEARCH 19 61 

Sadlick, Walter, ami Schaeffer, F. E., 1959, Dating of an 

Antler orogenic phase (Middle Mississippian) in western 

Utah [abs.] : Geol. Soc. America Bull., v. 70, no. 12, pt. 2, 

p. 1786. 

Sando, W. J., Dutro, J. T., .Jr., and Gere, W. C., 1959, Brazer 

dolomite (Mississippian) Randolph quadrangle, northeast 

Utah : Am. Assoc. Petroleum Geologists Bull., v. 43, no. 12, 

p. 27 41-2769. 

Williams, J. S., 1958, Geologic atlas of Utah, Cache County: 

Utah Geol. and Mineralog. Survey Bull. 64, 98 p. 

Williams, J. S., and Yolton, J. S., 1945, Brazer (Mississippian) 

and lower Wells (Pennsylvanian) section at Dry Lake, 

Logan quadrangle, Utah': Am. Assoc. Petroleum Geologists 

Bull., v. 29, no. 8, p. 1143-1155. 

Young~uist, Walter, and Haegele, J. R., 1955, Fusulinid-bearing 

rocks in Sublett Range, southern Idaho : Am. Assoc. Petroleum Geologists Bull., v. 39, no. 10, p. 2078--2084. 

214. TIDE-AFFECTED FLOW OF SACRAMENTO RIVER AT SACRAMENT 0, CALIFORNIA 

By FRANKLIN C. CRAIG, Sacramento, Calif. 

Work done in cooperation with the California Department of Water Resottrces 

The Sacramento River at Sacramento is subject to 

tidal influence when the flow is less than about 35,000 

cfs (cubic feet per second). Questions regarding the 

accuracy of flows computed by a method that was 

not designed specifically for unsteady flow conditions 

prompted a study. of the factors to be considered in 

establishing a rating between stage and discharge on 

a tide-affected· stream. The study ?as been in progress intermittently since 1952. 

The tide in the vicinity of Sacramento usually consists of a large tide and a. small tide each lunar day 

and has a maximum range of about 3 feet. Sacramento is more than twenty miles upstream from the 

zone of flow reversal and a hundred miles from the 

ocean. Tidal patterns are shown by the inserts on 

the map on figure 214.1. The tidal action at San 

Francisco is complex and a pattern results that is 

lt mixture of the diurnal and semi-diurnal types of 

tides. The mixed tidal pattern is characterized by 

succeeding tides that frequently vary considerably in 

magnitude and that do not oseillate about mean sea 

leveL 

Characteristics of tides vary considerably from day to 

day throughout fortnightly, monthly, and other tide 

eye les. Furthermore, the cha-racteristics ehange as the 

tides move upstream; differences in tide range become 

less, but differences between.the rate of change in stage 

in the rising and falling phases become greater. The 

rate of depletion of tidal energy depends, in part, 

upon the magnitude of the tide, the depth· of the 

stream, and the initial elevation of the water surface. 

Some small-range tides suffer a depletion of only a 

few tenths of a foot in range between San Francisco 

and Sacramento while large-range tides always suffer a depletion of many feet. 

The result of the depletion of tide energy as the 

tide moves upstream becomes apparent in several 

ways, such as. by changes in the rate of rise or fall. 

Most striking are differences in the gradients of the 

tide troughs between San Francisco and Sacramento, 

the gradient of the trough of ·a large-range tide being 

much greater than that of a small-range tide. There 

is not a great deal of difference between the gradient 

of tide crests. 

Brown (1932, p. 749) has stated that water rushing 

into the mouth of an estuary induces a wave of translation which transmits force and energy upstream 

until it is finally depleted by friction and the force 

of the downflowing stream. · Likewise as the tide recedes and water rushes out of the estuary a negative 

wave of translation is induced that also transmits 

force upstream until its energy is dissipated. 

It is evident at Sacramento that an active force is 

present. It has been observed many times that the 

rate of flow tends to decrease toward the end of the 

falling phase. Before the end of the phase is reached, 
-to 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-185 

... 

~ ~ V>S 

~4 

::E 3 

!!! 2 

1 ::E 

:I 

... JUl.Y 1949 < Q 

l~'WD1n; 214.1.-l\Jap o1: lower Sacl'nmento Riv~r and San Francisco Bay, showing ti(le pattel'n at Sacnunento and Collinsville, Cn 1 i r. 

however, there is a marked increase in the rate of 

fiow followed by a second decrease. Such phenomena 

could only occur as a result. of an active force. 

It is evident, too, from the pattern of depletion of 

tide range that waves of translation induced in the 

falling phase (ebb tide) lose their energy much more 

rapidly than those induced during the rising phase 

(fiood tide). There is, of course, much more work to 

be done during the falling phase because the water 

that enters the estuary during the rising phase plus 

t·he water from upland sources must be accelerated 

and moved out of the estuary during the f~lling 

phase. As the tidal energy in this phase is insufficient 

to .move this amount of water, a head must be created 

to accomplish the task. The head is created from the 

energy of the tide in the rising phase and from the 

force of the downflowing stream. 

The net effect of this head is to cause the mean 

wn,t:er surface elevation of a tide-affected stream to 

tend t:o 'assume the shape of a long flat arch extending 

from the ocean to the point of depletion of tide effect. 

The shape of the arch is; of course, dependent upon 

t· he geometry of· the stream. 

601530 0-61-13 

The extent of the arching action varies with tide 

range, water depths, volume of upland flow, and other 

factors. The arching action, or head, is considered 

to be largely an acceleration head although velocity 

and friction heads are contributing factors. Velocity 

observations have shown that with acceleration, de- · 

celeration, and the movement of water at varying 

elevations there is considerable variation in velocity 

distribution throughout the cross section of the stream. 

Hence, there is more internal friction present than 

there is in a stream flowing under steady flow 

conditions. 

The problem of developing a rating between stage 

and discharge for the Sacramento River at Sacramento becomes one of evaluating the effect of variable 

head. This evaluation becomes difficult because, for 

~xample, an increase in head may be caused either 

by an increase in tide range or by an increase in the 

upland flow. Variations in head as a result of varia-. 

tion in tidal activity have increasingly greater effect 

as flows decrease below 10,000 cfs and decreasing 

effect for greater flows. Techniques used in rating 

other streams subject to variable backwate·r effects 

have proved to be satisfactory J.n rating the higher 

flows, but are not dependable for low flows .when 

applied to th~ Sacramento River. A. technique developed for rating tide-affected streams in Florida has 

proved to be usable when flows are low, and changes 

in the variable head are mainly the result of changes 

in tidal activity. The method proved to be weak 

when the rate of flow from upland sources was changing rapidly. The technique makes use of.the depletion 

in tide range from the lower to the upper end of 

the rating reach as a factor in adjusting the rating. 

Since the variation in hmid, insofar as it relates to 

changes in tidal activity, is associated with depletion 

in tide range, the method is usable under limited conditions." A technique developed by the present author, 

also based upon the depletion of tide range in the 

ra6ng reach, has· proved to be usable over a wider 

range of flow. 

Techniques such as these, which are based on stage 

readings many miles apart, produced good results when 

limited to the conditions to which they are adapted· 

but are .not the final solution to the problem. The 

weakness of these techniques lies in· the fact that they 

take into consideration only partly the varying characteristics of individual tides. New developments in 

instrumentation promise to make it practical to· apply 

complex mathematical relationships that are involved 

in a rigid· analysis of a tide-affected stream, and hence 

permit using these relations to compute discharge on 
C-186 GEOLOGICAL SURVEY RESEARCH 1 9 61 

a day to day basis. Digital punches, which are now 

installed at both ends of the rating reach, will make 

stage, fall, and rate of change in stage over short 

intervals of time available to an electronic computer. 

Research is now being carried on by the Geological 

·Survey to bring all of the essential factors into a 

computer program for analyzing the characteristics 

of every type of tide. 

REFERENCE 

Brown, E. I., 1932, Flow of water in tidal canals: Am. Soc. 

Civil Engineers Trans., v. 96, p. 749. 

215. INTERCHANGE OF-SURFACE WATER AND GROUND WATER ALONG TRIBUTARY STREAMS IN THE 

CENTRAL VALLEY, CALIFORNIA 

By S. E. RANTZ and DoNALD RICHARDSON, Menlo Park, Calif., and Tacoma, Wash. 

Worlc done in cooperation with the California Department of Water Resources 

The seepage rates along the lower reaches of 21 

streams traversing the alluvial plain of the Central 

Valley provide a basis for estimating potential rates 

of' ground-water recharge through these stream channels under conditions of conjunctive use of surfaceand ground-water· storage. ·From 1952 to 1958 streamflow was measured periodically to . determine seepage 

rates, but no concurrent observations of ground-water 

elevation were . made. Discharge measurements were 

made at each end. of several reaches on each stream, 

the . measuring sites being selected at locations where 

the geology indi9ated that a ·definite change in the 

rate of gain or loss in streamflow might be expected. 

The streams investigated are listed in table ~15.1 and 

are shown on figures 215.1 and 215.2. Ten streams 

are .tributary to the San Joaquin River and flow intermittently; the other eleven are tributary to the 

Sacramento ~iver and flow perennially. 

Emphasis was placed on determining maximum 

seepage rates for each reach o~ channel. These maximum rates occur under the optimum combination of 

ground-:water elevation and maximum streambed permeability. Because qf the lack of information on 

ground-water, it was impossible to determine . these 

optimum conditions independently, but their occurrence was indicated by observing the greatest seepage rate per acre of wetted channel. High recharge 

rates would probably be maintained if surface- and 

ground-water reservoirs are to be maintained in conjunction. The seepage rate per acre of wetted channel may. vary widely during the course of a year as 

a result of the deposition of relatively impermeable 

silt on the streambed during the recession of a stream 

and the removal of this silt during a rise. However, 

under conditions of conjunctive storage, a high degree 

FIGUHE 215.1.-Tributary streams investigated in the San 

Joaquin Valley. 

/ 

r-
-+· 

·., 

r 

,. 

r 

:-

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-187 

of channel permeability could be maintained by mechanically scarifying or removing the more impermeable surface material on the streambed. The water 

table could probably be maintained at levels conducive to high recharge rates by the judicious pumping 

of ground-water, and water-table gradients might be 

reversed by pumping to permit recharge of the ground'" 

wa,ter reservoir through the beds of some channels 

that now receive effluent ground-water seepage. 

Table 215.1 gives the range of unit seepage rates 

observed during the period of investigation at the 

21 Central Valley streams. The plus sign indicates 

seepage gn,in to the stream; the minus sign represents seepage loss from the stream. Expressing the 

seepage rate in terms of cubic feet per second per 

acre of wetted channel permits direct comparison of 

the various channels, because this unit rate is independent of discharge, channel geometry, and length of 

reach. Doubling this unit rate gives the seepage in 

terms of acre-feet per day per wetted acre, a unit 

that is numerically equivalent to seepage expressed in 

feet of water (depth) per day. For example, the 

TABT.E 21.5.1.-S·ummary of observed unit seepage rates 

[+,seepage Into tho channel; -,seepage out of the channel] 

I 

Range In unit seepage Crook rates (cfs per acre of 

Los Gatos 

Cantua 

Panoche 

wetted channel) 

San Joaquin Valley 

Little Panoche 

Los Banos 

+O. 03 to -0. 6 

+. 10 to -1.. 7 

+. 06 to -2. 3 -. 1.2 to- . 8 

+. 3 to -1.. 6 

Snn Luis 

Garzas 

Orestimba 

Del Puerto 

Corrat Hollow 

Clear 

Cottonwood 

Red Bank 

Antelope 

Elder. 

Mill 

Thomes 

Deer 

Pine 

Big Chico 

Cnche 

0 to -2. 7 

+. 2 to -2.5 

0 to -3. 5 

+. 07 to -1.. 2 

0 to- . 8 

Sacramento Valley 

+O. 18 to -0. 15 

+1.8 to- .4 

+. 3 to- . 8 

+2. 0 to- . 9 

+. 04 to -2.5 

+3. 0 to -2. 4 

+. 8 to- . 4 

+2. 5 to -1. 5 

+. 5 to -1.. 5 

+. 6 to -2.3 

+ 1. 8 to -3. 0 

FIGURE 215.2.-Tributary streams investigated in the Sacrnmento Valley. 

highest unit seepage rate observed, 3.5 cfs per wetted 

acre, which occurred on Orestimba Creek, is equivalent to a seepage rate of 7 feet of water per day. 

Of the 10 intermittent Snn Joaquin Valley streams, 

only Del Puerto Creek contributes a large percentage 

of its flow direct.ly to the San tToaquin River. In 

years of nYerap:e rn.in:fall virtually all the runoff from 

the other Hh·enms is nhsorberl by permeable n.lluvial 

:fan deposits before reaching the vn.lley trough. Althoug-h a small pn rt. o:f this runoff is lost. by evnpotrn.nspira.tion, nnrl n, smn.ll part is nsPd for irrigation, 

most. of f·he watrr passPs downward throug-h the soil 

zone nnd e\·Pnlually rl'nelws the watm· table in the 

upper wah~r-hParinp: zonl'~~ ~t. is rstimnted that t.he 

:tVPl':tp;l' :lllll\l:tJ J'\IIIOfr of ~fTP:IIII~ Oil flw Wl'sf'. sidl' of 

t.he San .Joaquin· Valley is ()0,000 acre-feet., nnd t.hnt 

60 to 80 percent of t.his runoff reaches the groundwater body. 
C-188 GEOLOGICAL SURVEY RESEARCH 19 61 

216. SILURIAN AND DEVONIAN ROCKS OF THE KLAMATH MOUNTAINS, CALIFORNIA 

By C. ,V. MERRIAM, Washington, D.C. 

Paleozoic and Mesozoic rocks of the l\]amath Mountains are disposed in arcuate north-south belts (fig. 

216.1) as shown by vV. P. Irwin (1960, p. 15). In 

the southern and eastern parts of this region fossiliferous rocks ranging from Silurian to Permian in 

age crop out widely. Elsewhere in this region the 

fossil record is n1eager. 

WESTERN KLAMATH BELT OF PALEOZOIC AND 

TRIASSIC ROCKS 

Supposedly Devonian Proleeanitidae were collected by Diller ( 1903, p. 345) northwest of North 

Yolla Bolly ~fountain (locality 1a). Restudy indicates 

that. these ammonoids are probably Triassic arcestids 

(N. J. Silberling, written communication, 1958). 

Limestones along the southwest margin of this belt 

contain structures resembling Chaetetes and Solenoporaj these deposits may be of Paleozoic or early 

l\1esozoic age. 

Limestone on Knownothing Creek (locality 7) near 

the center of this belt yields calcareous algae, stromatoporoids, and Oladopora, suggesting a Silurian 

and Devonian_ age. 

SOUTHEASTERN KLAMATH BELT OF MIDDLE 

DEVONIAN ROCKS 

This belt of Paleozoic rocks, otherwise known as the 

Redding-l\1cCloud belt, (localities 19, 20, 21, 22) 1n4zo--------~~~~~~~~~~--~--~~~-4--~---,~~~==~~~---~ztz-o----~770~R~E~G=O~N~----~-~ztlo------------~ CALIFORN lA 

0 Red Bluff 

0 Paskenta 

0 Covelo 

0 10 20 

0 Loytonville 

EXPLANATION 

!::. 

Limestones and marbles of uncertain age, 

probably Paleozoic or Mesozoic 

Fossil-bearing rocks of known • age, mainly Paleozoic 

R Rocks of Triassic age 

D Rocks of Devonian age · 

so Rocks of Silurian and Devonian age 

s Rocks of Silurian age 

LIST OF FOSSIL LOCALITIES 

1. Gazelle formation, Willow Creek area 

2. Gazelle formation, Parker Rock area 

3. Gazelle formation, Grouse Creek area 

4. Gazelle formation, McConnahue Creek area 

7. Limestones on Knownothing Creek 

13. Triassic rocks with arcestids, Whiterock area 

16. Rocks of probable Permian age 

18. Rocks of probable Permian age 

19-22. Kennett formation of Middle Devonian age 

24. Montgomery limestone of Silurian age 

X Lassen Peak 

Quincy 0 

0 Chico 

Jaylorsville 

·s• 

BlairsdenO 

Fw URF. 216.1.--Map of Klamath Mountnins regiou, California, showing rock belts nnd nn•ns of fossilif(•rous or potentially fossiliferous 

outcrops. Adapted from map by W. P. Irwin (1960, fig. 3). 

.J 

) 

~-
I 

,, 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-189 

eludes the J\iiddle Devonian Kennett formation 

(Diller, 1903, p. 347). The ICennett rests upon the 

BalnJdala rhyolite which overlies the Copley greenstone (IC'inkel, Hall and Albers, 1956, p. 32). The 

Kennett of the type area includes three members: a 

lower 75-foot siliceous shale, a middle bluish limestone 

200 feet thick and an upper mudstone-tuff-sandstone 

unit about 325 feet thick. Overlying the ICennett is 

the Brag-don formation of supposed Mississippian age. 

The limestone member (Stauffer, 1930, p. 95), 

larg-ely a coral facies, contains abundant favositids, 

H eliolites, A lveolites, Oladopora, cyathophy llids, cystiphy ]lids and Phillipsa,straea.ff The abundant stromatoporoids include A1nphi7J01'a. Among the brachiopods are 

At'I'YJJa, a large robust Sohizophoria, and Cryptonella. 

Faunas of the mudstone in the upper part of the Kennett include Prod1.wtella, JJ/artiniopsis? Schizophoria, 

Oyrtina, At1•ypa and Olado7Jora. Ileliolites and complex cyathophyllids like those just below StringoCeJJhal7.t8 in Nevada suggest a late ]\fiddle Devonian 

age. 

NORTHEASTERN KLAMATH BELT OF SILURIAN 

AND LOWER DEVONIAN ROCKS 

The northeastern IClamath or Scott River belt includes the Gazelle formation (Wells, Walker, and 

J\ferrittm, 1959) now considered to be of Silurian and 

Early Devonian age. The Gazelle comprises gray, 

greenish and reddish shale, gritty sandstone and graywacke, siliceous conglomerate, bedded chert, and massive gray limestone. Tuffaceous interbeds are present. 

The limestone beds are lenticular; some lenses were 

small reefs on a sea bottom where accumulation was 

mainly graywacke and other silicious sediments. 

Significant faunas have been collected from argillaceous beds just below the upper limestone of the 

Gazelle on "VVillow Creek (locality 1) and from the 

limestone itself (Diller and Schuchert, 1894; Stauffer, 

1930, p. 98). These include Ohonophyllum, Heliolites, cystiphyllids, Oonohidium, Stricklandia.lf, Gypid?.tla cf. G. galeata (Dalman), Atrypa, Atrypella cf. 

A. rlunbm·i J{irk and Amsden, Eno'rinurus, and Bu-

·m.a:~tu.<:(. A dist-inctive trilobite assemblnge from shale 

in the Gazelle of the Willow Creek area ( Churkin, 

1961) comprises species of Leonaspis, Dioranopeltis, 

1'1·ooltru'J···w~, Rc'l.l.tell'ltm, (!heirtt'l"l.ts, Enorin'l.t'l"lt8, and 

P1·oet1.t8. 

Parker Rock (locality 2) is another massive limestone (Gazelle) of probable reef origin, near the base 

of which occur abundant favositids, Halysites and 

Ohono7Jhyllu1n. Other Silurian fossils from the 

Parker Rock vicinity include II eliolites, Oonchidium, 

At'I'YJJella?, cheirut·id trilobites, and OalynMne. Coralbearing limestones at Gregg Ranch east of Parker 

Rock have yielded Skenidioides?, Il 01.oellella, and the 

large cap-shaped gastropod H eroynella. 

Dark-gray carbonaceous limestone bodies at Grouse 

Creek (locality 3) contain Oladopora, Diversophyllun~?, Sohizoph01·ia sp cf. S. bisinuata 'Veller, St?·opheodonta sp. cf. S. varistriata (Conrad), Oyrtina, 

Ambocoelia, and P1·oetus. These appear to be the 

youngest Paleozoic rocks of the northeast belt, and 

are regarded as I-Ielderberg Lower Devonian. 

The oldest Silurian beds of the Gazelle formation 

occur on J\fcConnahue Creek (locality 4), 8 miles 

north of Callahan, where they contain OU:tdopora, 

Ilalysites, Ileliolites or Plasnwpora, and Sohizoramma~. 

CORRELATION 

The Silurian rocks of the northeastern Klamath 

belt are correlative with those of the Taylorsville area, 

California (locality 24) where the Montgomery limestone fauna with Halysites, Plasmopora, Sohizo1'ant1na?, and Bilobites suggests faunas in the lower 

part of the Gazelle. 

Higher Gazelle strata of the Willow Creek area 

(locality 1) were long regarded as Devonian (Diller 

and Schuchert, 1894, p. 417; Stauffer, 1930, p. 98) 

and equivalent to the ICennett formation of the southeastern IClamath belt. This interpretation now appears untenable . (J\ferriam, 1940, p. 48). It is not, 

however, unlilmly that the Gazelle formation with its 

tuffaceous interbeds is correlative with the Copley 

greenstone and Balaklala rhyolite which underlie the 

ICennett. 

The Gazelle strata containing distinctive Atrypella 

faunas are correlative with Atrypella-bearing Upper 

Silurian beds of southeast Alaska (IGrk and Amsden, 

1952, p. 53-55) and with beds carrying similar faunas 

in the Ural ]\fountains (IChodalevich, 1939, p. 90-

125). Trilobites, from the Gazelle formation, described by Churkin (1961) reveal affinity to ]\fiddle 

and Upper Silurian trilobites of Bohemia. 

Heliolites and large complex cyathophyllids of the 

limestone in the middie part of the ICennett resemble 

those of the Heliolites subzone in the central Great 

Basin Nevada formation (l\ferriam, 1940, p. 9). This 

subzone lies at the base of the Stringooephalus zone 

in the Great Basin and is of late ]\fiddle Devonian 

age. 

REFERENCES 

Churkin, Michael, .Jr., 1961, Silurian trilobites from the 

Klamath Mountains, California: .Jour. Paleontology, v. 35, 

no. 1, p. 168-175. 

Diller, .J. S., 1903, Klamath Mountain section, California: 

Am .. Jour. Sci., 4th ser., v. 15, p. 342-3G2. 
C-190 GEOLOGICAL SURVEY RESEARCH 19 6 1 

Diller, J. S., and Schuchert, C., 1894, Discovery of Devonian 

rocks in California: Am. Jour. Sci., 3d ser., v. 47, p. 416-

422. 

Irwin, W. P., 1960, Geologic reconnaissance of the northern 

Coast Ranges and Klamath Mountains, California: California Div. Mines Bull. 179. 

Khodalevich, A. N., 1939, Upper Silurian Brachiopoda of the 

eastern Urals: Trans. Ural Geol. Service ( Geol. Service 

of U.S.S.R.), p. 1-135. 

Kinkel, A. R., Hall, W. E., and Albers, J. P., 1956, Geology and 

base-metal deposits of West Shasta copper-zinc district, 

Shasta County, Calif., U.S. Geol. Survey Prof. Paper 285. 

Kirk, Edwin and Amsden, T. W., 1952, Upper Silurian brachiopods from southeastern Alaska: U.S. Geol. Survey Prof. 

Paper 233-G. 

Merriam, C. W., 1940, Devonian stratigraphy and paleontology 

of the Roberts Mountains Region, Nevada: Geol. Soc. 

America Spec. Paper no. 25. 

Stauffer, C. R., 1930, The Devonian of California : California 

Univ. Dept. Geol. Sci. ·Bull., v. 19, no. 4, p. 81-118. 

Wells, F. G., Walker, G. W., and Merriam, C. W., 1959, Upper 

Ordovician ( ?) and Upper Silurian formations of the northern Klamath Mountains, California : Geol. Soc. America 

Bull., v. 70, p. 645-650. 

217. CITY COLLEGE FAULT, SAN FRANCISCO, CALIFORNIA 

By M.G. BoNILLA, Menlo Park, Calif. 

A fault that separates two distinct bedrock assemblages and is marked by a wide zone of sheared rock 

was discovered in the southwest part of San Francisco. 

The fault is here named the City College fault after 

the City College of San Francisco, which is in the 

fault zone. The dimensions of the zone of sheared 

rock and the differences in the adjacent rocks indicate that the fault has a large displacement. The 

sheared rock presents special problems in engineering 

construction. 

The location and known extent of the fault are 

shown on figure 217.1. The zone of i;heared rock 

that marks the fault has a maximum width of about 

half a mile and is exposed discontinuously for 41j2 

miles along the strike. This is probably only a small 

part of the total length of the fault, but possible 

extensions are concealed by San Francisco Bay on 

the southeast and by Quaternary deposits on the 

northwest. 

Several kinds of rocks are exposed north of the fault 

but only two varieties are exposed in the area just 

south of it. The northern assemblage consists of 

sandstone (graywacke), shale, chert, greenstone, and 

schists of the Franciscan formation and serpentine, 

whereas the southern assemblage consists only of 

sandstone (graywacke) and shale. 

The rocks of the southern assemblage are less 

faulted and sheared than those in the northern assemblage. The rocks of the southern assemblage commonly show graded bedding and bedding-plane structures such as flow- and load-casts, and they contain 

appreciable quantities of K-feldspar whereas these 

features are scarce or absent in the sediments of the 

northern assemblage. 

The difference in the K-feldspar content of the two 

groups is very striking. Staining tests were made on 

51 widely distributed samples frem the area shown 

on figure 217.1 using the technique described by Bailey 

and Irwin ( 1959, p. 2802-2803). None of the 17 samples taken north of the fault zone contains K-feldspar. 

Of the 12 samples from the area south of the· fault, 

1 sample has no K-feldspar, 1 has 1 percent, and 

the rest range from 2 to 8 percent. Sandstones from 

both the northern and southern groups occur in the. 

zone of sheared rock along the fault. About onethird of the 22 samples from the zone of sheared rock 

contain 1 to 6 percent K-feldspar and the rest contain 

a trace or none. The faultline shown on the map was 

drawn so as to bise.<?t the zone of sheared rock ; the 

line also separates all 51 of the samples into two 

groups, the northerly group having no K-feldspar or 

only a trace. 

The sediments of the southern assemblage were designated by Lawson (1914) as Cahil sandstone, the 

oldest formation of his Franciscan group. However, 

the work of Bailey and Irwin ( 1959) suggests that 

because of the high K -feldspar content the southern 

assemblage should perhaps be excluded from the 

Franciscan formation. The other diffe:r;ences between 

the two assemblages strengthens this belief; for the 

purposes of this report, however, the term Franciscan 

is retained for the southern assemblage. 

·~ 

I 

·, 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-191 

37"42'30" -------

0 4000 8000 FEET 

FIGURE 217.1.-Generalized geologic map showing location of City College fault. Fault is dotted where concealed. Dashed lines 

show approximate limits of zone of sheared rock where zone is concealed by Quaternary deposits. Quaternary deposits, undifferentiu.ted (blank areas). Franciscan formation, sandetone and shale (light stippling, south of fault); sandstone contains 

potassium feldspar. Franciscan formation and serpentine, undifferentiated (dense stippling, north of fault); Franciscan includes 

sandstone, shale, chert, greenstone, and schist; sandstone contains no potassium feldspar. Sheared rocks derived from second 

and third groups above (diagonal ruling). 

The surface expression of the zone of sheared rock 

consists of isolated blocks of resistant rock protruding 

from the soil. The resistant blocks range from a 

few feet to many tens of feet in longest dimension 

and, where they are large or numerous, they form the 

cores of small hills. . Several kinds of rocks may crop 

out in a small area. One hill has exposures of sandstone, shnJe, chert, greenstone, schist, and serpentine 

in an area that is about 800 feet long and 500 feet 

wide. In contrast to some shear zones in the Coast 

Ranges, this one contains little serpentine. Artificial 

cuts show that the resistant rock is generally surrounded by sheared fine-grained rock that is brown 

and moderately soft where weathered but dark gray 

and moderately tough where fresh. Within the 

shen.l'ed material are sound pieces of various sizes, 

many of them elliptical o~ lenticular in cross section. 

No pln.stic, claylike gouge was seen in .the fault zone. 

Neither the dip .of the City College fault nor the 

relative ages of the adjacent rocks are known, and 

one can only speculate as to what type of fault it is. 

The fault js roughly parallel to the San Andreas 

fault, which lies about 4 miles to the southwest, and 

the Hayward £ault, which lies about 15 miles to ilie 

northeast. Both the San Andreas and Hayward are 

strike-slip faults and the City College fault may be 

one also. 

It is not known whether the fault is active. No 

scarps or other evidence of faulting have been seen 

in the late Pleistocene and younger sediments that 

overlie the fault, but such evidence could easily escape 

notice or be quickly destroyed in the soft sediments. 

Two of the epicenters shown on a map published 

by Byerly (1951, fig. 20) may indicate recent activity 

on the fault. One epicenter is shown on the extension 

of the fault and southeast of the area shown on fig-
C-192 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

ure 217.1, and the other is about two-thirds of a 

mile northeast of the fault. The proximity of the 

epicenters to the City College fault may be the result 

of the inaccuracies inherent in locating epicenters 

rather than the result of recent activity along the 

fault; the earthquakes may have originated along 

the nearby San Andreas fault. The question of the 

activity of the City College fault can probably 

be answered when more seismological data are 

accumulated. 

The sandstone near Point Lobos, about 3 miles 

northwest of the area of figure ~17.1, contains appreciable quantities of K-feldspar ( J. Schlocker, oral 

communication, 1961). The City College fault may, 

t.herefore, join the faults near Lands End that are 

shown on the San Francisco North quadrangle 

(Schlocker and others, 1958). 

The significance of the City College fault to engineering lies chiefly in the foundation characteristics, 

slope stability, and excavation properties of the zone 

of sheared rock. Test borings that encounter the 

inclusions of hard rock give a false impression of the 

soundness and configuration of the "bedrock." Piles 

or caissons may have a great range in -length at a 

particular building site because they rest on the 

erratically distributed hard blocks. The sheared rock 

can generally be removed with earthmoving equipment 

but the large blocks require blasting or other special 

handling. Slopes cut in the sheared rock, particularly where it is weathered, are generally less stable 

than similar slopes in sound rock. As indicated on 

figure 217.1, much of the sheared rock is concealed 

by Quaternary deposits, and the line that represents 

the fault was drawn merely to bisect the zone of 

sheared rock. No one should infer that the rock 

along this line is more intensely faulted than elswhere 

in the shear zone. 

REFERENCES 

Bailey, E. H., and Irwin, W. P., 1959, K-feldspar content of 

Jurassic and Cretaceous graywackes of northern Coast 

Ranges and Sacramento Valley, California: Am. Assoc. 

Petroleum Geologists Bull., v. 43, no. 12, p. 2797-2809. 

Byerly, Perry, 1951, History of earthquakes in the San Francisco Bay area, in Geologic guidebook of the San Francisco 

Bay counties: California Div. Mines .Bull. 154, p. 151-160. 

Lawson, A. C., 1914, San Francisco folio: U.S. Geol. Survey 

Geol. Atlas, Folio 193, 24 p. 

Schlocker, J., and Bonilla, M. G., and Radbruch, D. H., 1958, 

Geology of the San Francisco North quadrangle, California: 

U.S. Geol. Surv-ey Misc. Geol. Inv. Map 1-272. 

GEOLOGY AND HYDROLOGY OF ALASKA AND HAW All 

218. ORIENTATION OF PHENOCLASTS IN LAMINATED GLACIOLACUSTRINE DEPOSITS, 

COPPER RIVER BASIN, ALASKA 

Ry HENRY R. Sen MOLL, Washington, D.C. 

Pleistocene sediments in the intermontane Copper 

River Basin of south-central Alaska are dominantly 

deposits of Wisconsin age (Ferrians and Schmoll, 

1957) and of older proglacial lakes and associated 

glaciers. They range from till through till-like deposits with various degrees of bedding, sorting, and 

stone content to rhythmically bedded (varved) deposits referred to here as laminated silt. The lastnamed deposits also contain clay, fine sand, and scattered phenoclasts. Among other types of analyses, 

macrofabric studies of 80 100-stone samples are being 

undertaken to differentiate the deposits and to determine their origin. 

Field and laboratory methods for analysis of fabric 

are essentially those of Karlstrom (1952) modified by 

Schmoll and R. H. Bennett. The axes, of the stones 

are as follows : A, longest dimension ; B, longest dimension perpendicular to A; 0, longest dimension 

normal to the plane parallel to A and B. In the 

present studies, A -axis lengths are limited to the 32 

to 128 mm range. Contour diagrams were constructed 

by an independently derived method similar to that 

of Mellis (1942). 

Three samples (fig. 218.1) were collected at localities spaced about 0.6 mile apart within a laminated 

silt deposit of Wisconsin age exposed along the Cop-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-2.92 C-193 

F-4 A 

c 

FwuRJ<J 218.1.-Contour diagrams of A-axis and C-axis distribution of 3 100-stone samples of phenoclasts from a laminn.ted silt deposit of Wisconsin age. Sample numbers appear at the upper left of each diagram, axis designations at 

the upper right. North is indicated by a single line at the circumference. On A-axis diagrams, the azimuth of maximum point concentration is indicated by a double line at the circumference. Contoured areas, in percent per 1 percent of area, are as follows (values in parentheses apply at the centers of the C-axis diagrams within the solid unit) : 

blank, 0-2 (10-15); lightly stippled, 2-4 (i5--ZO); heavily stippled, 4-6 (20-25); diagonally lined, 6-8 (25--28); solid, 

8-10. 
C-·194 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

per and Gakona Rivers near Gakona, Alaska. Two 

other samples (fig. 218.2) are from older deposits 

in the same area. 

Both A-axis and 0-axis diagrams reveal a strongly 

preferred orientation. The A axes lie close to a horizontal plane and 0 axes approach vertical. The B 

axes must therefore also lie nearly horizontal, · and a 

field observation that the stones tend to lie "flat" is 

confirmed. 

Two features of the A -axis diagrams were rather 

unexpected : the high concent"rations of points within 

the horizontal girdle, and the close azimuth agreement of maximum point concentrations among all 

three coeval samples (fig. 218.1). This agreement is 

not found in samples of different ages. (Compare 

figs. 218.1 and 218.2.) 

To determine whether point concentrations as high 

as those obtained would result from random distribu-. 

tion, artificial diagrams (Flinn, 1958, p. 531) were 

constructed so that they would resemble the "natural" 

diagrams. Randomly selected "azimuth" values were 

randomly combined with "plunge" values distributed 

similarly to the plunges in the "natural" samples. 

Diagram R-1 (fig. 218.2) is typical of the results obtained. Concentrations of points are as high as those 

in the "natural" diagrams. Two types of chi-square 

significance tests (Flinn, 1958, p. 534, 536) compare 

each of the "natural" distributions with an "expected" 

distribution derived from means of the artificial distributions. The "area test," comparing the grouping 

of points, indicates that the "natural" distributions 

do not differ significantly from a random distribution. The "frequency test," comparing the spatial 

distribution of points, shows, however, a significant 

difference for each "natural" distribution at the 0.04 

probability level or below. 

A further comparison of the distribution of areas 

of high concentration of points around the horizontal 

girdle indicates that for all three diagrams from 

laminated silt of Wisconsin age, when considered collectively and when the maximum point concentrations 

are alined at an arbitrary zero azimuth, there is a 

higher-than-expected secondary maximum concentration at approximately 100 degrees in the clockwise 

direction. Similar relations are not obtained from 

the random diagrams, nor from a group of natural 

FIGURE 218.2.-Contour diagrams of A-axis distributions of 

samples of phenoclasts from two noncoeval laminated silt 

deposits of pre-Wisconsin age, and artificial "A-axis" distribution R-1. Diagrammed as in figure 218.1. 

,i-
-.~ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-195 

diagrams from noncoeval deposits, which suggests a 

nonrandom distribution. 

Near alinement of areas of maximum point concentration of three coeval.samples, value of chi-square 

in the "frequency test," and distribution of areas of 

high concentration around the girdle in coeval samples thus seem to indicate that the orientation of A 

axes within the horizontal girdle is not random but 

preferred. This preferred orientation is weak however, and requires more widespread sampling for 

confirmation. 

The :0-axis concentration centers do not seem to 

depart sufficiently from the center of the diagram to 

indicate any significant or consistent imbrication of 

the stones. The slightly noncircular shape of most 

of these point concentrations may be a manifestation 

of the secondary element of the fabric which is better 

expressed in the A-axis diagrams. 

Assuming that the stones arrived in the midst of 

otherwise fine-grained sediments by ice-rafting on the 

lake, any orienting force would then act upon each 

stone (a) when still in the ice ; (b) while/ falling 

through the water; (c) upon contact with the bottom; 

or (d) after initial deposition. The primary element 

of the preferred orientation is most likely the result 

of the stone's coming to its natural rest position on 

the flat, relatively firm floor with the two ·longest 

axes (A and B) essentially parallel to the floor. The 

cause of the secondary fabric element is more problematical. Proposition (a) seems unreasonable, especially for a time-space range as wide as the samples 

represent. Proposition (c) is improbable because any 

surface features which might guide the A-axes to a 

preferred azimuth would probably also remove the 

A-B plane from the horizontal. Proposition (d) is 

similarly discarded, inasmuch as most post-depositional movement would also alter the primary fabric 

element more than is apparent, and compaction itself 

is not considered competent. In addition, other evidence for the factors involved in (c) and (d) is lacking at the sample sites. Proposition (b) remains, 

and forces such as currents that acted on the sinking 

stones are tentatively considered the cause of the ·secondary fabric element. 

REFERENCES 

Ferrians, 0 .. J., .Jr., and Schmoll, H. R., 1957, Extensive proglacial lake of Wisconsin age in the Copper River Basin, 

Alaska [abs.]: Geol. Soc. America Bull., v. 68, p. 1726. 

Flinn, Derek, 1958, On tests of significance of preferred orientation in three-dimensional fabric diagrams: .Jour. Geology, 

v. 66, p. 526-539. 

Karlstrom, T. N. V, 1952, Improved equipment and techniques 

for orientation studies of large particles in sediments: 

.Tour. Geology, v. 60, p. 489-493. 

Mellis, Otto, 1942, Gefi.igediag-rnmme in sterographischer Projektion : Zeitschr. Min. Pet. Mitt., v. 53, p. 330-353. 

219. WEATHERED BASALT IN THE EASTERN PART OF KAUAI, HAWAII 

By SAM I-I. PATTERSON and C. E. RoBERSON, Beltsville, Md., and Menlo Park, Calif. 

lVm·lc done i.n coope1·a.t-ion with Hawaii Department of Land a1ul Natttral R.eso·wrces 

Alumina-rich soil and deeply weathered basalt occur in several extensive areas in the eastern part of 

Kauai, Hawaii (fig. 219.1). The richest deposits are 

restricted to the upper parts of a group of lava flows 

mapped as the J(oloa volcanic series by Macdonald, · 

Davis, and Cox ( 1960). The most deeply weathered 

rocks are on gently rolling uplands that were formed 

through modification of original flow surfaces by 

erosion. Land surfaces are younger in numerous 

stream valleys cut into the flows, and the least weathered rocks are in the deepest valleys. 

Depth of weathering, more than 60 feet in most 

places and locally more than 100 feet, is controlled 

chiefly by differences in ages of flows within the J(oloa 

series, to a lesser extent by rainfall of 80 to 150 inches 

a year, and by drainage and other factors. 
C-196 GEOLOGICAL SURVEY RESEARCH 19 61 

..------------------~----. 22°15 

Anahola 

~7a• 

0 

EXPLANATION 

ol 

Auger hole in 

weathered lmsalt 

o7 

Water-supply well 

in fresh basalt 

0 Area of high 

alumina soil and 

weathered basalt 

X 

()uh;rup SHIHJJlt_• 

FwuuE 219.1.-Areas of cleeply weathered qasalt in the eastern 

part of Kauai, Hawaii, showing water-sample localities. 

Most of the fresh basalt is dark gray to black. Pale 

shades of gray develop with weathering. As the rock 

loses its hardness, colors change to dark brown, grayish brown, and fina1ly to various shades of reddish 

brown. Nearly all the weathered rock is saprolite in 

which much of the basaltic structure and texture has 

been preserved; however, all but very small amounts 

of the original constituents have been replaced by 

secondary minerals. 

Deeply weathered rocks at the surface consist mainly 

of alumina and oxides and hydroxides of iron. Minor 

constituents include titanium oxides and clay minerals, and the concentration of minerals varies with 

depth. The rock at the surface is 25 to 40 percent 

gibbsite by weight, and 40 to 50 percent iron minerals. Clay minerals, titanium oxides, organic matter, and miscellaneous minerals make up the remainder. At depths of 15 or 20 feet clay minerals 

become abundant, a condition reported by Holmes, 

Takahashi, and Sherman ( 1960). At greater depths 

clays ordinarily make up more than 50 percent of the 

volume of the roc~s, and gibbsite is present only in 

minor amounts. As there is little loss of volum.e except 

in the very advanced stages of weathering, the greater 

concentration of gibbsite close to the surface indicates 

that gibbsite is formed in a late stage of weathering 

by alteration of clay minerals. Essentially all of the 

clay minerals belong to the kaolin group, and halloysite is the most common, if not the only member 

present. 

Iron minerals tend to be concentrated by weathering 

and to decrease in amounts with depth, but more 

gradually than does gibbsite. Goethite and hematite 

are the most commonly secondary iron minerals. 

Fine-grained magnetite occurs sparsely throughout 

the weathered rocks, and traces of ilmenite are common. Both magnetite and ilmenite are residual from 

the basalt. Amorphous materials, including iron and . 

alumina gels, are present" (Bates, 1960, p. 5), but their 

importance has not been evaluated because they have 

no diagnostic X-ray characteristics-the principal 

method used for mineral identification. 

The saprolite near the surface is in a very advanced stage of weathering; that at depth is in an intermediate stage of weathering. The analyses (table 

219.1) are of samples from an auger hole (fig. 219.1, 

hole 9) at a point where fresh rock was several feet 

below the bottom of the hole, as inferred from deeper 

holes nearby, and of a sample of essentially fresh 

basalt from an outcrop (fig. 219.1). They show the 

chemical gradation from the thoroughly weathered 

rock at the surface toward fresh rock at depth and 

indicate that most of the rock is in intermediate stages. 

Nearly all of the alkalies are removed before the intermediate stages of weathering are reached; however, 

small amounts do remain even in the advanced stages. 

Roughly half of the silica is removed early and the 

other half initia1ly remains in the form of clay minerals, and then is gradually lost as clays are leached 

and altered to gibbsite. 

Concentration of secondary iron minerals begins 

early and continues into the advanced stages. A large 

part of the iron concentration is due to the removal 

of silica. Alumina is not concentrated as much as 

iron in the weathering process, though concentrations 

at different depths and at different localities vary 

. much more than shown (table 219.1). Apparently 

some alumina is lost as clays are altered to gibbsite. 

In the early stages manganese 'remains in about the 

same proportions as in the basalt, and is leached very 

gradually as weathering progresses. Secondary manganese minerals are intimately associated with halloysite and gibbsite. Titanium is also concentrated pro-

.•. 

i 
'• r 

~HORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-2.92 C-197 

TABI-E 219.1.-Chemical and spectrographic results, in percent, of analyses of sam,ples of weathered basalt from an auger hole and of a sample of essentially fresh basalt in the eastern part of Kauai, Hawaii 

[Chomlcnl wet annlyscs by Paul I... D. Elmore, Samuel D. Botts, Ivan H. Barlow, and Gillson Chloe, using rapid rock analysis method described by Shapiro and Brannock, 1956. Spectrographic analyses by Sol Berman.] 

Chemical analysis Spectrographic analysis 

Dopth In 

foct 

- 0-4 ____ 4-10 ___ 0-14 ___ 1 

1 

1 

2 

3 

A 

4-19 ___ 

9-24 ___ 4-34 ___ 4-39 ___ 

2 

-----

SI02 Ah03 Fc203 

---------

5. 7 25. 6 40. 2 

8. 6 25. 5 39. 1 

11. 4 24. 6 37. 8 

17. 1 26. 2 32. 7 

19. 7 25. 8 32. 1 

21. 5 25. 1 30. 7 

25. 3 24. 4 29. 1 

45.0 11. 8 4. 3 

I<' co CaO MgO Na20 K20 

--------- -----

0. 40 <. 10 0. 65 0. 04 . 12 . 37 <. 10 . 72 . 05 . 09 . 82 <. 10 . 91 . 06 . 05 . 58 <. 10 . 83 . 06 . 03 . 50 <. 10 1.0 . 06 . 03 . 53 <. 10 1.0 . 06 . 03 . 44 <. 10 . 87 . 06 . 03 

9. 3 9. 7 12. 0 1.8 . 62 

1 Sample contained appreciable amounts of organic matter. 

H20 Ti02 P20~· MnO 002 Sum Or v Ca 

-------------------------

18. 6 5. 6 0. 27 0. 12 <. 05 I 97 0. 16 0. 069 0. 08 

17. 8 5. 6 . 30 . 14 <. 05 I 98 . 15 . 059 . 08 

17. 2 5. 7 . 36 . 20 <. 05 99 . 17 . 077 . 09 

15. 8 5. 1 . 31 . 25 <. 05 99 . 13 . 065 . 08 

15. 0 4. 9 . 32 . 27 <. 05 100 .11 . 052 . 07 

14. 6 4. 9 . 36 . 27 <. 05 99 . 12 . 058 . 08 

13. 9 4. 5 . 38 . 27 <. 05 99 . 14 . 060 .. 08 

3. 1 1.9 . 30 . 26 . 09 ·100 . 064 . 031 >I. 0 

2 Essentially fresh basalt from outcrop (fig. 219.1, location 9). 

gressively with advancing weathering. As only trace 

amounts of ilmenite are present, probably most of the 

titanium is in very fine grained anatase, but this has 

not been confirmed. 

The soil and weathered rocks at the surface are 

highly porous and permeable. Permeability decreases 

with depth, however, as the percentage of clay minerals increases, and local perched bodies of water 

have been found. The highly porous surface absorbs 

ordinary rainfn.ll, and runoff takes place only during 

very heavy rains. In angering, most of the perched 

bodies of water were penetrated at depths of 30 to 

50 feet. At a few places, nearly dry rock was present 

below the water. The size of the water bodies varies 

appreciably with the wet and dry seasons. Several 

were encountered at the end of an uncommonly dry 

season, and some are inferred to be permanent £eatltres. The perched water passes slowly downward 

into the basal ground water and laterally where it 

spills over the edge of the local. perching clay-rich 

zone into streams. 

The water in weathered basalt is weakly acidic and 

t"lutt in fresh rock is slightly alkaline. Oxidation, 

hydrolysis, and leaching in the presence of ground 

water appear to be the principal agents in the weathering process. Probably the weakly acidic water in 

weathered rock is neutralized as it passes through 

t.he zone where alkalies are released during the initial 

weathering of the basalt. Measurements of pH were 

made of perched water immediately after it was 

bailed from 36 auger holes and of two samples from 

town water-supply wells which penetrate fresh basalt 

of the l(oloa volcanic series. The samples from 

weathered basalt ranged in pH from 4.0 to 5.9, the 

average pH being 4.9. The cause of the low pH is 

probably due to both organic acids and to carbon 

dioxide produced by oxidation of organic matter in 

the soil. 

The two samples from fresh basalt had a pH o£ 

7.6 and 7.8. The samples from the two types o£ 

rock may not be directly comparable because the two 

water-supply wells may be slightly contaminated by 

sea water. The sodium and chloride in the water 

from weathered basalt (table 219.2) is probably due 

chiefly to the concentration of salt in rainwater. The 

content of sodium and chloride in the well-water 

samples is approximately three times that of the water 

from weathered basalt. 

TABJ-1~ 2H).2.-Chemical analyses of water satrtples from weathered and fresh basalt of the Koloa volcanic series, Kauai, Hawaii 

IAnnlysts, A. S. VanDenburgh and C. E. Roberson. Samples are from weathered basalt, exrept those from holes 7 and 8, which are from fresh basalt.] 

Parts per million Dis- Hard- N.C. Specific solved ness hard- conduct-

.Hole Cation Anion solids as ness ancc pH No. total total calcu- CaC03 as (mi- Si02 AI Fe Mn Or Ca Mg Na K Li NH1 HCOa 003 on so. 01 F I N02 NOa Po. B Ia ted (ppm) CaCOa crohms 

tppm) (ppm) at 25° C) ,. 

- - --- - - - - - - - - ------- - - --- - --- -·--------------- I 2.!} 0.11 0.00 0. 26 0. ()()() 0.8 1.911 0. 6 0. 00 o. 02 1 0 0 2. 7 19 0. 1 0.008 0.00 0. 6 0.02 0. 04 o. 70 0.64 41. 10 9 90 4.1l 2 1.2 .00 . 18 .13 ----- .9 1.9 6. 3 .6 .00 .02 6 0 0 4. 0 9. 1 . 1 .006 .00 .7 . 04 .02 . 49 . 46 28 10 5 60 Fi. 1 3 4.1 . 01 .00 .07 . 000 1.0 1.2 6. 9 .3 .00 .03 3 0 0 2.3 12 . 1 .003 .00 . 4 .03 .03 .46 . 46 30 7. 4 5 56 5. 6 4 3.0 .04 .00 . 12 .000 . 4 .7 7. 2 .0 .00 .02 2 0 0 3. 2 12 .2 . 006 .. 00 . 1 .02 . 03 . 39 .45 28 4.0 2 54 4. 8 5 2.6 .03 .06 . 54 .000 1.0 2.3 8. 6 .6 .00 .01 6 0 0 6.5 16 .1 .004 .00 .9 .02 .05 .63 .71 42 12 7 78 5. 3 6 2.5 .12 .00 .11 .000 .6 1.5 8. 5 . 5 .oo . 0:;! 0 0 0 2. 713 .1 .002 .00 .8 .00 .05 .53 .45 30 7. 6 8 67 4. 7 7 32 .03 .00 .00 ----- 13 14 30 1.3 .00 ----- 96 0 0 37 30 .2 .002 ........... 2.0 .43 .05 3.13 3. 23 201 92 12 331 7.8 8 42 .06 .00 .00 ; 00 13 11 21 .8 .00 . 01 78.· 0 0 5.2 34 .1 . 001 .00 1.5 . 16 .01 2. 48 2. 38 167 77 14 265 7. 6 
C-198 GEOLOGICAL SURVEY RESEARCH 19 61 

Smaller contents of dissolved solids were present 

in the water of lower pH from weathered rock than 

in the water from fresh rocks (table 219.2). Probably, this is because the water in the weathered zone 

moves rather fast and has less time to react with 

its host, and because during its history of downward 

migration it was in contact only with rocks that were 

already thoroughly leached. ·The water in fresh basalt 

has passed both through a weathered zone and through 

a second zone where the minerals in the basalt are 

actively being weathered; therefo~e, the water has had 

ample opportunity to pick up alkalies and silica. 

·REFERENCES 

Bates, T. F., 1960, Rock weathering and clay formation in 

Hawaii: Mineral Industries [Pa. State Univ.], v. 8, p. 1, 

4-6. 

Holmes, W. E., Takahashi, M., and Sherman, G. D., 1960, 

Distribution of gibbsite and kaolinite with depth in a 

gibbsitic soil on Kauai: Hawaii Agr. Expt. Sta., Tech. 

Prog. Rept. 125, Univ. of Hawaii. 

Macdonald, G. A., Davis, D. A., and Cox, D. C., 1960, Geology 

and ground-water resources of the island of Kauai, 

Hawaii: Hawaii Div. of Hydrography Bull. 13, p. 1-212. 

Shapiro, Leonard, and Brannock, W. w .. , 1956, Rapid analysis 

of silicate rocks: U.S. Geol. Survey Bull. 1036-C, p. 19-56. 

220. SORTING OF BEACH SEDIMENT, NORTHWESTERN ALASKA 

By GEoRGE W. MooRE, Menlo Park, Calif. 

Wo·rk done in cooperation with the U.S. Atornic Energy Cornrnission for the Plowshare Progra;rn, Project Chariot 

Beach sediment is well sorted partly because the 

finest fractions a.re carried to sea in suspension, 

leaving only the larger particles having more rapid 

settling velocities. The beach environment differs, for 

example, from that of rivers, where ever-present silt 

and clay may .settle with the sand in local areas of 

quiet water. The sediment remaining on a beach after 

the fine mat~ rial has been winnowed a way may range 

from very fine grained sand to boulders, depending 

chiefly on the size range of the material being supplied. This material is sorted by ~ave action into 

grain-size belts disposed as follows: moderately coarse 

on the unsubmerged part of the beach; very coarse 

on a bar directly below the break point of the waves; 

and progressively finer offshore from the break-point 

bar. The results of the present investigation suggest 

that much of this typical beach sorting, and perhaps 

most of it, occurs not during the prolonged. periods of 

uniform surf conditions when the beach profile is in 

equilibrium, but during relatively brief periods when 

the waves are changing from one set of characteristics to another. 

Field observations were made at Ogotoruk ·Beach, 

a pebble-gravel beach at lat 68°0' N., long 165°41' 

W., in northwestern Alaska. This area is especially 

suitable for studies of wave action because the mean 

tide range is only 0.4 meter. The data were collected 

jointly with David W. Scholl and Reuben Kachadoorian. 

Wave . and sediment characteristics of Ogotoruk 

Beach during a 35-hour period on July 19-20, 1960, 

are presented on figure· 220.1. The observation period 

included the crestal and waning parts of a storm. 

During the first half of the period, which was chiefly 

characterized by waves over a meter high, the beach 

underwent very slow erosion. At approximately 

2 :00 a.m. on July 20, deposition began, and the surface of the beach rose at a rate of about 10 centimeters 

an hour to the end of the observation period. 

The wave height remained about constant during 

the shift from erosion to deposition, but the wave period and wave length shortened appreciably. Probably deposition began because the waves with shorter 

wave length felt bottom at a shallower depth and begail to erode the outer face of the break-point bar. 

The abundant new supply of material thrown into 

suspension by this erosion resulted in deposition on 

the face of the beach. 

Grain-size analyses of beach samples collected during the period of change from erosion to deposition 

L 

., 

.. 
.... 

r 

+ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C.:..199 

JULY 19, 1960 JULY 20, 1960 

~~: t 10:00 NOON 2:00 4:00 6:00 8:00 10:00 MIDNIGHT 2:00 4:00 6:00 8:00 10:00 NOON 2:00 4:00 6:00 

J: ~ 0 I I 1:±±± I I= I IJ 

~r: I ~ 0 I ± I I l I I 

1=-r, I 

~ a: a: 

n::l ~.....--~=====-.~-~I ;±;:=-1-f~44===1 -=l =I :=k1=?1=4?E=·. ==I =f1==l4 ~ 

r: k~--=· i-1 ;r;~r·~+:kblJd-t---t----+------t-----t---++-l'\~b£--t---7""'<:±~·+~=+:~F---t=l ~+1 ~-0.5 ~--~----~--~----~--~--~~--~~~~--~--~~--~--~----~--~~--~----~--~~ 

I o.:l~=---r--R:::· ::: ............... ~1:-t::=·. ;=I ;:=I t=:=:1;:=±=:::::c ;E=C>..~t~::=l?£:;::~1 =1:1~1 ~ l.O ~--~--~~--~----~--~~~~--~--~ER~~~S~IO~N~D~E=P~OS~I~TI~O~N~----~--~----~--~~---L----~ 

Frou1u~ 220.1.-Wnve churncteristics (upper three graphs) und sediment properties (lower three .graphs) at Ogotoruk Beach, 

Alnsku, during the crestnl nnd waning parts of u storm. Sediment samples were collected from· the midpoint of the zone 

ulternntely covered and uncovered by the waves wash; the grain-size. properties follow the conventions of Inman ( 1952). 

show that the debris remaining on the beach during 

erosion is much finer than that added to the beach 

during deposition. When deposition began at about 

2 :00 a.m. on July 20, the median diameter of the 

beach material increased in an hour from about 6 to 

15 mm . (fig. 220.1). The grain-size distribution of 

four sets of beach samples, collected at 2-hour intervals from 11 :00 p.m., July 19, to 5 :00 a.m., July 20, 

are shown on figure 220.2. During the period of erosion, represented by the frequency curve at 11:00 p.m., 

t-.he sediment had a single grain-size mode near 6 mm. 

About an hour before the start of actual net deposition, the grain-size distribution became bimodal. As 

represented by the mode at 6 mm, residual beach sediment existed for several hours but steadily decreased, 

nnd the addition of new sediment is indicated by another mode near 15 mm. As deposition became dominant, and the eroded beach surface was completely 

covered by new sediment with a median diameter 

averaging 15 mm, the frequency curve retains only 

a single mode at the larger ·grain size as shown by 

the curve at 5 :00 a.m. on figure 220.2. The two modes 

suggest that the material being deposited was derived 

from a new source in the beach system, rather than 

merely representing a reversal in the· direction of 

movement of material formerly being eroded. 

The skewness of the sediment curve also changed 

during the transition from erosion to deposition. 

Negative skewness values characterize samples collected during erosion (fig. 220.1) and illustrate an 

excess of coarse sizes in the residual seaiment. This 

is typical of sediment undergoing erosion (Ellis, 1960) 

as the coarser fractions tend to lag behind. 'The skew-

. ness of the deposited material became less negative, 

as might be expected. If the deposited material was 

derived directly from the material fo~merly being 

eroded, without additional sorting, it would have a 

smaller median diameter than the residual sediment 

because of the earlier lag of the coarser sizes. · The 

opposite is actually true, however, further indicating 

a· separate source for the two materials. 

The following mechanism is proposed to explain 

the relations observed at Ogotoruk Beach, and it is 

suggested that the process may have general application. During the rise of abnormally high, long 

waves, the beach is stripped down, and a large bar 

is built at the break point of the waves (fig. 220.3). 

The material being eroded from the beach face accu~ulates at the break-point bar because it is stopped 

there by an opposing landward traction that is generated by the wave train beyond the break point where 
· C-200 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

FIGURJ<~ 220.2.-Frequency diagrams showing bimodal character 

of beach sedhnent during transition from net erosion to net 

deposition, suggesting that the deposited material was derivecl from a different part of the beach system than the 

.eroded materia 1. 

the waves drag on the bottom as .they begin to transform into breakers. As soon as this landward transporting force is met, the coarse fractions derived 

from the eroding face of the beach are deposited 

because of their rapid settling velocity. The finer . 

fractions disperse farther sea ward .in suspension because of the enormous turbulence in the breaker zone. 

This process causes a selective concentration of the 

coarse fractions on the break-poi~t bar. 

5 0 5 METERS 

FIGURE 220.3.-Generalized beach profiles during storm and 

calm periods. 

Later, as the waves become smaller after the storm, 

they . break nearer to shore, erode the outer face of 

the break-point bar, and move its crest landward. 

During this transportation, the coarse sediment from 

the bar is deposited on the exposed part of the beach. 

The classical view that most beach sorting is accomplished by the action of waves on beaches whose profiles are in equilibrium seems insufficient because at 

. such times only a thin layer on the surface of the 

beach is moving and, consequently, being sorted. The 

alternative mechanism outlined in this report is believed to be the chief one because a large percent of 

the beach sediment is processed, and the well-sorted 

coarse-grained sediment is stored close to shore where 

it can be moved quickly toward the unsubmerged part 

of the beach during the depositional stage. 

If fresh material is supplied from outside the beach 

system, it is quickly sorted by the nonequilibrium 

process outlined above. At other times, the grossly 

uniform increase in grain size toward the land is 

maintained by the balance between retention of coarse 

sizes near the unsubmerged beach during waxingwaning surf conditions, and movement of the remaining sizes landward to the breaker zone during steady 

surf conditions. 

REFERENCES 

Ellis, C. W., 1960, l\Iarine sedimentary environments in· the 

vicinity. of the Norwalk Islands, Connecticut:·· Geol. Soc. 

America Bull., v. 71, p. 1857-1858. 

Inman, D. L., 1952, Measures for describing the size distribution of sertiments: Jour. Sed. Petrology, v. 22, p. 125-145. 
r' 

SHORT PAPERS lN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-201 

GEOLOGY AND HYDROLOGY OF PUERTO RICO, PACIFIC ISLANDS, AND ANTARCTICA 

221. WATER-BEARING PROPERTIES OF THE ROCKS IN THE ARECIBO-BARCELONETA AREA, PUERTO RICO 

By TF~ ARNow, Salt Lake City, Utah 

Prepm·ed in cooperatio•n with the Oonnnonwealth of P·uerto Rico 

Large quantities of ground water have been developed from wells and springs in both consolidated 

and unconsolidated formations in the Arecibo and 

Barceloneta 7lj2 -minute quadrangh\s, north-central 

Puerto Rico (fig. 221.1). l\{ost of the water is potable, 

but without treatment is excessively hard for many 

industrial uses. 'Vells close to the coast eventually 

may be intruded by salt water. 

The geology of the Arecibo anq. Barceloneta area 

has been mapped in detail by R. P. Briggs (written 

communication). The southern two-thirds of the area 

is underlain by formations of Oligocene and Miocene 

age, which dip gently toward the north and crop out 

in. strips extending across the area from east to west. 

The formations are predominately limestone and have 

been eroded into a karst topography. Most of. the 

drainage is subsurface, but the area is crossed by two 

major northward-flowing streams, the Rio Grande de 

Manati and the Rio Grande de Arecibo. The northern third of the area is a relatively flat coastal plain 

dotted with limestone hills. The Rio Grande de 

Manati and the Rio Grande de Arecibo meander 

ac:ross the plain in wide alluvial valleys. 

The Lares limestone (Oligocene), which does not 

crop out in the a.rea, has a maximum thickness of 

about 1,650 fee~ in the northern part of the area, and 

is the oldest water-bearing formation. A well in the 

extreme southwestern corner of the area penetrated 

the Lares. It produced 50 gpm (gallons per minute) of water under artesian pressure. 

The Cibao formation (Oligocene or Miocene), which 

overlies the Lares limestone, has weathered to a subdued karst topography. It has a maximum thickness 

of about 1,000 ·feet in the northern part of the area. 

· Few wells have been drilled in the area of outcrop. 

'Vest of the Rio Grande de Arecibo, chalk and marl 

form a domin~ant part of the formation, and the Cibao 

yields little water. East of the Rio Grande de Arecibo, where the formation consists almost entirely of 

limestone, the average yield of two wells in the Cibao 

CARIBBEAN SEA 

67"00' 

0 

0 

10 

66~30' 

20 

.66"00' 

30 40 50 Mll.:ES 

60 KILOMETERS 

FIGURE 221.1.-Map of Puerto Rico. showing outline of Arecibo-Barceloneta area. 

601530 0-61-14 
C-202 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

is 15"5 gpm. Two large springs issue from the Cibao 

on the west wall of the valley of the Rio Grande de 

Arecibo. The average yield of each spring is about 

2,000 gpm, but the yield fluctuates greatly depending 

upon rainfall. 

The Aguada limestone (Miocene), which overlies 

the Cibao formation, has. a maximum thickness of 

about 580 feet in the northern part of the area. Relatively few wells have been drilled in the area of outcrop, and none of them has a large yield. The best 

well had a specific capacity of about 2. The formation has weathered to a mature karst terrain, however, attesting to its great overall permeability. The 

small yields of the wells suggests that they were not 

drilled deep enough to reach the main water table, 

which is close to sea level. 

The Aymam6n limestone (Miocene) overlies the 

Aguada limestone and has a maximum thickness of 

about 1,240 feet in the northern part of the area. 

The formation yields much water to wells. Data from 

tests of 13 wells in the Aymam6n show an average 

yield of 935 gpm and a range from 40 to 3,600 gpm. 

The specific capacity of 5 of the wells ranged from 

36 to 4,500. The water in the Aymam6n is 

under water-table conditions, and most of the wells' 

with the largest yields are close .to the large river 

valleys. 

Tertiary and Quaternary surficial deposits co:Q.sisting of alluvium, beach deposits, dunes, marine terrace 

deposits, swamp deposits, and landslide debris overlie 

the Oligocene and Miocene formations. Except for 

the alluvium, the surficial deposits are thin and do 

not yield large quantities of .water to wells. In the 

northern part of the area driven wells in the marine 

terrace deposits commonly yield small supplies of 

water for domestic use. 

The .alluvium, which reaches known depths of 220 

and 266 feet in the valleys of Rio Grande de Arecibo 

and the Rio Grande de Manati, respectively, yields 

large quantities of water to wells. Data from tests 

of 13 wells in alluvium indicate an average yield of 

1,540 gpm and a range from 300 to 4,000 gpm. The 

specific capacity of 8 of the wells averaged 158 

and ranged f1.:om 26 to 500. No significant difference was observed between yields of wells in the valleys 

of the Rio Gran¢le de Arecibo . and the Rio Grande 

de Manati. 

All the formations in the Arecibo and Barceloneta 

area yield water that is similar in chemical quality; 

the water being of the calcium bicarbonate type typical of limestone aquifers. Analyses of 21 samples 

from 6 different aquifer/ indicated a range in dissolved solids from 176 to 954 ppm (parts per million), 

with an average of 388 ppm; a range in hardness 

from 120 to 390 ppm, with an average of 251 ppm; 

and a range in silica content from 3.6 to 48 ppm, with 

an average of 12 ppm. Several deep wells close to 

the coast or in the low lying aJluvial valleys yield salt 

water, whereas nearby shallower wells yield fresh 

water. 

The temperature of the ground water, as observed 

at 11 wells and springs, ranged from 74° to 81°F. 

Temperatures higher than 76°F wererecorded at wells 

in the r~atively low lying northern third of the Arecibo and Barceloneta area. 

222. GROUND-WATER CONDITIONS IN THE LOWER TALLABOA VALLEY., PUERTO RICO 

By I. G. GROSSMAN, San Juan, P.R. 

Work done in cooperation with the Cornmonwealth of: Puerto Rico 

Favorable hydrologic and geologic conditions have 

permitted the establishment of a burgeoning petrochemical industrial complex and .an extensive irrigation system in the relatively small Rio Tallabmt valley on the southwest coast of Pue_rto Rico. The 

upper part of the Rio Tallaboa consists of two 

branches that drain a hilly area having an annual 

rainfall averaging about 65 inches. The junction of 

the two branches is the northern boundary of the 

l()wer Tallab~ Valley. 

T 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-203 

The lower valley is about 4 miles long and generally less than 1 mile wide. River water rapidly 

recharges permeable unconsolidated deposits of the 

flood plain· at some places, and this recharge is augmented by irrigation water leaking from canals and 

lnteral ditches. Rain falling directly on the lower 

valley is a comparatively small source of recharge, 

even though the n,verage annual rainfall here is about 

40 inches. Unconsolidated deposits on the valley flood 

plain nre made up of particles rnngn~g in size from 

fine clay to boulders. The deposits of sand and gravel, 

which supply most of the ground water used in the 

area,, range in thickness from less than 1 foot at the 

valley sides to at least 52 feet near the center. The 

yields of 52 wells tapping sand and gravel average 

about 245 gpm (gallons per minute) and range from 

20 to 1,200 gpm. 

Correlation of hydrographs of river stage with 

fluctuations of water levels in wells on both sides of 

the valley shows a hydrologic continuity between the 

river and the underlying alluvium. Water in shallmY 

sand and gravel is under water-table conditions. 

Deeper sand and gravel, separated from the shallow 

aquifer by rehttively impermeable clay, contains water under artesian conditions. 

Underlying the alluvium are three bedrock units: 

the Ponce limestone of late Oligocene and early Miocene age; the ,Juana Diaz formation of middle Oligocene age; and an older complex that is principally 

of late Cretaceous age (Zapp, Bergquist and Thomas, 

1948). The older complex, which may contain some 

beds of early Tertiary age, is exposed only in the 

northeastern part of the area. There it consists principttlly of intrusive and extrusive igi1eous rocks and 

some beds of partly metamorphosed limestone. 

The Ponce limestone, which underlies most of the 

area, is the only bedrock· that is an important source 

of wnter. Of 4 wells tapping the limestone, 2 in the 

upla11d area east of the lower Tallaboa Valley yield 

2~5 and 3.5 gpm and 2 in the valley yield 10 and 100 

gpm. The higher yields in the valley are in part the 

result of more extensive fractures and solution openings in the limestone and in part the result of the 

n10re favorable location for recharge from the river 

and river gravels. Locally water passes freely between the limestone and the overlying sand and 

gravel. The yields of 9 wells reportedly drawing 

water from both the limestone and the overlying sand 

and gravel range from about 100 to 2,500 gpm and 

average· about 1,300 gpm. 

The water table in the alluvial plain of the lower 

Tallaboa Valley slopes southward toward the sea with 

a gradient of about 50 feet per mile in the northern 

part of the plain and less than 10 feet per mile in 

the southern part of the plain. Static water levels 

measured in 1959 and 1960 show pronounced seasonal 

fluctuations. The maximum decline in the principal 

dry season (December to March) amounted to about 

5 feet, and occurred in the northern part of the area ; 

the minimum <;lecline during the same season in the 

same 2-year period w~s about 0.5 foot and occurred 

in the southern part. vVater returned to its former 

level during the principal rainy season (Augus,t to 

November). No large-scale downward trend in static 

wttter levels was detected in spite of the large increase 

in pumping for industrial use in recent years. 

Throughout most of the lower valley, ground water is rather uniform in chemical quality and is of 

the calcium-bicarbonate type. Hardness ranges from 

about 200 to 350 ppm (parts per million), chloride 

content from about 10 to 20 ppm, and silica content 

from about 20 to 30 ppm. The quality of water generally is satisfactory for agricultural, municipal, and 

most other uses, but treatment is necessary for some 

industrial uses. Near the coast, fresh ground water is 

underlain by saline water wh1ch is at progressively 

greater depths to the north. At least 14 wells drilled 

less than a mile from the Caribbean have yielded 

brackish or saline water at fairly shallow depths. A 

well drilled to a depth of 325 feet, slightly more than 

a mile north of the Caribbean, yielded water that 

contained 1,430 ppm chloride. After being plugged 

back to 145 feet it yielded water containing only 22 

ppm of chloride, which is suitable for industrial use 

without extensive treatment. 

REFERENCE 

Zapp, A. D., Bergquist, H. R., and Thomas, C. R., 1948, Tertiary geology of the coastal plains of Puerto Rico: U.S. 

Geol. Survey Oil and Gas lnv. (Prelim.) Map 85. 
C-204 GEOLOGLCAL SURVEY RESEARCH 19 61 

223. VOLCANIC SUITE OF PAGAN, MARIANA ISLANDS 

By GILBERT CoRWIN, Washington, D.C. 

Pagan, largest of the northern Mariana Islands, 

western Pacific Ocean, consists predominantly of 

Quaternary volcanic rocks ern pted from several volcanoes and numerous subsidiary centers, most of which 

are alined along the north-northeast-trending axis of 

the island. The rocks are made up of two major successions: an older precaldera succession of lava flows 

and pyroclastic deposits erupted prior to formation 

of two calderas (situated near the north and south 

ends of the island), and a younger post-caldera succession of lava flows and pyroclastic deposits concentrated in the caldera depressions (Corwin and others, 

1957, p. 111; Fosberg and Corwin, 1958, p. 3). Rocks 

of the two successions are not significantly different 

petrographically or chemically, although the variety 

of precaldera rock types is somewhat greater. 

EXPLANATION 

x Pagan, Mariana Islands 

+ Northern Mariana Islands 

excluding Pagan 

o Saipan, Mariana Islands 

• Guam, Mariana Islands 

0 Yap Islands . 

• Palau Islands 

.... Iwo Jima and Sin Iwo Jima, 

Volcano Islands 6. Bonin and Northern Volcano 

Islands 

C-Chichi-jima group 

H-Haha-jima group 

K-Kita Iwo Jima 

FIGURE 223:1.-Silica-alumina-total alkali diagram for volcanic rocks from Pagan and other northern Mariana Islands, and from 

the Bonin, Volcano, southern Mariana, Yap, and Palau Islands. Chemical analyses of rocks that show evidence in thi-n 

sections of appreciable hydrothermal alteration or weathering of feldspars have been excluded. Sources of data: Schmidt 

(1956, p. 151, 157) ; Macdonald (1948 •. p. 1015, 1016) ; Tsuya (1937, p. 224, 227, 284) ; and- unpublished analyses of Gilbert 

Corwin, C. G. Johnson, and J. T. Stark. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-205 

The most abundant rock variety of the island_ is 

olivine-augite basalt, which has 50 to 52 weight-percent silica. The range of rock types extends from 

augite-olivine basalt that has about 49 percent silica 

to hypersthene-augite andesite that has about 62 percent silica. No silicic andesites or dacites are known. 

Fragments of gabbro were found in precaldera tuff 

breccias but are scarce. 

. Mineral assemblag~s of the volcanic rocks are relatively simple. Plagioclase is generally the dominant 

mineral, both as phenocrysts and as a groundmass 

constituent. Plagioclase phenocrysts range in composition from nearly pure anorthite (approximately 

Antis), sodic anorthite and bytownite, to la;bradorite 

and andesine; zoned groundmass plagioclase has average compositions of sadie labradorite or andesine.' 

Mafic phenocrysts include olivin~ and augite in most 

specimens, and hypersthene and ·magnetite in a fe,Y 

basalts and most andesites. Augite, subcalcic augite, 

and pigeonite are the most abundant ferromagnesian 

minerals and magnetite is common in the groundmnss 

of nJl well-crystallized specimens. Other groundmnss 

constituents include scarce to common olivine in most 

basalts and basaltic andesites; scarce hypersthene in 

a few andesites; late cristobalite, tridymite, and potassic feldspars in most well-crystallized rocks; and, in 

a few specimens, phlogopitic biotite, probable pargasite, zeolites, and other late deuteric and hydrothermal 

minerals. 

Petrogt·aphically, all specimens belong to a pigeonitic rock series as defined by ICuno (1950, p. 992). 

Subcn.lcic augite and pigeonite are final primary ferromagnesian crystallization products of all well-crystuJlized lavas on Pagan, with the exception of a few 

augite-olivine basalts in which olivine appears to have 

been stable throughout groundmass crystallization, and 

a few andesites in which scarce late biotite and pargasite crystallized after the clinopyroxenes. Compared 

to basaltic and andesitic rocks of volcanic suites on 

Guam, Palau, and other islands to the south and southwest, the rocks of Pagan are much richer in olivine 

and slightly richer in plagioclase. The high calcium 

content o:f the plagioclase contrasts with sadie plagioclase reported for rocks of I wo Jima in the Volcano 

Islands to the north. 

Chemically, the Pa.gan volcanic suite belongs to the 

high alumina basalt type as defined by ICuno ( 1!)60, 

p. 121) with properties that are intermediate between 

those of tholeiitic and alkalic suites (figs. 223.1 and 

223.2). Compared to tholeiitic suites of the southern 

Mariana, Palau, and other island groups within the 

island system extending southward from Honshu, 

.Tapan, the Pagan volcanic suite has high proportions 

.4.----.1----~~-----.-l----lr----.1----~~-----.-1~ 

Alkalic field 

.3r 

k .2r 

. lr 

.. 

. 

. • . •

-

-

-

. ... . . Tholeiitic field 

00~--~~-----7~-----~~--~l~--~l~---7'-----~'~ .1 .2 .3 .4 .5 .6 . 7 

mg 

FIGURE 223.2.-Niggli k-1ng diagram for volcanic rocks from 

Pagan and othei· northern Mariana Islands, and from the 

Boni~, Volcano, southern Mariana, Yap, and Palau Islands. 

Chemical analyses of dacites (more than 65 percent silica) 

and rocks that show evidence in thin sections of appreciable 

alteration are excluded. Explanation and sourc~s same as 

figure 223.1. 

of total ·alkalis and alumina to silica and of potash 

to total alkalis, and a low proporti<?n of magnesia to 

total ferromagnesian oxides. The opposite relations 

exist with respect to the alkalic suite of I wo Jima and 

Sin I wo Jima in the Volcano Islands. 

Chemical analyses and petrographic descriptions of 

several samples from Kita I wo Jima in the Volcano 

Islands and from the Bonin Islands (Tsuya, 1937, 

p. 223-225, 284-285) suggest existence of high alumina 

volcanic suites, similar to that' of Pagan, within island groups to the north of the Mariana Islands. 

Data for these islands are insufficient, however, and 

satisfactory comparison of the suites with those of 

the northern Mariana Islands is not now feasible. 

The l\{ariana Islands are arranged along two concentric axes on the crest of the l\{ariana ridge, one 

of the prominent, dominantly submarine arcuate structtu·es forming the east margin of the Philippine Sea. 

Tholeiitic volcanic suites of the southern Mariana Islands lie along the outer eastern axis; the high-alumina 

suites of the northern Mariana Islands, including 

Pagan, along the inner western axis. The Volcano Islands are situated nea.r the intersection of the Mariana ridge and a broad, gently curving submarine 

ridge that extends southward west of the l\1ariana 

structure. Alkalic suites of I wo Jim a and Sin I wo 

Jima appear related to the western ridge; the highalumina or tholeiitic suite of ICita I wo Jim a to northward extension of the Mariana ridge. Distribution 

of tholeiitic suites on the outer side of the Mariana 

ridge, high-alumina suites on the· inner side, and alkalic suites related to a structure to the west is comparable to distribution of similar volcanic suites in 
C-206 GEOLOGICAL SURVEY RESEARCH 19 61 

the Japanese Islands which have been described and 

interpreted by Kuno (1960, p. 133-135, 142). 

REFERENCES 

Corwin, Gilbert, Bonham, L. D., Terman, l\1. .J., and Viele, 

G. W., 1957, Military Geology of Pagan, Mariana Islands: 

U.S. Army, Chief of Engineet·s, Intelligence Div., Headquarters U.S. Army Pacific, 259 p. 

Fosberg, F. R., and Corwin, Gilbert, 1958, A fossil flora from 

Pa·gan, Mariana Islands: Pacific Science, v. 12, p. 3-16. 

Kuno, Hisashi, 1950, Petrology of Hakone Volcano and the 

adjacent areas, Japan : Geol. Soc. America Bull., v. 61, 

p. 957-1020. 

--- 1960, High-alumina basalt: Jour. Petrology, v. 1, p. 121-

145. 

Macdonald, G. A., 1948, Petrography of Iwo Jima: Geol. Soc. 

America Bull., v. 59, p. 1009-1018. 

Schmidt, R. G., 195G, Geology of Saipan, Mariana Islands, 

Petrology of the volcanic t·ocks: U.S. Geol. Survey Prof. 

Paper 280--B, p. 127-175 [1957]. 

Tsuya, Hiromichi, 1937, On the volcanism of the Huzi volcanic 

zone with special reference to the geology and petrology 

of Idu and the Southern Islands (Nanpo Shoto) : Tokyo 

Univ. Earthquake Research lnst. Bull., v. 15, pt. l, p. 215-

357. 

224. STRUCTURE OF LOWER TAYLOR GLACIER, SOUTH VICTORIA LAND, ANTARCTICA 

By WARREN HAMILTON and PHILIP T. HAYES, Denver, Colo. 

Wo1·1c done with the support of the National Science Foundation 

The Ross Sea and Ross Ice Shel£ are bounded on 

the west by a system of high mountains, which dams 

the ice of the continental interior ice plateau. The 

Taylor Glacier flows eastward, through one of the 

passes in this mountain system, from the plateau into 

Taylor Valley (fig. 224.1). Although in the recent 

geologic past the glacier reached the sea, it has receded so that the lower part of the valley (Taylor 

Dry Valley) is free of ice except for small alpine 

glaciers coming into it from the sides. As part of our 

geologic study of the Taylor Valley region (Hamiltion and Hayes, 1960), we examined structures in Taylor Glacier. 

Taylor Glacier is 40 miles long, and its surface 

drops from an altitude of about 6,000 feet near the 

interior ice plateau to about 250 feet in Taylor Dry 

Valley. The cross profile of the glacier is gently convex upward, the slope increasing near the margins; 

the sides of the glacier for most of its length are nearvertical ice cliffs 20 to 50 feet high. Most of the glacier is free of snow during at least the summer 

months: precipitation, although entirely in the form 

of snow, is light, and most of the snow is swept a'-my 

by wind. Air temperatures are below freezing all 

year except near the snout of the glacier, where on 

occasional summer days it is as warm as 35°F. 

Longitudinal flow lines, a few of which are marked 

by sparse trains of rock debris, are conspicuous on 

the surface of the glacier (fig. 224.1) and in a few 

FIGURE 224.1.-View westward over Taylor Valley. Taylor 

Glacier flows from interior ice plateau (upper right) into 

upper Taylor Valley, and makes a sharp bend (upper center) 

into lower Taylor Valley. Frozen Bonney Lake in bottom 

of picture, Kukri Hills in left foreground, and Ferrar Glacier 

in left middle distance. The circle on Taylor Glacier marks 

the area where velocity was measured, 8 miles from the 

snout of the glacier; distance from foreground to mountains 

in upper right is 40 miles. U.S. Navy photograph. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-207 

places have been folded or sheared apart in plan by 

differential flow. The scarcity of rock material within 

or on the surface of the glacier even at its snout 

(figs. 224.1 and 224.2) is in marked contrast to the 

character of most temperate-latitude glaciers, and only 

small moraines have formed at the present ice front. 

Momines of more extensive past glaciations are widespread, but are of relatively small volume. Perhaps 

75 percent of the volume of the till is silt and sand. 

Lines of vertical aerial photographs made by the 

U.S. Navy in December 1956 and in November 1959 

cross on Taylor Glacier 8 miles above its terminus. 

Along· a flow line about 3,700 feet from the south 

side of the glacier, which, at that point, is 12,000 feet 

wide, rocks clearly recognizable on both sets of pictures moved about 300 feet in the 3 years, or 100 feet 

per year. Nearer the edge, 1,200 to 2,000 feet from 

the south side of the glacier, moraine-fold axes moved 

about half as far. 

Two sets of vertical photographs of the snout of 

the glacier were taken only a year apart, in December 

1956 and January 1958. These pictures show no apparent change in position of the ice front, and no 

detectable movement of points on the ice ; changes of 

50 feet should have been easily detectable had they 

occurred. 

The ice in Taylor Glacier is strongly foliated, the 

layers revealed by varying color (white to bluish 

white) in thick masses, or by varying transparency 

where thin. Where thin pinnacles of ice are backlighted by the sun, individual folia can be seen to 

be from a fraction of an inch to several inches thick, 

and to be continuous for tens of yards. Foliation 

produces the faint horizontal layering in the shaded 

ice cliff in the right part of figure 224.2. The foliation has a nearly horizontal trace along the side of 

the glacier near the snout, and dips gently toward the 

glacier edge in at least some places, apparently indicating obliquely outward flow of nearsurface ice. 

Discontinuous layers of dark silty ice, parallel to 

foliation, are conspicuous near the base of the glacier 

at its snout (fig. 224.2) and along the sides near the 

snout. Such layers are not exposed along the upper 

part of the glacier, near the interior ice plateau. The 

layers are nearly parallel and undulate gently, anastomosing at slight angles. At the snout of the glacier 

FIGURE 224.2.-Snout of Taylor Glacier, seen across solidly frozen Bonney Lake. The ice overhangs above many of the dark 

silty shear planes. Foliation planes, parallel to the shear planes, are visible in the ice cliff on the right. Ice at right 

is about 100 feet high. Below the cliffs, in the center background, fragments fallen from a hanging glacier ha,·e been 

rewelded into an apron glacier. 
C-208 GEOLOGLCAL SURVEY RESEARCH 1961 

(fig. 224.2) the ice above many of these planes overhangs that beneath, indicating that these layers are 

planes of active laminar shear, along which the upper 

ice slid out over the lower. Similar shear planes 

have been described by Klebelsberg (1948). The overhanging ice breaks off in blocks that form an ice talus. 

As the ice foliation is parallel to these obvious shear 

planes, we conclude that pervasive laminar shear operates also throughout the glacier, but at rates generally too slow to be expressed by frontal oYerhangs. 

Similar shear planes of silty ice-parallel to glacier bases and to ice foliation, and overhung by fastermoving ice-were seen also near the bases of a number of small glaciers, including some (for example, 

fig. 224.2) that reach their termini only after being 

fragmented over ice falls and rewelded into glaciers 

from ice taluses. Despite thicknesses locally less than 

100 feet, these re-formed glaciers flow smoothly by 

laminar shear. Motion by flow rather than fracture 

seems to operate at even very shallow depths in these 

glaciers. 

A large part of the glaciological literature (for 

example, Wright and Priestley, 1922, writing about 

the Taylor Glacier and others in this same region) 

treats foliation and shear planes as bedding layers, 

somehow preserved from original layers of sno"· despite many miles of complexly differential flow interrupted by ice falls and even by complete fragmentation and re\velcling. 

The silty shear planes are copfinecl to the basal part 

of the glacier, rather than curving up,Yarcl to the 

surface as is often the case with temperate-latitude 

glaciers. Presumably, most of the upward increase 

in velocity in the glacier takes place within the basal 

zone with its conspicuous shear planes. These planes 

must reach the base of the ice at some stages, and 

thus pick up the rock debris that colors them (a 

chemical analysis of the silt showed a granoclioritic 

composition similar to that of the local bedrock), but. 

FIGU I!E 224.3.-Silty layers deformed by isoclinal drag fold. 

Man below center gives scale. South side of '.ra~ lot· Glacier, 

about one-half mile from snout. 

there may be relatively little movement of the Ice m 

direct contact with the rock floor. 

The silty shear layers exposed along the sides of the 

lower part of the glacier are deformed in many places 

into spectacular isoclinal drag folds (fig. 224.3) whose 

axes are nearly perpendicular to the trend of the glacier and whose axial planes are parallel to the active 

shear layers. These drag folds are clue to laminar 

shear, for there are no open folds, but only isoclinal 

ones. The axial planes of these folds must mark velocity discontinuities, the ice above having moved considerably farther than the ice beneath, and the fold 

front migrating down-glacier at a speed midway between that of the ice above and beneath (fig. 224.4). 

Each drag fold remains isoclinal throughout its history. Similar structures were attributed to longitudinal compression of ice by Shumskii ( 1955, p. 334-335), 

Boulder\ 

~---

Boulder shows movement 

of ice surface 

Top of ice 

Ice moving relatively rapidly 

Silty shear 

planes""-

=====:::=-...:~~ear zone -- -------=-

Base of glacier 

iiiii1i1i;:, \ I \ I\ V # I 

-------= 

Slow moving ice 

near base 

Silty layers snubbed and rolled 

over at leading edge 

Upper limb of isocline moves past lower limb; 

fold crest moves at intermediate speed 

FIGURE 224.4.-Mechanism of isoclinal folding by differential flow . Longitudinal sections of glacier, in sequence from oldest (left) 

to youngest (right), at the same bedrock position. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-209 

despite a geometry which requires an origin by shear. 

Some isoclines point down-glacier, like the one in the 

photograph, but at least as many point up-glacier. 

Also present are sheared-off limbs of isoclines, lenses 

bounded by active shear planes, in which the fold 

structures are now relic rather than actively developing. To the r.ight of the isoclinal axis of figure 224.3, 

there is no silty layer or other obvious discontinuity, 

even though the axial plane must project into a thin 

zone of rapid shear. 

Probably most isoclinal folds in metamorphic rocks 

are :formed by a similar mechanism of drag accompanying laminar shear whereby folds are isoclinal at 

all stages of their development rather than being 

formed by progressive tightening of initially open 

folds. '\There, as is commonly the case, even thin 

formations in rocks deformed by intense isoclinal folding are planar sheets parallel to foliation and to axial 

planes, shear folding by differential laminar flow is 

required, because folding by compressive tightening of 

flexure folds would also fold formation contacts. 

REFERENCES 

Hnmilton, Warren, and Hayes, P. T., 1960, Geology of Taylor 

Glacier-Taylor Dry Valley region, South Victoria Land, 

Antarctica, ·in Short papers in the geological sciences: 

U.S. Geol. Survey Prof. Paper 4QO-B, p. B376-B378. 

Klebelsberg, R. V., 1948, Hanclbuch cler Gletsche1·kunde uncl 

Glazialgeologie, v. 1: Springer-Verlag, Vienna, 403 p. 

Shumskii, P. A., 1955, Osnovy strukturnogo ledovecleniya 

[Principles of structural ice study] : Akad. Nauk SSSR, 

'492 p. 

Wright, C. S., and Priestley, R. E., 1922, Glaciology: London, 

British Antarctic Expecl. 1910-13, 581 p. 

225. PETROCHEMISTRY OF PROBABLE PALEOZOIC GRANITIC ROCKS FROM THE 

ROSS SEA REGION, ANTA~CTICA 

By "\VAHREN l:IAl\HLTON, Denver, Colo. 

ll'o1·1.: do,ne w-ith the SnP1JO'rt of the Na,t,ional Science Foundation 

Between the large Precambrian shield of East A.ntartica and the Cretaceous (or early Tertiary~) granitic rocks of Palmer Peninsula lies a broad region of 

metasedin1entary and granitic rocks of inadequately 

known age. Although these intervening rocks have 

long been assumed to belong in part to the shield and 

in part to the ~1esozoic orogen, I (1960) interpret 

them, on the basis of much newly available information·, to belong instead to Paleozoic orogens, the ages 

of whose sediments, deformations, and granites all 

become progressively younger from the shield tmYard 

Palmer Peninsula (fig. 225.1). The recent finding of 

Lower Cambrittn fossils by New Zealand geologists 

in prebatholithic metasedimentary rocks near Beardmore Glacier (fig. 225.2) (Bernard ~1. Gunn, written 

communication, 1961) confirms the most important element of this new interpretation. 

The Precambrian shield is characterized, by charnockites-gneisses and granites containing orthopy-. 

roxene-ancl by polymetamorphic :rocks. The Palmer 

Peninsula, which contains all of the certainly known 

Cretaceous (or early Tertiary~) granitic rocks, is 

characterized by quartz diorite intrusive into metavolcanic rocks. Between the shield and Palmer Peninsula is a broad region of sedimentary rocks, metamorphosed at low, middle, or high grades, and 

intruded by batholiths of granitic rocks that are at 

least partly of Paleozoic age. 

The batholithic granitic rocks of early Paleozoic, 

probably Cambrian or Ordovician, age are known particularly well in South Victoria Land (for example, 

I-Iamilton and Hayes, 1960), west of the Ross Sea. 

The granites interpreted as being of middle or ]ate 

Paleozoic age are best known in western l\1arie Byrd 

Land (for example, "\Varner, 1945), east of the Ross 

Sea. 

A total of 29 new chemical analyses (fig. 225.3) have 

been made of granitic rocks from these and other areas 

within the Paleozoic ( ~) orogens. Of the 15 probable 

Cambrian or Ordovician rocks analyzed, 12 "·ere collected by P. T. Hayes and me in the ~1cl\furdo Sound 

region, two were collected by L. ~1. Gould in the 
C- 210 GEOLOGICAL SURVEY RESEARCH 19 61 

FraunE 225.1.-New interpretation of major tectonic elements 

of Antarctica. Submarine contour interval 1,000 fathoms. 

Queen Maud Mountains (and obtained from the Uni-

. versity of Michigan collection, through the courtesy 

of E. W. Heinrich), and one was collected in the 

Horlick Mountains by W. E. Long. Of the 14 analyzed samples of granitic rocks of likely Silurian to 

Permian age, 9 were collected by L. A. Warner in 

western Marie Byrd Land (and obtained from the 

U.S. National Museum) ; 1 each was collected from 

the same region by E. L. Boudette and by Col. Dan 

Crozier; and 1 each was collected from isolated nunataks in the deep interior of west Antarctica, in the 

region of long 90° W., lat 82° S., by J. C. Craddock, 

J. Pirrit, and W. E. Long. Three new analyses were 

made also of granitic rocks from the Palmer Peninsula region, collected by the Expedition Antarctique 

Francaise, 1903-05, and obtained from the University 

of Michigan collection. Most "elevant American collections are represented in this small suite of specimens, and it is a pleasur~ to acknowledge the assistance of the geologists who supplied them. These new 

analyses include all of the minor-element determinations known to me of granites from the Paleozoic 

terrane as shown in figure 225.3. (The published major-oxide analyses of granitic rocks from these regions are not. considered here because most of them 

are of poor quality.) Despite the small number of 

samples, trends and distinctions are suggested by the 

data. 

Most of the new analyses plot near the same variation curves. The obvious exceptions, those with Si02 

lower than 63 percent, are of probable Cambrian or 

Ordovician rocks collected within a few miles of extensive outcrops of silicated carbonate rocks, so that 

these aberrant granitic rocks may owe their character 

to loss of magmatic silica to the carbonate rocks and 

to accompanying diffusion of alkalis. The proportion 

of FeO to MgO is much higher in this same suite than 

in the others. Relative to Si02 content, the Cretaceous ( ? ) rocks from Palmer Peninsula appear higher 

in CaO and lower in K 2 0 than the others ; the more 

silicic of the analyses of Palmer Peninsula rocks by 

Adie (1955) show the same pattern. Other such contrasts are suggested within and between the suites of 

samples, and more analyses are desirable to test their 

validity. 

Frequency distributions of rock types are quite different in the several provinces, as is shown by the 

varying ranges and groupings of their components. 

The probable Cambrian or Ordovician granitic rocks 

include quartz diorite, granodiorite, and quartz monzonite. The later Paleozoic ( ? ) rocks include some 

granodiorite, but are mostly quartz monzonite and 

granite, so that their bulk composition is considerably 

more silicic and potassic. The Cretaceous ( ? ) rocks 

of Palmer Peninsula are dominantly quartz diorite 

(A die, 1955). 

Differences in abundances of some of the minor 

elements appear to have significance in characterizing petrologic provinces. As the minor elements vary 

with abundances of other components within each 

FraunE 225.2.-Geographic map of Antarctica, showing place 

names. BG, Beardmore Glacier; EF, Edsel Ford Ranges; 

HM, Horlick Mountains; MS, McMurdo Sound; QM, Queen 

Maud Ranges. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ART~CLES 147-292 

MAJOR OXIDES 

so 

. -. ~Fe ... A X A 

asFeO 0 x• 

0-t,·. ~0 

+ )( + 

Fe20a A ,OA . ... ~ x. 

... '· FeO 

MgO . . .: 

. . A 

CaO . A .. >0 x• OX'Ae 

••• ~S> + 

. . .. '· A XO ~. 0 .... • #X Na20 • 0 

~ 

. +-jcll> + 

A' ,_>Ok 

K20 . . >Ox·O\ 

A 

H20 . ... 55 60 65 70 75 80 

Si02 

EXPLANATION 

ROCKS OF CRETACEOUS OR EARLY TERTIARY AGE 

A 

Palmer Peninsula 

ROCKS OF PROBABLE SILURIAN TO PERMIAN AGE 

X 

Western Marie Byrd Land 

+ 

Interior West Antarctica 

ROCKS OF PROBABLE CAMBRIAN OR ORDOVICIAN AGE 

McMurdo Sound region 

0 

Horlick Mountains and Queen Maud Ranges 

Dashed fines indicate threshold abundances, below which the 

elements were not detectable; "not detected" determinations ore 

plotted arbitrarily beneath these fines 

50 

Ba 

Co 

Cr 

Cu 

F 

Mn 

Ni 

p 

Ti 

50 

MINOR ELEMENTS 

55 60 65 70 75 

.: A 

A "oA 

. - " . 

. .. " A ><0 Ax• 0 ,;.: .. +~ 

., ., xolJI(·o~: ~ 

)()( 

A +"><" 

. ' -. A XOAx• 0~"'\ +~ X 

+lOOt< 

• • • • + )0( 

-----~-----lL_L-~.3L_x_ e • A OA 0 

. .... -A 

)( 

+ X 

>0< X X 

• - •• +~ +,/'~ ---------0..-~---- .3<• ,.. 

• .• J A xo'\•o~, +xx +><xxx ----------o--x-

. ... 

__________ 

• .•. el A XOAX• ~-- ~ .1QL__ 

I + ~ 

. . . . 

55 60 

+ )(X 

- A x0 lY< 

0 

0 ~ )()( X 

65 70 75 

Si0 2 

C-211 

80 

80 

FIGURE 225.3.-Silica-variation diagrams of major oxides and minor elements in granitic rocks from Antarctica. Major 

oxides plotted on arithmetic scale; minor elements plotted on logarithmic scale. 
C-212 GEOLOGICAL SURVEY RESEARCH 19 61 

province,. these distinctions must be considered relative to accompanying amounts of other components; 

SiO!!, a good indicator of other variables, is used as 

the major reference here. Considered relative to 

SiO:.!, chromium, nickel, and vanadium, and probably 

copper, tin, and titanium, appear to be less abundant in the probable Cambrian or. Ordovician rocks 

than in the later Paleozoic(?) rocks, whereas zirconium, and possibly gallium, niobium, ytterbium, 

and yttrium, are apparently more abundant. The 

earlier Paleozoic (?) rocks thus appear considerably 

richer in rare earths, but poorer in ore metals, than 

the later Paleozoic( n rocks. This consistency shown 

by groups of related trace elements supports the suggestion that the apparent contrasts are real rather, 

than being mere illusions due to inadequate sampling.' 

'Vithin the probable Cambrian or Ordovician group, 

there are marked differences between the 12 analyses 

of rocks from the ~1c~1urdo Sound region and the 3 

from the Queen ~1aud Ranges and Horlick ~1ountains. The latter sample of 3 is so small that only a 

sampling inadequacy may be demonstrated-as is suggested by the virtual petrographic identity of Horlick 

~1ountains rocks. and some McMurdo Sound onesbut the data suggest conspicuous differences in Be, 

Nb, V, Y, and possibly other elements. 

Similarly, within the later Paleozoic ( ? ) group, 

there are apparent differences between western Marie 

Byrd Land (11 analyses) and interior West Antarctica ( 3 analyses) in several elements; but again, larger 

suites o£ samples are needed to evaluate such possible 

distinctions. 

In many provinces of igneous rocks, barium varies 

systematically with potassium. Here, however, determinations o£ barium in the probable Cambrian or Ordovician rocks yielded nearly constant values, near 0.05 

percent, regardless of potassium contents, whereas determinations in the later Paleozoic rocks showed the 

opposite pattern of widely variable barium with nearly 

constant potassium. This is perhaps related to desilication of the Cambrian or Ordovician magmas, 

in the low SiOz rocks, and to decreasing feldspar contents in the· most silicic rocks. 

Fluorine is higher, relative to Si02 content, in the 

probable Cambrian or Ordovicia~ rocks than in the 

later Paleozoic ( ? ) ones, and much higher in those 

than in the Cretaceous ( ? ) rocks of Palmer Peninsula. 

REFERENCES 

Adie, R. J., 1955, The petrology of Graham Land, II, The 

Andeari granite-gabbro intrusive suite: Falkland Islands 

Dependencies Survey, Sci. Rept. 12, 39 p. 

Hamilton, Warren, 1960, New interpretation of Antarctic tectonics, ·in Short papers in the geological sciences: U.S. 

Geol. Survey Prof. Paper 400-B, p. B379-B380. 

Hamilton, Warren, and Hayes, P. T., 1960, Geology of Taylor 

Glacier-Taylor Dry Valley region, South Victoria Land, 

Antarctica, in Short papers in the geological sciencies: 

U.S. Geol. Survey Prof. Paper 400-B, p. B376-B378. 

Warner, L. A., 1945, Structure and petrography of the southern Edsel Ford Ranges, Antarctica : Am. Philos. Soc. 

Proc., v. 89, p. 78-122. 

GEOLOGY AND HYDROLOGY OF OTHER COUNTRIES 

226. INVESTIGATION OF THE PRINCIPAL FLUORSPAR DISTRICTS OF MEXICO 

By RALPH E. VAN ALSTINE, Washington, D.C. 

1Vork done ·in oooperation with the Consejo de Rec·ttrsos Nat1wales No RenOVf!-bles, Secretar-ia del Pa.trimon:io Nacional, Mexico, 

D.F., and the Office of Minerals llfo1Jilization, U.S. Department of the Interior 

Since 1956 Mexico has been the world's largest producer and exporter of fluorspar. In the past 4 years 

~1exico has supplied more than 60 percent of the 

fluorspar imported into the United States, averaging 

about 330,000 tons a year. Twelve major .fluorspar 

districts in 9 states of Mexico were visited in AprilJune 1960, by the writer accompanied by Samuel Estrada and Ernesto de la Garza of the Consejo de Recursos Naturales No Renovables. The survey indicates that l\1exican reserves are adequate for many 

·' 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-213 

TABLE 226.1.-Districts and mining companies visited 

State District Mining company or mine Affiliate 

------------------------ Chihuahua ________ Parral_ _______________ Industriale de Fluorita _____________ General Chemical Div., Allied Chemical 

Coahuila__________ El Tule _____________ _ Corp. Minera Rosala ____________________ E. I. duPont de Nemours & Co. 

Do_ _ _ _ _ _ _ _ _ _ _ Encantada-Buena- Fluorita de Mexico________________ Continental Ore Co. 

vista. Do_ _ _ _ _ _ _ _ _ _ _ _ ____ do ______________ _ El Camaron mine ________________ _ Do ________________ do ______________ _ 

Do___________ Paila-San-Marcos _____ _ Do ________________ do ______________ _ 

Min era Rosala ___________________ _ Min era N acional _________________ _ 

San Marcos y Pinos ______________ _ 

E. I. du Pont de Nemours & Co. 

American Smelting and Refining Co. 

Reynolds Metals Co. Do ________________ do ______________ _ Min era Julieta ___________________ _ Do ________________ do ______________ _ Min era La V alenciana _____________ _ Do___________ Pico Etereo __________ _ La Domincia _____________________ _ Do ________________ do ______________ _ 

Durango _______ ·-- Villa Union __________ _ 

Guanajuato_____ _ _ _ Rio Verde ___________ _ 

Mal Abrigo mine _________________ _ Impulsora Min era ________________ _ Minera Rio Colorado _____________ _ 

Guerrero__________ Taxco _______________ _ Restauradora de Minas ___________ _ Do ________________ do ______________ _ Minas del Norte __________________ _ 

Mexico____________ Zacualpan ___________ _ Mexicana de Minas y Beneficios ____ _ San Luis Potosi_ _ _ _ Zaragoza ____________ _ Do ________________ do ______________ _ Minera Las Cuevas _______________ _ Minerales Pennsalt _______________ _ Do ___________ Rio Verde ___________ _ Minera La Valenciana ____________ _ Do ________________ do ______________ _ Fluorita de Rio Verde _____________ _ Sonora ____________ Esqueda _____________ _ Fluoresqueda ____________________ _ 

Zacatecas__________ Frio ________________ _ J osefina mine ____________________ _ 

TABLE 226.2.-Processing plants visited 

No. on flg. 220.1 Location Operating company 

1 Esqueda, Sonora ____________ San Luis M.inin~ Co _____________________ 

2 Heath Crossing, Coahuila ____ Dow ChemiCal o _______________________ 

3 Ea9£e Pass, Tex _____________ Reynolds Metals Co ___________________ --

4 El ule, Coahuila ___________ K I. duPont de Nemours & Co ___________ 

5 Muzquiz, Coahuila __________ Fluorita de Mexico_---------------------

6 Agujita, Coahuila ___________ American Smelting and Refining Co _______ 

7 Frausto, Coahuila ___________ St. Lawrence Corp. of Newfoundland, Ltd ___ 

8 Zaragoza district, San Luis Minerales Pennsalt ______________________ 

Potosi. 

9 San Luis 

Potosi. 

Potosi, San Luis Noranda Mines, Ltd., and others __________ 

10 Rio Verde, San Luis PotosL ___ Min era La V alenciana ___________________ 

11 Zacualpan, Mexico __________ Mexicana de Minas y Beneficios ___________ 

St. Lawrence Corp. of Newfoundland, Ltd. 

Dow Chemical Co. 

Mexus Minerals. 

General Chemical Div., Allied Chemical 

Corp. 

Minerales y Productos Derivados, Spain. 

La Consolidada. 

Noranda Mines, Ltd., and others. 

Pennsalt Chemicals Corp. 

Continental Ore Co. 

San Luis Mining Co. 

Aluminium Laboratories, Ltd. 

Process 

Approximate 

daily capacit y (tons of co neon tra tes) 

-- Flotation ___________________ 

_____ do ____ ~---------------- _____ do _____________________ 

Air separation pilot plant _____ Flotation ___________________ _____ do _____________________ 

Heavy media _______________ 

Crushing and sizing ___ ..: ______ 

_____ do _____________________ 

Washing and sizing __________ Flotation _____________ ·- _____ 

12 

10 

10 

3 

20 

15 

5 

0 

0 

0 

0 

0 

100+ 

30 

20 

7 

7 

0 

0 

5 

0 

years at the present rate of production. Brief visits 

were made to more than 30 fluorspar mines to obtain 

information on the deposits and their geologic settings. 

The deposits and. the processing plants visited are 

1 is ted in tables 226.1 and 226.2 and are shown on the 

index map (fig. 226.1). 

generally smaller but contain pigher. grade ore than 

the veins, pi pes, and conical bodies; they are abundant 

in several widely separated areas of limestone in 

northern and southern Coahuila. 

:More than two-thirds of the deposits examined are 

in limestone of Early Cretaceous age. The other 

deposits are mainly· in shale or volcanic rocks that 

overlie t·he limestone and are within or next to Tertiary 

rhyolite. 

The deposits are found as nearly flat manto bodies 

or as steeply clipping veins, pipes, conical bodies, tabuhtr and irregular replacement bodies, and filled sink 

holes a.nd collapse breccias. The manto deposits are 

The ore consists predominantly of fluorite, calcite, 

and quartz or chalcedony. The fluorite is highly variable in texture, grain size, and color. In some deposits the calcite content increases with depth; in 

others it decreases below a superficial caliche zone. 

Small quantities of barite, celestite, gypsum, native sulfur, pyrite, sphalerite, galena, chalcopyrite, iron oxides, or manganese oxides are present in most of the 

ores. 

Although detailed sample data were not available for 

most of the deposits being worked, the average grade 
C-214 GEOLOGICAL SURVEY RESEARCH 19 61 

~ Douglas r-

-..,. :..J 

SONORA 

CHIHUAHUA 

EXPLANATION 

Mining district 

(Mines visited are listed in table 226.1) 

0 50 I I I I 

0 50 100 

Processing plant 

(Described ·in table 226.2) 

100 

I I 

200 

I 

300 MILES 

I 

I 

200 300 KILOMETERS 

UNITED STATES 

•Marathon 

FIGURE 226.1.-Sketch map of part of Mexico showing fluorspar mining districts and processing plants visited, April-June 1960. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-215 

of ore, estimated at about 65 percent CaF 2, seems to 

be higher than that of fluorspar deposits in the United 

States. However, the overall range in grade from 

less than 40 to more than 90 percent CaF 2 is similar 

in the two countries. The silica content of the ore 

is commonly less than 10 percent and in some deposits 

is less than 1 percent; other deposits contain more 

than 30 percent calcite. The high quality of fluorspar 

shipped from some Mexican districts is the result of 

selective mining in lower grade deposits and repeated 

handpicking at the mines and mills. 

Fluorspar reserves in the twelve districts visited are 

estimnted nt about 5 million tons of measured and 

indicated ore and about 10 million tons of inferred 

ore, averaging about 65 percent CaF 2• Individual 

deposits containing these reserves range in size from 

less than 10,000 tons to more than 1 million tons. An 

additional potential reserve of about 5 million tons of 

acid-grade fluorspar is contained in about 45 million 

tons of tailings that have accumulated from the flotation of zinc-lead-copper ore in the Parra! area, Chihuahua. Undoubtedly additional fluorspar reserves will 

be found in the districts visited, especially in Coahuila 

and San Luis Potosi. 

The fluorspar deposits are mined chiefly by shrinkage stoping, modified cut-and-fill system, room-andpillar method, and benching in opencuts. .Some of 

the larger mines are highly mechanized; at most of 

the smaller deposits, however, modern mining techniques are not used, and only the highest grade, thickest, or most readily accessible ore is mined by hand 

and packed to the surface on the backs of the miners. 

High-grade fluorspar as little as 4 inches thick is 

mined profitably from one manto deposit. 

Water for mine use must be hauled to most of the 

·districts. Because of this lack of water near the mines, 

ore is hauled as much as 150 miles to a mill. 

As a result of the increasing need for fluorspar, 

especially in the United States, Canada, and Mexico, 

the Mexican fluorspar industry has expanded greatly 

and has become very profitable within the last 8 years. 

The mining and milling methods at the larger deposits are becoming more efficient, and the industry 

is continuing to flourish. 
C-216 GEOLOGLCAL SURVEY RESEARCH 1961 

227. EVIDENCE FOR LOCAL GLACIER STAGNATION IN EAST GREENLAND 

By JosEPH H. HARTSHORN, Boston, ~Iass. 

Work done in cooperation with the U.S. Air Fm·ce Oamb·l"'idge Research Labm·atodes 

Several glaciers on the islands and forelands of 

Greenland north of Scoresby Sund (fig. 227.1) show 

collapsed glacial stream deposits or ablation moraine 

that clearly indicate downwastage and stagnation during glacial retreat. Kettled glacial stream deposits 

that are now many miles from the nearest glacier 

were found as far north as the Haystack. 

During an older more extensive glaciation, a glacier extended southeast toward Moskusoksefjord and 

Loch Fyne from the mountains of Hudson Land. This 

ancient glacier, here called the Stordal Glacier, reached 

eastward nearly to Loch Fyne. The general eastward 

slope of the glacier surface is shown by marginal 

channels (fig. 227.2). 

The radiating pattern of former stream channels on 

the largest remaining uncollapsed outwash plains show 

that meltwater . from Stordal Glacier flowed south 

FIGURE 227.1.-l\Iap of East Greenland. 

and east and buried the terminus of the glacier under 

large quantities of glaciofluvial sediments. The collapsed part of the stream deposits shows the position 

of the stagnant ice. The forms of the ridges and 

hollows (fig. 227.2) lead to the conclusion that gen-

.eral downwastage and thinning had reduced the glacier 

front to a thin hummocky discontinuous mass. Aggradii1g streams flowed either on the ice or on the subglacial floor. Deposition in the lower parts of the 

· irregular ice topography and on the ground took place 

in areas where there is little or no collapse. In places 

where ice blocks or high knobs on the nearly buried ice 

protruded through the blanket of sediments, however, 

there are now low spots produced by the inversion 

of relief. 

Large flat-topped masses of stratified drift are 

bounded on all or nearly all sides by ice-contact slopes. 

Ridges of stratified drift that in many places completely surround depressions now filled with water indicate that erosion could have played no part in 

forming the features. The numerous mounds, icechannel fillings, and rimmed kettles are evidently remnants of a once extensive plain deposited on irregular 

stagnant ice. The ice melted a way after the streams 

from the Stordal Glacier had stopped flowing here 

and had begun to cut down to a new base level farther 

south, and after the glacier itself had retreated to 

some position farther back in the valley in the mountains. The pattern of collapse is similar to that in the 

better rna pped area of the southern New England 

States, where ice retreated by stagnation. 

Charcot Glacier (unofficial name) is a small valley 

glacier about 11 miles long that extends eastward 

from the ice cap covering the center of Milne Land, 

an island on the west side of Hall Bredning. It has 

a relatively clean surface, but it carries a heavy subglacial load that can be seen coming up along shear 

planes at the end of the glacier. The glacial streams 

flow at or near the base of the glacier near the terminus, and the heavy load of subglacial debris is 

picked up b:y the streams and delivered beyond the 

terminus. 

The topography in front of Charcot Glacier (fig. 

227.3) shows striking evidence of stagnation. Thin 

ice with an irregular upper surface was buried by 
.. 

> 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ART:rCLES 147-292 C-217 

Fw UR;E 227 .2.-Collapsed glaciofluvial deposits near Loch Fyne. View north from approximately 5,000 feet altitude. Area of 

marginal channels in bedrock (a), uncollapsed portions of outwash plains (b), kettle lakes (dark gray), and braided drainage 

(c), and reticulate ice-channel fillings (d) . Ice moved from left to right. 

glacial stream deposits from the last ice advance. 

The upper surface of these collapsed glaciofluvial deposits was once a smoothly aggraded plain. Collapse 

of areas underlain by thicker parts. of the ice has 

destroyed the smooth surface by creation of numerous 

irregularities, small pits, and large circular kettles. 

The water-filled kettle in the center of figure 227.3 

shows very steep sides and a fresh slump scarp along 

the left edge, indicating that collapse is still going 

on. The numerous ridges have formed from deposition of early channel deposits in low parts of the irregular ice sheet, later aggradation to a generally 

level upper surface, and final melting of the buried 

ice. The flat surfaces of parts of the ridges can be 

traced into uncollapsed outwash; elsewhere the narrower ridges have slumped below the general surface 

level. 

On the west side of Schuchertdal, a valley about 43 

miles long, are five glaciers that formerly must have 

601530 0-61-15 

been tributary to a large glacier in the main valley. 

The five glaciers are informally numbered in order 

from south to north; only the Third Glacier will be 

discussed. 

Third Glacier terminates well out on the main valley floor in an expanded ice foot and encircling drift 

deposits. A trimline and some small concentric arcuate moraines show that the glacier pushed almost all 

the way across the valley floor at some very recent 

time. A semicircular pattern of deposits was left behind after the retreat of the ice to its present position. 

Next to the present glacier margin is a semicircular 

belt of knobby topography composed of superglacial 

moraine let down onto the ground. At the outer edge 

of the belt, deformed deposits of stratified sand and 

fine-grained gravel show a series of arcuate concentric 

ridges with central cracks, parallel to and between the 

present ice margin and the outer limit of the last 

advance. It is possible that the deformed outwash 
· C-218 GEOLOGWAL SURVEY RESEARCH 19 61 

FIGURE 227.3.-Aerial view of collapsed stratified drift in front of Charcot Glacier, Milne Land; taken from an altitude of about 150 

feet. Breached end moraine (a), modern sandy outwash plain (b), older collapsed outwash (c), ice-channel filling at same 

elevation as uncollapsed part of older outwash (d), and recent slump scarp (e) on edge of kettle. 

was laid down in front of an advancing glacier and 

crumpled by advancing ice. An alternative possibility is as follows: the sediments were deposited as 

an outwash apron on a thin marginal zone of ice, consisting of alternate concentric arcuate bands of fast 

melting clean ice and slowly melting moraine-covered 

ice with a concentric pattern parallel to the snout of 

the glacier; as the last remnants of the thin ice melted, 

the clean bands formed shallow valleys and the dirty 

bands remained as small ridges; outwash deposited on 

this irregular surface consisted of thick belts over 

the valleys and thin belts over the moraine-covered 

ridges; when the ice finally melted completely, the 

thicker sections of outwash over the ice bands became 

low ridges and developed cracks owing to lateral 

slumping toward the areas of minimum outwash deposition, the present lows. Most of the ice buried under 

the superglacial deposits has melted away, but the 

presence of ponds with water clouded by rock flour 

sho"·s that there is still some ice beneath these deposits. 

At Third Glacier, as at Stordal Glacier and Charcot Glacier, a relatively recent expansion of ice has 

been followed by stagnation and burial of the glacier 

terminus. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTI·CLES 147-292 C-219 

228. THERMAL REGIME DURING THE THAW OF CENTRUM 80, NORTHEAST GREENLAND 

By D. B. l(RINSLEY, ''Tashington, D.C. 

lVork done hL coopcrntion wi-th ;lir .li'orce Oa:mbddgc Bcsea·rch Laboratory 

During May 1960, and prior to the thaw, two cables 

containing vVestern Electric thermistors were placed 

in Cellt'rum S0 (lake), not't.henst- Greenland. l'he 

cables, supported by floats resting on the ice surface, 

extended through 1 foot of snow and 6 feet of ice to 

t·he lake bottom where they rested on fine-grained 

sediments. The suspended cables were located near 

each end of a trough-shaped deep which lay along 

the longitudinal section of the lake (fig. 228.1). The 

thermistors in each cable were at approximately 10, 

100, 20l), and 260 feet below the ic·e surface. Readings accur:1te to 0.1 oc were made at intervals of from 

1 day to 3 weeks. During a 24-hour period beginning 

at noon l\iay 29, thermistors in cable 2 were read 

hourly. 

Overflow from Saefaxi Elv (river) spread over a 

quarter-mile square area adjacent to the river mouth, 

at". noon on l\iay 20. This overflow, resulting from incrensed fiow because of higher air temperatures, initinJed a general melt of the subjacent snow cbver. By 

l\iay 29, isolated ponds had developed on the lake ice 

NORTH 

r 80"10' 

and a moat 8 inches deep and 20 feet wide extended 

eastward along the north shore to point A (fig. 228.1). 

These changes at the surface and periphery of the 

lake were recorded on l\iay 31 when the thermistor at· 

10 feet in cable 1 indicated a rise of 0.1 °C, and thermistors at 200 and 207 feet in cable 2 each indicated 

a decrease of 0.1°C (fig. 228.2). 

During the period from l\iay 31 through June 6, 

Saefaxi Elv and Graeselven (river) eroded channels 

through the stream ice and a large volume of warmer 

water (3.0° to 8.0°C) poured into the adjacent moats 

and under the lake ice which had broken a way from 

the shore bottom. The water which had accumulated 

on the surface of the lake ice drained into the rapidly 

widening moats. Firm ice that had characterized the 

frozen surface had been transformed to candle ice 

which eKtended to a depth of 14 inches. On June 6, 

the thermistor at 110 feet in cable 1 indicated a decrease of 0.1 °C in the _water temperature. Ther1nistors 

at 6.5, 10, 200, and 207 feet in cable 2 indicated a 

rise of 0.5°, 0.4°, 0.1°, and 0.1 °C, respectively. 

80"10' 

EXPLANATION 

265 0 

DEPTH AT THERMISTOR CABLE 

LOW 

~ TERRACE 

LAKE ALTITUDE - 328 FEET 

SURVEYED :MAY-AUGUST, 1960 INTERVAL OF DEPTH CONTOUR- 20 FEfT 

=::C~:C=:=:CO ===i=====::I======i=====:34 MILES 

SCALE IN MILES 

l!'IGUltE 228.1.-Hydrogmphic map of Centrum S~, northeast Greenland. 

CAMPSITE 

~ 

~ 

TERRACE 
C-220 GEOLOGICAL SURVEY RESEARCH 19 61 

265' 

-~ ·-- 27 -----

-

u 

0 

;;;::z 

- - pJ9!----

------ atrt' 

-W~.·--------- --- ------

...JQP_______ I - ---;:.-:: / 

/ 

/ 

_10' ____ / // 

/ 

_6£...._·~/ 

MAY 24 

/ 

/ 

/ 

JUNE 19 

EXPLANATION 

THERMISTOR CABLE 

THERMISTOR CABLE 2 

265' 

DEPTH OF THERMISTOR BELOW 

ICE SURFACE, IN FEET 

JULY 12 

DAY OF THERMISTOR READING 

FIGURE 228.2,-W,a.ter temperature during the thaw at Centrum S~. 

A staff gauge for measuring the lake level was installed on June 7 as the water surface started to rise. 

Three days later, the lake had risen one foot, which 

· was sufficient to neutralize the current in Saefaxi Elv. 

The lake ice deteriorated rapidly by candling but by 

late June the level of the lake had stabilized. On 

.Tune 19 the thermistor at 10 feet in cable 1 indicated 

a 1.0°C rise in water temperature although all other 

thermistors in the cable recorded a decrease in water 

temperature (fig. 228.2). At cable 2 the upper three 

thermistors recorded a rise of 1.0°, 0.8°, and 0.2°C. 

As at cable 1, the lower thermistors of cable 2 indicated 

a decrease in water temperatures. 

During the first week in July, the lake rose 3.5 feet 

and a 15-foot wide crack opened in the vicinity of 

cable 2. The ice in this area had thinned from 72 

inches to 48 inches. The moat was continuous around 

the entire lake but it closed locally with shifting wind 

directions. By July 9, the lake had risen a total of 

8.3 feet, and water 2.5 feet deep flooded a low terrace 

adjacent to the campsite (fig. 228.1). The lake receded from this maximum flooding the next day. The 

moat was now from 25 to 50 feet wide around the 

lake, and several cracks formed near the center of the 

lake ice. On July 12, prior to their removal because 

of possible ice damage, the thermistors were read for 

the last time. At cable 1, all thermistors recorded a 

significant rise in water temperature; the maximum 

rise of 1.4°C occurred at a depth of 110 feet. At cable 

2, all thermistors recorded a significant rise in water 

temperature; the maximum rise of 1.2°C occurred at a 

depth of 10 feet. During the period July 10 to 25, the 

lake ice melted so rapidly that by July 26 all lake 

ice had disappeared except for scattered floating remnants at the north side of Centrum 89). 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-221 

The temperature data indicate that although water 

temperatures near the surface and on the lake bottom 

changed in the same direction, there were significant 

temperature differences between cables, in the same 

horizon at the same time. Temperature differences 

between the 10-foot thermistors ( 4 feet below the bottom of the ice) were not due to differences in the 

local environment because both instrument platforms 

were eovererl by a white canvas, and snow and ice cover 

were identical. Small temperature fluctuations along 

the lake bottom could not have been caused by different radiative properties of the sediments as suggested 

by Brewer (1958) because of the uniformity of the 

fine-grained sediments (red silt) at both cable ends. 

Temperature changes between cables were in the same 

direction in the 200- to 210-foot horizon but were in 

opposit·e directions in the 100- to 110-foot horizon durin~ the period ,June 6 through June 19 (fig. 228.2). 

The water t-emperature differences between levels 

were greater prior to melting of the insulating snow 

cover and they diminished during the thaw period. 

During a critical 24-hour period (l\1ay 30-31), on the 

threshold of the lake thaw, when the air temperature 

fluctunJect 5.0°C and the snow cover was reduced to 

slush, there was not· more than a 0.0:3°C ( 4 ohms resistance) fluchmtion in water temperature and this 

occurred at a depth of 200 to 207 feet. 

Solar radiation, even differentially applied, as in the 

case of sunlight and shadow alternately produced by a 

low arctic sun on topographic obstacles, cannot affect 

water temperatures prior to the removal of the snow 

cover. Th'e principal tributaries of Centrum 895 freeze 

to the bottom so that they cannot add heat to the lake 

until they break up (June 1). 

Prior to the thaw, heat may enter the system from 

the flow of ground water beneath the streams, from 

sublimnol springs, and from the bottom sediments. 

These potential heat sources are capable of generating 

local convective systems that could account for the 

horizontal temperature differences as well as the temperature anomaly which occurred at the 260-foot thermistor of cable 2 (fig. 228.2). 

During the breakup of the principal tributaries the 

persistence of the horizontal temperature differences 

at depth appears to be the result of local displacement 

by the warmer denser_ water which may flow in currents controlled by the bottom configuration. 

REFERENCES 

Barnes, D. F'., ancl Hobbie, .T. E., 1960, Rate of melting at the 

bottom of floating ice, 'in Short papers in the geological 

sciences: U.S. Geol. Survey Prof. Paper 400-B, p. B392-

B394. 

Brewer, l\f. C., 1958, Thermal regime of an Arctic lake: Am. 

Geophys. Union Trans., v. 39, no. 2, p. 278-284. 

Hobbie, J. E., 1960, Limnological studies on Lakes Peters and 

Schradet·, Alaska: Air Force Cambridge Hesearch CenterTN-60-261, Scientific Heport no. fl. 

229. FACIES CHANGE IN NEOCOMIAN ROCKS OF THE TERESITA-CHULO AREA, ATACAMA PROVINCE, CHILE 

By l(ENNETH SEmJRSTROl\f, Santiago, Chile 

lVorl,; tlone 'in coo1Jerntion 'W'ith the InstUttto de hwesUgncione.'l Geol6gicns, Santiago 

Recent detailed mapping in the Teresita-Chulo area, 

10 to 15 km northeast of Copiap6, Chile, shows major 

chan~es in facies in northerly and westerly directions 

from marine calcareous rocks of the Chaiiarcillo group 

(Segerstrom and Parker, 1959) to predominantly continental volcanic and clastic rocks of the Bandurrias 

formation (Segerstrom, 1960a). Interfingering of the 

Banrlurrias formation and the Chaiiarcillo group is 

most convincingly shown along the crest and on both 

limbs of the Tierra Amarilla anticline, a large fold 

that extends south of the area for at least 200 km. 

(See fig. 229.1.) Both facies are truncated with angular discordance by the continental clastic and volcanic 

Cerrillos formation. 

The Chaiiarcillo group comprises a sequence of four 

marine formations, Abundancia, N antoco, Totoralillo, 

and Pabel16n, which were named and defined by Biese 

(1942). The sequence, chiefly li1nestone, was named 
B 

GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

1000 M 

SEA LEVEL • 

1000 M 

Limestone Sandstone Conglomerate Lava Andesite sill 

Andesite dikes and sill 

Cerrillos formation 

UNCONFORMITY 

B 

Coarsely porphyritic andesite sill 

Bandurrias formation and 

Chaiiarcillo group 

Inferr~ contact 

23 

..L 

Strike and dip of beds 

R' 

75 

Strike and dip of overturned beds 

EB 

Horiwntal beds 

Anticline 

Showing trace of axial plane and direction 

of plunge of axis, where lcnown 

Chert 

~ Syncline 

Showing trace of axial plane and 

direction of plunge of axis 

u ---0--

Fault 

U, upthrown side; D, downthrown 

side 

_-:L-:L::I...:::::L. 

Thrust fault 

T, upper plate 

B' 

1000 M 

SEA LEVEL 

Andesite dike 

and sill 

FIGURE 229.1.-Bedrock map and structure sections of Teresita-Chulo area, Atacama Province, Chile. 

IJ) 

:J 

0 

w 

u 

< 1-

w 

~ 

u 

_I 
+ 

... 

•· 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-223 

Chnfiarcillo formation by Whitehead (1919) and 

Chafiarcillo group by Segerstrom and Parker (1959). 

The group is prominently exposed from the TeresitaChulo area to the region of Vallenar about 145 km 

to the south. 

A complete section of the Chafiarcillo group is exposed in Quebrada Melendez, 16.3 km south of Teresita. mine, where it overlies massive lava of the older 

Punta del Cobre formation. At that place, general 

lithologic succession from oldest to youngest is as 

follows: The basal Abundancia formation consists of 

ao m of alternating limestone and graywacke succeeded 

by 175 m of limestone with intercalated chert, sandstone, and conglomerate. The N antoco formation consists of about 500 m of limestone overlain by 225 m 

of interbedded limestone and calcareous shale and 

topped by 125 m of gypsiferous limestone. The Totoralillo formation is about 255 m thick and contains 

abundant marl and calcareous shale, as well as limestone. The Pabell6n formation, which is the uppermost member of the group consists of 430 m of limestone with abundant intercalations of chert, conglomet·ate, and breccia and is intruded by several small 

sills of andesite. According to Corvalan and Perez 

(1958) on the basis of paleontological evidence this 

group of four formations ranges in age from late 

VnJanginian to the Barremian substage of Neocomian 

('Early Cretaceous) time. 

The Bandurrias formation, comp.osed principally of 

elastic and pyroclastic material, interfingers with the 

ealcn.reous rocks of the ChafiarciUo group along the 

erest. and flanks of the Tierra Amarilla anticline in the 

central part of the Teresita-Chulo area. The lower 

and middle parts of the formation occupy approximately the same stratigraphic position as the Chafiarcillo group, and the upper part occupies a higher position. The oldest beds in the formation that are exposed in the Teresita-Chulo area-those immediately 

north of Teresita mine-consist of lava and marine 

breccia, sandstone, and conglomerate. These rocks 

totnJing about 1,000 m in thickness n,re overlain by 

about 1,000 m of red crossbedded conglomerate and 

sandstone, siltstone (all of continental origin), and 

lava. Some of the lava beds are coarsely porphyritic 

n.nd n:re similar lithologically to the great andesite 

sill along the eastern edge of the area. 

The continental sequence is cut out completely along 

the unconformity at the base of the Cerrillos formation, in the Llampos quadrangle, about 13 to 40 km 

north of the area. The marine sequence thickens to 

about 3,000 m in the Llampos quadrangle and contains lenses of limestone and chert. About 1.2 km 

north of the quadrangle, ammonites of the genera 

Acantlwdiscus ctnd H olcostephanus are contained in 

one of the limestone lenses (Segerstrom, 1960b). The 

ammonites indicate that the lower part of the Bandurrias formation, north of the Teresita-Chulo area, is of 

late Valanginian age (Corvalan and Perez, 1958) and 

is correlative with the Chafiarcillo group. The continental part of the formation is probably correlative 

with the lithologically similar Veta Negra and Colimapu formations of central Chile that are believed to 

be of Aptian to Turonian (mid-Cretaceous) age 

(Thomas, 1958), and which are younger than any formation in the Chafiarcillo group. 

Limestone beds at the Teresita mine belong to the 

Chafiarcillo group and have been thrust up from the 

west limb of the Tierra Amarilla anticline. These 

beds contain the ammonites, Thurmannia quintucoensis "\Veaver _var., Acanthodiscus aff. A. rad§atus Bruggen var. (Juan Tavera, written communication, 1951), 

as well as Liticoceras sp. and Simbirskites ~ sp. (R. W. 

Imlay, written communication, 1958). These ammonites have been assigned to the late Valanginian 

substage of Neocomian time by Tavera and to the late 

Valanginian and early Hauterivian substages by Imlay. 

Overlying the limestone at the Teresita mine are 

clastic and pyroclastic rocks, assigned to the Bandurrias formation, that contain the late Hauterivian ammonite, Orioceras andinum ( Corvalan and Perez, 

1958). The same species is found 4 km to the southeast in the core of the Tierra Amarilla anticline in 

beds of limestone of the Chafiarcillo group. 

REFERENCES 

Biese, \V. A., H)42, La distribuci6u del Cretaceo inferior al 

sm· de Copiap6: Santiago, Anales del Pt·imer Congreso 

Pan-amet'icano de Ingenierfa de Minus y Geologia, v. 2, 

p. 429-4GG. 

Corvuh\n, D., .Jose, and Perez D'A., Emesto, 1958, F6siles guias 

chilenos, 'J~itoniano-Neocomiano: Santiago, Instituto de Inve~tigaciones Geol6gicas, Manual No. 1, 48 p. 

Segerstrom, Kenneth, ·1960a, Geologia del cuadr(tngulo QueL)I'ada Paipote: Santiago, Instituto de Investigaciones Geol6gicas, Carta Geol6gica de Chile, v. 2, no. 1, 35 p. 

-- 1960b, Geologia del cmtdn'"mgulo Llampos: Santiago, 

Instituto de Investigaciones Geol6gicas, Carta Geol6gica 

de Chile, v. 2, no. 2, 40 p. 

Segerstrom, Kenneth, :md Parket·, R. L., 1959, Geologic del 

cuadr{mgulo Cerrillos: Santiago, Instiuto de Investigaciones Geol6gicas, Carta Geol6gica de Chile, v. 1, no. 1, 33 p. 

Thomas, Herbert, 1958, Geologia de la Cordillera de la Costa, 

entre el valle de La Ligna y Ia Cuesta cle Baniga: Santiago, Instituto de Inve~tigaciones Geol6gieas, Bol. 2, 8G p. 

'Vhitehead, W. L., 1919, The veins of Chafiarcillo, Chile: Econ. 

Geology, v. 14, p. 1-45. 
C-224 GEOLOGI;CAL SURVEY RESEARCH 1 9 61 

230. RHYOLITE TUFF, A SOURCE OF THE SALTS OF NORTHERN CHILE 

By GEORGE E. EPJCKSEN, Santiago, Chile 

Work done in cooperation with the Instituto de Investigaciones Geologicas, Santiago 

Although many investigators have described the 

well-known nitrate deposits of northern Chile and 

have advanced theories to explain their origin, few 

have considered the more general field of the saline 

deposits of which nitrates are a small but closely related fraction. Geologic field investigations in northern Chile, made by the writer since 1955, have led to 

the conclusion that geoiogic, physiographic, and climatic conditions of today are similar to those prevailing since the saline deposits started to accumulate, 

probably during the Pleistocene, and that any explanation for the origin and accumulation of the salts 

must be in terms of these known factors. 

Field evidence leads to the conclusion that the salts 

came from erosion and leaching of rocks, chiefly rhyolite tuft's, in those areas of the high Andes and the 

western Andean slopes where rainfall is sufficient. 

Average annual rainfall above an altitude of 4,000 

meters is on the order of 200 to 300 mm per year 

and this decreases progressively at lower altitudes 

until at 1,000 m altitude rainfall is almost nil. The 

salts we.re and still are carried by surface and ground 

water and precipitated in closed basins or broad fiat 

areas in the high Andes, the coastal range, and the 

intervening lower lying region (fig. 230.1). The nitrate deposits, in contrast to other saline deposits, 

are along the lower eastern slopes of the coastal range 

and the lower hillslopes bordering salt pans within 

the coastal range in the region extending from near 

Iquique southward to Taltal. 

Rhyolite tuff covers extensive areas in the Andean 

cordillera and is interstratified with unconsolidated 

piedmont sediments that extend as far westward as 

the western limit of the Pampa del Tamarugal (fig. 

230.1). The tuft' is considered to be of late Tertiary 

age (R. J. Dingman and C. A. Galli, written communication). A considerable quantity of the rhyolite 

tuff is welded, indicating deposition from gaseous, 

high-temperature ash flows, or nuees ardentes. 

The writer, in attempting to explain the number, 

size, and distribution of the saline deposits of northern Chile, was led to postulate that the :r;hyolite tuffs· 

contained soluble salts as primary constituents. 

To test for soluble salt, samples of rhyolite welded 

tuff were collected from two areas, one a quarry near 

Mamifia and the other a road cut near Pachica (fig. 

230.1); the localities are well-drained areas in which 

(.) 

c 

-

-

u 

o C~bpaquina ~\ ~ • \ 'P . ; \ . \ 

\ '%. • 

\0" 

~·\ ~ '\, ~·' 'P .. 

0 \~ ""\ '%. ) \ ~ "Q I ,• 

OJ 

0 

\ l> '.! ~ Pachica ( (I)'~· "0 0 : .. '""'\ii 'J>o 0 I ,.J--+-

l> 1 ~ Mamiiial I ..., I ~ 

rI-o I (. \ ... 0\ • 

\~ ~ -\ ';> \ ~ \ : 

·'"' I;· -t ... , I "'"' ·. 

:c: ~ 1 n \ .~ ~ ;: 0 : tO ~ "< I 

:~ ~ ; ~ ~ \, 

r:=:C:: (;\ o'l I Q. G) .\ 

: ~ ~ __ ,_ - ·. -------122° •a. r- ' r \ I \ I 

,'o Maria ~\ ' : 

; .. Elena ~\tT\ \ / •: \ ~: <' : 3' \ 1> \.,_ - ••. 

I ca c>o\ .. • ~ 

.. ~\ I 

~ , 

I 

{ I I , /J> ,....., .. .,...,.·· ;o 

I / 

,/ ;· 

,'' '\ ,' r~ I 

I ~. 

\ 

z 

l> 

r---~--~-----~~~~-----~26° 

) 

0 50 100 150 Kilometers 

FIGURE 230.1.-lndex map of northern Chile. 

-f.· 
··~· 

·\, 

;· 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTI·CLES 147-292 C-225 

TABI,J<~ 230.1.-Partial analyses of soluble salts· contained in 

samples of rhyolite t~tff, Mamina and Pachica 

[In weight percent or entire specimen] 

Mamifia sample Pachica sample 

I 1 31 

--·-----·---------------------- Total soluble salt_______ 0. 1930 0. 2705 0. 1250 

NOs----------------- . 0014 . 0055 . 0018 

CL------------------ . 0317 . 0367 . 0213 SOs • _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . 0660 . 1171 . 0428 

F _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . 0004 

B _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ______ - _ _ _ _ _ _ _ _ . 0003 

COs- ___________________________ - _- _- . 0009 

Si02_________________ • 0036 . 0081 . 0014 

Fe20s and Al20s------- . 0003 . 0025 -------- CaO_________________ . 0066 . 0448 . 0029 

Na20 ________________ -------- -------- . 0510 

K20----------------- .0005 .0110 .0036 MgO _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ trace trace trace 

I Analyses by lahorntory or the Superintendencla dol Salitre, Iquique. 

0. 1935 

. 0055 

. 0332 

. 0484 

. 0159 

. 0032 

. 0026 

. 0048 

trace 

I Analyses by lnbomtory or the Cia. Salitrern Anglo-Lautaro, Maria Elena. 3 Annlysos by laboratory or tho Instituto de Invostigaclones Oool6gicas or Chile, 

Santiago. 

• Sulphate Is reported as SOs in conventional analyses or nitrate oro. 

rainwater would tend to leach soluble salts rather than 

deposit them. The sample from Mamifia is a pink, 

porous tuff, welded only to a slight degree; that from 

Pn.chica is a light-tan, dense welded tuff that has a 

very high percentage of glass. Portions of these 

samples were analyzed by three different laboratories 

to give the results listed in table 230.1. 

The analytical techniques used by the laboratories 

of the Superintendencia del Sal~tre and Compafiia 

Salitre~·a, Anglo-Lautaro were those used in the analy-

~es of nitrate ores; the laboratory of the Instituto de 

I1n-estigaciones Geol6gicas employed the techniques of 

shmdard water :tnalyses. Analyses were made of the 

salts in solutions prepared by leaching pulverized 

rock with distilled water kept at constant boiling 

temperature. The laboratory of the Instituto de Investigaciones Geol6gicas made a single 10-minute 

leaching and obtained a solution of less than one liter; 

the other laboratories made separate leachings and 

washings of a 4-kilogram sample over a period of 

several hours and obtained a solution of several liters. 

The leach solutions had a pH of approximately 8.5 . 

Any conclusions drawn from data based on analyses of samples from only two localities are at best 

tentative; perhaps most important is that this work 

shows the need of testing certain volcanic rocks for 

soluble salts that may be residual from late-stage 

magmatic fluids. However, the analyses do show that 

the rhyolite tuffs from these areas contain the principal ions ( Cl, S04, N03, Ca, N a, and !() that occur 

in the saline deposits of northern Chile. Soluble salts 

in the amounts indicated by the analyses, contained 

in the rhyolite tuffs that have been eroded or leached, 

would be more than sufficient to supply the existing 

saline deposits, including nitrates. 

The soluble salt was evidently a wide-spread constituent of the tuff at the time of extrusion and not 

the result of later contamination. It is possible that 

the nitrate formed by oxidation of nitrogen or ammonia, perhaps in the presence of minerals that acted 

as catalysts, within the hot gaseous ash flows. The 

problem remains of accounting for the formation of 

anions of high redox potential such as chromate, iodate, and perchlorate, which occur in the nitrate 

deposits. Additional information is needed to determine whether the salts are primary magmatic constituents or whether they were contained in sediments incorporated into the magma as it moved to the surface. 

PALEONTOLOGY, GEOMORPHOLOGY, AND PLANT ECOLOGY 

231. CORRELATION OF THE ARCTIC PERMIAN 

By .J. THOMAS DuTRO, Jr., "\Vashington, D.C. 

Arctic Permian faunas have attracted the attention of paleontologists and stratigraphers since Toula 

(1873, 1874, 1875) first described fossils from Spitzbergen. George Girty and ,James Steele "\Villiams 

spent many years studying Permian collections from 

Alaska and assisting other geologists with problems 

involving ages and stratigraphic correlations of the 

various rock units. Extensive lists of the faunas of 

the Tahkandit limestone and the Mankomen formation were published long ago (Mertie, 1930, and ~{offit, 1938, among others), but the rich faunas have 

never been described. 
C-226 GEOLOGICAL SURVEY RESEARCH 19 61 

Several taxonomic papers in the past few years 

have stimulated interest in the Arctic Permian. In 

1955, Dunbar described the brachiopods of east-central Greenland. Faunas from Grinnell peninsula in 

the Canadian Arctic were recently treated by Harker 

and Thorsteinsson ( 1960). A fauna from Oregon related to the Arctic Permian fauna was the subject 

of a paper by Cooper ( 1957). In addition, the monograph on the Productoidea by Muir-vVood and Cooper 

(1960) prepared the way for extensive taxonomic 

work on the late Paleozoic brachiopod faunas everywhere. 

ARCTIC PERMIAN FAUNAS 

A study of the Permian brachiopods of northwestern Alaska has led me to examine, among other things, 

the age significance of a peculiar group of spiriferoid 

brachiopods including the distinctive genus Licharewia.. This brachiopod has a shell that is wider than 

long with simple rounded ribs and a broad, relatively 

flat, unmodified fold and sulcus. The genus is. considered a guide to the Upper Peqnian of the U.S.S.R. 

(Sarycheva and Sokolskaya, 1952; Likharev, 1959) 

and is represented in the well-known Zechstein fauna 

of western Europe. Similar brachiopods have been 

reported from Spitzbergen, east-central Greenland, 

the Grinnell peninsula, Novaya Zemlya, and elsewhere. 

~fany specimens of Lichare1via occur among the 

brachiopods collected from the Permian clastic sequence in the DeLong ~fountains, Alaska (Tailleur 

and others, 1958). Associated genera are . typical of 

Permian faunas elsewhere in the Arctic, but I consider the total assemblage to indicate an early Late 

Permian age (probably a l{azanian equivalent). vVith 

Licharewia are: Derbyia. sp., Linoproductus sp., · 

Stepanoviella sp., W aa.g,e.noconcha aff. W. payeri 

(Toula), Antiquatonia spp., Kochiproductu.s cf. K. 

freboldi (Stepan ow), H orridonia cf. H. horrida 

(Sowerby), JJ!uirwoodia cf. JJ{. greenlandica Dunbar, 

Ohori.stite8 spp., N eospirifer sp., Spiriferella cf. 8. 

keilhavii (von Buch), Spiriferella sp., Stenoscisnw 

sp., Squa1nularia sp., Spirigerella sp., Rhynchopora 

cf. R. kochi Dunbar, and Dielasm.a spp. 

The correlations of the Arctic Permian fauna sug-: 

gested by Harker and Thorsteinsson ( 1960) place this 

important assemblage too low in the Permian. On 

the other hand, the position of the Greenland fauna 

indicated by Dunbar and others (1960) is probably 

much too high. The beds in Alaska, and their correlatives, probably are assignable to the l{amian stage 

as defined by Likharev (1959) to include the lHimian 

and l{azanian substages in the Upper Permian. A 

suggested revision of these correlations is indicated in 

figure 231.1, which shows related sequences in the Arctic region. ~fy interpretations of how the Arctic Permian fits into the type Russian Permian and the west 

Texas sequences are also shown. 

CORRELATION OF WEST TEXAS AND RUSSIAN 

SEQUENCES 

The correlation of the west Texas sequence with the 

Russian type area differs from both that shown by 

Dunbar and others ( 1960) and that adopted by the 

U.S. Geological Survey (Cohee, 1960). This is due, 

in part, to my acceptance of the l{amian as suggested 

by Likharev ( 1959). However, I interpret faunal 

evidence from the west Texas region differently from 

Dunbar. As a basis for correlations, the faunal ranges 

of the fusulinids, ammonites, and brachiopods are 

considered together and compared with generic ranges 

recently defined by ~fiklukho-~faklay and others 

(1958), Ruzhentsev (1960), and Likharev (1959). 

Fusulinid genera found in the higher beds in west 

Texas, for which ranges were given by the Russian 

workers, include Oodonofusiella, Leella, Rausserella, 

folydiexodina., and Y abeina.. AU except the last are 

shown starting at the base of the Upper Permian. 

Yabeima. is shown to range only through the upper 

part of the lJpper Permian. Taken together with the 

ranges given on the Permian chart of Dunbar and 

others ( 1960), these data suggest a Lower-Upper Permian boundary most likely near the 'Vord-Capitan 

boundary or, at most, no lower than the base of the 

Cherry Canyon equivalents. 

Ammonite ranges suggest that the base of the l(amian (as I would interpret it) might be placed at 

least as low as the South "'Yells limestone member of 

the Cherry Canyon formation, perhaps as low as the 

base of the Getaway limestone member of the Cherry 

Canyon formation. 

There seems to be no question that all the Bone 

Springs is an Artinskian equivalent and Cooper ( 1957, 

p. 19) has suggested that the brachiopod faunas of 

the lower part of the 'Vord formation of the Glass 

~fountains are upper Artinskian equivalents. 

For these reasons I am suggesting that the vVord 

straddles the Lower-Upper Permian bo.undary. Perhaps it is roughly the equivalent of the l{ungurianUfimian interval. 

As regards the top of the l{azanian equivalents, the 

occurrence in the Lamar limestone member of the 

Bell Canyon formation of both Strigogoniatitie8 

(Newell and others, 1953, p. 232) and Yabm'na (Skinner and Wilde, 1955) suggests that the Lamar is l{azanian in age. I interpret the entire span of the 

., 
....,.._ 

U.S.S.R. 

Tartarian 

~ 

w 

~ 

~~-r------~ 

~ 

c: 

ro .E 

ro 

Kazan ian 

~-~?--

Ufimian 

2 

NORTHWEST 

ALASKA 

~~?·~,~ 

Unnamed 

clastic 

sequence 

y 

3 

GRINNELL 

PENINSULA 

.&......"-...~ f ........ ?·~ 

Assistance 

formation 

t----Kung~r~~ ill [ ~ l ill ID 1 ill [ ID 

Artinskian 

~ 

w ~---------------------~ ~ 

0 

~ 

Sakmarian 

Siksikpuk 

formation 

I T'T"'T ? T"""'i""l ?1 ..,..,-

Belcher 

Channel 

formation 

'~' ~ T'1l t? I~ 

4 

EAST -CENTRAL 

GREENLAND 

Martinienkalk 

-?-?-

Brachiopodenkalk 

Posidoniaschiefer 

I 

-4 

5 

SPITZBERGEN 

I...J.......J... ( ..1....J....... 1?1--1-J,.... 

Product us 

Keiselgestein 

--? -- ?--

Spiriferenkalk 

- ? -- ? :=::::.__ I ---, ? -- ? -

Dolomite 

and gypsum 

(with corals) 

--?--?--

Basal 

conglomerate 

I"""T" 7 r-rr-t?. ..,...-,-

~ 

-ro 

~ 

E 

.=! 

>. 

..c; 

a. 

0 

£ 

ro 

>- (.) 

,....,..... 

Corakalk 

Fusulinenkalk 

~,?,-r-rt 

~ 

6 

NOVAYA ZEMLYA 

Karmackul 

series 

-?-?-

Sedov 

series 

Barents 

series 

r-T"'""'r" ,? ,.,...., r T""T"" 

<L 

7 

WASHINGTONOREGON 

·~tl.......J......'?...J......IGranite Falls 

limestone 

(Anderson, 1941) 

Beds with 

fusulinids 

1m r mYITf! il 

I 

I 

i 

..... 

8 

WEST TEXAS 

Ochoa 

series 

Capitan 

formation 

formation 

Leonard 

series 

Wolfcamp 

series 

Vl 

cv 

-~ 

Vl 

cv 

a. 

~ 

-ro 

" ro 

~ 

<.!} 

FIGURE 231.1.-Suggested correlation _of some Permian formations in western North America and the Arctic regions. Vertical-lined pattern indicates probable absence 

of beds. Columns 3 to 6 modified from Harker and Thorsteinsson (1960). 

~ !:" 

8 

"'d 

> "'d 

t<.1 

!:" 

Ul 

z 

8 

~ t<.1 

0 

t<.1 

0 

t"4 

0 

0 

~ 

0 

~ t:::1 

~ 

~ 

t:::1 

!:t1 

0 

t"4 

0 

0 

~ 

0 

Ul 

0 

~ 

t:::J 

z 

0 

t:::J 

~Ul 

> !:t1 

8 

~ 

0 

t"4 

t:::J 

Ul 

.... 

iol=-

....:r 

I 

1:..;) 

co 

1:..;) 

0 

I 

tv 

tv 

~ 
C-228 GEOLOGWAL SURVEY RESEARCH 1 9 6 1 

Capitan formation and its equivalents to be correlative with the J(azanian. 

REFERENCE:S 

Anderson, R. A., 1941, Fusulinids of the Granite Falls limestone 

and their stratigraphic significance: Washington State 

Coli. Research Studies, v. 9, no. 3, p. 189-202. 

Cohee, G. V., 1960, Series subdivisions of Permian system: 

Am. Assoc. Pett·oleum Geologists Bull., v. 44, no. 9, 

p. 1578-79. 

Cooper, G. A., 1957, Permian brachiopods from central Oregon: 

Smithsonian Misc. Coli., v. 134, no. 12, 79 p., 12 pis. 

Dunbar, C. 0., 1955, Permian brachiopod faunas of central east 

Greenland: Meddelelser om Gr~nland, v. 110, no. 3, 169 p., 

32 pis. 

Dunbar, C. 0., and others, 1960, Correlation of the Permian 

,formations of North America: Geol. Soc. America Bull., 

v. 71, p. 1763-1806, 1 pl. 

Harker, P., and Thorsteinsson, R., 1960, Permian rocks and 

faunas of Grinnell Peninsula, Arctic Archipelago: Canada 

Geol. Survey Mem. 309, 89 p., 25 pls. 

Likharev, B. K., 1959, On the boundaries and pl"incipal subdivision of the Permian system: Sovietskaya Geologiya, 

no. 6, p. 13-30. [Translation by G. Rabchevsky, Dec. 0 1959.] ' . 

:Mertle, J. B., .Jr., 1930, Geology of the Eagle-Circle district, 

Alaska: U.S. Geol. Survey Bull. 816, 168 p. 

Miklukho-l\iaklay, A. D., Hauzer-Chernousova, D. 1\I., aml 

Rozovskaya, S. E., 1958, Sistematika i filogenija Fuzulinidej: Voprozy l\Iikropaleontologii, v. 2, p. 5-21, figs. 1, 2. 

[French translation, 1960.] 

Moffit, F. H., 1938, Geology of the Slana-Tok district, Alaska: 

U.S. Geol. Survey Bull. 904, 54 p. 

Muir-Wood, H. 1\I., and Cooper, G. A., 1960, Morphology, classification and life habits of the Productoidea (Brachiopoda) : 

Geol. Soc. America Mem. 81, 447 p., 135 pis. 

Newell, N. D., and others, 1953, The Permian reef complex of 

the Guadalupe Mountains region, Texas and New Mexico: 

~36 p., San Francisco, W. H. Freeman and Co. 

Ruzhentsev, V. E., 1960, Systematic principles, classification, 

and phylogeny of Paleozoic ammonites: Akad. Nauk. SSSR, 

Paleont. Inst., Trudy, v. 83, 331 p. [In Russian] 

Sarycheva, T. G., and Sokolskaya, A. N., 1952, Guide de determination des brachiopodes Paleozoiques de la depression 

de Moscou: Akad. Nauk. SSSR, Paleont. Inst., Trudy, 

v. 38, 307 p., 71 pls. [French translation S. I. G. no. 1814, 

1956] 

Skinner, J. W., and Wilde, A. L., 1955, New fusulinids from 

the Permian of west Texas: Jour. Paleontology, v. 29, 

no. 6, p. 927-940, pl. 89-96. 

Tailleur, I. G., and others, 1958, Unusual upper Paleozoic rock 

sequence in northern Alaska [abstract] : Geol. Soc. America Bull., v. 69, no. 12, p. 1746-1747. 

Toula, Franz, 1873, Kohlenkalk-Fossilien von der Siidspitze von 

Spitzbergen: Akad. Wiss·. Wien, Sitzungsber., v. 68, p. 267-

291, pls. 1-5. 

--- 1874, Kohlenkalk und Zechstein-Fossilien· a us dem 

Hornsund an der Sud-,Vestkiiste von Spitzbergen: Akad. 

Wiss. Wien, Sitzungsber., v. 70, p. 133-156, 1 pl. 

--- 1875, Permo-Carbon-Fossilien von der Westkiiste von 

Spitzbergen: Neues .Jahrb. l\fineralogie, Geologie, u. PaUi.eontologie, p. 225-264, pis. 5-10. 

232. AGE OF THE KEECHELUS ANDESITIC SERIES OF THE CASCADE RANGE, WASHINGTON 

By ,JAcK A. WoLFE, Menlo Park, Calif. 

The J(eechelus andesitic series of Smith and Calkins ( 190()) is a thick sequence of andesitic lava, tuff, 

and brecci.a cropping out in an extensive area of the 

Cascade Range of vVashington. The age of these rocks 

has previously been determined almost entirely by 

their stratigraphic position "·ith respect to other rock 

units whose ages are uncertain. The. one fossil previously reported from the J(eechelus was determined 

as Eporeodon sp. by R. A. Sti1'ton (Grant, 1941), but 

both the stratigraphic position within the J(eechelus 

and the specific identity of the specimen are unknown. 

Attempts to date the J(eechelus andesitic series by 

its stratigraphic relations prove unsatisfactory because 

of the general lack of accurate knowledge of the age 

of the underlying units. The J(eechelus rests conformably on rocks of the Puget group and unconformably on those of the Guye formation. The latter 

unit was dated as probably late Eocene on the basis 

of plants by R. ,:V. Brown (Foster, 1960). The plants 

from the· Guye formation identified by Brown definitely indicate an Eocene age, although Foster (1960) 

reevaluated the significance of Brown's determinations 

and concluded that the plants could equally well indicate a Paleocene age. The age of the Puget group 

has also been in doubt, but recent work demonstrates 

an early through latest Eocene age (Art. 233). 

Conclusive evidence on age of the lower part of the 

J(eechelus andesitic series has been obtained by analy-

·-~ ' 
... 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-229 

N 

I 

WASHINGTON 

-.&.L Mt St Helens * Mt Adams 97sa8 ""¥ "71' 

8 9760 

0 10 20 30· 40 MILES 

FIOUIU<~ 232.1.-Mnp of western Washin~ton showing source of 

fossil plants in the Keechelus andesitic series. The numbers 

nre U.S. Geological Sm·vey paleobotanical locality numbers, 

listed below. 

sis of fossil plants from eight new localities. These 

localities (fig. 232.1) lie in a continuous belt of andesitic volcanic rocks assigned to the ICeechelus andesitic series (vVaters, 1955) that extends south from 

the area east of Seattle (Warren and others, 1945) to 

the :Mount St. I-Ielens area. 

The stratigraphic position of ·the plants at all of 

the .localities is not precisely known, but those in the 

Green River val1ey east of Tacoma are almost cerhtinly lower than those south of l\1ount Rainier (H. D. 

GmYer, oral communication, 1961). The Green River 

localities occur 200 to 700 feet stratigraphically above 

the contact of the ICeechelus with the underlying Puget group. The localities south of l\1ount Rainier are 

1t few thousand feet higher stratigraphically and taken 

together may represent a stratigraphic range of considerable thickness. 

]{eechelus fossil localities in the Green River valley 

contain elements which superficially appear to represent different ages. Species characteristic of the Eocene flm·a are: ill acolintod~ia sp., Ory]Jtooarya prega,-

nw,rensis Sanborn, As]Jleni'll/Jn hulrleyensi.s of Sanborn, 

and Aralia ta'l.l/rinensis of Sanborn. Another group of 

species suggests an Oligocene age: Oo1'dia ?'otunda 

Chaney and Sanborn, 0'ltpan.ia, oregona Chaney anrl 

Sanborn, Ocotea eooernua Chaney and Sanborn, tuld 

1'et1·aoera oregona Chaney and Sanborn. A third 

group of species is represent~d by Lau1·ophyllu1n 

rrzmtinervnm, Rotbury and Phyllites alohorneOJ)sis Potbury. This last group and the mixed character of 

the flora. indicate a correlation "·ith the La Porte flora 

of California (Pot bury, 1935) and other floras of the 

same age as the informal ICeasey "stage" of the invertebrate paleontologists. The flora, from the uppermost part of the Puget group east of Seattle is essentially identical with that from the ICeechelus in 

the Green River valley localities, but is not similar to 

the uppermost Puget flora of the Green River area. 

Thus, paleontologic· evidence indicates that the uppermost part of the Puget group east of Seattle is 

correlative with the lowermost part of the ICeechelus 

east of Tacoma. 

The l(eechelus localities south of 1\1t. Rainier have 

a flora differing from that of the l(eechelus in the 

Green River valley. The former contains: OeroidiJJhyllu1n O?'enat'lt1n (Unger) Brown, Prun'ltS j?·an~~linen..gi-s Sanborn, f. pri.stitna Brown, Ficus q'ltiS'I.t?nbingi 

Chaney and Sanborn, F. plinerva Chaney and Sanborn, 11/ elios11ut aesO'I.tlifolia Chaney a~1d Sanborn, Alangi'lt?n th01nae (Chaney and Sanborn) Lakha.npal, 

and other species that occur in the Goshen (Chaney 

and Sanborn, 1933) and Scio (Sanborn, 1947) floras 

of Oregon. These last two floras occur in nonmarine 

rocks equivalent to the lower and upper parts of the 

Lincolh "stage," respectively. Floras from two of the 

l(eechelus localities (9758, 9759) appear to correlate 

with the Goshen flora, but the floras from localities 

9760 and 9761 correlate with the Scio flora. 

The evidence cited thus indicates that the lower part 

of the ICeechelus · andesitic series is the nonmarine 

equivalent of the l(easey and Lincoln "stages." This 

correlation was suggested by ''raters ( 1955) on petrographic evidence. In turn, the upper part of the 

Keechelus can be no oldei.· than late Oligocene and 

may be as young as early l\1iocene. 

PLANT FOSSIL LOCALITIES 

9682. NW:14NW:14 sec. 36, T. 21 N., R. 7 E. 

9689. SE:!4NW:!4 sec. 36, T. 21 N., H. 6 E. 

9690. SE:!4NW:I4 sec. 36, T. 21 N., R. 6 E. 

9693. NE:14NW1,4 sec. 13, T. 21 N., R. 7 E. 

9758. NW:!4NW:I4 sec. 32, T. 8 N., R. 4 E. 

9759. SW:!4NE:I4 sec. 17, ~r. 13 N., R. 7 E. 

9760. 6700 feet N., 30° W. from summit of Timbered Peak. 

9761. 2500 feet N. of SW cor. sec. 9, T. 13 N., R. 9 E. 

REFERENCES 

Chaney, R. W., and Sanborn, E. I., 1933, The Goshen tlora of 

west centml Oregon: Carnegie Inst. Washington Pub. 439, 

103 p. 

Foster, R. J., 1960, Tertiary geology of a portion of the central 

Cascade Mountains, Washington: Geol. Soc. America Bull., 

V. 71, p. 99-126~ 
C-230 GEOLOGICAL SURVEY RESEARCH 19 61 

Grant, R. Y., 1941, A John Day vertebrate fossil discovered in 

the K~echelus series of Washington: Am. Jour. Sci., v. 239, 

p. 590-593. 

Potbury, S. S., 1935, The La Porte flora of Plumas County, 

California: Carnegie Inst. Washington Pub. 465, p. 31-81. 

Sanborn, E. I., 1947, The Scio flora of western Oregon : Oregon 

State College Mon., Studies in Geology, no. 4, 47 p. 

Smith, G. 0., and Calkins, F. C., 1906, Description of the 

Snoqualmie quadrangle, Washington : U.S. Geol. Survey 

Geol. Atlas, Folio 139. 

Warren, W. C., Norbisrath, H., Grivetti, R. M., and Brown, 

S. P., 1945, Preliminary geologic map and brief description 

of the coal fields of King County, Washington: U.S. Geol. 

Survey Prelim. Map. 

Waters, A. C., 1955, Volcanic rocks and the tectonic cycle: 

Geol. Soc. America Spec. Paper, No. 62, p. 702-722. 

233. AGE ANn CORRELATION OF'THE PUGET GROUP, KING COUNTY, WASHINGTON 

By JAcK A. WoLFE, HowARD D. GowER, and JAMES D. VINE, ~{enlo Park, Calif. 

Wo·rk done in cooperation with the Division of .Mines and Geology of the Washington Department of Oonservat·ion 

The Puget group, a thick sequence of predominantly continental coal-bearing sedimentary rocks, is 

one of the most widespread ·stratigraphic units in the 

Pacific Northwest. These rocks underlie a large area 

in the western foothills of the Cascade Range and in 

the Puget Sound lowlands of western Washington. 

Fossil leaves are well preserved and abundant in the 

Puget group and, during the course of recent geologic investigations in IGng County, many of these 

leaves were collected from known stratigraphic posi7 

tions. The localities where the fossils were collected 

are shown on figure 233.1, and the stratigrapliic positions of the fossil collections are shown on figure 

233.2. 

In King County, the Green ;River has cut a canyon 200 to 300 fe~t deep, exposing ai1 almost continuous section of about 5,600 feet of strata of the Puget 

group. The base of the Puget group is not exposed 

in the canyon, but its upper contact with the overlying 1\:eechelus andesitic series of ,vVarren and others 

(1945) is exposed. Coal beds, which crop out within 

the canyon and can be traced through underground 

mine workings into the adjacent hills, provide stratigraphic oontrol for determining the posi.~ion of floral 

zones within the Puget group. All of the 17. fossil 

flora localities shown in figure 233.1 south of the Cedar River can therefore be related ,-i,rith confidence to 

the sh;atigraphic section exposed in the canyon of 

R. 5 E. 

~ Newcastle 

EX PLANATION 

.6.9685 

Fossil plant locality 

eM Fossil marine invertebrate 

locality 

2 3 4 5 MILES 

/Area of larger map 

R. 6 E. R. 7 E. 

FIGURE 233.1.-l\Iap of part of King County, Wash., showing 

localities where fossils were collected. 

... 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-231 

Green River. Fossil-leaf collections from these .localities are within the Puget group and the lower part 

of the K.eechelus andesitic series, and they can be 

grouped into 7 floral zones. 

The characteristic species and correlative floras of 

each zone are summn.rized in table 233.1. The zones 

are established by means of two widely-used methods 

of biostTatigraphy: detailed analysis of selected phylads to determine phylogenetic sequences, and overlap 

of ranges of selected species. The floral differences 

between any two successive zones are slight, and most 

of the species range through two or more zones; thus, 

species listed as characteristic of a particular zone are 

not necessarily restricted to it. Although most of the 

zones can be recognized elsewhere in the western 

United States, additional. studies may proYe them to 

be zonules. 

The several floras known in the predominantly marine rocks of .Eocene age in ''Tashington, Oregon, and 

California permit a tentative correlation of the plant 

zones with the standard "Test Coast invertebrate megafossil chro11ology. The Comstock flora (Sanborn, 

1935), which is placed in zone 6, occurs in the basal 

part of the 1\:easey and uppermost part of the "Tejon" 

stages (Vokes and others, 1951). The undescribed 

Cowlitz flora, which is in zone 5, is in beds assigned, 

as n. bulk unit, to the "Tejon" stage ("Teaver and 

others, 1D44). Zone 3 has been recognized near Elkton, Ore., in predominantly marine beds assigned to 

the upper part of the "Domengine" stage. The Chalk 

Bhrffs flora (zone 1) is in a nonmarine facies of the 

lone formation of California (~{acGinitie, 1941) which 

is part of the "Capay" stage (early Eocene). The 

floral zones in the Puget group can also be recognized 

in the nonmarine Clarno formation of Oregon and in 

beds near La. Porte, California (table "233.1). . 

Leaf fossils were also collected from several ·localities .near Tiger ~fountain and Issaquah, 10 to 15 miles 

north of the Green River area. The oldest rocks in 

the 'riger ~1ount:ah1 area are a thick sequence of mfrrine secli~nehtary rocks tl1nt contain marine mollusks 

of middle Eocene age (F. Stearns ~'[acNeil, written 

communication, Nov. 9, 1960). These rocks are probably equivalent in part to the nonmarine rocks of 

floral zones 2 and 3 in the Green River n.rea. 

Overlying the marine rocks in the Tiger ~{onntnin 

area. are cont.inental coal-bearing sedimentary rocks 

1,000 t"o 2,000 feet thick that are in turn overlain by 

volcanic rocks more than 8,000 feet thick, the Eocene 

volcanic series of "Tarren and others ( 1945). The 

volcanic rocks contain a flora similar to that in zone 4, 

n ncl are therefore considered t:o be laterally equivalrnt to the pnrt of the coal-bearing sedimentary sec: 

~ ro 

Cll :;:: 

c: 

Cll 

u 

0 

~ 

GREEN RIVER AREA 

Locality 

No. 

9682 

9689 

9690 

9693 

Floral 

zones 

7 

1-,Q-~..I>....I:L....II-A....!l-..D.....Cll 

~::_::);=;:::·~.\:·::~:::_:;::::_::;· 

Cll 

c: 

Cll 

u 

0 

LLI 

0. 

::J 

0 

6D 

~I ::J 

a.. 

9681 

9679 

9680 

9691 

9728 

9694 

9695 

9732 

9735 

9678 

9675 

9676 

9677 

. ~: :.-::: :_ 

.:·;.r<.•i.····· 

Base not exposed 

EXPLANATION 

~ C] Volcanic Nonmarine sedirocks mentary rocks 

Marine sedimen- Coal beds 

tary rocks 

9685 

Plant fossil locality 

M 

Marine fossil locality 

1000 

0 

TIGER MOUNTAIN AREA 

Locality Floral 

No. 'T 9688 

.. . <'• 

I I 

"· 

9729 5 

FIGURE 233.2.-Stratigraphic sections in King County, Wash., 

showing positions of fossil collections and floral zones. 
C-232 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TABLE 233.1.-Summary of floral zones in the Puget group 

Pacific Coast 

Series standard marine Floral Characteristic species in the Green River area [h.o. denotes highPst known occurrences Correlative floras 

megafauna} zones and l.o. denotes lowest known occurrence of species present in more than one wne] 

stages 1 

Oligo- JY! acclintockia sp.; Tetracera oregona, l.o.; Cryptocarya presamaren- cene 7 sis, h.o.; Ocotea eocernua, l.o.; Laurophyllum raminervum; La Porte 

Phyllites alchorneopsis. 

Keasey Mallotus oregonensis ; Cinnamomum dilleri, h.o.; Platanophyllum 

angustiloba, h.o.; Cryptocarya presamarensis, l.o.; Laurophyllum Comstock (Sanborn, 1935) 

6 aff. L. litseafolia h.o.; Cercidiphyllum elongatum, h.o.; Alnus sp. Clarno (in part) 

"B", h.o. 

"Tejon" 5 Carya sp., h.o.; Alnus sp. "A", l.o.; Rhus sp., h.o.; Castanopsis longietiolata, h.o.; Laurophyllum aff. L. litseafolia, l.o.; Viburnum sp. Cowlitz 

------? ------ Ardisia sp.; Hemitelea pinnata, h.o.; Triumfelta sp., h.o.; Platano-

"Transition" 4 phyllum angustiloba, l.o.; Laurophyllum litseafolia, h.o.; Ulmus (None known) 

Eocene beds sp. "B", h.o.; Machilus sp., h.o.; Cupania sp.; Alnus sp. "B", 

h.o.; Anemia eocenica, h.o. 

------? ------ 3 Ficus omballi; Alnus sp. "B", l.o.; Machilus sp. l.o.; Carya sp., 

l.o.; Ulmus sp. "B", l.o.; Engelhardtia nevadensis, h.o. 

Elkton 

''Domengine'' 

2 

Microcos sp.; Phytocrene sp.; Triumfelta sp., l.o.; Juglans sp.; 

Rhus sp.,l.o.; Ulmus sp. "A", h.o.; Pericampylus sp.; Rhamnus 

plena, h.o.; Stephania sp. 

Clarno (in part) 

------.? ------ Laurophyllum litseafolia, l.o.; M allotus riparius; Ulmus sp. "A" I Chalk Bluffs 

"Capay" 1 l.o.; Rhamnus plena, l.o.; Gordonia egregia. ( MacGinitie, 1941) 

• Weaver and others (1944). 

quence assigned to zone 4 in the Green River area. 

South of Tiger ~1ountain, at locality 9729, the volcanic rocks are overlain by coal-bearing sedimentary 

rocks that contain the flora of zone 5. 

west of Tiger ~1ountain is equivalent to strata in the 

lower part of the J(eechelus along the Green River. 

REFERENCES 

The volcanic rocks of the Tiger ~1ountain area extend westward nearly to Lake 'Vashington. They are 

overlain on the north by nonmarine coal-bearing sedimentary rocks of the Puget group which are about 

:3,000 feet thick. Locality 9688 near Issaquah is in 

the Puget group, and is about 1,000 feet stratigraphically above the contact with the volcanic rocks. 

The rocks at this locality contain a zone 7 flora, which 

in the area of the Green River is in the lower part of 

the J(eechelus andesitic series of 'Varren and others 

( 1945). The paleobotani<;:al evidence, therefore, indicates that the upper part of the Puget group northMacGinitie, H. D., 1941, A middle Eocene flora from the central 

Sierra Nevada: Carnegie Inst. Washington Pub. 534, 178 p. 

Sanborn, E. I., 1935, The Comstock flora of west central Oregon: Carnegie Inst. Washington Pub. 465, p. 1-28, 10 pis. 

Vokes, H. E., Snavely, P. D., Jr., and l\Iyers, D. A., 1951, 

Geology of the southern and southwestem border area, 

Willamette Valley, Oregon: U.S. Geol. Survey Oil and 

Gas Inv. OM-110. 

Warren, ,V. C., Norbisrath, Hans, Grivetti, R. M., and Brown, 

S. P., 1945, Preliminary geologic map and brief description 

of the coal fields of King County, Washington: U.S. Geol. 

Survey Prelim. Map. 

Weaver, C. E., and othe_rs, 1944, Correlation of the marine 

Cenozo~c formatio•1s of western NOJ;th America (chart 

11) : Geol. Soc. America Bull., v. 55, no. 5, p. 569-598. 

·• 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTI·CLES 147-292 C-233 

234. EARLY MISSISSIPPIAN FAUNAS IN SOUTHWESTERN ELKO COUNTY, NEVADA 

By l\{ACKENzm GoRDON, Jr., and HELEN DuNCAN, Washington, D.C. 

Early l\{ississippian faunas under study occur in 

roeks along- the "·estern flanks of the Pinyon and Sulphur Springs Ranges in the Carlin and Pine Valley 

f!Uadrangles and at two localities on the east side of 

t·he rang-es in the Dixie Flats and Hobinson l\1ountnin 

cpmclrnngles. These :four 15-minute quadrangles are 

being mapped by .J. F. Smith and IC B. ICetner, who 

have est.ablished the general stratigraphic sequence 

and areal relations of the units, and found and collected :fossils from the localities shown on figure 234.1. 

The rocks are dark brown and gray shale and yellow 

siltstone, marl, and calcareous sandstone, locally intercaln.t"ed with conglomerate in beds and lenses as 

much as 500 feet". thick. This facies resembles that of 

the Diamond Peak formation at its type locality in 

the Eureka district, about 40 miles south of the southern-most outcrop studied, but the fossils show that the 

Elko County beds are mostly Early l\1ississippian in 

age, whereas those of the Diamond Peak formation 

are LnJe l\fississippi:u~. 

The Early l\1ississippian beds, except where faulted 

locally aga.inst Late l\1ississipian and Pennsylvanian 

rocks (particularly in the northern part of the area) 

are overlain unconformably by.. Permian rocks. 'rhe 

beds immediately beneath the unconformity are of 

some\\·hat different ages at different localities, the older 

ones occulTing at the southern end of the belt of outcrop. 

The oldest l\{ississippinn assemblage occurs in the 

Pine Valley quadrangle about a mile south of Papoose 

Canyon. Approximately 35 species occur in gray limestone pods in shale and include fragmentary corals, 

together with brachiopods and many mollusks. The 

imporhmt fossils at one locality include lHenophyll~tlm.·? sp. 13, Oy((.thamonia sp., Tet?·acrl//11e1Yt? cf. T. subt1··ig01ut (:Meek and "\~T orthen), 8pi1·ijer n ff. 8. grimesi 

IIall, Dinwgela.snw cf. D. plenrttlm (I-Inll), and P1·otocamites lyon.i (l\1eek and "\Vorthen). The brachiopods 

resemble Osage species, but the goniatite P. 7yoni has 

long been eonsidered to be confined to a relati ,·ely 

rlfllTOw stratigraphic zone in the late IGnderhook of 

Hte 'United States and the late Tournaisian of northwestern Europe. 

A dominantly brachiopod assemblage similar to that 

of fhe beds with P1·otocanites is found at several localities in the Pine Valley quadrangle between Papoose Canyon and Trout Creek. The principal speeies are Le7Jtagonia cf. L. ama.loga (Phillips), 8etige1·ites sp., Lab'ri/Yroducttts cf. L. 'W01•theni (H~tll), 

601530 0-'61-1,6 

L. aff. L. keokuk (Hall), Spirifero afi. S. grimesi Hall, 

S. a:ff. S. nw.rion.en~i.s Shumard, S. aff. S. missmtriensis Swallow, Dinwgela~nw cf. D. plen~t1n (I-Iall), 

and Oleiothyridina a:ff. 0. ten~dlineata (Rowley). A 

similar fauna occurs in the Dixie Flats quadrangle 

4 miles southwest of the summit of Grindstone 1\{ountain in rocks mapped by Dott ( 1955, fig. 5) as ""\~Thite 

Pine-like shale and quartzite." 

The sontheasternmost occurrence of this fauna is in 

the Robinson l\{ountain quadrangle 4 miles south and 

about half a mile east of the summit of Robinson 

1\iountain. Echinoid spines, brachiopods, and pelecypods occur in light-gray siliceous siltstone, the more 

common species being Chonetes a:ff. 0. illinoisensis 

"\~T orthen, Lab1·iprod~wt'lt8 cf. L. ~vortheni ( I-Iall), 

Rhipid01nella a:ff. R. theimA3i (vVhite), SzJirifer aff. 

S. shepa.1·di vVeller, S. a:ff. S. nd~sou1·iensis SwaUow, 

and To1·ynijer aff. T. cooperensi8 (Swallow). 

"\Vhat appears to be the youngest faunule of this 

shale sequence in the Pine Valley quadrangle occurs 

about %, mile north of Papoose Canyon. A collection 

fronl" 75 feet of clark-gray shale with scattered thin 

limestone pods contain some significant corals associated with brachiopods. Thirty feet higher is a conglomerate overlain by limestone of Permian age. The 

fossils include "J/ enophyllwn? cf. sp. A., Trochophyllum~ sp., Perrnia sp., A1nplexizaplwentis cf. A. 1..velle1·i 

(Grove), "An11Jlexus" sp., Oyathaxonia sp., LezJtagonia cf. L. analoga (Phillips), Setige1·ites sp., 8chizo7Jhoria sp. A, 8pirifer aff. 8. i1nb1·ex I-Iall, S. a:ff. 8. 

floydensis "\Veller, Oleiothyri&hw cf. 0. incra~sata 

(I-Iall), 8t1·aparoll'l.tS (E~wmphal~tS) sp., and Lmnonenut sp. The corals in this faunule resemble those of 

the New Providence shale at Buttonmould ICnob, ICy. 

In the Carlin quadrangle all the Early Mississippian fossils occur in light creamy gray shale and yellow calcareous siltstone and sandstone. These beds 

probably are slightly younger than those previously 

discussed, the fauna resembling that of the late Osage 

shale beds of north-central J(entucky. Collections were 

made through 250 feet of section on Ferclelford Creek. 

The 10\Yer 100 feet contains an assemblage of corals, 

bryozoans, brachiopods, and ostracodes along with 

several mollusks. The principal fossils are 111 enOJJhylz,wn? sp. A, Lepta.gonia cf. L. analoga (Phillips), 

8etige1·ites n. sp. A, Schizopho1·ia sp. A, 8pirijfe1· aff. 

8. i1nb1·ex Hall, S. aff. 8. floydensi$ "\Ve1ler, Dinwgela~nut cf. D. neglectu1n (HaH), Oleiothy1·iditna cf. 0. 
C-234 GEOLOGI:CAL SURVEY RESEARCH 1 9 61 

·. I 

···~ ............. , 

tl 

GRINDSTONE 

MOUNTAIN 

ROBINSON 

MOUNTAIN 

... .....__/ 

/ 

X /""·- ../ ··. 

-_/ ... ......_ ... 

,.,..,.·'""'- ... 5 MILES 

EXPLANATION 

X 

"'-.:·· Fossil locality · .. ._._,..._ ___ ......_ ___ ....._ _ __._ __________ __, 40°15' 

Fwun~<~ 234.1.-Map showing Early Mississippian localities in 

southwestern Elko County, Nev. 

glenparken8is vVeller, Oomposita cf. 0. pentagona 'Veller, Strapa1?oll1t8 (Eu01nphalus) sp., and Loxonema 

sp. These are mostly Osage forms. 

In a· 22-foot zone 90 feet higher, the beds contain 

compound and solitary corals, bryozoans, brachiopods, 

· and ostracodes. The fauna includes "ill enophyllu1n~' 

sp.,, SiphonodendrrYn n. sp., Diphyphyllurn sp., Spirlje1' 

aff. S. fioyden.sis 'Veller, S. aff. S. suba.equalis Hall, 

and Oleiothyridina cf. 0. glenparkensis 'i\Teller. 

The uppermost fossiliferous bed, 24 feet higher, is 

an 8-foot marl containing a distinctive large ramose 

stenoporoid bryozoan. vVith it occur Litlwstrotionella 

sp., Spirifer aff. S. fioyden.sis 'Veller, and Oomposita 

cf. 0. pentagrYna Weller. 

The phaceloid lithostrotionoid corals in the 22-foot 

zone described above suggest a possible early Meramec 

age for the uppermost beds here. l\1:oreover, collections made for microfossils believed to have come from 

the upper part of this section contain such Late l\iississippian elements as Worthenopora cf. W. spinosa 

Ulrich, Ooryellima sp., and Bairdiolites sp. (the ostracodes identified by I. G. Sohn). 

Near the western end of Carlin Canyon, a similar 

faunule occurs in rocks of similar lithology. The 

lower 100 feet of a measured section contains about 

the same species as the lower 100 feet of the Ferdelford Creek section. The occurrence near the top of 

this zone of a new species of the 1\:eokuk bryozoan 

genus Oyclopora is of particular interest. 

· Fossils from a 15-foot zone 150 feet above the base 

of the same section include another distinctive large 

ramose stenoporoid bryozoan together with 11/ enophyllun!J? sp., new genus aff. Oanadiphyllu1n, and Dim,egelasma cf. D. neglectu1n (Hall). 

Dott (1955, fig. 3) mapped the yellow calcareous 

siltstone in west Carlin Canyon with his Tonka formation but he pointed out (p. 2232) that it may be 

below the Tonka or interbedded ·with the lower part. 

The Tonka type section (Dott, 1955, p. 2222, 2292; 

2293), however, contains beds of Late Mississippian 

and Early Pennsylvanian age only, equivalent to the 

upper part of the Diamond Peak formation and the 

lower part of the Ely limestone in the Eureka district. 

Possible wider distribution in Elko County of this 

Lower l\1:ississippian fine clastic facies is indicated by 

· Dott's mention of a similar faunufe in black .. shale 5 

miles northwest of Elko (Dott, 1955, p. 2230) and by 

the occurrence of Protocanites lyoni (l\1:eek and 

vVorthen), identified by Furnish, Miller, and Youngquist ( 1955), in black shale in the Pequop Range, 20 

miles east of 'Vells, Nev. 

. REFERENCES 

Dott, R. H., Jr., 1955, Pennsylvanian stratigraphy of Elko and 

northern Diamond Ranges, northeastern Nevada: · Am. 

Assoc. Petroleum Geologists Bull., v. 39, no. n·, p. 2211-

2305. 

Furnish, W. 1\f., Miller, A. K., and Youngquist, Walter, 1955, 

Discovery of the Early Mississippian goniatite Protocanites 

in northeastern Nevada: Jour. Paleontology, v. 29, no. 1, 

p. 186. 

.1 
SHORT PAPERS IN THE, GEOLOGIC AND HYDROLOGIC SCIENCES, ARTJ.CLES 147-292 C-235 

235. CONTINENTAL VERTEBRATES AND THEIR STRATIGRAPHIC CORRELATION WITH MARINE MOLLUSKS, 

EASTERN CALIENTE RANGE, CALIFORNIA 

By c. A. R:gp}~NNING a,nd J. G. v}~DDER, :M:~nlo Park, Calif. 

Five and possibly six North American provincial 

(mammalian) ages, as defined by Wood an~ others 

( 1941), are represented by vertebrate faunas In u?per 

Tertiary rocks of the eastern part of the Caliente 

R.ange. This record of superimposed mammalian assemblages is equalled at few places in the. world. By 

tracing fossiliferous beds, faunas representi_ng three of 

these ages can be correlated with assemblages of 

abundant marine mollusks in this same area. 

The eastern part of the Caliente Range is composed primarily of clastic sedimentary rocks of Miocene and Pliocene age that attain a thickness of over 

16,500 feet near Caliente ~fountain (fig. 235.1). These 

rocks have been mapped in detail from the Caliente 

1\1ountain area eastward for a distance of about 16 

miles to the eastern end of the range, where they apparently are less than- 2;500 feet thick. The Miocene 

part of the thick stratigraphic succession gra?es eastwn.rd from a dominantly marine facies into. largely 

nonmarine deposits. 

The continental deposits into which the marine beds 

O'rade and some of the overlying nonmarine beds that ,..., ' c 1" have no marine equivalents in the eastern a Iente 

Range, have been described as the Caliente !ormation 

by I:Iill, Carlson, and Dibblee (1958). The Caliente 

formation in this area contains vertebrate faunas referable to the Arikareean, I-Iemingfordian, Barstovian, 

Clarendonian, and I-Iemphillia.n ages of Wood and 

others.1 Continental beds about 2,300 feet stratigraphically n.bove the top of the Caliente formation contain 

vertebrates that suggest a Blancan age. 

A ril.~a'reean age.-Vertebrate fossils of Arikareean 

age, listed in table 235.1, have been found only in the_ 

eastern part of the Caliente Range, from . the .area 

indicated by section 2, figure 235.2, to a point about . 

3 miles east of section 3 where "fossil mammals o.ccur 

as low as 700 feet above the base of the Soda Lake 

member 2 of the Vaqueros formation. Two· thousand 

feet to the west of these stratigraphically lowest ver- · 

tebrate localities the mammal-bearing beds intertongue .. 

with marine sandstone in the upper part of the Soda 

Lake member. This sandstone contains Turritelkt 

'lneza·na and Lyropecten magnolia, forms that presumably are restricted to strata of early Miocene age. 

1 The United States Geological Survey has not adopted the North 

Amcrlrnn provlncinl (mammalian) ages of· Wood and others· for offielnl usage. 

2 NomcMlnture ot Hill, Carlson, and Dlbblee, 1958. 

FIGUJ{E 235.1.-Eastern Caliente Range showing location of 

sections in figure 235.2. 

The youngest mammals believed to be of Arikareean 

age are from beds that c~n be traced into the top of 

the Painted Rock sandstone member 2 of the Vaqueros 

formation, which locally contains Tu'rritella inezana, 

Rapana vaquerosensis, Lyropecten migu.elensis, and 

"Orassatella" granti. These mollusk species also are 

present in the lower 500 feet of the Saltos shale member 2 of the Monterey shale in the central and western 

par.ts of the eastern Caliente R.ange between section 2 

and Caliente Mountain. 

1\{ammalian faunas from beds that are laterally 

equivalent to the basal part of the Saltos shale member are tentatively assigned an Arikareean age. From 

these nonmarine beds east of section 2, D. E. Savage 

of the University of California collected a small 

dromomerycine at a point about 200 feet stratigraphically above the highest Arikareean fanna and an equal 

distance below the lowest known Hemingfordian fauna. 

DouO'herty (1940, fig. 3, C.I.T. loc. 325) lists "Merycoid~d9nt" from about the same position in the section. 

If the small dromomerycine is of Arikareean age, 

the Arikareean-Hemingfordian boundary falls ·close 

to the boundary between the early and middle Mio-

.cene as based upon the larger marine invertebrates; 

if this deerlike animal is of Hemingfordian age, there 

is, in the Calie~te formation only slight disagreement 

about the boundary. 

The stratigraphically lowest beds of" Arikareean age 

have not been determined in the Caliente Range. 
w 

THOUSANDS 

OF FEET 

7 

6 

c:-

0 

;::; 

Ill 

E 

E 

~ c: 

2 

5 4.5 MILES 3 

MILES - ;;;!;;;;;;;'····· ,'i~li.~i::,~~~~~~~~~i~~~~ 

5 ~ ;:;;t;\)1'{ 

4 

2 

0 

~~-If >. 

Q) 

~ 

i~~:~;?;.{}W: .-.,. .. :.{·:--· 

t/:.:··· 

~ nterval about 

5400 ft 

to Soda Lake 

member 

t 

~:: 

·:{,i~.:.:::::::':: 

··:~=-~:;:: 

. ·."· .. :.::·-:-:... 

. ·.::~·:::: ... 

·\~·· Interval about 

2000 ft 

to Soda Lake 

member 

~ 

:::::~ 

~:-:-:·:· .-· 

/ 

/ 

/ 

}::.:·:{:: 

~:::::::::::::::::::::: 

EXPLANATION 

R Marine sandstone Marine • sandy siltstone Continental 

-

deposits 

1 Stratigraphic nomenclature of Hill, Carlson, and Dibblee, 1958 

'i:D~· V\!vAJ ~ l} 

I 

Basalt-flows 

c:-

0 

:;::; 

Ill 

E 

.E 

~ c: 

.~ 

iii 

u 

~ ~- "' Q) 

E 

...J.O Ill 

~ ~ ~ ~E ~ 

Ill 

> 

FIGURE 235.2.-Stratigraphic diagram of rocks of Miocene and Pliocene age in the eastern Caliente Range. Vertical dashed line marks arbitrary boundary in area of 

intricate intertonguing. B, Hh, and the like show approximate stratigraphic location and also indicate age of collections of diagnostic fossils; explanation given 

on table 235.1. 

4' 

0 

CJ.j 

~ 

~ 

0 

t:_:rj 

0 

t"4 

0 

0 

t) 

> t"4 

U1 

q 

:::0 

< 

t:_:rj 

~ 

:::0 

t:_:rj 

U1 

t:_:rj 

> :::0 

~ 

...... 

c:o 

Q) 

...... 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-237 

TA RI..J<J 235.1.-Correlation of faunal divis1:ons based upon vertebrates and mollusks from the eastern Caliente Range showing discrepancies 

between continental and marine age assignments 

Faunal divisions and ago assignments based upon vertebrates 

A~ro names applied to continental 

bods In North America and 

their correlation with Lyolllan epochs as proposed by Wood 

and others (1941) 1 

Middle 

Pliocene Her1_1.p hillian 

Hh 3 

Continental vertebrates collected 

from tho Caliente formation of the eastern Caliente Range (Identifications by C. A. Repenning) 

megalonychid 5 

leporid 

felid 5 

Pliohippus cf. P. osborni 

Frick 

cnmelid 

Capromeryx cf. C. altidens 

(Matthew) -----1-------------- - - - -----

Early 

Pliocene 

Chtrendonian 

C3 

felid 6 

Pliohipp1ts cf. P. tehonensis (Merriam) 

Pliohippus cf. P. leardi 

(Drescher) 6 

--------1------·---------1-

Late 

Miocene 

Middle 

Miocene 

Bttrstovian 

]33 

Hemingfordian 

Hf 3 

crocodilian e 

Tomarctus sp.o 

rhinocerotid11 

Archaeohippus mourningi 

(Merriam) 8 

Hypohippus sp." 

Jl!I erychi ppus brevidontus 

Bode 

Merychippus sumani Merriam8 

J.l.tferychippus sp. 

Dyseohyus sp. 

T1:choleptus calimontanus 

(Dougherty)7 11 

Protolabis? sp. 

Dromomeryx sp. or Rakomeryx sp. 

Amphicyon aff. A. frendens 

Matthew 

Archaeohippus 

(Cope) 

Parahippus? sp. 

ultimus 

M erychippus carri zoensis 

Dougherty 

.M erychippus cf. M. sever sus (Cope) 

Hesperhys vagran.'l Douglass · Prosthennops? sp. 

Ticholept1ts calimontanus 

(Dougherty) 

camelid 

Dromomeryx? sp.7 s 

·-------·1-----------1- - -- --- --

Early 

Miocene 

Arikareean A a 

Archaeolagus sp. 

Jl!fiohippus sp. or Archaeohippus sp. Parahippu.~ sp. 

chalicotberiid 

oreodont 

Oxydactylus brachyodontus 

Peterson [? = Par.,atylopus 

cameloides (Wortman)] 

Parablastomeryx aff. P. falkenbachi Frick dromomercine 6 

Faunal divisions and age assignments based upon mollusks 

Selected common mollusk species from assemblages that sug~est faunal divisions In marine strata of the eastern Caliente Range 

(Identifications by J. G. Vedder) 

l\Iarine faunas not known to be present 

- -?- - - - - - - - -?-

Turritella carisaensis padronesensis Grant 

and Eaton 10 

"Siphonalia" danvillensis Clark 

Lyropecten cf. L. estrellanus (Conrad) 11 

Ficus ( Trophosycon) ocoyana (Con- rad)12 

Kellet?:a posoensis (Anderson and Martin) 

Macron merriami Arnold 

Bruclarkia barkerianum (Cooper) [?= 

B. geniculata (Conrad)] 11. 11 Phos" dumbleanus Anderson in Hanna 

N as sari us antiselli (Anderson and 

Martin) 

Oliva californica Anderson 12 

"Cancellaria" condoni Anderson 12 

Conus owenianus Anderson 12 

M egasurcula keepi (Arnold) 

Turricula wilsoni (Anderson and Martin) 12 

Strioterebrum cooperi (Anderson) 

Anadara osmonti (Dall) 

Saccella ochsneri (Anderson) 

Aequipecten andersoni (Arnold) 

Dosinia mathewsonii (Gabb) 

Chione temblorensis (Anderson) 12 

Chione panzana Anderson and Martin 

Turritella inezana Conrad 

Turritella inezana ho.ffmannii Gabb 

Turritella inezana altacorona Loel and 

Corey 

Rapana vaquerosensis (Arnold) 

"Lyropecten" magnolia (Conrad) 

Lyropecten miguelensis (Arnold) 

"Crassatella" granti (Wiedey) 

Informal stage names based upon marine megafaunas of the Pacific 

Coast and their correlation with 

Lyellian epochs as proposed by Weaver and others (1944) 2 and 

Durham (1954) 2 

"Neroly" 

"Cierbo" 

"Briones"' 

83 

"Temblor" 

Ta 

"Vaqueros" 

ya 

Late 

lVfiocene 

Middle 

Miocene 

Early 

Miocene 

1 Those ago names not officially used by the U.S. Geological Survey. 2 Those Informal stage names not officially used by the U.S. Geological Survey. 3 Symbol used on figure 235.2 to indicate approximate stratigraphic location of 

soloctcd diagnostic collections. 

7 Collected by J. F. Dougherty (1940). s Resembles Dromomeryx borealis (Cope) according to Dougherty (1940). 

4 These three "stages" often are collectively referred to the "Santa Margarita stage" In southern California. 3 Collected by University of California (D. E. Savage, oral communication, 1960). 8 Vertebrates found with a middle Miocene marine rr.ollnsk fanna which includes: 

Melongena californica Anderson and Martin, Anadara topangaensis Reinhart, Crasso- strea cr. 0. altatemblorentris Grant and Eaton, Cra&~ostrea ati. 0. ashlevi Hertlein. 

v Vertebrates found with or stratigraphically near the late Miocene marine mollusk 

fauna at Padrones Spring. 10 Tbe typical form of Turritella carisaensislocally ranges down into strnta of middle 

Miocene age in the eastern Caliente Range. 11 This species ranges into strata of middle Miocene age at localities outside the eastern Caliente Range. 12 These species range into strata or early Miocene age in the eastern Caliente Range but are uncommon or rare in rocks ol this age. 
C-238 GEOLOGICAL SURVEY RESEARCH 19 61 

Hen~ingfordian age.-The oldest vertebrate assigned 

a Hemingfordian age was collected from the Caliente 

formation 2 miles east of section 2 about 100 feet above 

a conspicuous marine tongue that contains the stratigraphically highest occurrence of diagnostic early 

~Eocene mollusks in the area of section 2. The youngest mammals assigned to the Hemingfordian are from 

a locality near section 2 and about 30 feet below 

the lowest of three basalt flows called the "triple 

basalts" by Eaton (1939, pl. 4). These basalt flows 

form prominent markers throughout most of the 

eastern Caliente Range. All Hemingfordian mammal 

localities are from beds that intertongue with the 

marine Saltos shale member of the Monterey shale 

or with the Branch Canyon formation. 2 These marine units contain large mollusk assemblages similar 

to faunas from other areas that are assigned a middle 

Miocene age in California. 

The I-Iemingfordian fauna of the Caliente formation 

shown on table 235.1 contains four species of horses. 

All four have been found in one quarry in a 3-footthick bed, the type locality of 11/ erychipp1.~ carrizoens7:s (Dougherty, 1940, p. 130-133). Although M. carrizoensis is generally considered indicative of a Hemingfordian age, its occurrence with the other horses 

suggest that the entire fauna should be considered 

late Hemingfordian or possibly even early Barstovian. 

The few specimens referred to 11/ erychippu.s cf. 11!. 

·seve1'S1.t8 are indistinguishable from individuals of this 

species from the ~1ascall formation of late Miocene 

age in eastern Oregon. A rchaeohippus ultimu.s is 

also a ~1ascall form. 

The generic assignment. of the horse called PaNt-

. hippus? sp. is debatable although it is represented by 

a large number of specimens. It is morphologically 

intermediate between a large and progressive parahippine as Parahippu.s leonensis Sellards and 11/ erychipp?.ts brevidontu.s Bode. The enamel pattern of 

the upper cheek teeth is nearly identical to that of M. 

brevidontus from the overlying beds of Barstovian 

age. It is less hypsodont than 111. bre;vidontus and has 

less or no cementation, being quite variable in this 

respect. 

Barstovian age.-Vertebrate fossils of Barstovian 

age (table 235.1) are relatively abundant in the Caliente formation. They have been found through the 

section from about 10 feet above the lowest flow of 

the "triple basalts" to about 200 feet above the middle 

of these flows in the area of section 2 on figure 235.2. 

Near Caliente Mountain, in the area of section 1 of 

figure 235.2, the "triple basalts"' are in the Branch 

Canyon formation, which is laterally continuous with 

the Caliente formation. In this area the highest 

typical middle Miocene mollusk fauna is about 35 feet 

below the highest flow of the "triple basalts" (about 

960 feet above the middle of the three flows). Except 

at Padrones Spring, all Barstovian faunas of the 

Caliente formation are from beds that have been traced 

into marine rocks that contain mollusk assemblages 

assigned a _middle Miocene age. At Padrones Spring, 

a marine lens with a meager molluscan fauna (including Tu1·ritella carisaensis pad1'011/3ensis and "Siphonalia" danvillensis, which suggest a late Miocene 

age) contains mammals of Barstovian age. These 

youngest marine beds of the eastern Caliente Range 

are not continuous with marine rocks to the west 

but presumably represent a northward extension of a 

marine basin that lay chiefly to the south. 

The apparent upper limit of beds of Barstovian 

age in the Caliente formation is marked locally by a 

disconformity. The disconformity has been recognized only in the central part of the eastern Caliente 

Range where the upper flow of the "triple basalts" 

has been cut out (fig. 235.2). Near section 1, figure 

235.2, strata about 600 feet thick separate the upper 

flow of the "triple basalts" from the lowest fossils of 

Clarendonian age. No mammals have been found in 

these intervening beds, and they may be deposits of 

Barstovian age in part younger than the disconformity. 

Olarendonian age.-Few vertebrate fossils of Clarendonian age have been found in the Caliente formation of the eastern Caliente Range (table 235.1). In 

most of the area the part of the formation that is of 

this age contains a conspicuous unit composed of several flows. This unit was called the "main basalt" 

by Eaton (1939, pl. 4). Fossils of Clarendonian age 

have been found in beds about 150 feet below to about 

30 feet above the "main basalt" in the area between 

sections 1 and 2. In the Pacific Coast region faunas 

of Clarendonian age have been separated into two 

groups; in some areas the lower group is generally 

found interbedded with strata containing late Miocene molh~sks, and the upper group with strata containing Pliocene mollusks (Savage, 1955). The known 

mammalian fauna of the Caliente formation is not 

adequate to identify upper and lower parts of the 

Clarendonian fauna. 

I-I ernphillian age.-The stratigraphically lowest occurrences of fossil vertebrates of Hemphillian age in 

the Caliente formation are about 100 feet above the 

"main basalt" and the highest about 400 feet above 

the same unit. In the area of section 1, figure 235.2, 

the youngest fossils of Hemphillian age are found 

about 250 feet below the top of the Caliente formation. 
,_ 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-239 

REFERENCES 

Doughert:y, .J. F., 1940, A new Miocene mammalian fauna from 

Caliente Mountain, California: Carnegie lust. Washington 

Pub. 514, p. 109-140. 

Dm·ham, J". \V., 1954, The marine Cenozoic of southern Ctilifornia, Pt. 4, ·i·n Chap. III of .Jahns, R. H., eel., Geology of 

southern California: California Div. Mines Bull. 170, 

p. 23-31. 

l~nton, .T. E., 1939, Geology and oil possibilities of Caliente 

Runge, Cuyama Valley, and Carrizo Plain, California: 

California .Tour. Mines and Geology, v. 35, no. 3, p. 255-274. 

Hill, l\1. L., Carlson, S. A., and Dibblee, T. W., .Jr., 1958, 

Stratigraphy of Cuyama Valley-Caliente Range area, California: Am. Assoc. Petroleum Geologists Bull., v. 42, no. 12, 

p. 2973-3000. 

Savage, D. E., 1955, Nonmarine lower Pliocene sediments in 

California: California Univ. Pub. Geol. Sci., v. 31, no. 1, 

p. 1-26. 

Weaver, C. E., and others, 1944, Correlation of the marine 

Cenozoic formations of westem North America·: Geol. Soc. 

America Bull., v. 55, p. 569-598. 

Wood, H. E., and others, 1941, Nomenclature and correlation 

of the North American continental Tertiary: Geol. Soc. 

America Bull., v. 52, p. 1-48. 

236. STRATIGRAPHIC DISTRIBUTION OF ENDOTHYRID FORAMINIFERA IN CARBONIFEROUS ROCKS OF 

THE MACKAY QUADRANGLE, IDAHO 

By BETTY A. L. SKrrr, Denver, Colo. 

Preliminary studies of Carboniferous endothyrid 

Foraminifera from three measured sections in the 

1\'fn.ckay quadrangle, Idaho (fig. 236.1) indicate that 

the endothyrids are valuable for the interpretation of 

gross stratigraphic relations in the thick sequence of 

miogeosynclinal sedimentary rocks ~f the area. The 

measured sections (fig. 236.2) contain rocks presently 

assigned to the Brazer limestone (Sando and others, 

1959, p. 2768) and to an unnamed formation that 

interfingers with the Brazer limestone and which is 

described by Ross ( 1960, p. B-232-233) as containing 

lithologic equivalents of the Milligen and Wood River 

formations and the Brazer limestone, with detrital 

rocks predominant over limestones. Endothyrid Foraminifera indicate that both formations, as represented in the three measured sections, range in age 

from Early ~1ississippian (Osage, possibly l(inderhook) to at least Early Pennsylvanian (Morrow). 

Studies of megafossils from the ~1ackay quadrangle 

indicate that the Brazer and associated beds are Late 

~1ississippian in age at most places, and are Pennsylvanian· in age at a few (Anderson, 1929, p. 11; 

Umpleby, 1917, p. 28; Ross, 1960, p. B232; Skipp, 

1961). 

Girty ('in Anderson, 1929, p. 11) identified an upper 

~1ississippian fauna from be~s stratigraphically equivalent to the mudstone beds 350-750 feet above the 

dolomite of the Timbered Dome section. He also 

assigned a collection of fossils from the limestones . 

above the lower zmie of j asperoid of the same section 

to the Upper Mississippian, but with some doubt. No 

fossils were found in the more than 650 feet of lightgray 'veathering dolomite and quartzitic sandstone at 

114"00' 113"30' 44 •oo r-:R:--::-21-E-~--22----,--.~;::----2-3-~--R-24-E ---, 

~~ Cabin Creek 

~ section 

.... ~ . ./ 

e.~ 

r-1 

I I 

I \ 

: ~ ( 

) (/ 

/ MACKAY\,,..._, 

l QUADRANGLE I 

1§.1 I 

I 

: IDAHO I L _____ _ 

Timbered ) Dome 

section 

~~\ ·T 1. \ 2 

43"30 ,_____ ______ _.___..___ ___ _._{_.__ ____ _,_N_, 

FmuuE 236.1.-Index map of Mackay quadrangle. 
C-240 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TIMBERED DOME 

Sec. 31, T. 4 N., R. 25 E., and sees. 6, 

7, and 8, T. 3 N., R. 25 E. 

CABIN CREEK 2 

Sees. 13, 14, 15, and 22(?}, 

T. 6 N., R. 22 E. 

c 

0 

:;; 

«< 

E 

.g~ 

"0 

Q) 

E 

«< 

c: 

c: 

::::> 

Q) 

c: 

.9 

Vl 

Q) 

:§ 

... 

Q) 

N 

«< 

cD 

Challis volcanics 

dllmt1Fault'77Thn: I 

. I 

1--l--'---l...--44---About 8 miles~ 

I Challis volcanics 

I I I 

I 

I '

L- About 13 miles __ 

11/"':=lc-~---~~[2~::]1~1-- Paramillerella designata (D. Zeller) 1953 

I 

CHERRY CREEK 

Jasperoid 

(replacement of 

calcareous 

sandstone and 

sandy limestone} 

Sees. 32 and 33, T. 5 N., R. 24 E. 

PENNSYLVANIAN 

0 0 0 0 0 0 0 0 .-:-

0 .:.....1...!...· 0 ·-L: 0 0 

•••• 0 ••• 0. 

~~~"~A~~A~A~"~I-- Plectogyra sp 

lA lA AI 

I I 

I I 

I I I 

A 

I 

I 1 /' 

/ 

1-- Paramillerella 

I I I 1--r--'-----.-....1...----r--'-----L.-

,. circuli (Thompson) 1945 

I I I 

I I I 

I I I 

I I I 

1.----'--

Jasperoid 

(largely 

replacement of 

limestone) 

l 

UPPER 

MISSISSIPPIAN ~ 

(Chester) ~ 

Q) 

Paramillerella tortula ,§ 

(D. Zeller) 1953 

Plectogyra sp .... ~ .... 

Endothyra? sp ,......,_ .............. ~ ........ al 

1- Plectogyr.a spEndothyra sp j...-1_ ........ 

"0 ·e 

Q) 

5,l 

.!!!_ 

"0 

c: 

«< 

Q) 

c: 

0 

1il 

Q) 

E 

:.:::; 

I 

I I 

I I 

I 

I I 

I I 

I 

!0 

~ ::J 

Vl 

«< 

Q) 

E 

0 

.s 

AA 

l _I 

I 

I 

I I 

I 

I 

I I 

UPPER I 

MISSISSIPPIAN / 

(Chester) /· 

I 

I 

/ 

I "·' 

I 

I 

I 

I 

I 

Paramillerella cf P. cooperi 

(D. Zeller) 1953 

Plecjogyra sp 

"I UPPER Q) 

c: 

.9 

I I I 

/. MISSISSIPPIAN 

1--r...J.__-.--'-.,-J---t'l; (Meramec) Vl 

Q) 

:§ 

" "I A lA AI 1- Endothyra cf E. I~ 

symmetrica 1 ~ 

-- 1- -1-~1- (E. Zeller) 1957 "/ 00 

I Plectogyra sp 1 • 

I J J I 1 A 1 " 1 r- Plectogyra sp I A 

A I 

I 

I 

~:..J..:-~-·=-·.-·-::·_-.-.-.- .. -~-:-.J...:-·=:-:=.:--Ir p~~:ER u IIilli :. ·.·:.·.·.·::. MISSISSIPPIAN t::::._..!...."....!...=.=:-::=-:= .. : .-=-:.· .. . ~:. (Meramec) 1 !1/////Faultl/////1, 

"( 

LOWER 

MISSISSIPPIAN 

(Osage) 

••• 0 ••• 0. 

~-.-.-. ~-.-.-. 

~i:i /, ·.·.·.·.·.·.·.·.·.· __,,.--' 0 0 0 0 0 0 0 0 ,..,,.,... . 

~A.· • • • • • ·1· · · · · · · · · · Wood impressions ·7· -:-; ·/· 0 • 1------- ... I . .. I. . -----? 

;' I I Age 

• " . " • " • ". " • · unknown 

z 

Covered 

Covered 

FEET 

0 C) 0 0 

0 0 0 0 0 

() 0 0 0 1\) 

0 0 C> 0 0 

EXPLANATION· 

I 

.o .. o .. o. ~- p,q 9. 

.cg!;: ~ ~ 000<>0000 

T I T 1--L----.--'-----.-'----..-t- Plectogyra. sp l I I 

I A I A I 

1-1-----

00000 oo ooooooo 

Plectogyra sp 

l I I ~::::;:::::r:: 1

::::;:

1

I:::;1;:+._ Plectogyra sp 

-1--I- -1- Endothyra sp 

?o ~.o.~. •:•'l·O.df>. . . . • . • • • • . f- Plectogyra sp 

1- -I- -I- - Granuliferella? sp 

I I I 

T I T 

~ ... ...:..:..:.. ... .:..:..:. I I I IT T T 

T T I 

Plectogyra sp 

Granuliferella? sp 

Granuliferella sp 

Plectogyra? sp 

~--,....T.J.__~J...._l......-~1_ ~o- Granuliferella sp T T 1 

I I I 

I I I 

I I I 

I I 

I I I 

T I 1 T T I 1-- Granuliferella sp 

/::c::::!=I=:;::c::~ 

......... .. .-.:.;.:. 

Argillite 

(not measured) 

~------~ -------

~-==-==~~- ----------=---

- -

Limestone or 

calcareous 

Conglomerate Sandstone or 

sandy 

Siltstone or silty Mudstone or 

clayey 

Argillite Dolomite 

1. Described by C. P. Ross (1960) 

2. This section described in detail by Skipp (1961) 

Quartzitic 

sandstone 

A .4 A b. 1:1 

A 1:1 A· A 

1:1 6 1:1 0. ·(}. 

Chert Calcareous 

sandstone 
.. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-241 

the base of the Timbered Dome section, and therefore 

stratigraphic relations are in doubt. 

Girty (in Umpleby, 1917, p. 28) regarded all the 

collections he saw from the Brazer and associated 

beds in the vicinity of the Cabin Creek section as 

Late Mississippian in age, but with varying degrees 

of confidence. Preston Cloud, David Dunkle and I 

(in Skipp, 1961, p. 385) also suggest a Middle or 

Late l\fississippian age for the upper part of this 

section. 

An Upper l\fississippian fauna similar to that described by Girty from the mudstone of the Timbered 

Dome section, containing the distinctive brachiopod, 

Leio,rhynchus carbonifcrum var. polypleurum Girty, 

was recognized by me approximately 250 feet above 

the fault at the base of the Cherry Creek section. 

Beds probably stratigraphically higher in the Brazer 

limestone contain fusulinids of Pennsylvanian age near 

the Cherry Creek section, as identified by R. C. Douglass (written communication, 1958). 

In general, the age assignments based on the endothyrid Foraminifera support age assignments based on 

available megafossils, but suggest two important modifications: 

1. The Mississippian-Pennsylvanian boundary lies in 

the thick sequence of limestones above the lower 

zone of jasperoid in the Timbered Dome section. 

2. The Cabin Creek section contains a rninimum of 

3,500 feet of Lower Mississippian limestone and 

interbedded siltstone. 

Tentative correlations of the three sections are given 

in figure 236.2. Meramec time is represented by sandstone, siltstone and mudstone in the Timbered Dome 

area and by quartzose conglomerate and clastic. limestone in the Cabin Creek area (Skipp, 1961) just 20 

miles to the northwest. Both appear to be shallow 

water deposits. Chester time appears to be represented mainly by limestone in all three areas. During 

Pennsylvanian time quartzose clastic rocks interbedded 

with limestone accumulated in the Timbered Dome 

area. 

ENDOTHYRID ANATOMY AND 

STRATIGRAPHIC DISTRIBUTION 

]~ndothyrid Foraminifera are minute calcareous 

forms commonly found in pure limestones ranging in 

age from Devonian to Triassic. In the Mackay region, 

they are best preserved in medium- to coarse-grained 

clastic limestones that have finely crystalline matrices 

and are not recrystallized to any appreciable extent. 

FIGURE 236.2.-Columnar sections of Carboniferous rocks. 

They are commonly associated with corals, brachiopods, gastropods, ostracods, echinoids, and crinoids. 

At places, they are also found in oolitic limestones. 

Figure 236.3 illustrates the stratigraphic succession 

of the endothyrids in the l\fackay quadrangle. Early 

l\fississippian forms, Granuliferella sp., are characterized by a homogeneous single-layered wall and a plectogyrid coil (Zeller, 1950, p. 3) and appear contemporaneous with the ubiquitous Carboniferous form, Plectogyra sp. This form is characterized by a heterogeneous wall structure composed of three primary 

layers; a fourth, secondary layer of variable characteristics (Zeller, 1957, p. 693); and a plectogyrid coil. 

Endothyra sp. is characterized by a layered wall, distinctive secondary deposits, and a planispiral coil, and 

. is a common form in Upper Mississippian rocks, but 

it may also be present in Lower Mississippian rocks. 

Paramillerella sp. of Late Mississippian and Pennsylvanian age has a layered wall structure, dominantly 

a planispiral coil, and rudiments of chomata which 

characterize true fusulinids. The distinctions between 

endothyrid populations of different ages in the l\{ackay 

quadrangle are those recognized by me, but the bases 

for this work were developed by Thompson (1942, 

1944, 1945, 1951), E. J. Zel1er (1950, 1957), D. E. N. 

Zeller (1953), vVoodland (1958), and others. 

Osage forms : 

Gra,nulife'rella, sp. is the most abundant form. Walls are 

homogeneous, single layered, and variable in thickness. 

·Coil is plectogyrid. Specimens are generally small, averaging 0.2-0.3 mm in length. (Fig. 236.3, Q to U.) 

Plectogym sp. is rare. Wall layering is indistinct, total 

rotational distortion is small, and rare secondary deposits 

consist of small generally rounded nodes on chambe1· 

floors and no, ot· very thin, connecting layers. Specimens are generally small. (Fig. 236.3, P.) 

Endothyra,? sp. is very small and rare. 

1\Ieramec forms : 

PlectogJJ?'a, sp. is very abundant. Wall layering is distinct, 

secondary deposits are common and consist of hamuli, 

acanthi, nodes, thin to thick layers on chamber floors, 

and qeposits on septa. Amount of rotational distortion 

and size of specimens ranges from small to large, although very large forms, up to 1.2 mm across, are more 

usual. (Fig. 236.3, K to N.) 

Ewlothyra, sp. is common. It is very closely related to 

Pa,ramillerella, and .M-ille1·ella, but secondary deposits are 

restricted to hamuli, acanthi, and nodes in final chamber in contrast to the rudimentary chomata which characterize the other genera. Other, less diagnostic differences are stubby septa, strong anterior direction of 

septa, and generally fewer chambers per volution. (Fig. 

236.3, o.) 

Chester forms : 

Paramille1·ella sp. is abundant. It is characterized b~· 

rudimentary chomata in early volutions and is differentiated from !Jfillerella sp. in having a more nearly spherical shell (Thompson, 1951) . (Fig. 236.3, G to J.) 
·C-242 GEOLOGICAL SURVEY RESEARCH 19 61 

z 

~ 

z 

<( 5: > 0 _J 0:: 

>- 0:: (/) 0 z ~ z 

w 

o._ 

0:: 

w 

t-

(/) 

w 

I 

u 

z 

<( 

a:: 

o._ 

Ui 

~ (/) - (/) 

~ 

0:: 

w 

o._ 

o._ 

:J 

u 

w 

~ 

<( 

0:: 

w 

~ 

z 

~ 

0:: o._ w w o._ (j - 5: (/) <( 

0 (/) (/) 

_J Ui 0 (/) 

~ 

FIG R~; 236.3.- Representative endothyrid Foraminifera from the Mackay quadrangle, Idaho. Morrow, Chester, Meramec, and 

Osage are corre~ative provincial series in the Mississippi Valley and Mid-continent region. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-243 

Cht:>stet· forms-Continued 

Plccto{JIIrn St). is common and is largely indistinguishable 

from l\Iet·nmec forms on the basis of present work. 

(11'1g. 236.3, JJJ, F.) 

Endoth1Jnt? sp. Is present. 

Penns:vlvnnlan fot·ms: 

Pa·ra m illcrdla. circuli (Thompson)' 1945 was first described 

hy ~rhompson (1945, p. 47) from the Belden formation of 

Pennsylvanian nge in Colorado and Utah, and is here 

used liS n Pennsylvanian iJ1dicator. It is larger, has 

more volution~, more chambers per volution, and better 

developed ehomnta than related Chester forms. (Fig. 

28(1.3, C, D.) 

Plcotormrn sp. is common but is not presently recognized 

ns dl11gnostic. (l1'ig. 236.3, A, B.) 

CONCLUSIONS 

Generic and specific divisions of endothyrid Foraminifera in the Carboniferous rocks of the Mackay 

quadrn,ngle are recognizable in sufficient detail to show 

that they have. limited stratigraphic range and are 

useful :for age determination. Although specific divisions of Plectogyra are recognized, their nomenclature 

has not yet been determined in the lVIackay region 

because many of the original descriptions of species 

are incomplete, and limits of specific variables are not 

shttecl. Size differences have been emphasized in past 

descriptions although the size varies with environment 

and with megalospheric and microspheric forms of the 

same species. The coiling habit has not been described 

IDxplanation for figure 236.3 

[All drn.wings of photographs X 1001 

A. B, Plc(·tornJra. sp., showing ex•tensive secondary deposits; 

4,850 feet nhove dolomite at base of Timbered Dome 

section. A., oblique axial sec.tion, USNM 628595; B, 

oblique nxinl section; USNM 628596. 

0 ]) , Pa.ra·m'illcrclln oirouU ('nwmpson), 1945, showing numerous ehnmhers nnd well developed chomata; 4,850 feet 

nhove dolomite ttt base of l'imbered Dome section. C, 

::;ugittnl seetion, USNM 628G96; D, axial section missing 

proloculns, USNl\1 62859G. 

.J.J ./1', PlcetornJI'a. sp., showing large size, secondary deposits, 

utal nngnlnr rotation; not in direct line of section, but 

(•onsidere<l to be ahont 3,300 feet above dolomi>te at base 

of l'imbered Dome sectioi1. B, oblique axial section, 

USN.i\1 62SG!)7; 1•', ,·ertical axial section, USNM 628597. 

G H, ParMnillerclla, tortu Ia. (D. Zeller), 1953, showing small 

fully for most species. The degree of rotational distortion (Zeller, 1950, p. 3) is useful as a basis for 

classification although in some specimens it changes 

from volution to volution and has never been calibrated more precisely than the individual worker's 

estimate-small, moderate, large-and these vary. The 

same holds true for rate of coiling. 

REFERENCES 

Anderson, A. L., 1929, Geology and ore deposits of the Lava 

Creek district, Idaho: Idaho Bur. Mines and Geology 

Pampb. 32, 70 p. 

Ross, C. P., 1960, Diverse interfingering Carbonifet·ous strata 

in the Mackay quadrangle, Idaho, in Short papers in the 

geological sciences: U.S. Geol. Survey Prof. Paper 400-B, 

p. B232-B233. 

Sando, ,V, J., Dutro, J. T., .Jr., and Gere, ,V. C., 1959, Brazer 

dolomite (Mississippian), Randolph quartrangle, northeast 

Utah : Am. Assoc. Petroleum Geologists Bull., v. 43, no. 12, 

p. 2741-27q9. 

Skipp, B. A. L., 1961, Interpretation of sedimentary features 

in the Brazer limestone near Mackay, Custer County, 

Idaho: Am. Assoc. Petroleum Geologists Bull., v. 45, no. 3, 

p. 376-387. 

Thompson, 1\l. L., 1942, New genera of Pennsylvanian fusulinids: Am .. Jour. Sci., v. 240, no. 6, p. 403-420. 

--- 1944, Pennsylvanian Morrowan rocks and fusulinids of 

Kansas: Kansas State Geol. Survey Bull. 52, pt. 7, p. 409-

431. 

I\. L, Plectogyra sp., showing large size and extensive secondary deposits; 1(, vertical axial section; USNM 628600; 

6,000 feet above argillite of Cabin Creek section: 

L, horizontal axial section ; USNM: 628601; 4,800 feet 

rubove argillite of Cabin Creek section. 

.M, Pleotogyra sp., oblique section showing small size and node 

in final chamber; USNM 628602; 2,500 feet above dolomite at base of Timbered Dome section. 

N, Plectogyra sp., horizontal axial section, partly recrystallized ;USNM 628603; 2,100 feet above base of Cherry Creek 

section. 

0, Endothyra cf . .E. 81fnt?netrica E. Zeller, 19G7, sagittal section; 

USNM 628603; 2,100 feet above base of Cherry Creek 

section. 

P, Plectogyra sp., horizontal axial section showing small size, 

small rotational distortion and lack of secondary deposits; 

USNM, 628604; 4,200 feet above ·argillites of Cabin Creek 

section. 

size, uneven coiling and rudimentary chomata ; 3,950 Q-U, Gl'(l'll·nUferella ·Sp., showing homogeneous wall and small 

feet nbove dolomite at base of Timl.Jered Dome section. 

G, sag-itt:nl section, USNl\1 (i28D98; H, axial section 

mii:;slng vroloculns, USN~I 621:i598. 

I J, Paramillcrclla. dcsigna.ta. (D. Zeller), 1953, showing eYolute final volntion nnd rudimentary chomata; 7,300 feet 

above argillite of Cabin Creek section. I, sagittal section, USNl\1 628501); J, a:dal section missing proloculus, 

U SNM ()28599. 

rotational distortion; all specimens from Cabin Creek 

section: Q, oblique section, USNl\1 628605, 4,200 feet 

above argillites; R, oblique axial section, USNl\1 628606, 

2,200 feet above argillites; S, partial oblique section, 

USNl\1 628607, 1,800 feet above argillites; '1', oblique 

section, USNl\1 628608, 1,800 feet above argillites; U, 

Gmnttli!e1·ella? sp., vertical axial section. USNl\1 

628609, 800 feet above argillites. 
C-244 GEOLOGICAL SURVEY RESEARCH 1 9 61 

Thompsoii, M:. L., 1945, Pennsylvanian rocks and fusulinids of 

east Utah and northwest Colorado correlated with Kansas 

section: Kansas Univ. Geol. Survey Bull. 60, pt. 2, p. 17-84. 

-- 1951, New genera of fusulinid Foraminifera: Cushman 

Found. Foram. Research Center, v. 2, pt. 4, p. 115-119. 

Umpleby, J. B., 1917, Geology and ore deposits of the Mackay 

region, Idaho: U.S. Geol. Survey Prof. Paper 97, 129 p. 

Woodland, R. B., 1958, Stratigraphic significance of Mississippian endothyroicl Foraminifera in central Utah: Jour. 

Paleontology, v. 32, no. 5, p. 791-814. 

Zeller, D. E. N., 1953, Endothyroid Foraminifera and ancestral 

fusulinids from the type Chesteran (Uppei· Mississippian) : 

Jour. Paleontology, v. 27, no. 2, p. 183-199. 

Zeller, E. J., 1950, Stratigraphic significance of Mississippian 

endothyroid Foraminifera: Kansas Univ. Paleont. Contri., 

Protozoa, art. 4, 23 p. 

-- 1957, Mississippian enclothyroid Foraminifera from the 

Cordilleran geosyncline [Rocky Mountains] : .Jour. Paleontology, v. 31, no. 4, p. 679-704. 

237. ANCIENT EROSIONAL CYCLES OF THE LITTLE COLORADO RIVER, ARIZONA AND NEW MEXICO 

Ry 1\1AumcE E. CooLEY and JAY P. AKERS, Tucson, Ariz. 

Worlc done in C001Jemt-ion with the Arizona State Land Depart,ment anrl the Navajo Tribe 

The Little Colorado River drains most of the southern part of the Colorado Plateau. It flows in a large 

valley carved in soft strata in the northwest-trending 

Tusayan downwarp, which has been described by 

Gregory (1917, p. 112). The Tusayan downwarp and 

the surrounding highlands are shown on figure 237.1. 

Recurrent movements of the highlands and periods 

of accelerated regional upwarping throughout middle 

and late Tertiary time have controlled the erosional 

stages of the Little Colorado River system, as shown 

on figure 237.2. Four distinct erosional surfaces have 

been recognized : the Valencia surface, named in this 

report after Valencia County, N. Mex.; the Hopi 

Buttes and Zuni surfaces, undifferentiated, named and 

described, respectively, by Gregory ( 1917) and McCann ( 1938) ; the Black Point surface, named and 

described by Gregory (1917); and the 'Vupatki surface, named and described by .Childs (1948). The 

discussion in this report is confined principally to the 

Valencia and Hopi Buttes and Zuni surfaces and the 

related deposits. 

Early studies of the Colorado Plateau by Dutton 

(1882), Davis (1901), Robinson (1907 and 1910), and 

Gregory (1947) led them to postulate a general entrenchment and development of the Colorado River 

system from a widespread erosion surface formed in 

middle and late Tertiary time. This period of ero- , 

sion has been known generally as the "Great Denudation" (Dutton, 1882) and the "Plateau Cycle" (Davis, 

1901). The following cycle, during which the river 

system was entrenched in canyons, was called the 

"Canyon Cycle." In the Little Colorado River area 

the Valencia and Hopi Buttes and Zuni cycles are 

correlative roughly with the Great Denudation and 

the Plateau Cycle, and the Black Point and vVupatki 

cycles are equivalent to the Canyon Cycle. 

After the northeastward retreat of the Late Cretaceous seas from the Arizona part of the Colorado 

Plateau, it seems likely that early Tertiary streams 

flowed in a northward direction as postulated by 

Hunt (1956, p. 73-77). Evidence for northward flow 

at this time is found in a sequence of nonvolcanic 

rocks believed to be correlative with, the Baca formation of Eocene ( ~) age, which contains pebbles of 

quartzite, granite, and fossiliferous chert and limestone derived from the Central Mountains beyond the 

southern border of the Colorado Plateau. 

The Baca formation is overlain conformably by 

the Datil formation (Oligocene), which is largely of 

volcanic origin (Winchester, 1921, p. 4)_. The Datil 

seems to have been deposited in the vicinity of the 

Arizona-New Mexico State line northward from the 

rim of the Colorado Plateau. Deposition of these 

volcanic rocks was probably accompanied by slow 

regional upwarping that caused a shift westward of 

the earlier northward flowing streams. 

These streams constituted the initial stages of the 

Little Colorado system. Differential uplift of the 
SHORT ,PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147·-292 C-245 

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Froum;; 237.1.-Iudex map of the southern part of the Colorado 

Plntf'nu showin~ structul'al elements that contt·ol the Little 

GoloJ·:Hlo Hive1· dminage system. 

Central ~fountains and of the Zuni-Defiance-Monument uplift area confined the newly developed stream 

system to the Tusayan downwarp-Mogollon slope region. This new drainage, here assigned to the Valenein. cycle, flowed generally westward and carved an 

open valley 50 to 125 miles wide. Evidence for this 

aneient valley is preserved on the relatively flat North 

Plains at altitudes between 7,000 and 7,500 feet (fig. 

237.3), and on the general accordance of summits on 

Black ~1esa at altitudes above 7,000 feet. Erosion 

surfaces of the Valencia cycle are present at altitudes 

of more than 7,500 feet beneath lavas capping Red 

Butte near the Grand Canyon and on other buttes and 

smH.ll mesns in the '\Thite ~fow1tains volcanic field. 

The reconstruction of the Valencia cycle stream 

pattern, shown on figure 237.3, was based on· contours 

drawn on the Hopi Buttes and Zuni surfaces representing the succeeding cycle (fig. 237.3) and on the 

Valencia surfaces preserved beneath volcanic caprocks. 

The amount of downcutting that occurred during the 

Valencia cycle was nearly 2,000 feet near the ArizonaNew Mexico State line, as indicated by the removal 

of much of the Datil formation and some of the underlying 1\{esozoic rocks. 

Accelerated downcutting during the early part of 

the Hopi Buttes-Zuni cycle entrenched the ancestral 

Little Colorado system to an average depth of about 

1,200 feet below the level of the Valencia surface. 

Subsequently, the lacustrine lower member of the 

Bidahochi formation (Reagan, 1924; Repenning and 

Irwin, 1954) was deposited within this valley. Later, 

after through-flowing drainage was re-established, 

eruptions in the Hopi Buttes field, represented by the 

volcanic member of the Bidahochi formation, blocked 

this old valley and caused the accumulation of the 

upper member of the Bidahochi only in the upstream 

reaches. The volcanism also diverted the ancestral 

Little Colorado River southward around the Hopi 

Buttes field to nearly its p;resent position. The upper 

member of the Bidahochi completely filled the valley 

and overlapped for short distances upon broad terraces that represented the level of the Valencia surface. 

The Hopi Buttes and Zuni surfaces on which the 

Bidahochi formation was deposited were contoured 

from data obtained from about 50 drilled wells and 

from altitudes of the outcrops (fig. 237.3). The contours indicate that an integrated drainage system was 

present and that the Defiance uplift-Chuska Mountains and the Zuni Mountains formed a divide between 

the ancestral Little Colorado system and the drainage 

in the San J nan Mountains area. The closure of the 

5,800- to 6,600-foot contour lines downstream from the 

Hopi Buttes suggests at least 700 feet of differential 

uplift between these two areas since Bidahochi time. 

The contours indicate also that the "rim gravel" near. 

Show Low and some of the volcanics on the Sari Francisco Plateau are part of the Hopi Buttes-Zuni cycle 

a11d presumably are a lateral equivalent of the Bidahochi formation. In addition, the contours confirm 

a correlation of gravel and volcanic rocks at altitudes of about 7,000 feet near Fence Lake, N. Mex., 

with the Bidahochi formation. 1 

Vigorous downcutting caused by regional uplift of 

the Colorado Plateau region during late Cenozoic time 

t G. K. Sin·ine, 1958, Geology of the Springerville-St. Johns area. 

Apache Count~·. Ariz.: 'l't>xas Unh·., AuRtin, unpublished doctoral thesis. 
C-246 

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GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

High-level deposits(?) 

Valencia surfaces and volcanics 

- --- ---- -- Erosion --- --- --- - 1------1 

c: 

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and nonvolcanic .sediments 

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Mesaverde group 

FIGURE 237.2·.-Chart showing the deposits and surfaces in the valley of the Little Colorado River. 
ID t·:. ·. ·. ·.\ COLORADO 

~ ::; \\\\·· .. _, RIVER ;2 Q. ..... # J\i ~.5 .\. ... ~roo:'~ 

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CONTOUR INTERVAL 200 FEET 

DATUM IS MEAN SEA LEVEL 

111° 

110° 

;>«oo. ?6oo ••.. ;>6'oo. 

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0 \:· ._:-::.. ">.>.. \Hopi Buttes-Zuni cycle 

'-""' ' (.' I~ ·.·.·.· 

· ... .. · .. ··.···~ - .•. - '\' ' . ........ 

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GALLO AND MANGAS 

MOUNTAINS 

WHITE MOUNTAINS 34° 

FIGURE 237.3.-:VIap showing the configuration of the base of the Bidahochi formation and the Hopi Buttes and Zuni erosion surfaces, drainage of the Hopi ButtesZuni cycle, and approximate drainage of the Valencia cycle. 

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C-248 GEOLOGICAL SURVEY RESEARCH 1 9 61 

ended the Hopi · Buttes-Zuni cycle, and during the 

following Black Point and Wupatki cycles all the 

present Little Colorado drainage system was outlined 

and entrenched. In the vicinity of Holbrook, Ariz., 

the valley of the Little Colorado River was excavated 

about 800 feet below the base of the Bidahochi formation. Downstream, the cutting was more severe, but 

upstream between St. Johns and Springerville it was 

less than 200 feet. 

REFERENCES 

Childs, 0. E., 1948, Geomorphology of the valley of the Little 

Colorado River, Arizona: Geol. Soc. America Bull., v. 59, 

p. 353-888. 

Davis, W. M., 1901, An excursion to the Grand CanyoH of the 

Colorado: Harvard Coli. Mus. Comp. Zoology Bull. 38, 

p. 108-200. 

Dutton, C. E., 1882, Tertiary history of the Grand Canyon district, with atlas: U.S. Geol. Survey Mon. 2, 264 p. 

Gregory, H. E., 1917, Geology of the Navajo country: U.S. 

Geol. Survey Prof. Paper 93, 161 p. 

-- 1947, Colorado drainage basin: Am .. Jour. Sci., v. 245, 

p. 694-705. 

Hunt, C. B., 1956, Cenozoic geology of the Colorado Plateau: 

U.S. Geol. Survey Prof. Paper 279, 99 p. 

McCann, F. T., 1938, Ancient erosion surface in the GallupZuni area, New Mexico: Am. Jour. Sci., v. 235, p. 260-278. 

Reagan, A. B., 1924, Stratigraphy of the Hopi Buttes volcanic 

field, Arizona : Pan-Am. Geologist, v. 41, no. 5, p. 355-366. 

Repenning, C. A., and Irwin, J. H., 1954, Bidahochi formation 

of Arizona and New Mexico: Am. Assoc. Petroleum Geologists Bull., v. 38, p. 1821-1826. 

Robinson, H. H., 1907, The Tertiary peneplain of the plateau 

district, and adjacent country, in Arizona and New Mexico: Am. Jour. Sci., ser. 4, v. 24, p. 109-129. 

-- 1910, A new erosion cycle in the Grand Canyon district, 

Arizona: Jour. Geology, v. 18,· p. 742-763. 

Willard, M. E., 1959, Tertiary stratigraphy of northern Catron 

County, New Mexico: New Mexico Geol. Soc. Field Conf., 

lOth, 1959, Guidebook of west-central New Mexico, p. 92-99. 

Winchester, D. E., 1921, Geology of Alamosa Creek valley. 

Socorro County, New Mexico, with special reference to the 

occurrence of oil and gas: U.S. Geol. Survey Bull. 716-A, 

p. 1-15. 

238. VEGETATION. IN RELATION TO FLOOD FREQUENCY NEAR WASHINGTON, D.C. 

By RoBERT s. SIGAFOOS, vVashington, D.C. 

Vegetation along the Potomac River near Washington, D.C., is being studied to determine the relationship between the form and distribution of plants and 

the magnitude and frequency of floods. Flood-plain 

vegetation has long been recognized as being different 

from upland vegetation (Cain and Castro, 1959; Curtis, 1959; Dansereau, 1957; Putnam and others, 1960; 

and 1Vi~tendah1, 1958). The zonation of vegetation 

from the river bank to adjoining uplands is considered by many to represent a normal succession or 

change in the development of vegetation with time. 

That is, the belief is held that the type of vegetation 

in the zone along the bank will be replaced by vegetation in the adjoining zone, and it in turn by the 

vegetation in the next zone toward the upland. In 

contrast to this view, preliminary results of this 

study show that the form and kind of trees growing 

on flood plains are determined in large part by the 

magnitude and frequency of floods. 

The study area, upon which this report is· based, 

is a small section of the flood plain of the Potomac 

River at Little Falls, a few hundred yards upstream 

from the Washington, D.C.-Maryland boundary, between the Chesapeake and Ohio canal and the left 

bank of the low water channel. The flooded area is, 

for the most part, a bedrock surface, which nearest 

the canal is covered with alluvium of undetermined 

thickness. The forest is composed of typical floodplain species. Twenty-four wood species were identified in the plots. Of these willow. (Salix L.) , 

1 

eastern cottonwood (Populus deltoides Bartr.), river 

birch (Betula nigra L.), swamp white oak (Quercus 

bicolor Will d.), slippery elm (Ulmus rubra Muhl.), 

American sycamore (Platanus occidentalis L.), boxelder (AceT negundo L.), silver. maple (Acer saocharinum L.), and ash (Fraximlus L.) are predomi-

. nant. Shingle oak (Quercus imbricaria Michx.) is 

present outside the plots, and it, along with swamp 

white oak, grows only on bedrock. 

Seven 2,500-square-foot plots were distributed in an 

area where the vegetation and topography differ with 

distance away from the river bank. Within each plot 

1 Nomenclature follows Little (1953). 
,· 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-249 

all living stems were counted, and those larger than 

0.3 inch in diameter were measured. From these data, 

the total basal area (or the total cross-sectional area 

of the stems at the point of measurement) was calculated for each plot. From this the diameter of a circle 

having an area equivalent to the mean basal area was 

determined (Spurr, 1952, p. 14). This diameter: combined with the number of stems per plot is the basis 

for describing qua'ntitatively three types of vegetation. 

These data are plotted on .figure 238.1 ( p. C-250), along 

with the elevations of the crests of 3 floods. The 3 

types of vegetation suggested by the graphical representation are as follows1. Trees about 15 inches in diameter. Plot 15 has 

14 tree species and 1 vine species. 

2. Trees about 3 to 5 inches in diameter. Plots 14a, 

14b, 16, and 17 have 7 to 13 tree species and 1 

vine species. 

a. Trees growing as shrubs having stems less than 1 

inch in diameter. Plots 21 and 22 have 3 and 4 

species respectively, of woody plants. 

The trees were inundated by floods of varying magnitude during the period of study from January 1, 

1958, to ,January 1, 1961. The. records of all floods 

during the period, March 1, 1930 to December. 31, 

1960, were examined to determine the average number of floods per year that (a) inundated the shrubby 

veget.at:on, (b) inundated small trees, and (c) inundated lower parts of the large trees. Elevation of the 

crest of each flood was measured on a crest-stage gage 

(Ferguson, 1942) located within the area, and peak 

discharge was d.etermined from U.S. Geological Survey gaging-station records. High-water marks of some 

floods were mapped on aerial photographs soon after 

the water receded. 

During the period of study the highest flood occurred May 10, 1960. The peak discharge was 124,000 

cfs (cubic feet per second) and covered all types of 

vegetation except the large trees. The depths to which 

each type of vegetation was inundated by this flood 

are shown in .figure 238.1 During the period of record, 31 years and 10 months, 17 floods equalled or 

exceeded this discharge. A flood equal to or exceeding 

this discharge thus occurs 0.5 times per year or has 

a recurrence interval of 2.0 years (Darling, 1959) 

based on the annual flood series methods described by 

Dalrymple (1960). 

The shrubby vegetation was covered by the flood 

that occurred January 25, 1958, during which the 

mean discharge for the day was 33,100 cfs; and by 

801.530 0-61-17 

the flood of March 1, 1958, with a peak discharge of 

49,000 cfs. The lower flood of January 25, 1958, covered the vegetation to depths of 1 to 6 feet. The 

higher flood of March 1, 1958, covered it to depths of 

3 to 8 feet and barely covered the bases of some of the 

small trees. 

During the period of record, the shrubby vegetation 

has been flooded 155 times, or on an average of 4.8 

times per year. The small trees have been flooded 17 

times or approximately once every 1.8 years. The 

larger trees have been flooded less frequently. 

The shrubby vegetation is scarred by occasional 

minor ice floes like one that occurred on January 20, 

1958, but these floes are of minor extent and are not 

recorded. It is not known whether 155 floods plus 

occasional ice floes and jams are more important in 

determining the shrubby form of these plants than are 

the higher stream velocities and greater depths during 

17 floods greater than 124,000 cfs that occurred during 

the same period. 

The 3 types of vegetation that occur on the flood 

plain of the Potomac River in the study area are thus 

flooded at different frequencies, and the vegetation at 

10\ver elevations is flooded at greater depths. The 

form and species composition of these types are related to the magnitude and frequency of flooding. 

An analysis of flood history would aid in any study 

of flood-plain vegetation, and conversely. a study of 

flood-plain vegetation wi1l aid in the analysis of flood 

frequency of selected areas. 

REFERENCES 

Cain, S. A., and Castro, G. l\L de 0., 1959, Manual of vegetation 

analysis: New York, Harper and Brothers, 325 p. 

Curtis, .J. T., 1959, The vegetation of Wisconsin: Madison, 

Univ. Wisconsin Press; 657 p. 

Dalrymple, Tate, 1960, Flood-frequency analyses: U.S. Geol. 

Survey Water-Supply Paper 1543-A, p. 1-80. 

Dansereau, Pierre, 1957, Biogeography: New York, The Ronald 

Press, 394 p. 

Darling, .J. M., 1959, Floods in Maryland-magnitude and frequency: U.S. Geol. Survey open-file report, 9 p. 

Ferguson, G. E., 1942, Gage to measure crest stages of streams: 

Civil Eng., v. 12, p. 570-571. 

Little, E. L., Jr., 1953, Check list of native and naturalized 

trees of the United States: U.S. Forest Service Agr. 

Handb. 41, 472 p. 

Putnam, .J. A., Furnival, G. M., and McKnight, .J. S., 1960, 

Management and inventory of southern hardwoods: U.S. 

Forest Service Agr. Handb. 181, 102 p. 

Spuu, S. H., 1952, Forest inventory: New York, The Ronald 

Press, 476 p. 

Wistendahl, W. A., 1958, The flooo plain of the Raritan River, 

New .Jersey: Ecol. Mon., v. 28, p. 129-153. 
C-250 

5 

Type 1 

Large trees 

GEOLOGICAL SURVEY RESEARCH 19 61 

Type 2 

Small trees 

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Shrubby trees 

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0 50 100 0 0 50 

15 16 14b 

A 

0 50 100 0 50 

NUMBER OF WOODY STEMS COUNTED 

14a 17 

PLOT NUMBER 

., 

I 

I 

I 

0 50 

21 

0 50 100 

22 

FIGURE 238.1.-Graphical representation of flood and botanical data. Three vegetation types are separated by vertical dashed lines. 

.~-

A, Number in bar is number of woody species counted. B, Diagrammatic representation of plots and vegetation types. Dashed \' 

horizontal lines indicate crests of observed floods. 
.. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-251 

239. SOIL-WATER AVAILABILITY AND USE BY GRASSLANDS ON ADJACENT STONY AND SHALE-DERIVED 

SOILS IN COLORADO 

By F. A. BRANSON, R. F. MiLLER, and I. S. McQUEEN, Denver, Colo. 

Worl.; done in cooperation with U.S. Soil Conservation Service 

Adjacent to the foothills of the Rocky Mountains in 

Colorado the number and variety of plants growing on 

stony soil are greater than the number and variety 

growing on shale-derived soil. A study of the causes 

of this difference was carried out at two nearby sites 

about 8 miles north of Golden, Colo. 

One study site is on a stony soil that has developed 

on a pediment surface locally known as Rocky Flats 

(fig. 239.1). The gravel capping on Rocky Flats is 

from 1 to 50 feet thick and averages about 10 feet 

thick (Mal de, 1955). This deposit is believed to be of 

Pleistocene age and has been named Rocky Flats alluvium (Scott, 1960). The other site is nearby on a 

soil derived from the Pierre shale of Late Cretaceous 

age (fig. 239.2) (Van Horn, 1957). 

The Rocky Flats site is 6,250 feet in altitude; the 

Pierre shale site is 300 feet lower at 5,950 feet. This 

difference is negligible in effect on the plant communities. 

The climate in the area of the study sites is similar 

to that of other parts of the central Great Plains in 

that dry cool winters and moist warm summers are 

characteristic. The average annual precipitation at 

Boulder, Colo., about 11 miles north of Rocky Flats, 

is 18.3 inches. The precipitation probably is slightly 

greater on the study sites, which are 700 to 1,000 feet 

higher in altitude. About 66 percent of the preFIGURE 239.1.-Vegetation on stony soil. Mountain muhly and 

big bluestem are the dominant grasses shown. 

FIGURE 239.2.-Vegetation on soil derived from the Pierre shale. 

The conspicuou!; midgrasses are western wheatgrass and 

Japanese brome. The shortgrass in the foreground is 

buffalograss. The rock outcrop in the background is sandstone of the Laramie formation. 

cipitation occurs during the growing season of April 1 

to September 30. Average monthly temperature at 

Boulder ranges from 32.5°F in January to 73.6°F in 

July and the average annual temperature is 50.8°F. 

The data i.il table 239.1 show that most of the species occurring on the two soils are different and that 

the few species common to both sites are present in 

different amounts. The numbers of species present 

are also greatly different on the two soils. As shown 

in table 239.2, many more species of forbs and grasses 

and fewer species of shrubs are present on the stony 

soil than on the shale-derived soil. 

Most of the species present on the shale-derived soil 

are those commonly found at altitudes of 1,500 to 6,000 

feet on the central and northern Great Plains. They 

are classified as the mixed prairie association of the 

grassland formation (Weaver and Clements, 1938) . 

Western wheatgrass (Agropyron smithii Rydb.), blue 

grama (Bouteloua gracilis (H.B.K.) Lag.), and buffalograss ( Buchloe dactyloides (N utt.) Engelm.) are 

the most abundant perennial plants on the shale-derived soil. 

Most of the species present on the stony soil are 

those usually found at altitudes above 6,000 feet in 

the Rocky Mountains. The plant assemblage on the 
C-252 GEOLOGICAL SURVEY RESEARCH 1 9 61 

·stony soil is remarkable, however, because it contains 

relatively large quantities of a few true prairie species typical of grasslands of eastern Nebraska and 

Iowa (Weaver and Fitzpatrick, 1934). Big bluestem 

(Andropogon gerardi Vitman.), _little bluestem (.A. 

scoparius Michx.), and Indian grass ( S orghastrwm 

TABLE 239.1.-Vegetation and surface features on a stony soil 

and an adjacent shale-derived soil as determined by the allcontacts point-quadrat method (Levy and Madden, 1933) 

Stony son 

Vegetation 

Grasses 

Muhlenbergia montana (Nutt.) 

Hit.chc. 

Mountain muhly ________ 

Schedonnardus paniculatus 

(Nutt.) Trel. 

26.0 

Tumblegrass ___________ ------ Sitanion hystrix (Nutt.) J. G. 

Smith 

Squirrel taiL ____________ 

Sorghastrum nutans (L.) Nash. 

1.2 

Indiangrass ____________ 

Sporobolus cryptandrus (Torr.) 

3. 2 

A. Gray 

Sand dropseed __________ 0. 1 Other grasses _______________ 0. 6 

Forbs 

Arenaria fendleri A. Gray Sand wort ______________ 3. 0 

Artemisia ludoviciana Nutt. Sagewort _______________ 1. 6 

Carex heliophila Mack. 

Sun sedge ______________ 

Erigeron strigosus Muhl. ex Will d. 

0. 5 

Fleabane _______________ 1.3 

Liatris punctata Hook. 

Blazing star ____________ 

Paronychia jamesii T. & G. 

2. 5 

Whitlow-wort __________ 2. 5 

Petalostemon purpureum (Vent.) 

Rydb. Purple prairie clover _____ 1. 1 

Chrysopsis villosa (Pursh) 

Nutt. 

Hairy gold aster ________ 1. 7 Other forbs _________________ 8. 3 

Shrubs 

Gutierrezia sarothrae (Pursh) 

Britt. 

23. 6 

--------

1. 1 

2. 9 

0. 1 

0. 6 

2. 8 

1.4 

0. 5 

1.2 

2. 3 

2. 3 

1.0 

1.6 

7. 3 

Shale-derived soil 

Percent I Hits per compo- 100 pins 

sition 

------ --------

1.7 1.7 

------ --------

------ --------

1.0 1.0 

1. 1 1. 1 

------ --------

------ --------

1.9 1.9 

------ --------

------ --------

------ --------

------ --------

------ -------- 2. 5 2. 4 

Snake weed_________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4. 4 4. 3 

Other shrubs_______________ 0.1 0. 1 1.1 1. l 

Mulch __ ---________________ 34. 9 65. 1 50. 1 99. 8 

Rock---------------~------ 12.0 22.3 _____________ _ Bare- - - - - -- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4. 3 8. 1 3. 3 6. 5 

Total hits ________________________ 1, 545.0 -,----- 1, 793.00 

Total pins________________________ 830.0 900.0 

TABLE 239.2.-Numbers of species of grasses, forbs, and shrubs on stony soil and on shale-derived soil 

Pl811t group Stony soU Shale-derived son 

Grasses ____________________________ _ 25 13 Forbs _____________________________ _ 56 21 Shrubs ____________________________ _ 2 4 

TotaL _________________________ _ 83 38 

nut(]Jfl)3 (L.) Nash.) are the dominant species in true 

prairie and are a significant part qf the vegetation of 

Rocky Flats. Livingston (1952) proposed that true 

prairie species occurring in and near the Black Forest 

of Colorado have persisted on high mesas since theretreat of the continental glaciers about 10,000 years ago, 

and this may be true of the species found at the Rocky 

Flats site. Although these true prairie grasses are 

abundant on Rocky Flats, they are of minor importance in terms of numbers of species present (table 

239.3). 

Different rates of percolation into the two soils 

affect the quantities of soil moisture available for plant 

use. In table 239.4 infiltration rates for two plant 

types on each of the two soils are shown. The highest 

rate measured on the shale-derived soil was 1.90 inches 

per hour, which was less than one-half the lowest rate 

measured on the stony soil. The higher rates oi infiltration on the stony soil permit greater storage of 

moisture for use by vegetation (fig. 239.2). 

Other factors that may explain the presence of contrasting plant communities on the two soils include 

soil-moisture percentage, soil-moisture tension, and 

soil temperature (fig. 239.3). 

Based on the assumption that soil moisture would 

not be retained by fine and coarse gravel, soil-moisture 

percentages' were computed only for the smaller than 

2 mm fraction of the stony soil. Soil-moisture percentages were considerably greater in the stony soil 

early in the growing season and remained higher during the entire growing season. 

TABLE 239.3.-Relationships of nurnbers of species present on stony and shale-derived soils near Golden, Colo., w other vegetation associations and geographic locations 

Vegetation type or geographic origin 

True prairie _______________ ~ ________ _ Montane ___________________________ _ 

Mixed prairie _______________________ _ 

Mixed prairie and true prairie ________ _ Mixed prairie and montane __________ _ 

Introduced-----------~---~---------­

Mixed prairie, true prairie, and montane_ 

Total __________ ~----------------

Stony soil 

6 

31 

24 

6 

11 

4 

1 

83 

Shale-derived son 

----------3 

24 

1 

4 

4 

2 

38 
+, 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTfCLES 147-292 C-253 

MOISTURE, IN PERCENT, OR TEMPERATURE, IN DEGREES CENTIGRADE 

20 

IJ) 

UJ 

J: 

u 

~ 

~ 

:i 

li: 

UJ 

0 

40 

500 100 50 10 54 3 100 50 10 5 4 3 

MOISTURE TENSION. IN ATMOSPHERES 

EXPLANATION 

... -~-~ 

Shale-derived soil Stony soil 

Fin UIUD 23H.3.-Soil moisture (M), soil-moisture tension (T), and soil temperature (C), in adjacent stony- and shale-derived soils for 

samples obtained April 11. and August 11, 1960. 

TABJ..l<:: 239.4.-lnfiltration rates of sinmlated rainfall on shalederived and stony soils under given kinds of vegetation 

['l'wo 1-hour measurements were made on each plant-soil type) 

Infiltrntlon rnte (inches per hour) 

Hate or ralnrall Shale-derived soli Stony soil 

BufTnlo- Western Di~ bluestem Cheatgrnss 

grass wl1eatgrnss Blue grama brome 

High __________ 1. 90 1. 10 4. 80 7. 35 Low ___________ 1. 87 . 40 3. 90 4. 60 

A vemge _____ -- 1. 89 . 75 4. 35 5. 98 

Soil-moisture tensions were generally higher in the 

shale-derived soil than in the stony soil. 

Early in the growing season (April 11) soil temperatures in the upper 10 inches of the stony soil 

exceeded those of the shale-derived soil, but near the 

end of the growing season soil temperatures were 

higher n,t all depths in the shale-derived soil (August 

11). 

These results indicate that the greater quantities 

of available soil moisture in the stony soil apparently 

is the major causative factor for the presence of the 

more varied flora on this soil. 

REFERENCES 

Levy, E. B., and Madden, E. A., 1933, The point method of 

pastm·e analysis: New Zea:Jand Jour. of Agriculture, v. 46, 

p. 267-279. 

Livingston, R. B., 1952, Relict true prairie communities in 

central Colorado: Ecology, v. 33, no. 1, p. 72-86. 

Malde, H. E., 1955, Surficial geology of the Louisville qua.drangle, Colorado: U.S. Geol. Survey Bull. 996-E, p. 217-

257. 

Scott, G. R., 1960, Subdivision of the Quaternary alluvium east 

of the Front Range near Denver, Colorado: Geol. Soc. 

America Bull., v. 71, p. 1541-1544. 

Van Horn, Richard, 1957, Bedrock geology of the Golden quadrangle, Colonulo: U.S. Geol. Survey Geol. Quad. Map 

GQ-103. 

Weaver, .J. E., nnd Clements, F. E., 1938, Plant ecology: New 

York, McGraw-Hill Book Co., Inc., 601 p. 

Weaver, J. E., and Fitzpatrick, T. J., 1934, The prairie: 

Ecol. Mon., v. 4, no. 2, p. 112-259. 
C-254 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

GEOPHYSICS 

240. A SEISMIC RECORD OF MESOZOIC ROCKS ON BLOCK ISLAND, RHODE ISLAND 

By CuRTIS R. TuTTLE, "riLLIAM B. ALLEN, and GLENN W. HAHN, Boston, Mass., and Providence, R.I. 

Work done in cooperation with the Rhode Island Water Resou,rces Coordinating Board 

In June 1960, six refraction seismic traverses were 

made on Block Island, R. I.; three of these were reversed. Seismic travel times have been compared with 

drillers' logs from 4 borings made in June 1960, and 

6 borings from existing water wells. The location QT 

seismic and boring sites and the profile made from the 

physical measurements are shown on figure 240.1. 

Four subsurface geologic units, based on longitudinal wave speeds (Vo, V1, V2, and Va) were found: 

a weathered zone ( V0 ) , an underlying unconsolidated 

zone (V1), a semi-consolidated zone (V2), and a crystalline zone (V3 ). This nomenclature is defined by 

Ewing and others ( 1937). 

The seismic low-velocity layer (weathered zone of 

Ewing and others, 1937) is mostly drift of Pleistocene age 16 to 153 feet thick and it has an average 

longitudinal wave speed (Vo) o£ 3,200 feet per second. 

All material above the base of brown sediments shown 

on figure 240.1 is of Pleistocene age; some light-colored sediments below this line are probably of Pleistocene age. Clearly the V0-V1 discontinuity (fig. 240.1) 

does not represent a sharp lithologic or age boundary 

except at boring 62 where a change in wave speed, a 

change in color, and a change in lithology occur at 

the same horizon. 

Fenneman (1938, p. 14-15) implies that Block Island has a Cretaceous substratum which is the crest 

of a cuesta whose inner lowland is· submerged in 

Block Island Sound. The presence of a subsurface 

zone of Cretaceous age is verified by the presence of 

an unconsolidated zone that is 408 to 856 feet thick 

and extends beneath the entire profile shown on figure 

240.1. This zone has an average longitudinal wave 

speed of 6,270 feet per second. It is believed to be 

represented in part by white clay exposed in the northern Cretaceous outcrop, figure 240.1, and identified as 

the Magothy clay by Woodworth (1934). At this locality, sediments of Cretaceous age are unconformably 

overlain by brown Pleistocene drift. Further, boring 

62 penetrated 35 feet of white clay and 135 feet of red 

clay similar to that described as Cretaceous by Woodworth. At points 4 A and 4 0 (fig. 240.1) only the 

m1n1mum thickness of the unconsolidated zone is recorded because a much shortened traverse was necessitated by topography and culture. The maximum 

wave speed at this site ranges from 5,900 feet per second to 6,600 feet per second. 

The unconsolidated zone is probably correlative with 

other geologic units found nearby. Suter and others 

( 1949) list Cretaceous rocks from well 189 in Suffolk 

County, Long Island, N.Y. This well is about 35 

statute miles west of Block Island. Offshore from 7 

to 21 statute miles southeast of the island is 600 feet 

of so-called "semiconsolidated" material with a longitudinal wave speed of 6,470 feet per second (Oliver 

and Drake, 1951). This layer is thought to be correlative with the unconsolidate.d zone on Block Island. 

At a second offshore site, 36 to 37 statute miles east of 

Block Island, Ewing and others ( 1950) measured a 

layer with a longitudinal wave speed of 5,800 feet 

per second. 

The semiconsolidated zone has a thickness of 755 

feet and an approximate average longitudinal wave 

speed of 12,200 feet per second at point 3 .A. This 

traverse was unreversed; however' the maximum speed 

computed for trayerses 2 A to 2 D and 5 A to 5 D 

ranges from 11,300 to 12,900 feet per second. The 

short traverses required· by the topography and the 

culture did not allow measurement of the entire thickness of this zone. This material may be of Cretaceous 

age, as suggested by the wave speed of 9,750 to 11,500 

feet per second of a semiconsolidated layer reported 

offshore east of the Island by Ewing and others 

(1950). Or, the semiconsolidated zone on Block Island may be sandstone of Triassic age, similar to the 

Longmeadow sandstone-which has a wave speed of 

13,000 feet per second in the Connecticut River valley 

as measured by Tuttle and others (1960). Stetson 

(1949) reports sandstone of Cretaceous age obtained in 

place from tows along submarine canyons on Georges 

Bank. 

The crystalline zone at point 3 A has a speed of 

19,700 feet per second and is inferred to consist of 

Paleozoic or older rocks similar to the bedrock ex-

.+ 
\. 

-500 

-1000 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

EXPLANATION 

68 • 

Boring 

3A,.•~---

Seismic profile unreversed 

50* 1t5A 

Seismic profile reversed 

Outcrop of Cretaceous • rock 

{JBLOCK ISLAND 

INDEX MAP 

,.-----WEATHERED ZONE -----... 

BLOCK ISLAND 

C-255 

N 

1 

lMILE 

Plan of seismic traverses and borings 

········ Base of. b~o~ii· secfirr1ents. . .. 

UNCONSOLIDATED ZONE V 1-6270 feet per second 

------- --

SEMICONSOLIDATED ZONE V2-12,200 feet per second 

CRYSTALLINE ZONE V3 -19,700 feet per second 

SUBSURFACE PROFILE 

FtoURl'J 240.1.-Map showing seismic traverses and borings, and subsurface profile, Block Island, H..I. 
C-256 GEOLOGICAL SURVEY RESEARCH 1961 

posed on the mainland of eastern Connecticut and 

western Rhode Island. Speeds of 18,625 to 19,450 

feet per second were measured by Oliver and Drake 

(1951) offshore 7 to 21 miles southeast of the island 

and are of the same order of magnitude. 

The identification of subsurface geologic units of 

Cretaceous age and of possible Triassic age are similar 

to findings of other geophysicists along the coast of 

New York and New England. No sediments of Tertiary age were recognized in the zones measured ; however, speed discontinuities do not occur everywhere 

at age or lithologic boundaries. Tertiary rocks may 

be present inasmuch as Eocene rocks have been reported by Zeigler and others ( 1960) from eastern 

Cape Cod. The speed of seismic waves in these Eocene 

silt and sand units is 4,900 to 5,900 feet per second (C. R. 

Tuttle and R.N. Oldale, written communication, 1960). 

REFERENCES 

Ewing, Maurice, Crary, A. P., and Rutherford, H. M., 1937, 

Geophysical investigations in the emerged and submerged 

Atlantic Coastal Plain, Part I, methods and results: Geol. 

Soc. America Bull., v. 48, p. 763-764. 

Ewing, W. M., 'Vorzel, J. L., Steenland, N. C., and Press, Frank, 

1950, Geophysical inves"tigations in the emerged and submerged Atlantic Coastal Plain, Part V, Woods Hole, New 

York, and Cape May sections: Geol. Soc. America Bull., 

v. 61, no. 12, pt. 2, p. 877-892. 

Fenneman, N. M., 1938, Physiography of eastern United States: 

New York, McGraw-Hill Book Co., Inc., 714 p. 

Oliver, J. E., and Drake, C. L., 1951, Geophysical investigations 

in the emerged and submerged Atlantic Coastal Plain, 

Part VI, the Long Island area: Geol. Soc. America Bull., 

V. 62, p. 1287-1296. 

Stetson, H. C., 1949, The sediments and stratigraphy of the 

east coast continental margin; Georges Bank to Norfolk 

Canyon: Massachusetts Inst. '£echnology and Woods Hole 

Oceanog. Inst. Papers in Physical Oceanography and 

Meteorology, v. 11, no. 2, p. 33, table 1. 

Suter, Russell, deLaguna, Wallace, and Perlmutter, N. M., 

1949, Mapping of geologic formations and aquifers of Long 

Island, New York: New Y,ork Water Power and Control 

Comm., Bull. GW-18, p. 117. 

Tuttle, C. R., Koteff, Carl, and Hartshorn, J. H., 1960, Seismic 

investigations in the Connecticut River valley, southern 

Massachuetts [abs.] : Geol. Soc. America Bull., v. 71, no. 12, 

p. 1994. 

Woodworth, J. B., 1934, Geology of Block Island, in Woodworth, J. B., and Wigglesworth, Edward, Geogt·aphy and 

geology of the region including Cape Cod, the Elizabeth 

Islands, Nantucket, Martha's Vineyard, No Man's Land, 

and Block Island: Harvard College Mus. Comp. Zoology 

Mem. v. 52, p. 212-219. 

Zeigler, .T. M., Hoffmeister, W. S., Giese, Graham, and Tasha, 

Herman, 1960, Discovery of Eocene sediments in subsurface 

of Cape Cod: Sci., v. 132, no. 3437, p. 1397-1398. 

241. ELECTRICAL PROPERTIES OF SULFIDE-MINERALIZED GABBRO, ST. LOUIS COUNTY, MINNESOTA 

By C. J. ZABLOCKI, Denver, Colo. 

During geophysical exploration of the Duluth gabbro, the Bear Creek Mining Co. discovered extensive 

conductive areas that were later drilled in the search 

for sulfide ore. The holes penetrated the Duluth 

gabbro and older sedimentary rocks. All the rocks are 

of Precambrian age. Sulfides, predominantly pyrrhotite, and some disseminated graphite occur in an olivine-rich gabbro, in hornfels, and in a dense finegrained gabbro containing hornfels. In-hole measurements have been made of self-potential, resistivity, 

conductivity, induced polarization, and magnetic susceptibility. The logging devices used are described 

by Zablocki and Keller ( 1957). Typical logs obtained 

in the study are shown on figure 241.1. The Bear 

Creek Mining Co. kindly gave permission to make 

the study, and Mr. James Mancuso provided core logs 

and assay data. 

Very large potential differences, as great as 0.5 volt, 

were recorded on the self-potential logs; potentials 

opposite sulfide-bearing rocks were positive relative 

to potentials opposite barren gabbro. These large potential differences are caused by electrochemical reactions within the sulfides. 

The resistivity of rocks containing neither g.raphitc 

nor sulfide minerals in large amounts is moderately 

large, about 2,000 ohm-meters. Rocks containing more 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-257 

SELF -POTENTIAL 

IN MILLIVOLTS 

4-INCH NORMAL 

RESISTIVITY, IN 

OHM-METERS 

GUARD CONDUCTIVITY 

IN MHOS PER METER 

INDUCED 

POLARIZATION 

MAGNETIC SUSCEPTIBILITIES 

IN X 10- 3 CGS UNITS 

CORE 

DESCRIPTION 

SULFIDES. IN 

WEIGHT PERCENT 

(VISUAL ESTIMATE) 

r-:-_,2ooo""--_4;:_,o, 0 5 10 15 1oo 10-4 10- 3 10- 2 

oo phase--

90° phase25 

50 

75 

100 

125 

150 

175 

200 

225 

250 

275 

Olivine gabbro 

with 60 percent 

mafic minerals 

Hornfels 

FumRE 241.1.-Geophysical borehole logs in sulfide-minerali2'ed gabbro and hornfels, near Babbitt, Minn. The guard conductivity 

log is plotted on a nonlinear scale; the induced polarization logs are plotted in relative units. 

than 7 percent sulfides by weight are highly conductive, and have resistivities less than 0.1 ohm-meter. 

Cert11in hornfels were found to have a low resistivity 

regnrdless of whether they contnined large amounts 

of sulfide minerals. Apparently the sulfide-free 

hornfels contain a high enough concentration of 

graphite to render them conductive. 

Induced-polarization logs were made using the repeating pulse method. A standard normal resistivity 

array was used, except that the current electrodes 

were powered by a series of current pulses rather than 

by a continuous current. The voltage at the pickup 

electrodes during the current pulses is separated electronicuJly from the voltage at the pickup electrodes 

duritlg the intervals between current pulses. These 

two voltag-es were recorded separately as the in-phase 

and out-of-phase signals, as indicated on figure 241.1. 

The ftmplitude of the induced polarization is proportional to the. ratio of the out-of-phase voltage to inphase voltage. 

The largest ratios, and thus the greatest induced 

polarization, were recorded in gabbro containing only 

a few percent of sulfide minerals. The highly mineralized conductive zones exhibit. much lower induced 

polarization. This behavior is typical of rocks in 

TABLE 241. I.-Average values of the properties measured. 

Induced 

polari- Magnetic 

zation, suscepti- Rock description Resistivity (ohm- ratio of bility meters) out-of-phase (10-6 cgs to in-phase units) 

(percent) 

Olivine gabbro (barren) __ >4, 000 <I 1,000 

Olivine gabbro ( ~ 2.5 

percent sulfides) _______ >2, 000 3 to 5 1, 500 

Olivine gabbro <> 10 

percent sulfides) _______ < .. 1 1 to 3 4,000 

Hornfelsic gabbro .(barren, fine-grained, hornfelsic texture) _________ 2, 500 -------- <1, 000 

Hornfelsic gabbro ( < 7 

percent sulfides) _______ <.01 to >2, 000 -------- 5,000 

Hornfelsic gabbro (>7 

percent sulfides) _______ <.1 -------- 15,000 

Iron formation (10 to 15 

percent Fe304)-- __ ---- <2, 500 -------- 45,000 

Hornfels (disseminated 

graphite and quartzite)_ <0.1 to >4, 000 -------- <500 

Hornfels (>7 percent sulfides) ______________ <· 1 1 to 3 10,000 

which the conductive minerals occur in conti\1uous 

chains rather than as disseminated particles. 

The I'nagnetic susceptibility appears to be determined by the amount of pyrrhotite in the rock. Very 

little magnetite was observed in the core samples. 
C-258 GEOLOuiCAL SURVEY RESEARCH 1 9 6 1 

The susceptibility of the hornfels is about hYice as 

high as that of the gabbro, even though both rocks 

contain about the same amount of pyrrhotite. However, the pyrrhotite appears to form continuous chains 

in the hornfels and not in the gabbro. The same 

amount of magnetic material may ''"ell have a higher 

susceptibility when it is continuous than when it is 

disseminated. 

The average values of the properties measured are ·· 

tabulated in table 241.1 according to rock type. 

REFERENCE 

Zablocki, C. J., and Keller, G. V., 1957, Borehole geophysical 

logging methods in the Lake Superior district, in Seventh. 

annual drilling symposium, exploration drilling: Minnesota Univ. Center for Continuation Study, p. 15-24. 

242. STRUCTURE OF PLUTONS FROM GRAVITY MEASUREMENTS 

By MARTIN F. l{ANE, Washington, D.C. 

Detail gravity measurements made in 1959 show the 

subsurface shape of two outcropping mafic intrusives, 

one in l\1aine and one in Pennsylvania. Mafic intrusives "·ere chosen for study because their high density 

usually causes large positive gravity anomalies. The 

outcrops form the upper surface of the gravitating 

bodies, 'vhich makes interpretation much more certain 

than usual. The stations were placed along traverses 

normal to the outcrop pattern and were spaced short 

distances apart compared to the width of the outcrop. 

Closer spacing was used in the immediate vicinity of 

the surface contacts. The measured gravity profiles 

and best-matching theoretical values for hypothetical 

bodies are shown in figures 242.1 and 242.2. The theoi'etical values were computed graphi.cally, using the 

densities of representative. rock samples from each 

area. 

One of the intrusives is a gabbro body (fig. 242.1) 

near the south end of Moosehead Lake in l\1aine. It 

has an east-trending linear outcrop pattern and intrudes highly compacted sedimentary rocks of Paleozoic age. The measured and computed gravity ·anom-

; alies show. that the boundaries of the gabbro are 

marked by steep gravity gradients; the dip is shown 

by the direction of offset in the peak amplitude. The 

best-matching computed values indicate that the body 

is dike like in shape, dips east about 60°, and extends 

to a depth of a few miles. The small departures between the two profiles are probably caused by small 

changes in density or by .a. slight widening or curvahire of the body with depth. A series of profiles were 

computed for different shapes, and in all the profiles 

the steep gradients noted above occur over the contacts and therefore can be used to locate them. For 

dikelike bodies, the direction of offset in the peak amplitude indicates the direction of dip; ho,vever, the 

depth extent of the bodies can only be expressed approximately because the resolving power of gravity 

decreases sharply with depth. 

A diabase sill (fig. 242.2) that forms Solebury 

l\1ountain in Bucks County, Pa., was also studied. 

The sill and the sedimentary ·rocks it intrudes are Triassic in age. As with the gabbro, the contacts and 

direction of dip are shown by the characteristic steep 

gradients and the offset in the peak amplitude. The 

best-matching computed values indicates that the sill 

dips about 20° and extends at least· half a mile deep. 

A comparison of the gravity profiles in figures 242.1 

and 242.2 shows a marked difference in the shape of 

the profiles. The difference is caused by the change 

in dip, indicating that a rough estimate of the amount 

of dip can be obtained by simply inspecting the measured gravity profile. 

Comparison of several computed profiles suggested 

that the range of density contrasts that give a good 

definition of the intrusive is limited. In l\1aine, profiles made over irregularly shaped felsic plutons that 

are less dense than the rock into which they were 

intruded gave much information on location of contacts, and on size and shape of the intrusives, but the 

profiles are less helpful than profiles over dikelike 

bodies. 
N 

Sea level 

1-

LJ..J 

LJ.J 

5000 

I.&... 10,000 

15,000 

(/) 

.....J 

<( 

(.!) 

::J 

.....J 

~ 2 

1 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, .ARTICLES 147-292 

EXPLANATION 

..,...,------ Residual measured gravity 0 Computed gravity 

0 --- --- 0 0 

Paleozoic sedimentary rocks 

Density=2.8 g per cm3 

Paleozoic sedimentary rocks 

Density=2.8 g per cm3 

0 2 3 4 5 MILES 

FIGURE 242.1.-Gravity profile and section over gabbro body near south end of Moosehead Lake, Maine. 

0 ,1' ...... ~ 

/ 0 ' o/ o, 

/ ' / '0 0 ..... 

/ ' 

I '~ 

EXPLANATION 

,.,--- ........ -._-- _.,., 

Residual measured gravity 

0 

Computed gravity 

/0 ' / '0 

/o ~, 

/ ' 0 

~ ' o---: o ', o ...... ....... 

0 

C-259 

s 

0~------------------------------------------------------------------~'~--------------~ 

1-

w 

w 

LL. 

s 

Triassic sedimentary rocks 

Density=2.6 g per em~ 

0 

Triassic sedimentary rocks 

Density=2.6 g per cm3 

1 Ml LES 

l<'InURE 242.2.-Gravity profile and section over diabase sill, Solebury Mountain, Bucks County, Pa. 

N 
C-260 GEOLOGICAL SURVEY RESEARCH 1961 

243. RELATION BETWEEN GRAVITY AND STRUCTURE OF PART OF THE WESTERN FLANK OF THE BLACK 

HILLS, SOUTH DAKOTA AND WYOMING 

By R. A. BLACK and J. C. RoLLER, Denver, Colo. 

Work done in cooperation with the U.S. Atomic Energy Commission 

A regional gravity survey delineates the major 

structural features of part of the west flank of the 

Black Hills in the area between lat 43°30' and 44°00' 

and long 103°521j2 ' and 104°30', South Dakota and 

Wyoming (figs. 243.1 and 243.2). Results are presented in this report. 

The Black Hills are described by Darton and Paige 

( 1925) as an irregular dome-shaped anticline, elongated northwest and southeast, asymmetrical with the 

steep side on the west, and covering an area about 

125 miles long and 60 miles wide. Bartram ( 1940) 

states that the Black Hills were formed during the 

Laramide Revolution in Late Cretaceous to early Eocene time. Noble ( 1952) regards the Black Hills as 

consisting of two uplifted blocks,. the main one with 

its axis trending nearly north, and the other with an 

axis trending northwest. The uplift is most abrupt 

on the western flank of the Black Hills near the town 

of Newcastle, Wyo., where the two blocks join. Noble 

(1952) proposed that predominantly vertical forces 

--goComplete Bouguer 

anomaly. Contour i·nte1'Val2 milligal• 

A A' 

Geologic section, figure 3 

FIGURE 243.1.-Complete Bouguer gravity map of part of the 

western flank of the Black Hills. 

104"30' 44"00' 

EXPLANATION 

--2000--

Structure contour Drawn on top of the Fall River formation. 

Contour interval 500 feet 

CAVE 

NW 

103'52' 30" 

FIGURE 243.2.-Structural contour map of part of the western 

flank of the Black Hills. 

associated with igneous intrusion are responsible for 

the main structural features of the Black Hills. Chamberlin ( 1945) suggested that compression in a northeast-southwest direction may have produced north 

and 'vest.:.northwest shear zones that determined the 

outline of the. Black Hills and perhaps produced the 

uplift~ Whatever the origin of the uplift, it is of sufficent magnitude to be reflected in the regional gravity measurements, especially near Newcastle. 

Standard gravity field methods and reduction techniques were used in the work. Stations were occupied at intervals of about 1 to llj2 miles. Where 

available, 71f2-minute topographic maps were used to 

locate gravity stations at points where elevations were 

known to the nearest foot. Altimeters an~ county 

road maps were used in areas where topographic 

.maps were not available. 

Observed gravity was based on a value of 980,145 

milligals for pendulum station 270 at Newcastle, Wyo. 

(Duerksen, 1949). The gravity data were reduced to 
.:.... 

~· 

,-

SEA 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

~B <( 

(.!) 

:J 

..J 

~ 

~ 

~ 

B' ~--~------------~~--------~~--~-100 

Complete Bouguer gravity profile 

-110 $ 

Computed gravity value 

> <( 

0::: L-------------------------------------------------------------------~-120 

(.!) 

6000' r4000' 

2000' 1-

LEVEL 1-

2000' t4000' 

6000' 

0 

A 

-75 

-85 (/) 

..J 

<( 

(.!) 

:J 

..J -95 

~ 

~ 

~ -105 

> <( 

0::: 

(.!) 

- 115 

- 125 

(/) 

;;_ 20 (.!) 

:J 

..J 

::!E 

z 10 

I 

10,000 

I 

10,000 

.l 

20,000 

Ground surface profile 

Sedimentary rocks 

J 

Basement rocks _l 

30,000 

I .l 

40,000 50,000 

HORIZONTAL DISTANCE, IN FEET 

Residual gravity profile 

0 

Computed gravity value 

_.... .... Ground surface profile......., 

Sedimentary rocks 

I 

J Basement rocks 

I l I 

20,000 30,000 • 40,000 

-

-

-

-

-

-

60,000 

A' 

""' 

-= 

'-

-

-

50,000 

C-261 

FtGURE 243.~.-Generalized geologic sections along.lines A-A' and B-B' determined by two-dimensional graticule analysis. 
C-262 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

a sea level datum by using an elevation correction 

factor of 0.063 milligal per foot, which corresponds 

to a density of 2.43 grams per cubic centimeter. This 

value was computed as the weighted average of the 

densities of the sedimentary section in the southern 

Black Hills, and the Bouguer anomaly values therefore represent changes in configuration of the more 

dense basement rocks. 

The complete Bouguer anomaly map of the area 

discussed is shown on figure 243.1. The contour interval is 2 milligals and all gravity values are negative. The most prominent feature of the gravity map 

is a north-trending zone having a steep east-west 

gravity gradient that extends from the southwest 

corner of the Dewey SW 71j2 -minute quadrangle to 

north of the Fanny Peak quadrangle. A second zone 

of steep gravity gradient, less pronounced than the 

north-trending zone, extends northwest to southeast 

and intersects the north-trending zone in the Fanny 

Peak quadrangle. 

Figure 243.2 is a structure contour map of the area 

drawn on the top of the Fall River formation. The 

structure data are from Dobbin and others ( 1957) and 

from unpublished data by D. A. Brobst, N. C. Cuppels, and ,V. A. Braddock. The map shows two· 

monoclines, one trending north and the other trending 

northwest, which intersect in the western part of the 

Fanny Peak quadrangle. A structural terrace is 

formed between the two monoclines in the Dewey 

quadrangle. The uniform slope in the southwest part 

of the map represents regional dip into the Powder 

River basin. 

Comparison ·of figures 243.1 and 243.2 shows a good 

general correlation between the monoclines and the 

zones of steep gravity gradient. In detail, the tightening of the monoclinal gradient just north of the 

Osage SE quadrangle is reflected by an increase in 

the gravity gradient at this point; the intersection 

of the two monoclines at the western edge of the 

Fanny Peak quadrangle, and the apparent offset of 

the northwest-trending monocline is reflected by the 

gravity contours. The terrace in the Dewey quadrangle is clearly shown by the gravity data. 

Two gravity profiles, A-A' and B-B' (fig. 243.1), 

were selected for theoretical analysis using a twodimensional graticule. These gravity profiles, assumed 

geologic cross sections, and computed gravity values 

are shown on figure 243.3. A density contrast of 

0.35 grams per cubic centimeter was used between 

the sedimentary and basement. rocks. On profile 

A -A', 3 faults or steep folds with a combined throw 

of approximately 4,000 feet provide a .close fit to the 

residual gravity profile in the zone of north-striking 

gravity gradient; the fault or steep fold with a throw 

of approximately 900 feet at the horizontai distance 

of 43,500 feet (fig. 243.3) is related to the northwesterly trending zone. Although the gravity data 

are insensitive to the dip of fault planes, it seems 

probable, from reverse slopes of the basement surfaces on the upthrown blocks, that the faults are 

reverse faults. No faults parallel to the monoclines 

break the surface rocks and the assumed reverse 

faults, if present, die out upward. Gravity profile 

B -B' (fig. 243.2) is essentially perpendicular to the 

· regional gradient. A single fault or steep fold with 

a throw of approximately 3,200 feet provides a close 

fit to the observed gravity profile. The gravity data 

thus indicate that there has been greater vertical 

movement along the north -south direction than has 

occurred along the northwest-southeast direction. 

This is shown also by the structure map, figure 243.2. 

REFERENCES 

Bartram, J. G., 1940, The stratigraphy and structure of eastern 

Wyoming and the Black Hills area, in Kansas Geol. Soc. 

Guidebook, 14th Ann. Field Conf., Aug. 26 to Sept. 1: 

p. 113-120. 

Chamberlin, R. T., 1945, Basement control in Rocky Mountain 

deformation: Am. Jour. Sci., v. 243-A (Daly Volume), 

p. 98-116. 

Darton, N. H., and Paige-, Sidney, 1925, Central Black Hills: 

U.S. Geol. Survey Geol. Atlas, Folio 219. 

Dobbin, C. E., Cmmer, W. B., and Horn,. G. H., 1957, Geologie 

and structural map of the southeastern part of the Powder 

River Basin: U.S. Geol. Survey Oil and Gas Inv. 1\Iap 

Ol\I-185. 

Duerksen, .J. A., 1949, Pendulum gravity data in the United 

States: U.S. Coast and Geodetic Survey Spec. Pttb. 244. 

Noble, .J. A., 19!32, Structural features of the Black Hills and 

adjacent areas developed since pre-Cambrian time: Billings 

Geol. Soc. Guidebook, 3i·d Ann. Field Conf., Sept. 1952: 

p. 31-37. 
... 

SHORT PAPERS IN THE GEOLOGIC AND· HYDROLOGIC SCIENCES, ARTICLES 147-292 C-263 

244. GRAVITY PROFILE ALONG ROBERTS TUNNEL, COLORADO 

By DoNALD PLOUFF, Denver, Colo. 

During 1960 gravity stations were established in the 

IIarold D. R.oberts Tunnel as part of a regional gravity survey of the Colorado Rocky Mountains. This 

tunnel was built to transport water for 23 miles from 

the western to the eastern slope of the Continental 

Divide. The Roberts Tunnel penetrates three major 

groups of rocks: granite and schist (Precambrian), 

sedimentary rock (:~1esozoic), and quartz monzonite 

(Tertiary) (fig. 244.1). 

Roberts Tunnel affords a unique opportunity to 

establish a closely spaced line of gravity stations 

across the Rocky J\1ountains, without entailing extensive surveying or time-consuming access to the area. 

Gravity measurement at two levels-in the tunnel and 

at the surface-provides data for study of the density of the intervening rocks and the variation of the 

vertical gradient of gravity. with depth and location. 

The gravity values for 10 stations at the surface, 

established near the tunnel line, are compared with 

gravity values at stations in the tunnel. The surface stations are near bench marks or points whose 

elevations were determined photogrammetrically. The 

elevations in the tunnel were surveyed by Tipton and 

J(aJmbach, Inc., supervising engineers, on behalf of 

t·he Denver Board of Water Commisioners. The staEXPLANATION 

Quartz monzonite 

(Tertiary) 

Sedimentary rocks 

(Mesozoic and Paleozoic) 

Chiefly granite and schist 

(Precambrian) 

X 

Gravity station 

Roberts tunnel 

0 

tions a.t the surface are no more than 730 feet horizontally from the tunnel line. Errors in latitude 

correction and in location relative to the Bouguer 

gravity anomaly caused by this offset are considered 

negligible. 

The values of observed gravity were established 

relative. to a value of 979,633.0 milligals at Stapleton 

J\1unicipal Airfield in Denver, (Woollard, 1958, p. 

532). The accuracy of the measurement of the observed gravity within the limits of this survey is 

believed to be about 0.3 milligals. Corrections for 

terrain were calculated through zone "0" of the 

U.S. Coast and Geodetic Survey system (Swick, 1942), 

corresponding to a distance of 104 miles from the 

station. Corrections also were made for the small 

second-order term in the free-air correction and the 

effect of curvature on the Bouguer correction (Swick, 

1942, p. 64, 67). 

Terrain corrections for gravity stations at the surface ranged from 3.1 milligals at Dillon, where the 

elevation is 8,832 feet, to 25.8 milligals along the 

Continental Divide, where the elevation· is 13,180 feet . 

above sea level. Terrain corrections for gravity stations in the tunnel ranged from 33.6 milligals about 

midway between the access shaft and the West Portal, 

105°45' 

5 10 MILES 

Fwum~.: 2~t4..l.-Gcologic mttp of the area near H.obcrts Tunnel. Geology generalized from Lovering and Goddard (1950, pl. 2). 
C-264 GEOLOGICAL SURVEY RESEARCH 1 9 61 

~ -220 c( 

(!l 

~ 

..J 

i -240 

~ 

> ...J 

~ -260 

0 

z 

c( 

~ -280 

~ a: 

(!l 

a: -300 UJ 

::J 

(!l 

::J 

X X 

Value for station on surface 

Value for station in tunnel 

g-320~--------------------------------~----------------------------------------------~ 

14,000' Xp 

Location of gravity station 

12,000' 

10,000' 

..... 

I.&. 

~ (/) 

(/) 

(/) 

liJ 

(.) 

(.) 

~ 

X ...J 

~ Q:: 

0 

a. 

14,000' 

12,000' 

~ ! C-' ~ 

10,000' 

->t---- ---41---- w 8000'~----------------------------------------------------------------------~~~~~~ 8000' 

0 5 10 MILES 

VERTICAL EXAGGERATIONx5.28 

FIGURE 244.2.-Bouguer gravity anomaly and calculated densities along Roberts Tunnel. 

·where the tunnel is 544 feet beneath the surface, to 

110.6 milligals where the tunnel is 4,497 feet beneath 

the surface. Thus an error as small as 1 percent in 

terrain correction will limit the accuracy of the 

Bouguer anomaly to 0.3 milligal at the surface and 

1.1 milligals in the tunnel. The correction for material excavated from the tunnel is 0.1 milligal and 

that for the shaft is 0.0 milligals. 

The Bouguer gravity anomaly has a relief of about 

70 milligals (fig. 244.2) along a line extending from 

Dillon southeastward to Shawnee via the Roberts 

Tunnel. An average density of 2.67 g per em 3 for 

the rocks between the surface and sea level has been 

assumed for "these calculations. The most negative 

point along the gravity profile is west of the access 

shaft, rather than in the vicinity of the Continental 

Divide, as would be expected if the density of underlying rocks is inversely related to elevation. 

The difference between the Bouguer gravity anomaly 

along the Roberts _Tunnel, as measured at the surface 

and in the tunnel, is largely caused by variation from 

the assumed average density of 2.67 g per cm3 in the 

density of the intervening rocks, incompleteness or inaccuracy of the terrain r.orrection, and variation of the 

vertical gradient of gravity with depth and location. 

If the difference is entirely caused by the effect of the 

density variations, the density is given by: 

where Dis the average density of the intervening rocks 

calculated from gravity data, GnA is the difference of 

observed gravity at the surface and in the tunnel, F is 

the free-air correction factor (0.09406 millignJs per 

foot), hnA is the difference in elevation between the 

two stations, fnA is the difference of second-order freeair corrections between the two stations taken from a 

nomograph (Swick, 1942), M is the Bouguer correction 
·' 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-265 

Jn,ctor (0.01276 milligals per foot per unit density), and 

TnA is the difference of terrain n,nd curvature corrections 

between the two stn,tions for unit density. The densities cn1culated with this formuht show n, positive correlation with topography (fig. 244.2). The range is from 

2.61. to 2.81 g per cm3• Carrying the terrain correction 

beyond 104 1niles tends slightly to increase the calculnted densities. 

The mean density for 144 representative samples of 

Precambrian rock collected from the Alva B. Adams 

·Tunnel, about 45 miles north of the Roberts Tunnel, 

is 2.67 g per em 8 (Birch, 1950, p. 608). The mean 

densities for granite and quartz monzonite (78 samples), quartz diorite gneiss ( 18 samples), and injec-

('.ion sehist and gneiss ( 48 samples) are 2.63, 2.67, 

~-tnd 2.73 g per em 8 , respectively. Variations in density alone do not account for the difference of the 

Bouguer gravity anomaly, as calculated at stations 

in the tunnel and on the surface. 

Near the Roberts Tunnel, the most negative gravity values of the gravity low that is associated with 

the deficiency of mass deep in the crust beneath the 

Rocky ~1ountains (Woollard, 1943, p. 768-769; 

Qureshy, 1!)()(); Stuart and 'Vnhl, Art. 245, are near 

the west end of Roberts Tunnel. The vertical graclient of gravity, F, is less than 0.09406 milligals per 

foot-the value usually assumed for free-air corrections-in this area of anomalously negative gravity. 

Hence the calculated densities are consistently too high 

and increase with the thickness of cover, hn.-t, over 

the tunnel. The general correspondence of calculated 

density with topography is attributed largely to the 

decrease of the vertical gradient of gravity near 

the major gravity low associated with the Rocky 

~fountains. 

REFERENCES 

Birch, Francis, 1950, Flow of heat in the Ft·ont Hange, Colorado: Geol. Soc. America Bull., v. 61, p. 567-630. 

Lovering, T. S., and Goddard, E. N., 1950, Geology and ore 

deposits of the Front Range, Colorado: U.S. Geol. Survey 

Prof. Paper 223, 319 p. 

Qureshy, l\1. N., 1960, Airy-Heiskanen anomaly mal) of Colorado, 'in Guide to the geology of Colorado: Geol. Soc. 

America, Rocky Mountain Assoc. of Geologists, and Colorado Scientific Soc., Denver, p. 8-9. 

Swick, C. H., 1942, Pendulum gravity measurements and isostatic reductions: U.S. Coast and Geod. Survey Spec. Pub. 

232, 82 p. 

Woollard, G. P., 1943, Transcontinental gmvitational and magnetic profile of North America and its relation to geologic 

structure: Geol. Soc. America Bull., v. 54, no. 6, p. 7-:1:7-790. 

-- 1958, Results for a gt·avity control network at airports 

in the United States: Geoph~·sics, v. 23, no. 3, p. 520-535. 

245. A DETAILED GRAVITY PROFILE ACROSS THE SOUTHERN ROCKY MOUNTAINS, COLORADO 

By DAyio tT. STUART and RONALD R. vYAHL, Denver, Colo. 

Gravity measurements discussed in this paper are 

part of a gravity survey that will provide a network 

across Colorado between the 39th and 40th parallels 

of latitude. Earlier, less detailed work in the area 

has been described by vVoollard (1943), Holmer 

(1!HS4), and Qureshy (1958). 

A LaCoste and Romberg portable geodetic gravity metet: with a scale value of about 0.01 mgal (milligal) per dial division was used to make the measurernents. Stations were established at bench marks and 

spot-. elevations shown on U.S. Geological Survey maps, 

1ind n,t locations where elevations could be obtained 

from road profiles of the Colorado Depart~nent of 

Ilighwn,ys. Observed gravity values are referred to 

tt sr1·ies of 19 U.S. Geological Survey base stations 

t.hat are tied to airport gravity network stations at 

601,580 0~61--18 

Denver and Colorado Springs ('V"oollard, 1958). Instrumental readings, corrected for drift, have .beerr 

reduced to sea level on the assumption that rocks between stations and sea level have an average density 

of 2.67 g per em 3• Terrain corrections, through Hayford letter-zone "0," have been added to all the 

station$ (Swick, 1942). Suitable maps for the estimation of terrain effects of the inner zones were available for most of the stations; however, terrain corrections for 23 stations were made from Army l\1ap 

Service 1/250,000 sheets. An attempt was made. to 

locate these stations at points where the effect of 

nearby topography would be small. 

Gravity values at 261 stations were projected at 

right angles onto seven straight-line segments that 

generally follow U.S. Highway 6 west of Denver 
C-266 GEOLOGICAL SURVEY RESEARCH 19 61 

Geologic map generalized 

after Oriel (1954) 

-160 

~ -180 C) 

j -200 

:E - 220 z . 

:-240 

~ -260 

~ -280 < 

0 20 40 . 60 80 100 MILES 

EXPLANATION 

D 

Cenowic, Mesowic, and Paleozoic 

sedimentary rocks 

Tertiary and Upper Cretaceous 

igneous rocks 

"Tf'l 1 1 1 I I I I t-rr Normal or high-angle reverse fault 

Hachures on downthrown block 

........ ._ Thrust fault 

Teetn on upper plate 

..... Axis of anticline or broad arch 

Arrow showing directwn of plunge 

Axis of syncline of trough 

Segment of profile 

-160 

-180 

-200 

-220 

-240 

-260 

-280 

-300~A--~B--------~~--------------------~--------~~--~~~--------~-------------------L -300 c D F G H 

12,000' 

10,000' 

8000' 

6000' 

4000' 

Cl> 

I;:; 

ii: 

I 

B c 

Geologic cross section generalized 

after Vanderwilt (1948) 

,:,(, 

0 

til 

..0 

llO 

0 

I 

D E 

"0 Cl> cUl 

til(/) E 

~~ ::s 

0 iS: ...J I 

F 

~ 

·~· p., 

en 

G 

12,000' 

10.000' 

8000' 

-......-------------1 6000' 

4000' 

10 0 10 20 30 40 50 60 MILES 

Topographic profile based on 

average elevation of circles 2.8 miles in diameter, centered 

at gravity stations 

FIGURE 245.1.-Bouguer-gravity profile and generalized geology across the Southern Rocky Mountains, Colorado. 

and extend due east from Denver (fig~ 245.1). None 

of these stations is more than 4 miles from the profile segments, and most stations are within 2 miles. 

Total length of the profile is 264 miles, so average 

spacing is nearly one station per mile. 

The broad gravity low, extending from one end of 

fhe profile to the other, demonstrates that the Southern Rocky Mountains are, to some extent at least, 

isostatically compensated on a regional scale. Absence of gravity lows associated with the 'White River 

uplift and .other prominent topographic highs suggests that large but geographically limited loads are 

not locally compensated. Qureshy (1960) has observed that isostatic equilibrium prevails only on a 

broad scale in Colorado. 

Superimposed on the broad regional low are anomalies that show some relation to the configuration 

of the upper surface of Precambrian basement rocks. 

At the eastern end of the profile (fig. 245.1), the 

gravity field decreases westward at a fairly uniform 

rate to about the area near Denver where contact 

between the basement rock and overlying sedimentary 

rocks dips ·westward to its greatest depth. Gravity 

values become more positive across steep gradients on 

approaching the more dense metamorphic rocks of 

the Front Range. West ward toward the Continental 

Divide, the gravity field decreases with steep gradients as a result of the deep-seated mass deficit which 

tends to compensate the mass excess of the mountains. 

Little gravity relief is observed in traversing the 

Colorado mineral belt between Idaho Springs and 

Silver Plume. A gravity high of 7 mgals amplitude, 

based on 8 stations near Silver Plume, may bear 

some relation to the mineral belt. The 10-mgal high 

immediately west of Dillon corresponds to a sequence 

of relatively dense Precambrian metasedimentary 

rocks. 

It is· difficult to distinguish, without additional data; 

whether the anomalous gravity lows on either side 

of Wolcott are the expression of density contrasts 

within the sedimentary basin or within the underlying 

Precambrian basement rocks. 

;.1, 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCI~NCES, ARTICLES 147-292 C-267 

Precambrian basement rocks are exposed east of 

Glenwood Springs where the gravity profile crosses 

the 'Vhite River uplift. These rocks are more dense 

than the rocks to the east and to the west, so they 

(Tive rise to a gravity high about 35 miles wide and 0 •. 

of about 25 mgals amplitude (fig. 245.1). Shght 

gravity relief superimposed on this high is probably 

the result of inaccuracy in the terrain corrections. 

Terrain corrections of more than 30 mgals were computed for some stations in this area of strong topo-

.nTaphic relief. The gravity low west of the White n . River uplift is probably related to the Piceance basin; 

however, the largest negative values do not occur 

near the structural axis of the basin west of Rifle, 

but are displaced eastward to a point near Grand 

I-Iogback, as was noted by Holmer ( 1954). 

The increase in gravity field level west of Grand 

:Hogback is caused, in part, by increased distance 

from the region of maximum gravity influence of 

the Rocky l\{ountain compensating mass, and to a decrease in thickness of the sedimentary-rock section on 

the western flank of the Piceance basin. 

REFERENCES 

Holmer, R. C., 1954, A regional gravity survey of Colorado: 

Colorado School Mines Thesis 801, 94 p. 

Oriel, S. S., 1954, Major tectonic elements of Colorado: a re- · 

view, ·in Oil and gas fields of Colorado: Rocky Mountain 

Assoc. Geologists, Denver, p. 41-48. 

Qureshy, M. N., 1958, Gravity anomalies and computed variations in thickness of the earth's crust in Colorado: Colorado School Mines Thesis 862, 41 p. 

-- 1960, Airy-Heiskanen map of Colorado, ·in Guide to the 

geology of Colorado: Geol. Soc. America, Rocky Mountain 

Assoc. Geologists, and Colorado Sci. Soc., Denver, p. 8-9. 

Swick, C. H., 1942, Pendulum gravity measurements and isostatic reductions: U.S. Coast and Geod. Survey Spec. Pub. 

232; 82 p. 

Vanderwilt, J. W., 1948, Field trip no. 3, Denver, Glenwood 

Springs, Rifle, Leadville, South Park, in Guide to the 

geology of central Colorado: Colorado School Mines Quart., 

v. 43, no. 2, p. 73-116. 

Woollard, G. P., 1943, Transcontinental gravitational and magnetic profile of North America and its relation to geologic 

structure: Geol. Soc. America Bull., v. 54, no. 6, p. 747-790. 

-- 1958, Results for a gnwity control network at airports 

in the United States: Geophysics, v. 23, no. 3, p. 52Q-535. 

246. AFTERSHOCK-ENERGY RELEASE VERSUS TIDAL EFFECTS, HEBGEN LAKE EARTHQUAKE, MONTANA 

By RENNER B. HoFMANN, Denver, Colo. 

Distance, magnitude, and energy were calculated 

from 876 seismograms of aftershocks which followed 

the lTebgen Lake, l\1ontana, earthquake of 1959. Two 

portnble seismic stations, approximately 40 km southwest and 130 km soutli of the epicentral area, recorded the aftershocks for about 21j2 days (Stewart 

and others, 1960). 

Only shocks of magnitude 2.2 and greater, obtained 

from 475 seismograms, were used. During 90 percent 

of the reeording time, instrument gains and background noise in the epicentral area were such that 

n,U shocks of magnitude 2.2 and greater should have 

been recorded. 

Chester Glenn, meteorologist at Stapleton Airfield, 

Denver, Colo., and Roy I~. Fox, Director, and Gerald 

L. Barger of the National Weather Records Center, 

Asheville, N. C., provided meteorological data and 

bnrograms for the Yellowstone Park area. 

ENERGY CALCULATIONS 

The magnitude of each aftershock and the energy 

released were calculated from formulas developed by 

Gutenberg for California earthquakes near a depth 

of 18 km (Richter, 1958). Uncertainties caused by 

focal depth, polarization, and ground character at the 

station are unavoidable, but are not believed to be 

serious for the purposes of this study. Continuous 

operation at the stations was not possible. Interruptions in recording were caused by changing recording paper, instrumental difficulties, and field testing 

the seismic systems. 

Energies released by aftershocks recorded during 

0.1-day intervals were summed, and each sum was 

divided by the fraction of the interval during which 

the instruments were operating. The resulting number, shown on figure 246.1, is assumed to be the energy 

that would have been recorded during the interval 
KEG SPRING STATION 

Weighted energy released 

per 0.1 day x 1016 ergs ............ .... 3.39 0.88 2.26 2.74 7.72 15.00 2.45 2.13 4.71 9.56+ 1.68 . ... 2.79 2.23 1.05 

Fraction of 0.1 day 

station operated . .... .23 .99 .57 1.0 .60 .76 .77 .80 0.10 .80 .68 .30 .34 .69 .59 

Energy released 

per 0.1 day x 1016 ergs. .78 .88 1.29 2.74 4.63 1.14 1.89 1.70 .185 3.73 6.50+ .50 ... .95 1.54 .62 

Number of shocks recorded 

during 0.1 day .. 2 19 12 20 21 34 14 18 3 23 33 9 ... 10 18 12 

Times of operation. .... 

-- ---·---····· •••••• .._ ... ._ Time (days following main shock). 

3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 6.1 

Time (m.s.t.). . . . . . ___ _ 

Weighted energy released 

per 0.1 day x 10 16 ergs. 

Fraction of 0.1 day 

station operated . Energy released 16 per 0.1 day x 10 ergs. 

Number of shocks recorded 

duringJU day ......... . 

Times of operation. 

Time (days following main shock). 

Time (m.s.t.). : 

August 21 August 22 August 23 August 24 

VICTOR STATION 

I"·' 6.43 0.81 3.10 7.58 13.8 6.73 4.49 0 .. 42 1.77 22.0 4.46 3.49 0.45 3.93 51441 22.07 0.70 2.89 

0.22 0.13 .85 1.0 .74 1.0 .96 1.0 .90 .94 1.0 .82 .95 .74 .72 .70 .89 .70 0.13 .26 .55 .81 I 0.33 

. . . . . . 1.48 I .0 28.0 5.83 .60 3.10 7.28 13.8 6.06 4.22 .42 1.45 20.9 3.30 2.51 .32 3.50 3.6+ .60 5.89 .38 2.34 .004 

4 I o I 13 In I 4 113 119 I 20 I 24 120 I 6 I 3 I 31 I 9 I II I 5 Ill 17 I 2 I. .. .1 .. I .... 1. . . I . .. I I I 2 IIO_l! I. - --- ·--·II······· -·-··· . .. 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 6.1 

12:00 00:00 12:00 00:00 12:00 00:00 

August 21 August 22 August 23 August 24 

FIGURE 246.1.-Times of station operation and energy-release data for aftershocks of magnitude 2.2 and greater. 

F- ~ --

Q 

tG 

~ 

00 

0 

tr.l 

0 

t"' 

0 

0 

~ 

a 

> t"' 

Ul 

q 

~ 

< tr.l 

~ 

~ 

trl 

tn 

tr.l 

> 

~ 

~ 

..... 

<0 

Q) 

..... 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-269 

I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I 

1018 

VICTOR STATION DATA ..0. 

1016 

lOIS 

10 

10 

0.90 

0.50 

AUGUST 21, 1959 

I I II I I I I I I I II I I 

AUGUST 22, 1959 

I I I I I I I I I I I I I I 

12.00 00.00 12.00 

I ? \ 

I \ 

\ 

I 

0 

VERTICAL TIDAL GRAVITY CORRECTION (GOGUEL, 1958) 

OR (V. CO~PONENT) / 1.2 

AUGUST 23, 1959 

I II I I I I I I I I I I I I 

00.00 12.00 

I I I 

AUGUST 24, 1959 

I I I I I I I 

00.00 

MOUNTAIN STANDARD TIME 

I Instrument operated less than half of 0.1-day interval 

Fw URE 246.2.-Compnrison of nftershock-energy-reJease with barometric pressure and components of tidal acceleration caused· by 

the sun and moon. 

i:f the station hnd been in continuous operation. For 

most intervals, the correction caused by inoperative 

time is small. Any inoperative time, however, may 

contribute n. significant error because the sample size 

is inherently limited and most of the energy is contributed by the ln.rger aftershocks. Curves were plotted from the weighted energies released per 0.1 day 

(.fig. 246.1). These aftershock-energy-release curves 

seem to hn.ve a smoother shape for times when recording wns continuous; however, the proportion of time 

the stations were operating seems unrelated to the 

maxima and minima of the energy-release curves. 

'Vith the exception of two values (figs .. 246.1 and 

246.2), energy was plotted only for those intervals 

during which the instruments operated more than 

half of the 0.1-day interval. Points labeled with a 

question mark (fig. 246.2) represent a sequence of 

aftershocks that ran together and whose amplitudes 

were sufficient to cause clipping on records from both 

stations. The energy could not be estimated as accu-
C-270 GEOLOGICAL SURVEY RE-SEARCH 19 61 

rately for this period as for the others, but the values 

sh0wn are believed to be at least the minimum. Except for the weighting procedure, there is no normalization or other statistical process applied to the data. 

Other 0.1-day intervals could have been used. 

TIDAL ACCELERATIONS AND 

BAROMETRIC PRESSURE 

The vertical tidal gravity correction (fig. 246.2) 

was taken directly from Goguel (1958). The horizontal components of tidal acceleration (force per unit 

mass at the surface) for each hour were computed 

using the stereographic nomogram method of Doodson and W arburg ( 1941). The attractions of both the 

sun and the moon were taken into account. The predominant period of the tidal accelerations, in the epicentral region of the aftershock sequence during the 

time of recording, is semidiurnal. The ~nergy released (fig. 246.2) also has a semidiurnal period, and 

the maxima and minima correspond closely in time 

with maxima and minima of tidal accelerations. Tidal 

accelerations are not the same over large areas and 

are not exactly periodic, so a better correlation might 

be expected if the actual tidal accelerations for a 

given latitude, longitude, and time were used. 

The barogram from West Yellowstone, Mont., does 

not have a semidiurnal period (fig. 246.2). The barogram is somewhat irregular but seems to have a predominant period of about one day. Barograms from 

Cody, Wyo., and Livingston, Mont., for the same time 

have similar shapes. Changes in atmospheric loading, 

therefore, had no obvious relation to the variation of 

aftershock -energy release. 

Diurnal variations in numbers of earthquakes at 

other places have been reported by Cotton (1922), 

Davison (1934), Stetson (1935), and Romana and 

Lobato (1948). Nishimura (1950) found that at the 

times of smallest observed strain "* * * seismic activity was nearly zero * * *." These and similar studies, however, have been concerned mainly· with earthquakes or aftershocks occurring over large areas and 

over long time intervals. 

REFERENCES 

Cotton, L. A., 1922, Earthquake frequencies with special reference to tidal stresses in the lithosphere: Seismol. Soc. 

America Bull., v. 12, p. 47-198. 

DaYison, Charles, 1934, The diurnal periodicity of earthquakes: Jour. Geology, v. 42, no. 5, p. 449-468. 

Doodson, A. T., and 'Varburg, H. D., 1941, Admiralty manual 

of tides : His Majesty's Stationery Office, London, Chapter 3, 270 p. 

Goguel, Jean, 1958, Tidal gravity corrections for 1959: Geophys. 

Prosp., v. 6, Suppl. 1. 

Nishimura, Eiichi, 1950, On earth tides: Am. Geophys. Union 

Trans., v. 31, no. 3, p. 357-376. 

Richter, C. F., 1958, Elementary seismology: San Francisco, 

W. H. Freeman and Co., 768 p. 

Romana, Antonio ( S. J.) and Lobato, Aurora, 1948, Sur la 

periode annuelle et diurne des tremblements de terre : 

Internat. Union Geodesy and Geophysics, Series A, v. 17, 

p. 205-215. 

Stetson, H. T., 1935, The correlation of deep-focus earthquakes 

with lunar angle hour and declination: Science, v. 82, 

no. 29, p. 523-524. 

f;tewart, S. W., Hofmann, R. B., and Diment, W. H., 1960, 

Some aftershocks of the Hebgen Lake, Montana, earthquake of August 1959, in Short papers in the geological 

sciences: U.S. Geol. Survey Prof. Paper 400-B, p. B219-

B221. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-271 

247. DETERMINATION OF THICKNESS OF A BASALT FLOW BY ELECTRICAL RESISTIVITY METHOD ON 

BUCKBOARD MESA, NEVADA TEST SITE, NYE COUNTY, NEVADA 

By J. C. RoLLER and R. A. BLACK, Denver, Colo. 

Wo1·k done in cooperation with the U.S. Atomic Ene1·gy Commission 

As part of the selection and evaluation of a test 

site for a nuclear cratering experiment. in basalt, the 

electrical resistivity method was used by the Geologica] Survey to determine the thickness of a basalt flow 

on Buckboard Mesa at the Nevada Test Site, Nye 

County, Nev. 

Buckboard Mesa, in the western part of the Nevada 

Test Site, is approximately 5 miles long and 2 miles 

wide. The surface is relatively flat except at the 

northern end where a cinder cone rises 500 feet above 

the mesa and a low ridge extends southeastward several thousand feet frmn the cone. The basalt, which 

ranges in thickness from 50 feet on the rim to more 

than 200 feet in the center of the mesa, is underlain 

by alluvium and a soft bedded tuff of the Oak Spring 

formation, Miocene ( ~) or younger. A welded tuff 

n.bout 50 feet thick is present approximately 100 feet 

below the base of the basalt. Technical criteria for 

the proposed nuclear cratering experiment required 

knowledge of the thickness of unweathered basalt in 

the immediate vicini.ty of the point of burst. Comparison of the known physical properties of the bedded tuff with average physical-property values published for b~salt indicated that a large contrast in 

seismic velocity and electrical resistivity could be 

expected across the interface between the basalt and 

the underlying bedded tuff. The seismic velocity of 

the basalt is greater than that of the bedded tuff, 

and the resulting velocity inversion prohibits the use 

of the refraction seismic method to determine the 

thickness of unweathered basalt. Because of the large 

electrical contrast between the basalt and bedded tuff 

the electrical resistivity method was 'used. 

The electrical resistivity of the bedded tuff ·was 

known to be about· 50 ohm . .::meters (1\::eller, 1960) and 

tabulated values for unaltered basalt (Slichter and 

Telkes, 1950) range from 1,000 to 10,000 ohm-meters. 

Therefore, it was expected that field curves obtained 

w.ith the electrical resistivity method would exhibit at 

least three electrical layers as follows: a low-resistivity 

surface layer, presumably representing weathered 

basalt; a high-resistivity layer representing the unweathered basalt; and a low-resistivity layer representing the bedded tuff. 

The resistivity measurement's were made with standard direct current equipment and non,polarizing electrodes. The field technique used was that of depth 

profiling with the Lee-partitioning configuration. The 

location of the stations are given on figure 247.1. 

The field data were interpreted by superposition of 

theoretical two- and three-layer curves and by partial 

curve matching. The field curve obtained at station 4 

(fig. 247.2), plotted on a log-log scale, sliows six distinct electrical layers. The top layer has a resistivity 

of 80 ohm-meters, is 1.7 feet thick, and represents 

alluvium. The second and third layers have thicknesses of 5 and 32 feet, resistivities of 3,120 and 50 

ohm-meters, and are presumed to represent dry and 

partially saturated weathered basalt or cinders, respectively. Under these three layers lies a thick layer of 

N 

z 

.,., 

co 

.., 

0 

<.0 

co 

585,145 E 

'\..6 0 450 

1/ 

/ 0 240 

'\.~ 200 

'\. 

'

2 o, 250 

5 / 

/0325 

4 / /i 210 

Drill hole 1 

s/ 

/ 0 150 

7/ 

/0160 

0 100 200 

EXPLANATION 

-aResistivity station 

"~ 260 ' 

300 FEET 

Dashes show direction of measurement. Upright 

number indicates station designation. Slant number 

indicates computed depth in feet 

'\. 

FIGURI'~ 247.1.-Locations of resistivity stations (Nevada Test 

Site coordinates). 
C-272 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

material having a resistivity of 1,260 ohm-meters 

interpreted to be unweathered unsaturated basalt. 

The depth to the base of this layer, as computed from 

the resistivity curve for station 4, is 210 feet. This 

agrees very closely with the depth of 211 feet as determined by drilling at hole 1, which is near station 4 

(fig. 247.1). The low resistivity layer beneath the 

basalt is presumed to represent alluvium and bedded 

tuff. The rise in the resistivity curve beginning at an 

electrode spacing of approximately 350 feet is presumed to be caused by the layer of welded tuff, which 

has a high resistivity. 

APPARENT RESISTIVITY, DRILL HOLE I 

RESISTIVITY, IN 

OHM-METERS JN OHM-METERS X 10- 3 

~E~~~T 

1 i-1 ------T-2 __ 3:;:-----:;4-i'-5 -r-r--'i'--'1 ----.--r- 3120 

~ 

~ 

z 

10 

u 20 

(I) 

~ 

UJ 

g 30 

~ 

~ 40 

50 

60 

70 

80 

90 

100 

200 

300 

400 

Station 4 

Theoretical curve 

RESISTIVITY VERTICAL PROFILE 

LEE-PARTITIONING CONFIGURATION 

18 

100 

200 

211 

300 

350 ? 

50 

Cinders and weathered 

basalt 

1260 Unsaturated 

basalt 

50 Alluvium 

and bedded 

tuff 

Welded tuff, contact 

approximate 

EXPLANATION 

Alluvium Basalt Alluvium 

and bedded 

tuff 

FIGURE 247.2.-Resistivity depth curve at station 4 and lithologic log of drill-hole 1. 

300 

100 

200 

300 

400 

300 

400 600 800 

Station 2 100 

200 

300 

600 800 200 400 600 

600 

800 

.100 

200 

300 

400 

800 200 400 600 

100 

200 

300 

400 

500 

600 

700 

800 

900 

600 

EXPLANATION 

Resistivity vertical profile 

Vertical scale, electrode separation in feet. 

Horizontal scale, apparent resistivity in 

ohm-meters 

-~Contact between high-resistivity 

layer (basalt) and low-resistivity 

(bedded tuff) 

800 

800 1000 

FIGURE 247.3.-Resistivity depth curves for stations shown on 

figure 247.1. 
;.. 

SHOHT PAPEHS IN THE GEOLOGIC AND HYDHOLOGIC SCIENCES, AHTICLES 147-292 C-273 

The curves computed from the field data are shown 

on figure 247.3 for nine resistivity stations in the 

vicinity of the proposed test site. These curves and 

t-he numbers on .figure 247.1 show· depths to the base 

of the unweathered basalt. 

The computed thickness of the basalt is much 

gTeaJer at·. stations 5 and () than a.t t-he other stations. 

There n.re. at least: two possible explanations for the 

anomalously large values for the basalt thickness at 

st-ations 5 and 6. The first is that the low ridge extending southeastward from the volcanic cone is the 

surface expression of a fissure from which the basalt 

flowed to cover the mesa. In this event, stations ·5 

and 6, which lie on a line perpendicular to the ridge 

(wit-h st-ation 6 closest to the ridge), could be expected 

to show increased thicknesses of basalt. A second 

possibility is that. the basalt is underlain by welded 

tuff in the vicinity of stations 5 and 6, and as both 

the welded tuff ftnd basalt have a high resistivity, 

their contact could not be determined. In support 

of this exp)ana.tion, the curves for stations 2, 8, and 9 

indicate a thinning of the bedded tuff layer that lies 

between the basalt and the welded tuff. 

REFERENCES 

Kellet·, G. V., 1960, Physical pt·operties of tuffs of the Oak 

Spring formation, Nevada, ·in Short papers in the geolog-ical sciences: U.S. Geol. Survey Prof. Papet· 400-B, 

p. B396-B400. 

Slichtet·, L. B., and Telkes, :Maria, 1950, Electrical properties 

of rocks _and minet·als, in Handbook of physical constants: 

Geol. Soc. America Spec. Paper 36, p. 299-319. 

248. GRAVITY STUDY OF CRUSTAL STRUCTURE IN WESTERN WASHINGTON 

By DAVID J. STUART, Denver, Colo. 

A gravity survey of western Washington was made 

during the period 1956 to 1959 to investigate the relations of the gravity field to major structural units 

and to study the configuration of Tertiary basins. 

About 2,100 gravity stations were established in an 

area of approximately 25,000 square miles bounded on 

the east by the western foothills of the Cascade Range, 

n.nd on other sides by the Washington State boundaries (fig. 248.1). Topographic altitudes within this 

region range from sea level to nearly 8,000 feet. 

'I)r·ift-corrected instrument readings were reduced 

to a common datum on the assumption that material 

between station altitude and sea level has a density 

of 2.67 g per em 8• Measurements were reduced to an 

absolute datum by reference to Seattle, Wash., and 

Portland, Oreg., airport gravity networ~ stations 

('Voollnrd, 1958). Topographic corrections, through 

I-Iayford letter-zone "0," were added to only those 

Olympic ~fountains stations having topographic effects 

greater than 3 milligals. 

The most conspicuous feature of the gravity field 

is its correlation with lower and middle Eocene volcanic rocks (fig. 248.1). Where these dense rocks are 

at or near the surface, gravity va,lues are relatively 

high, and where they are absent or deeply buried the 

gravity field is lower.. A continuous gravity high 

forms a westward-opening U-shaped pattern around 

the Olympic Mountains, along the limbs of what 

appears to be a southeast-plunging anticlinorium. 

The southeast-plunging nose of this eroded fold is 

clearly outlined by the gravity high between Seattle 

and Tacoma. These gravity maximums and also the 

intensely negative anomalies such as those associated 

~vith the thick Tertiary sedimentary sections at Seattle and Everett, are superimposed upon a broad gravity minimum of about -35 milligals. A general lack 

of correlation between elevation and Bouguer anomaly 

value indicates that individual highs and lows are 

not a response to local isostatic conditions. An exception is in the Olympic ~fountains where the Bouguer 

anomaly level changes to significantly greater negative values with increase in elevation, thus indicating 

some degree of compensation for the mass of the 

mountains. 

A gravity anomaly alone does not give enough information to determine uniquely the mass distribution responsible for the variation; however, some 

information concerning the size and depth or thick-
C-274 

125" 

49"1 

EXPLANATION 

@) 

Contours of Bouguer anomaly 

Values in absolute milligals. Dashed in 

areas of poor control. Hachures indicate 

gravity lows with closure inside the 

mapped area. Contour interval 20 milligals 

Lower and middle Eocene 

volcanic rocks 

Basalt flows, pillow lavas, breccias and 

intercalated sedimentary beds. Outcrop 

pattern generalized from geologic map of 

Washington (Washington State Division 

of Mines and Geology, 1961) 

GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

124" 

.-.-

FIGURE 248.1.-Bouguer anomaly and generalized outcrop pattern of lower and middle Eocene volcanic rock in 

western Washington. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-275 

ness of the disturbing body can be estimated from 

the ~tmplitude, gradient, and width of the anomaly 

varinJion. For a first approximation, the Seattle low 

might be considered the gravitational expression of 

a hemisphere of low-density material enclosed in a 

higher density medium. The difference between the 

regional field level and the most negative Bouguer 

value near Seattle is about -95 milligals. If the density contrast is assumed to be 0.3 g per cm,3 the 

radius or depth to the bottom of the hemisphere 

will be about 50,000 feet. Little reliance should be 

placed on the precise magnitude of this figure because 

the density contrast and the approximation of the 

structure by a hemisphere are merely assumptions; 

however, this result does show that the thickness of 

low-density material underlying Seattle is measurable 

in t"ens of thousands of feet. 

1\fountains are. influenced by a deep-seated mass deficiency which tends to compensate for the mass of 

the mountains. In order to remove or reduce this 

influence, Airy-Heiskanen isostatic reductions ( T = 

30 km) were made for several stations in the mountains ancJ. for some stations established on the lower 

and middle Eocene volcanic rocks ( Heiskanen, 1938) . 

Isostatic reductions for the first group averaged about 

-32 milligals and for the second, about + 33 milligals. The average of 5 published Airy-I-Ieiskanen 

values ( T = 40 km) for stations in Puget Sound is 

-26 milligals (I-Ieiskanen, 1939). These three gravity levels, which define the amplitude of the isostatic 

anomaly, have been connected by reasonable gradients 

to form a composite or average profile extending 

from the Olympic }\fountains into Puget Sound 

(fig. 248.2). 

The gravity lows in Puget Sound and the Olympic 

}\fountains are separated by a high over the lower and 

middle Eocene volcanic rock outcrop west of Hood 

Canal. Bouguer anomaly values in the Olympic 

Some conception of the amount of high-density 

material required to produce this high can be obtained 

from a two-dimensional mass distribution capable of 

giving rise to the composite profile (fig. 248.2). An 

+30 

(/) 

~ (!) 

::::i +20 ~ 

:;; 

~ 

> 

~ +10 <( 

:I: 

0 

z 

<( 

(.J 0 ~ <( 

1-

(/) 

0 

!!? -10 z 

u..J 

z 

<( 

:0:: 

(/) 

;:;:; -20 :I: 

>- a: 

:cc 

-30 

0 

.., 

II 

t:. 

"' c 

0 

~ 

/ 

o-·-.. /~c. " 

I E \ 

I g \ 

I -~ \ 

I ~~ \ 

I =~ \ I ~~~ \ I ~t:. \ 

I g \ 

/ i ', I iii '\, 

I ' 

I ' I ', 

I ', / ,, I ', / ,, / ,_ 

~ :0:: 

0 

...,. 

II 

t:. 

"' c 

·~ 

1il 

"'C 

c 

::I 

0 

(/) 

/ / --~0 

o------AVERAGE OUTCROP WIDTH OF LOWER AND MIDDLE EOCENE VOLCANIC ROCKS 

ALONG SOUTHEAST MARGIN OF OLYMPIC MOUNTAINS 

SEA LEVEL ----------------------- ~"""T""""lr-r""""T""""l.--r--.--,~ --------------------------------------

(/) 

~ 4 :;; 

~ 6 

~ 8 0.. 

u..J 

0 

10 

12 

p=2.65 

0 4 6 8 10 MILES t I I I I 

NO VERTICAL EXAGGERATION 

F1 n URE 248.2.-Two-dimensional mass distribution capable of producing the composite gravity profile extending from the Olympic 

Mountains into Puget Sound, Wash. On the gravity anomaly profile, circles represent the average value of reduced data collected at the indicated locations. The dashed line represents gravity values computed from the mass distribution shown on· 

the lower part of the figure. 
C-276 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

assumed density contrast of 0.2 g per em 8 between 

dense rock and the less dense surrounding material 

was used in deriving the section. Use of one crustal 

thickness, T = 40 km, for isostatic reductions in the 

Puget Sound group of stations and use of another, 

T = 30 km, for the other groups will introduce only 

a slight error in the solution. The same is true for 

use of a two-dimensional mass distribution which 

assumes an infinite length of structure normal to the 

section. Other sections could explain the profile 

equally well but as long as geologically reasonable 

densities are assigned to rocks involved, the thickness 

of the volcanic rocks or dense crustal rocks associated 

with them will always be measured in tens of thousands of feet and the depth to the base of the dense 

rocks will be of the same order of magnitude. 

REFERENCES 

Heiskanen, W. A., 1938, New isostatic tables for the reduction 

of gravity values calculated on the basis of Airy's hypothesis: Suomalainen Tiedeakatemin, Annales Acacl. Sci. Fennicae, ser. A, v. 51, no. 9, p. 1-42. 

-- 1939, Catalogue of the isostatically reduced gravity 

stations: Suomalainen Tiedeakatemia, Annales Acad. Sci. 

Fennicae, ser. A, v. 51, no. 10, p. 1-140. 

Washington State Division of Mines and Geology, 1961, Geologic map of Washington. 

Woollard, G. P., 1958, Results for a gravity control network 

at airports in the United States: Geophysics, v. 23, no. 3, 

p. 520-535. 

249. REGIONAL MAGNETIC AND GRAVITY ANOMALIES IN THE DARWIN AREA, CALIFORNIA 

By DoN R. MABEY, Menlo Park, Calif. 

Work done partly in coopemtion with the Oalifon~ia Division of Mines 

In eastern California, between the southern end of 

the Inyo Mountains and the north end of the Argus 

Range, lies an upland area with moderate local relief 

(fig. 249.1A). This upland area has an average altitude of about 5,000 feet above sea level. The slope 

from the upland through Lower Centennial Flat into 

Owens Valley is relatively gentle, but there is an 

abrupt front on the Panamint Valley side. Several 

canyons over 1,000 feet deep are cut through this 

front. 

GENERAL GEOLOGY 

The oldest rocks in the area are sedimentary rocks 

of Paleozoic age which are intruded by r plutonic 

rocks of Mesozoic age. Volcanic rocks of late Cenozoic age cover much of the area, and about half of 

the area is overlain by late Cenozoic sedimentary 

rocks. 

The plutonic rocks exposed in the northeast part 

of the map (fig. 249.1A) are part of an extensive 

batholith around Hunters Mountain in the Panamint 

Range which consists mainly of the Hunter Mountain 

quartz monzonite (McAllister, 1956). Those exposed 

extensively in the southwest corner of the map (fig. 

249.1A) are part of a large batholith, also· chiefly 

quartz monzonite, that forms part of the Coso and 

Argus Ranges. 

Near plutonic rocks the Paleozoic sedimentary rocks 

commonly have been altered to calc-hornfels and, in 

Darwin Canyon north west of Zinc Hill mine, to a 

body of diorite, gabbro, epidote amphibolite, and 

amphibolite. Hall and Macl{evett (1958, p. 12) report that this body grades into calc-hornfels. The 

average density determined for 9 samples of this rock, 

which is the dense.St large rock mass sampled in the 

region, was 3.15 g per cm. 3 The density of the calchornfels near this body covers a wide range but is 

generally higher than either the quartz monzonite or 

the unaltered sedimentary rocks. The area contains 

numerous mines and prospects, mainly for lead, zinc, 

and silver, or for talc. 

The late Cenozoic volcanic rocks described by Hall 

and M:acl{evett ( 1958) consist of older basalt pyroclastics with interbeds of andesite and pumice in the 

upper part and younger olivine basalt flows. The 

pyroclastic rocks reach a thickness of about 1,000 feet 

near local vents. The basalt, which covers much of 
0 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-:-292 C-277 

EXPLANATION 

D 

Cenozoic sedimentary rocks 

Cenozoic volcanic rocks 

Mesozoic plutonic rocks 

• Calc-hornfels 

Paleozoic sedimentary rocks 

---160()-

Mngnetic contours 50 gamma interval 

---850--

Gravity contours DashctL in arett of poor control; co11tour intcrvttl S milligal 

• Gravity station 

~ 

Mine 

---. I 

I 

< t ... ..t.. " ', 0 'Darwin Area 

~ • '< ,.., ' ~ " "/ ~ 

_ _( 

5 

• 

• 

SANTA R_OSA 

1.0 MILES 

• 

A 

117°30' 

• 

\ \ 

B6o--........._ \ \ 

""" \ \\ 

• 

-" "-.j I 

(

870-" \1. j t· 

\ I • • ./. 

• • \ \ u:\l_~ • .,t" 

• • 

DARWIN 

MINES 

B 

. . . " . ~-

MODOC 

'X' 'X' DEFENSE 

36°" 

30' 

FwuRI<J 24!Ll.-A, Aeromagnetic and generalized geologic map of the Darwin area. The magnetic data were obtained along eastwest flight lines 2 miles apu.rt at 10,000 feet above sea level. The geology is generalized from the Death Valley sheet of the 

geologic mu.p of Ctdifornia (Jennings, 1958) with supplemental data from Hall and MacKevett (1958). B, Complete Bouguer 

gmvity anomaly map of the Darwin area, with terrain corrections through zone 0 of H.ayford-Bowie charts. 
C-278 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

the surface, occurs in flows 10 to 100 feet thick. The 

maximum aggregate thickness of the flows is about 

600 feet. 

GEOPHYSICAL SURVEYS 

Figure 249.2 shows gravity and magnetic profiles 

from the Sierra Nevada at Owens Lake to the east 

side of Death Valley near Badwater. The largest 

magnetic feature on the profile is a high of about 

700 gammas in the Darwin area. The dominant 

gravity feature is a westward decrease of the Bouguer 

anomaly values corresponding to a westward rise in 

the average elevation of the land surface. Sup~rimposed on this regional anomaly is a gravity high in 

the Darwin area. The gravity high, which is offset 

to the east of the magnetic high, is difficult to isolate 

from the regional anomaly, but it appears to have 

an amplitude of more than 10 milligals. 

The Cenozoic sedimentary rocks, which cover much 

of the area of figure 249.1, are generally less than a 

few hundred feet thick and do not have a major 

effect on the magnetic and gravity anomalies. 

The volcanic rocks are not believed to show a major 

effect on the magnetic and gravity maps. The volcanic rocks range from very light puinice to moderately dense basalt; however, the average density of 

any thick accumulation of volcanic rocks is probably 

1000 

(/) 

<X: 

~ 

~ 

<X: 

~ 

0 

80 

100 

120 

(/) 

...J 140 <X: 

~ 

::::i 

...J 

:E 160 

180 

200 

220 

12,000' w 

Owens Valley 

SEA LEVEL 

0 

less than that of the pre-Tertiary rocks. The warping of 

the gravity contours 6 miles west and slightly north of 

Panamint Springs may be produced by volcanic rocks. 

The magnetic effect of the volcanic rocks is harder to 

evaluate. Ground profiles over the basalt flows show 

that the basalt is highly magnetic; however, the 

anomalies produced by the basalt are alternatin<r . b 

h1ghs and lows that probably do not have a large 

net effect on the magnetic field several thousand feet 

a:bove the surface. The ground data, an inspection of 

profiles from airborne data, and comparison with data 

over similar volcanic rocks in the region indicate that 

the larg~r magnetic anomalies are not produced by 

the volcanic. rocks. The volcanic rocks probably do 

not produce much more than 100 gammas variation 

in the magnetic field at the flight level. 

In the northeast part of the magnetic contour 

map (fig. 249.1A) is an area of high magnetiG intensity that includes five local magnetic highs. Three of 

these highs are certainly produced by the plutonic 

rock, and others are also probably produced by plutonic rock. Much of the southwest edge of the exposure 

of Hunter J\1ountain quartz monzonite is bordered by 

volcanic rocks; however, the steep magnetic gradients which flank the area of the extensive magnetic 

high in the northeast part of the map are between outTotal 

25 MILES 

FIGURE 249.2.-Total ~agnetic intensity and complete Bouguer gravity anomaly along a profile from the Sierra Nevada at Owens 

Lake to the ~ast stde. of Death Valley near Badwater. The flight level of the aeromagnetic profile was 10,000 feet above sea 

level. Gravtty data m Owens Valley from Kane and Pakiser (1961). 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-279 

crops of the pre-Tertiary sedimentary rock and the 

plutonic rock. Clearly this extensive magnetic high 

is produced by the quartz monzonite. 

The magnetic high near the center of the map is 

in an area covered extensively by Cenozoic alluvium 

and volcanic rocks; however, intrusive rock is exposed in the deep canyons in the area of the anomaly 

and at two places on the highland. Thus it is inferred 

that this magnetic high is produced by a large intrusive body that is only partly exposed. Two magnetic 

noses extend south and southeast from the main 

high. One of these is over the intrusive outcrops 

near the town of Darwin and the other is over the 

intrusive outcrop at Zinc Hill mine. The general 

level of the magnetic ·field is low over the batholith 

t:hnt crops out· in the southwest corner of the map. 

The intrusive rock underlying the magnetic high in 

the central part of the map appears to have magnetic 

properties more like the batholith of Hunter Mountain 

to the north than like the batholith of the Coso Range 

immediately to the south. 

The gravity high, along the east side of the large 

magnetic high, is in an area of extensive exposures of 

calc-hornfels. The gravity high is probably produced 

by dense rocks formed by the alteration of sedimentary rocks along the east side of the intrusive body 

that produces the large magnetic high. 

A small magnetic high was observed in the area of 

the Santa Rosa mine. This anomaly could be produced by the volcanic rock, which is within 2,300 feet 

of the flight elevation in the south end of the Inyo 

Mountains. The two exposures of Paleozoic rock in 

the area of the anomaly are calc-hornfels, however, 

and a small exposure of intrusive rock occurs at the 

south edge of the anomaly. This small magnetic high 

may be produced by a body of intrusive rock underlying the area of the Santa Rosa mine. 

REFERENCES 

Hall, W. E., and MacKevett, E. l\f., 1958, Economic geology 

of the Dai:win quadrangle, Inyo County, California: California Div .. Mines Spec. Rept. 51, 73 p. 

.Jennings, C. W., 1958, Geologic map of California, Death Valley sheet: California Div. Mines. 

Kane, M. F., and Pakiser, L. C., 1961, Geophysical study of the 

subsurface structure in southern Owens Valley, California: 

Geophysics, v. 26, no. 1, p. 12-26. 

McAllister, .J. F., 1956, Geology of the Ubehebe Peak quadrangle, Inyo County,· California: U.S. Geol. Survey Quad. 

Map GQ-95.· 

MINERALOGY, GEOCHEMISTRY, AND PETROLOGY 

250. VANADIUM AND ASSOCIATED ELEMENTS IN THE PHOSPHORIA FORMATION IN THE AFTON AREA, 

WESTERN WYOMING 

By J.D. LovE, Laramie, 'Vyo. 

Work done partly in cooperation with the U.S. Bu.reau of .Mines 

Vanadium in phosphate rock in the Phosphoria formation of Permian age in western Wyoming and 

Idaho has been known since 1911 (Mansfield, 1927, 

p. 21~, 299-300), and W. W. Rubey has discovered 

shale and mudstone beds that contain more vanadium 

than the phosphate rock (Rubey, 1943). During 1942 

and 1943, the Paris-Bloomington area in Idaho 

(l\1:cl\:elvey and Strobell, 1955) and the Sublette Ridge 

and Afton areas in Wyoming (fig. 250.1) were sampled in detail in trenches and adits. 

The Phosphoria formation in the Afton area is 

composed of three members: (a) At the base is the 

~1:eade Peak pho~phatic shale member, which consists 

of 90 to 120 feet of soft, black and gray, slightly to 

moderately vanadiferous shale, mudstone, siltstone, 

and oolitic phosphate (fig. 250.2). The phosphate 

beds are in two zones, one near the top and the other 

near the base of the member. (b) Above the Meade 

Peak is the Rex chert member, 112 to 150 feet thick, 

composed of gray and black massive to bedded and 
C-280 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

ln1·oo· I 

--+-+-----------1------43°00' 

l 

' 

.· 

:' "' I 

Afton; 

:~~ I - _ 

O! I I 

! \ \.l 

i /~ui iAfton ......._J 

; area 

Sublette Ridge area 

' 

.\\C.okeville 

-f----+-----!:-------........... ---------42°00' 

I 

I 

~I~ <ps 

bl~ 

I~ 

~ 

....... ·. " '··-·· _,.· '" I , 0 10 20 MILES 

I L__ _____ _~_ _____ ___.J 0 Kemmerer 

111 •oo· Geology by W. W. Rubey, compiled on 

Geologic Map of Wyoming, by J.D. Love, 

J. L. Weitz, and R. K. Hose, 1955 

nodular chert, cherty and locally phospha~ic gray 

limestone, and thin beds of gray quartzite. (c) The 

uppermost is the Retort phosphatic shale member 

(Mcl{elvey and others, 1959, fig. 5), which consists 

of 0 to 20 feet of non-vanadiferous black to dark 

gray shale, siltstone, and phosphatic limestone. Underlying the Phosphoria formation is the Grandeur 

member of the Park City formation, which consists of 

25 to 50 feet of hard gray limestone, and which in 

turn overlies the sandstone and quartzite of the Wells 

formation. 

Although several vanadiferous zones were found by 

sampling, only one has sufficient thickness, grade, and 

continuity to be of possible economic interest. It is 

a 3- to 5-foot zone of black shale and dark gray 

mudstone about 5 to 10 feet below the upper phosphate 

in the l\1eade Peak member and 15 to 40 feet below 

the top of the member. Within the Afton area, the 

zone averages 4.15 feet in thickness and consists of 

6 beds of shale and mudstone. Chemical analyses 

show that (a), a central shale bed 0.5 to 1 foot thick 

is richest, averaging 1.6 percent Vz05 (maximum 

2.5 percent) ; (b), beds abve and below the richest 

one are successively lower grade toward the margins 

of the zone; (c), the full zone averages 0.7 percent 

V zO,; and (d), the vanadium content of the richest 

3 feet of the zone varies from a minimum of 0.7 percent Vz05 in the northern part of the area to a maximum of 1.0 percent V z05 in the central part. 

The delimitation of this zone, and the determination of grade and tonnage of vanadium in the Afton 

area, are based on nearly 2,000 field tests (Axelrod, 

1946) and more than 1,000 chemical analyses for 

vanadium of samples from 89 trenches and 6 adits on 

4 lines of outcrop of the Meade Peak member within 

an area of less than 10 square miles (fig. 250.2). 

Except in the vicinity of faults, the continuity of the 

zone is such that the average grade and thickness 

can be predicted with· some confidence. It is estimated that within the area shown on figure 250.2, 

reserves classed as indicated total 45 million tons of 

rock having an average grade of 0.9 percent Vz05 

and an average thickness of 3 feet, between the 

outcrops and a depth of 500 feet below major 

drainage level (35 million tons above drainage 

level, 10 million tons from drainage level to 500 feet 

below). Excluded from this estimate are areas where 

~,IGURE 250.1.-Map of part of western Wyoming showing outcrops of Phosphoria formation (black), outline of area within which the Phosphoria formation was sampled at widely 

separated intervals (black dots), and the Afton and Sublette' 

Ridge areas within which the formation was studied and 

sampled in detail (enclosed by uashes). 
.• 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

74 

EXPLANATION 

Area of indicated vanadium reserves in 

vanadiferous zone above drainage level 

1/' 

/J ,, ;!; 

Area of indicated vanadium reserves in vanadiferous 

zone between drainage level and 500 feet below 

drainage level 

Fault 

Dnshed where npproximntely located 

-+-

Crest line of anticline 

--A--

Overturned anticline 

-+-

Trough line of syncline 

Outcrop of Meade'Peak 

~ 

phosphatic shale member 

of Phosphoria formation showing numbered 

trench sampled for vanadium 

0 

4y 

Strike and dip of beds 

8~ 

Strike and dip of overturned beds 

t 

Strike of vertical beds 

2 

Geology by W. W. Rubey, slightly modified by 

J.D. Love and L. E. Smith 

t N 

3 MILES 

110°50'W X 

C-281 

Frc URE 250.2.-Geologic map of Afton area showing outcrops of Meade Peak phosphatic shale member of Phosphoria 

formation, generalized structure, and location of computed reserves of vanadiferous rock. 

aoMao 0-61--19 
C-282 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

faulting is intense or where mining difficulties can be 

expected. 

Small amounts of selenium, molybdenum, zinc, 

nickel, cobalt, titanium, and cadmium are present in 

the six beds comprising the vanadiferous zone. The 

middle beds that contain the most vanadium likewise 

contain the greatest concentration of these elements. 

Chromium is also present, but unlike the other metals, 

is apparently concentrated in the upper ·and lower 

beds of the zone. 

The selenium content of the vanadiferous zone in 

the Afton area as a whole has not been accurately 

established. The maxi~um quantity obtained (from 

adit 2, fig. 250.2) is 0.068 percent selenium in a 0.8-

foot bed containing 2.12 percent V205 (Beath, Hagner, and Gilbert, 1946, p. 14-15). At this locality, 

the vanadiferous zone has a weighted average of 

0.042 percent selenium and 0.94 percent vanadium for 

3.85 feet of strata. 

The highest chemical analysis of 1\tlo03 is 0.1 percent. However, selected samples from the most vana..: 

diferous middle part of the zone (containing 1.3 to 

2 percent V20fi) in unweathered sections from several adits average 0.02 to 0.05 percent Mo03 • The 

highest chemical analysis of ZnO is 1.3 percent, that 

of TiO 2 is 1.0 percent, .?f NiO, 0.3 percent, and of 

Cr20a, is 0.5 percent. Semiquantitative spectrographic analyses of samples obtained by D. F. Davidson in 1960 (Art. 267) from ad its 1, 6, and 8 (fig. 250.2) 

show maximum cadmium content of 0.02 percent. 

The upper and lower phosphate beds in the Meade 

Peak member contain small quantities of uranium, 

with maximum knO\vn content ranging from 0.0~ to 

0.02 percent. One phosphatic shale 5.7 feet thick in 

the middle of the member contains 0.009 percent 

uranium (Rubey, 1958). 

It is the "-rit'er~s belief that the vanadium, uranium, 

molybdenum, selenium, nickel, zinc, titanium, chromium, cadni.ium, and probably other trace elements, were 

deposited contemporaneously \Yith the rocks of the 

~ieade Peak member as precipitates frmn solution in 

a unique marine environment, the nature of which is 

not fully understood. There is little evidence of leaching or secondary concentration of these elements, with 

minor localized exceptions in the near-surface zone of 

weathering. REFERENCES 

Axelrod, .J. l\L, 1946, A field test for YatUl.dinm, i'n Contributions 

to geochemistry, 1942-45: U. S. Geol. Survey Bull. 9GO, p. 

19-23. 

Beath, 0. A., Hagner, A. F., and Gilbert, C. S., 1946, Some rocks 

and soils of high selenium content: Geol. Survey of 'Vyoming Bnll. 36. 

l\IeKelvey, Y. E. aud other~. 1!)50, The Phosphoria, Park City, 

and Shedhorn formations in the western phosphate field: 

U. S. Geol. Survey Prof. Paper 313-A. v. 1-47. 

McKelvey, V. E., and Strobell, J. D., .Jr., 1!)55, Preliminary 

geologic maps of the Paris-Bloomington vanadium area, 

Bear Lake County, Idaho: U. S. Geol. Survey Mineral Inv. 

Field Studies ~lap M:F-41. 

:\fansfield, G. R .. 1927, Geography, geology, and mineral resources of part of southeastern Idaho: U. S. Geol. Survey 

Prof. Par1er Hi2. 

Rubey, ,V. "r., 1!)-l-3, Vanadiferous shale in the Phosphoria 

formation, "ryoming and Idaho [abs.] : Econ. Geology, v. 

38, no. 1, p. 87. 

1958, Geology of the Bedford quadrangle, 'Vyoming: 

U. S. Geol. Snrvey Geol. Quad. l\Iap GQ-109. 

.... : 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTI·CLES 147-292 C-283 

251. SOME GEOCHEMICAL ASPECTS OF GROUND WATER IN NORTHERN ST. LAWRENCE COUNTY, NEW YORK 

t 

By RALPH C. HEATH and EDWARD H. SALVAS, Albany, N.Y. 

Work done in cooperation with the New York State Power Authority and the 

New Yo1·k Water Resources Commission, 

In 1957, the U.S. Geological Survey began an investigation of the ground-water resources of 480 square 

miles of area bordering the St. Lawrence River near 

Massena, N.Y. The bedrock of the area consists, from 

oldest to youngest, of crystalline rocks of Precambrian 

nge and the Potsdam sandstone, Theresa dolomite and 

Beekmantown group, all of early Paleozoic age. The 

crystalline rocks and Potsdam sandstone crop out at 

n few places in the southern part of the area. The 

Theresa formation, which consists of alterna-ting beds 

of sandstone and dolomite, is the uppermost· unit of 

bedrock in most of the southern part of the area. The 

Beekmn,ntown group, which is a gypsiferous dolomite 

more than 500 feet thick at Massena, is the uppermost 

bedrock unit in the central and northern parts of the 

area. The bedrock in the Massena area dips north 

toward the center of a structural basin in Ontario, 

Canada. Pleistocene deposits, most of which were deposited by continental ice sheets but which include 

some marine and lake sediments, form an almost continuous blanket, in places more than 100 feet thick, 

over the bedrock. Ground water occurs in a continuous 

zone of saturation that extends downward from the 

water table, which is in the Pleistocene deposits in 

nearly the whole area, into the crystalline rocks. 

Data on the chemical quality of the ground water 

provide significant information on the following aspects of the geochemistry : (a) the occurrence in the 

area of two distinctly different types of ground water, 

nnd (b) evidence of ion exchange. 

The differences in chemical composition of the two 

types of ground water are shown graphically in figure 

251.1. For convenience in discussion, these waters may 

be referred to as fresh water and saline water. The 

fresh water contains a relatively low concentration of 

sodium and chloride ions, but these ions are dominant 

constituents in the saline water. Fresh water is in the 

upper part of the zone of saturation in the recharge 

areas between streams, and the saline water is in the 

lower part of the bedrock. Because there are no extensive impermeable beds in the bedrock, the fresh and 

saline waters are in contact and are rather thoroughly 

mixed in the zones of ground-water discharge along 

the principal streams. Several analyses which show 

the intermediate chemical content of mixtures of fresh 

and saline water also are presented on figure 251.1. 

(See, for example, analyses of water from wells 455-

452-4 and 440-459-1). 

Areal variations in chloride content of water from 

the upper part of the bedrock are shown in figure 

251.2 (p. C-285). The areas of higher chloride in the 

midst of low-chloride areas reflect the few available 

analyses from wells penetrating the deeper rock. Conversely, areas of low chloride in the midst of higher 

chloride areas reflect the influence of localized recharge 

through northeast-southwest elongated hills. An important feature of the map is the discontinuous areas of 

high chloride adjacent to the principal streams, which 

are believed to show areas where saline water is moving 

upward from the deeper zones, mixing with fresh 

ground water and discharging into the streams. The 

upper part of the bedrock in the intervening areas of 

low chloride content along the streams is believed to 

have such a low vertical permeability that little, if any, 

saline water is moving upward and being discharged. 

Differences in the fresh and saline waters, as reflected by changes in the ratio of chloride to dissolved 

solids, are shown in figure 251.3 (p. C-286). The analyses in the lower left-hand part of the graph show the 

relation of chloride to dissolved solids in the fresh water. 

The values at the extreme left-hand side of the graph 

are believed to reflect the chemical content of water at 

the time it reaches the water table-that is a chloride 

content of 1 ppm (part per million), which is present in 

the precipitation, and a dissolved solids content of 280 

ppm, most of which is calcium and magnesium bicarbonate dissolved froin the materials above the water 

table. Higher values on the graph show principally 

the addition of chloride to the initial composition. The 

additional chloride is believed to be derived largely 

from saline water but some, particularly in the lower 

concentrations, may be derived from salts used to deice roads, from fertilizers, and the effluent from septic 

tanks. The relation of chloride to dissolved solids for 
C-284 GEOLOGICAL SURVEY RESEARCH 19 61 

3000 

2000 

1500 

1000 

900 

800 

700 

600 

500 

400 

300 

200 

150 

100 

90. 

80 

70 

60 

50 

40 

30 

20 

15 

10 

the saline water is shown by the steeply sloping trend 

line. Because of natural mixing of the fresh and saline 

waters a larger number of water samples having intermediate chloride contents (from about 20 to about 200 

ppm) would doubtless have shown a merging of the 

two trends shown on figure 251.3 into a smooth curve . 

. Ratios of chloride to dissolved solids for water samples 

from mineral springs and wells in eastern Ontario (Elworthy, 1918, p. 22-63) also are shown on figure 251.3. 

These analyses, which plot along the trend of the 

Massena analyses, are of waters from the bedrock in 

the norther~1 part of the basin. 

The fresh water is derived from precipitation falling 

on the area. The saline water probably is sea water 

that entered the ground when the area was covered by 

the Champlain Sea, an arm of the Atlantic Ocean that 

covered the area for a period of about 2,500 years following the m~lting of the last ice sheet, about 7,000 

years ago. Salt beds and connate water are also possible sources of the saline water, although supporting 

evidence is lacking. If the Champlain Sea were the 

source of the saline water, the present distribution of 

the water reflects the extent to which flushing has taken 

place. It is noteworthy that salty water has been reported in some of the marine clays deposited in the 

Champlain Sea in eastern Ontario (John Terasmae, 

Geological Survey of Canada, written communication, 

~June 29, 1960). 

The anaJyses in figure 251.1 show. differences in the 

behavior of' certain ions brought in by sea water during 

the proc~sses ·of dilution and flushing. Chloride is not 

_adsorbed appreciably by the minerals in the aquifers. 

However~ s.odium is adsorbed to some extent by min-

~raJs ·having ion-exchange capacity. During early 

stages of :.dilution the saline water contains a high 

amount' of chlo·ride as compared to sodium. During 

later stages ,-\rhen the chloride concentration has 

reached a lo'v hwel the sodium that had been adsorbed 

is gr~dually displaced by calcium and magnesium from 

the fresh water. Hence, the ratio of chloride to sodium 

is lower in the fresh water than in the saline water. 

REFERENCE 

Elworthy, R. T., 1918, Mineral springs of Canada, itt The 

chemical character of some Canadian mineral springs, Pt. 

2 : Canada Dept. Mines Bull. 16, 173 p. 

FIGURE 251.1.-Analyses, in parts per million, of ground water 

in the Massena area, as plotted on logarithmic nomograph. 

Serial numbers identify wells sampled. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 

EXPLANATION 

Chloride content, in parts per million 

c=J 

Less than 10 

f:.·:.::::':::.::l 

10 to 100 

t'··.:::':'··.:.i More than 100 

11111111111111111 

Dike 

= Dam 

455-458-15 

'''2~ 

Upper number is well number. Lower number is chloride 

content in parts per million 

YQRK 

(;) 

0 5 

C-285 

N 

10 MILES 

F1cu1m 251.2.-Areal distribution of chloride in ground water in the upper part of the bedrock in the Massena area, Kew York. 
C-286 GEOLOGICAL SURVEY RESEARCH 1961 

50,000 I T I I I 

EXPLANATION 

• 7- Well in bedrock in Massena area 

- f-

-+- / Well in unconsolidated deposits 

- in Massena area 

20,000 

10,000 0 69 z 

0 

::J Mineral spring in eastern Ontario 00 - I I I 

...J 

~ 

0:: 5000 UJ 

Cl. 

(/) 

~· 0 

• / • - ./ -

/,(' 

• /0. 

f0:: 

<( 

Cl. 

~ 2000 vi 

0 

::J 

0 

(/) 

0 

,/./ • 

• 

-+- - -

-+- ... _ ... _./.e. :.---

UJ 1000 > 

~ (/) 

0 

500 

:t+:_ ... i--t-• •• -

• .. . - .. • 200 -

I . I I I I I I I 

2 5 10 20 50 100 200 500 1000 2000 5000 10,000 20,000 

CHLORIDE, IN PARTS PER MILLION 

FIGURE 251.3.-Graph of chloride versus dissolved solids of fresh and saline ground water in the Massena area and saline ground 

water in eastern Ontario. 

252. X-RAY DETERMINATIVE CURVE FOR SOME NATURAL PLAGIOCLASES OF COMPOSITION Anao-ss 

By EVERETT D. JACKSON, Menlo Park, Calif. 

The usefulness of X-ray powder diffraction methods 

for estimating An content of natural plagioclase has 

been seriously questioned in a number of recent publications on grounds that diffraction parameters are 

strongly influenced by structural state and degree of 

inversion of the plagioclase. 1 Smith and Yoder ( 1956), 

while cautioning against indiscriminate use of X-ray 

diffraction curves for plagioclases. from diverse environments, suggested that such curves might be useful 

for suites of plagioclases of closely similar origins and 

1 'rhe plagioclaRe X-ray determinative curve of Overkott (1958) is 

based on an absorption method and is not sensitive to structural 

factors. 

thermal histories. In particular, they suggested that 

plagioclases of the Bushveld type formed such a suite. 

However; Smith and Gay (1958) saw no reason to 

attach special importance to plagioclases from thick 

layered intrusions, nor to exclude them from their 

reservations about the usefulness of diffraction measurements for determinative purposes. 

In order to determine whether a useable determinative curve could be constructed for use within a single 

layered intrusion, the 20 ( 131)- ( 131) and 2(} ( 131)-

( 220) reflection separations of 12 analyzed plagioclases 

from the Basal and Ultramafic zones of the Still water 

complex, Montana, were measured and plotted against 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-287 

An content. The resulting curve appears to be linear 

over the investigated range and to have sufficiently 

narrow confidence limits to warrant its use to estimate 

the composition of plagioclases from the lower part of 

the complex. 

Plagioclase concentrates from 5 specimens of plagioclase-bearing rocks from the mtramafic zone and 5 

specimens from the Basal zone were crushed to ·-325 

mesh and cleaned by centrifuging in dilute bromoform. 

Optical grain counts indicate that the samples thus 

obtained are more than 99 percent pure plagioclase. 

Two of the samples were split to make hidden duplicates, which were then treated as separate samples. 

All 12 samples were analyzed by a spectrogravimetric 

method devised by Stevens and others ( 1960), and 

the An content was calculated as 100 times the atomic 

ratio of Ca and Sr to Ca, Sr, Na, and K. Three subsamples were split from each of the samples prior to 

analysis for X-ray examination. These 36 subsamples 

were assigned random numbers to determine run 

order, prepared as slurrys on circular cover glasses, 

placed in a rotating sample holder, and allowed to 

oscillate twice up and twice down between 28° and 

32° 29 on a Norelco diffractometer using unfiltered 

Cu 1\::a radiation. A one-degree divergent slit, onequarter degree scatter slit, and 0.006-inch receiving 

slit were used; the scan speed was one-quarter degree 

per minute; the chart scale was 2 inches per degree 

29. The distances between (131) and (131) peaks and 

between the (131) and (220) peaks were measured 

directly in degrees from the charts and compiled, and 

means and standard deviations of ~ 29 were calculated 

from them. The r parameter of Smith and Gay ( 1958, 

p. 748) was obtained by subtracting the (131)-(220) 

separation from the (131)-(131) separation. An content, calculated from the analyses, and X-ray data are 

summarized in table 252.1. 

TABLE 252.1.-An content and X-ray diffraction measurements 

(using Cu Ka radiation) of JS plagioclase samples from the 

Stillwater complex 

628(131)-(131) 

(degrees, 12 readLnh. Ant ings) Field no. no. (percent) Mean Standard 

deviation 

------------- 53IN-2 21 59.9 1.857 :1:0.0025 

53NB-11 16 60.0 1. 889 .0030 

55MV-29 20 f>8. 5 2.012 .0019 

55NB-1 2 17 70.1 2.039 .0028 

s2n1<:;-35 13 70.3 2.027 .0031 

55BE-2 23 70.3 2.029 .0016 

55BE-4 14 72.0 2.071 .0014 

55MV-32 25 73.0 2.073 .0018 

55NB-2 a 24 73.6 2.066 .0022 

52BE-29 22 76.6 2.121 .0024 

55BE-7 15 76.9 2.138 .0028 

56BE-1 19 83.3 2. 206 .0009 

'Atomic ratio of Ca+Sr/Cn+Sr+Na+KaiOO 2 Hidden duplicate of 52BE-35 a Hidden duplicate of 55MV-32 

628(131)-(220) 

(degrees, 12 read- r togs) [628(131)-(131)-

628(131)-(220)] 

(degrees) Mean Standard 

deviation 

--

1. 246 :1:0.0010 +0.611 

1.199 .0025 +.690 

1.080 .0010 +.932 

1.053 .0021 +.986 

1.060 .0037 +.967 

1.058 .0021 +.971 

1. 018 .0016 +1.053 

1. 016 .0034 +1.057 

1. 019 .0021 +1.047 

0.1156 .0027 +1.165 

0. 947 .0037 +1.191 

o. 875 .0011 +1. 331 

CD 

N 

<J 

+1.40 

+1.30 

~ + 1.20 1.1.1 

a:: 

<.:) 

1.1.1 

0 

,....:; + 1.10 

0 

N 

N 

'( 

I~ +1.00 

N' 

~ 

<J 

I . 

~-+0.90 

I:! 

X 

~ +o.8o CD 

N 

2! 

t.. +0.70 

"+0.60 

60 65 . 70 75 

I 

I 

I 

80 

I 

I 

o I 

I 

I 

85 

An (ATOMIC RATIO Ca+Sr/Ca+Sr+Na+Kx100),PERCENT 

FIGURE 252.1.-X-ray determinative curve for plagioclase from 

the lower part of the Stillwater complex. 

The information in table 252.1 forms the basis for 

the determinative curve in figure 252.1. The value r 

is plotted directly as degrees ~28 on the ordinate, the 

An value on the abscissa. A regression analysis was 

made considering the 12 measurement sets to represent 

individual samples, using the average X-ray parameter 

r as the dependent variable, and taking the chemically 

derived value of An as the independent variable. 

The equation for the straight line curve is: 

r=.029868 An-1.1268 

The 95 percent confidence intervals (based on assumed 

normal distribution) for the regression equation are 

±0.064°20 at 70 percent An and ·±0.070°20 at 60 

and 80 percent An. These limit~ correspond to an 

uncertainty of about ±2'.1 percent An at the center 

of the curve and ±2.4 pei·cent An at the ends of the 

curve. This uncertainty is considerably larger than 

that obtained in much the same way for estimating 

composition of olivines (Jackson, .1960), although the 

standard deviations of the X-ray data and the differences in reported chemical constitu~nts between hidd.en 

duplicates are of the same order of magnitude in both 

sets of data. 
C-288 GEOLOGICAL SURVEY RESEARCH 19 61 

No marked displacement of the curve is noted in 

the interval An7o-75 in response to the abrupt structural 

change in plagioclases within that compositional range 

(Bown and Gay, 1958). Furthermore, there seem 

to be no systematic differences between samples from 

the Basal and Ultramafic zones. The entire curve, 

however, lies an average of about 0.08°r above one 

constructed in the same manner from data given by 

Smith and Yoder (1956, p. 637). The analyses on 

which these authors' An values are based are systematically poorer in K20 than those analyzed for the 

present study, and it may be that the displacement 

is at least partly due to different analytical methods 

of K20 determination .. 

It is concluded that the determinative curve is 

useful over a limited range of compositions of plagioclases from a restricted environment, and that its 

use within that environment should lead to An values 

at least as precise as those usually obtained by optical 

methods. Additional data will be needed to determine 

whether or not the curve can be applied to other 

plagioclases of the Bushveld type. 

REFERENCES 

Bown, M. G., and Gay, P., 1958, The reciprocal lattice geometry 

of the plagioclas~ feldspar structures: Zeitschr. Krist., v. 

111, p. 1-14. 

Jackson, E. D., 1960, X-ray determinative curve for natural 

olivine of composition Foso-oo, in Short papers in the geological sciences: U.S. Geol. Survey Prof. Paper 400-B, p. 

. B432-B434. 

Overkott, E., 1958, Eine rontgenographische Methode zur 

Bestimmung der · An-Gehalte von Plagioklasen: Neues 

Jahrb, Mineralogie Monatsh., v. 5, p. 113-120. 

Smith, J. R., and Yoder, H. S., Jr., 1956, Variations in X-ray 

powder diffraction patterns of plagioclase feldspars: Am. 

Mineralogist, v. 41, p. 632-647. 

Smith, J. V., and Gay, P., 1958, The powder patterns and 

lattice parameters of plagioclase feldspars. II : Mineralog. 

Mag., v. 31, p. 744-762. 

Stevens, R. E., Chodos, A. A., Havens, R. G., Godijn, E., and 

Neil, S. T., 1960, Combination of gravimetric and spectrographic methods in the analysis of silicates, in Short 

papers in the geological sciences: U.S. Geol. Survey Prof. 

Paper 400-B, p. B499-B501. 

253. BORON IN BENTONITE AND SHALE FROM THE PIERRE SHALE, SOUTH DAKOTA, WYOMING, AND MONTANA 

By HARRY A. ToURTELOT, LEoNARD G. ScHULTz, and CLAUDE HUFFMAN, Jr., Denver, Colo. 

The boron content of shale has been of interest 

since Landergren ( 1945) noted that boron in finegrained sedimentary rocks is proportional to the 

amount of clay-size material and to the salinity of 

the water in which each rock was deposited. (See also 

Degens, Williams, and Keith, 1957.) Frederickson and 

Reynolds ( 1960) reported that the illite contains nearly 

all of the boron in shale samples. Harder ( 1959) also 

considered micaceous clay minerals the principal carrier of boron in most sedimentary rocks. 

The Pierre shale is entirely marine. Bentonite samples are nearly pure montmorillonite and their boron 

content ranges widely (fig. 253.1). Other rocks are 

mixtures of montmorillonite, mixed-layer illite-montmorillonite, illite, quartz, and generally minor amounts 

of kaolinite, chlorite, and other minerals; carbonate 

minerals are abundant in a few samples. The boron 

content of individual samples shows little relation to. 

the total clay or organic ca:rbon content. 

Five samples of bentonite and five of other rocks 

were selected from those previously analyzed (fig. 

253.1) to represent a range of boron content convenient 

to work with and a range of mineralogical composition. Two splits of each sample were separated into 

fractions coarser than 1 micron and finer than 1 

micron by repeated disaggregation in distilled water 

and centrifuging. The coarse and fine fractions of one 

split intended for boron analysis were handled in 

plastic containers to avoid any possible contamination 

with boron dissolved from glassware (Wichers and 

others, 1941). A blank sample of distilled water was 

run to monitor possible contribution of boron by distilled water or the sodium metaphosphate dispersing 

agent. The two fractions of the split for mineralogical 

analysis by X-ray were stored in glass containers. A 

third unfractionated split of each sample represents 

the original sample. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-289 

100 • ' .. 

'' • . 

' 

80 •• ~ : + ,/ . . )( 

. +l~+~ ~ 

1- ~ +'\ /x ...., 

z f. 

' +•~ M+ )( (.) 

0: 

...., + • +x ~ . I( 

a.. 

~ 60, ·~ I( + )( 

....,.. ~ \ _, EXPLANATION a.. 

t' • ~ Bentonite 

iJi . . ~ )(+ Shale and claystone containing 

>- <0.5 percent organic carbon 

:s 40 • + (.) Shale and claystone containing 

_, • 0.5-1.0 percent organic carbon 

c( )( b • Shale containing >LO percent 1- organic carbon 

... Marlstone 20 .... Sample studied in more detail 

Note: diagram based on spectrographic analyses by Paul R. Barnett. Figures differ slightly 

from detailed analyses in table 1 

0 

0 0.010 0.020 0.030 

BORON, IN PERCENT 

FIGURE 253.1.-Relutions between boron und clay contents in 69 

samples of Pierre shale from South Dakota und parts of 

adjacent Stntes. 

Boron was determined by the carminic aciq method 

of I-Iatcher and Wilcox (1950). The precision indicated by 20 duplicate runs made of 10 solutions of our 

samples is ±0.001 percent boron. The sum of the 

boron in the two fractions of each sample is systematically higher than the boron in the original, unfractionated sample (table 253.1), but differences are within the precision: of the determinations. No boron was 

found in the reagent ·blank. 

X-ray analyses (table 253.1) of the mineralogy 

have a precision of about 10 percent (Schultz, 1960, 

and written communication). Total clay is reported 

to the nearest 5 percent. The amount of each clay 

mineral in the total rock was calculated by multiplying the relative proportion of each clay mineral by 

the percentage of total clay. 

The boron contents of the fine and coarse fractions 

of 3 of the 5 bentonite samples are very similar (fig. 

253.2), apparently because both fractions are almost 

entirely montmorillonite. The fine fraction of bentonite 

sample 259548 contains less boron than the coarse fraction. This relation is reversed in sample 259588, 

apparently because the coarse fraction contains abundant feldspar and jarosite which probably contain 

little boron. The most important factor controlling 

the boron content of the different size fractions of the 

bentonite is the total amount of clay minerals rather 

than the particle size of the clay. 

Boron content of the fine fraction of all 5 shale 

samples is greater than that of the coarse fraction by 

20 to 100 percent (fig. 253.2). The principal nonclay 

mineral is quartz (table 253.1), with appreciable 

carbonate and sulfate minerals in two samples. 

These minerals characteristically contain little boron 

(Harder, 1959). On calculating percent boron to 100 

percent clay (table 253.1), the boron content of the 

coarse and fine fractions is about the same within the 

limits of analytical techniques. The boron content of 

the size fractions of the shale as well as the bentonite 

from the Pierre shale thus is related to the total clay 

content and apparently is independent of the clay 

particle size. 

fz 

LLJ 

() 

0:: 

LLJ 

a.. 

100 

80 

~ 60 

LLJ 

....J 

a.. 

~ 

<{ 

en 

~ 

>-

::5 40 () 

....J 

<{ 

f0 

f20 

548 

f;=-C 

f 

EXPLANATION 

Whole sample 

c 

Fraction coarser than 1 micron 

Fraction finer than 1 micron 

573, 537 

Numbers are last 3 digits of sample 

numbers (table 1). Underlined 

numbers indicate bentonite 

0~----------~----------J-________ ___, 0 0.010 0.020 0.030 

BORON, IN PERCENT 

FIGURE 253.2.--Boron and total clay contents in whole sample 

and size fractions. 
TABLE 253.1-Boron content and mineralogical composition of 10 samples of bentonite, claystone, shale, and marlstonefrom the Pierre shale in South Dakota, Wyoming, 

and Montana 

[Chemical analyses for boron by Claude Huffman, Jr.; X-ray mineralogical analyses by L.G. Schultz. Mineralogical data for whole samples obtained by multiplying data on fractions by weight percent of the fractions] 

Relative proportions Sample Boron of clay minerals in 

total clay 

is.s a ::, .8 

== "" ~ .£o ·a ·- 0 50 a ggs ~ ~~ Location Description of material Stratigraphic unit Fraction 1 .s ~£= ;>,0 Q;> ;>, i:! 0 .:sa .:s ... "i: ..., .8 Q;> 

~ ::::: bO :::-oQ;> s ~~ :s <.> ..0 Q;> Q;> 0 

~~~ "i: 'C s 8 bO a a;>o Q;> 0 ·a; ~ 0 <.> 

.::s s ..., .... 0 :a ::I Q;> Q;> 

~ Q;> .... Q. "" 0 z ~ p.. p.. p.. ;:;s ;:;s ;::::< 0 ~ E-< 

Bentonite 

[Samples are in numerical order] 

25ll037 1 NWJ( ""'· 1, T. 111 N.,l Bantonlte, VO'Y light I Aganoy 'halo man!"" I Coru-M 1. 23 42.1 0. 0090 ·111 0.010 100 ---- ---- ---- ---- 90 R. 80 W., Hughes gray, biotitic. (Russel, 1930). Fine 1. 69 57.9 .011 185 .011 100 ---- ---- ---- ---- 100 County, S. Dak. 

{(296) Whole ------ 100.0 } .009 . 009 262 100 ---- ---- ---- ---- 95 

259542 I Sec. 30, T. 6 N., R. 31 I Bentonite, light I Upper part of Virgin I Coarse 1.23 38.3 .0098 120 .010 100 ---- ---- ---- ---- 100 E., Stanley County, greenish-gray. Cre~k member. Fine 1.97 61.7 .0098 193 .010 100 ---- ---- ---- ---- 100 S.Dak. 

{(313) Whole ------ 100.0 .0080 } .008 256 100 ---- ---- ---- ---- 100 

259548 I NW~NE~ sec. 17, T., Bentonite, yellowish- I Sharon Springs mem-, Coarse 1.27 42.2 .023 292 . 024 100 ---- ---- ---- ? 95 104 N., R. 71 W., Ly- gray with abundant ber. Fine 1. 74 57.8 .020 348 . 021 97 ---- ---- ---- 3 95 man County, S. Dak. jarosite. {(640) Whole ------ 100.0 . 021 } .022 632 98 ---- ---- ---- 2 95 

259557 I SW~NE~ sec. 18, T.l B~nto~i~e, white, I Lower part of Virgin I Coarse 2. 75 80.7 .016 440 .016 100 ---- ---- ---- ---- 100 96 N., R. 67 W., Greg- JarosJtic. Creek member. Fine .65 19.3 (') (') ------- 100 ---- ---- ---- ---- 100 ory County, S.Dak. { (') Whole ------ 100.0 .016 } . 016 544 100 ---- ---- ---- ---- 100 

259588 I SE~SE~ sec. 21, T. 71 BentoJ?.ite, pale I Lower part of Mitten I Coarse 1.00 33.6 . 012 120 .018 100 ---- ---- ---- ---- 65 S., R. 56 E., Carter grayish-orange. black shale member. Fine I. 97 66.4 .016 315 . 018 100 ---- ---- ---- ---- 90 County, Mont. 

{(435) } .014 100 1---- ---- -· -- ---- Whole ------ 100.0 .013 386 80 

Shale, claystone, and marlstone 

[Samples are in order of decreasing montmorillonite content] 

259578 SE~NE~ sec. 22, T. Shale, medium dark- Middle unnamed Coarse I. 74 55.4 0. 0099 172 0. 014 28 30 30 8 4 70 38 N., R. 62 W., Nio- gray. member. Fine 1.40 44.6 .016 224 . 018 67 24 8 0 1 90 brara County, Wyo. {(396) Whole ------ 100.0 . 012 } . 015 377 47 28 19 4 2 80 

259565 SE~SE~ sec. 31, T. 7 Claystone, yellowish- Upper part of Pierre Coarse 1. 70 59.7 .0094 160 . 016 10 22 49 12 7 60 N., R. 11 E., Meade gray, silty. shale, equivalent to Fine 1.15 40.3 .013 150 .014 40 40 15 2 3 95 County, S.Dak. Mobridge (?) {(310) member. Whole ------ 100.0 .010 } . 013 285 26 31 32 7 4 75 

259573 NE~NE~ sec. 31, T. 7 Shale, brownish-gray, Gammon member _____ Coarse 1. 73 53.3 .014 242 . 020 10 35 45 0 10 55 S., R. 7 E., Fall River platy, with fish re- Fine 1. 52 46.7 .020 304 . 025 26 54 18 ? 2 80 County, S. Dak. mains. 

{(546) Whole ------ 100.0 .016 } .025 520 19 45 30 0 6 65 

259531 NE~SE~ sec. 34, T. Shale, medium-gray, Mobridge member_ ___ Coarse .88 43.7 .012 105 .020 ? ? 70 15 15 60 124 N., R. 79 W., Wal- calcareous. Fine 1.13 56.3 .022 248 .023 19 37 26 6 12 95 worth County, S. 

{(353) } .020 Dak. Whole ------ 100.0 .016 321 13 25 40 9 13 80 

259556 sw~sw~ sec. 18, T. Marlstone, medium Mobridge member ____ Coarse 1. 53 48.8 .0078 119 . 022 3 21 49 18 9 35 96 N., R. 67 W., Greg- gray. Fine 1. 61 51.2 . 018 290 .026 15 50 19 5 11 70 ory County, S.Dak. 

{(409) Whole ------ 100.0 .012 } .022 377 11 42 28 9 10 55 

1 Coarse fraction is >I micron; fine fraction is <I micron; whole means whole sample. 2 Based on weight of samples and fractions multiplied by boron content in percent. Figures in parentheses are sums of micrograms of boron in fractions. 3 The syT".bol "?"indicates that presence of the mineral is doubtful. • Insutfident sample for analysis. 

'{-

Whole rock 

Clay minerals Other minerals 

Q;>Q;I 

.8 :E~ 

= ::::o 

~ ~ .. s Q;>r-. 

;>,0 Q;> 0 ~£ .8 ... .8 d ..., s Q;> :§ N 

~ .8 s "i: "0::::: 'C ..., c:>o :§ c; § 0 0 a C) 0 0 .::ss :s "' 0 :a c; 0 ~ 0 "" ;:;s ;:;s ::I Q;> a 0 ~ a ~ 0 ~ ..... p.. E-< 

90 ---- ---- ---- ---- ---- 8 ---- ---- ---- ---- . 98 

100 ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 100 

95 ---- ---- ---- ---- ---- 3 ---- ---- ---- --·- 99 

100 ---- ---- ---- ---- ---- 3? ---- ---- ---- ---- 100 100 ---- ·--- ---- ---- ---- ---- ---- ---- ---- ---- 100 

100 ---- ---- ---- ---- ---- ---- ---- --- ........ ---- 100 

95 ---- ---- ---- ? ---- 5 ---- ---... ---- ---- 100 92 ---- ---- ---- 3 ---- 7 ---- 102 

93 ---- ---- ---- 2 ---- 2 ---- ---- 4 ---- 101 

100 ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 100 100 ......... ---- ---- ---- ---- ---- ---- ---- ---- ---- 100 

100 ---- ---- ......... ---- ---- ---- ---- ---- ---- ---- 100 

65 ---- ---- ......... ---- ---- 10 ---- ---- 25 ---- 100 90 ---- ---- ---- ---- ---- ---- ---- ---- 7 ---- 97 

80 ---- ---- ---- ---- ......... 3 ---- .. ....... 13 ---- 96 

19 21 21 6 3 25 5 ---- ---- ---- ? 100 60 22 7 0 1 7 ? ---- 97 

39 22 15 3 2 17 3 ---- ---- ---- ---- 100 

6 13 30 7 4 36 5 ---- ---- ---- ---- 101 38 38 14 2 3 5 1 ---- ---- ---- ---- 101 

19 23 25 5 3 23 3 ---- ---- ---- ---- 101 

6 19 24 0 6 35 3 ---- ---- ---- 2 95 21 43 14 ? 2 8 1 ---- ---- ---- 9 98 

13 29 19 0 4 23 2 ---- ---- ---- 5 95 

? ? 42 9 9 35 3 ---- ---- ---- ---- 98 18 35 25 6 12 5 ---- ? ---- ---- ---- 100 

10 20 33 7 10 18 1 ---- ---- ---- ---- 99 

1 7 17 6 3 21 3 27 2 ---- 10 9S 11 35 13 3 8 5 

-;- : --;- :::r;· 97 

6 23 15 5 6 13 00 

0 

~ ~ 

0 

0 

trJ 

0 

~ 

0 

0 

H 

(i 

> 

~ 

r:tl 

q 

l:t1 

< trJ 

~ 

l:t1 

l:_:l:j 

r:tl 

l:_:l:j 

> l:t1 

~ 

~ 

co 

0) 

~ 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-291 

60 

50 ~ 

z 

UJ 

(.) 

a:: 

UJ 

Cl.. ~ 

z ~ f UJ 

I (.) uj a:: 40 ...J UJ Cl.. Cl.. ~ 

~ <( 

en 

uj 

...J ~ 

~ UJ 

~ <( 

en z 

0 

~ 30 ...J 30 ...J 

UJ a: ~ 0 

z ~ 

0 ~ 

...J z ...J 0 

a: ~ 

0 uJ ~ ~ 

~ 20 :::::i 20 0 

z = ~ a:: 

UJ 

>-

5 

6 

UJ 

X 

~ 10 

60 

50 

~ 40 z 

UJ 

(.) 

a:: 

UJ 

Cl.. 

~ 

uj 

...J 

Cl.. 30 ~ 

<( 

en 

~ 

UJ 

~ 

:::::i 

= 20 

556C 

10 

EXPLANATfON 

c Fraction coarser than 1 micron 

f 

Fraction finer than 1 micron 

537 

Numbers are last 3 digits of sample 

numbers (table 1). 

"'\ 

\ 

f f 

0~--~----~~~----~--~ 

0.020 0 0.010 0.020 

BORON, IN PERCENT BORON, IN PERCENT BORON, IN PERCENT 

F1oum~ 2i33.3.-Boron and clay mineral contents in size fractions of 5 samples of shale, claystone, and marlstone. 

Montmorillonite and mixed -layer illite-montmorillonite are strongly concentrated in the fine fraction: of 

the shale samples (fig. 253.3) ; illite and other minerals 

are concentrated in the coarse fraction. Amounts of 

kaolinite and chlorite generally are too small to influence the boron content appreciably. Without considering dilution by nonclay minerals, the greater 

abundance of boron in the fine fraction might suggest 

that boron is contained preferentially in the montmorillonite and (or) niixed-layer clay. Illite, however, is the only clay mineral in the coarse fraction of 

sample 259531 that can account for its boron content, 

just as montmorillonite is the only clay mineral that 

can account for the boron content of bentonite. This 

relation and those between the fractions of the other 

shale samples indicate little difference in the amount 

of boron that these individual clay minerals can 

contain. 

Tourmaline, if present in significant amounts in the 

Pierre shale, almost certainly would be concentrated 

in fractions coarser than 1 micron (Harder, 1959, 

tables 4-9). As illite also is concentrated in the coarse 

fraction, tourmaline would decrease the amount of 

boron inferred in illite rather than montmorillonite. 

Stability of boron in clays subjected to strong acid 

treatment (IIarder, 1959; Frederickson and Reynolds, 

1960) indicates the boron is in the clay structure rather 

than in exchange positions. Boron ions are small. 

Cation positions in the tetrahedral clay layers are 

appreciably smaller than cation positions in the octahedral layers. Thus, substitution of boron for silicon 

in the tetrahedral layer seems most likely. Such a 

substitution is reported by Eugster and Wright (1960) 

for micas and by Stubican and Roy (1960) for saponite (:Mg-mont.morillonite). Stubican and Roy also 

report that substitution of aluminum in the silicon 

tetrahedrons limits substitution of boron, possibly 

because substitution of the relatively large aluminum 

ions expands the lattice, and thus a poorer fit for the 

small boron ions is provided. Generally greater tetrahedral substitution of aluminum in illite than in montmorillonite should make illite a less favorable host for 

boron. 
C-292 GEOLOGICAL SURVEY RESEARCH 1 9 61 

~{ontmorillonite and mixed-layer clay apparently 

contain as much boron as illite in the Pierre shale. In 

fractionated samples, the boron content is related to 

total abundance of clay minerals rather than abundance 

of specific clay minerals. The wide range of boron 

content of samples of Pierre shale (fig. 253.1) indicates, however, that other factors must also be involved. 

Such factors may include composition of source material, the boron content of sea water and, possibly, the 

rates of sedimentation that controlled the length of 

time the clay minerals were in contact with sea water. 

REFERENCES 

Degens, E. T., Williams, E. G., and Keith, M. I1., 1957, Environmental studies of Carboniferous sediments : Am. Assoc. 

Petroleum Geologists Bull., v. 41, no. 11, p. 2427-2455; v. 

42, p. 981-997. 

Eugster, H. P., and Wright, T. L., 1960, Synthetic hydrous 

boron micas, in Short papers in the geological sciences : 

U.S. Geol. Survey Prof. Paper 400-B, p. B441-B442. 

Frederickson, A. F., and Reynolds, R .. c., .Jr., 1960, How 

measuring paleosalinity aids exploration: Oil and Gas 

Jour., v. 58, no. 5, p. 154-158. 

Harder, Hermann, 1959, Beitrag zur Geochemie des Bors, Pt. I, 

Bor in Mineralen u.nd magmatischen Gesteinen; Pt. II, 

Bor in sedimenten: Akad. der 'Wiss. Gottingen Nachr., 

1\fath.-Phys. Kl., Pt. I, v. 1959, no. 5, p. 67-122; Pt. II, v. 

1959, no. 6, p. 123-1R3. 

Hatcher, J. T., and Wilcox, L. V., 1950, Colorimetric determination of boron using carmine: Anal. Chemistry, v. 22, 

p. 567-569. 

I1andergren, Sture, 1945, Contribution to the geochemistry of 

boron. II, The distribution of boron in some Swedish 

sediments, rocks, and iron ores. The boron cycle in the 

upper lithosphere: Arkiv for Kemi, l\fineralogi och Geologi, 

v. 19 A, no. 5, paper no. 26, 31 p. 

Russell, W. L., 1930, South Dakota Geol. Nat. History Survey 

Rept. Inv. 7, p. 5. 

Schultz, L. G., 1960, Quantitative determinations of some 

aluminous clay minerals in rocks, in Swineford, Ada, ed., 

Natl. Clay Conf. on clays and clay minerals, 7th, Washington, 1958, Proc. : London, Pergamon Press, p. 216-224. 

Stubican, V., and Roy, Rust:um, 1960, Boron substitution in 

clays [abs.] : Natl. Clay Conf., 9th, Lafayette, Ind., 1960, 

Program and abstracts. 

'Vichers, Edward, Finn, A. N., and Clabaugh, W. S., 1941, 

Comparative tests of chemical glassware : Indust. and Eng. 

Chemistry, Anal. Ed., v. 13, p. 419-422. 

254. ACCESSORY BASTNAESITE IN THE PIKES PEAK GRANITE, COLORADO 

By ,JoHN W. ADAMS and EDWARD J. YouNG, Denver, Colo. 

During an examination of rare-earth pegmatites in 

the vicinity of Raleigh Peak in southern Jefferson 

County, Colo., specimens of the surrounding Pikes 

Peak granite were found to contain bastnaesite. Further sampling of the granite has shown that it may 

contain from 0.006 to 0.19 percent bastnaesite that is 

apparently unrelated to the pegmatites. 

Bastnaesite, a fluocarbonate of dominantly cerium 

group rare earths, was until recently considered to be 

a very rare mineral. Its best known occurrences, which 

have been summarized by Glass and Smalley (1945), 

are in contact metamorphic zones, pegmatites, and 

fluorite deposits. In 1949, however, bastnaesite was 

recognized as an abundant mineral in the carbonatite 

and related veins at Mountain Pass, Calif. (Olson and 

others, 1954), a discovery that has raised bastnaesite 

to the status of an important ore !llineral. 

The new bastnaesite occurrence 'is at the north end 

of the Pikes Peak batholith in coarse- to mediumgrained granite that contains either biotite or hornblende as the dominant mafic mineral, and which 

probably belongs to the outer zone rocks that Hutchinson (1960) concludes are older than the other rock 

types that comprise the batholith. Biotite is the only 

mafic mineral in the sam pies from the Raleigh Peak 

area, but about equal proportions of hornblende and 

biotite are present in bastnaesite-bearing granite collected 6 miles to the north west. 

In the granites that were sampled, the bastnaesite is 

associated with monazite, wholly or partially metmnict 

allanite, or both. The bastnaesite appears invariably to 

be a constituent of impure microcrystalline aggregates 

that may be seen in some hand specimens as irregular 

yellow-brown areas surrounding grains of black glassy 

allanite. The aggregates have a waxy luster and, when 

examined with the microspectroscope, show weak but 

characteristic neodymium absorption bands, a property 

not shown by allanite. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-293 

In thin section the bastnaesite-bearing aggregate 

may have sharp boundaries with the residual allanite 

or may pervade the al1anite, commonly in lath-shaped 

areas that probably represent compositional zones of 

the host. This replacement is complete in some grains, 

with only the crystal outline of the allanite remaining. 

The bastnaesite in the aggregates appears as minute 

birefringent fibers in a groundmass of an isotropic to 

weakly birefringent material of variable index of 

refraction. The minute size of the fibers and their 

enclosure in the other material prevent the determination of most of the optical properties of the bastnaesite. 

I:Iowever, uniaxial positive interference figures, which 

are characteristic of bastnaesite, were seen in some 

aggregate areas that contain fibers in parallel growth. 

Positive identification of the bastnaesite has been' 

possible only by X-ray methods. X-ray diffraction 

patterns of the aggregate show bastnaesite lines 

accompanied by generally weaker lines ascribable to 

one or more other minerals including allanite, quartz, 

zircon, monazite, and hematite. The isotropic to weakly 

birefringent groundmass of the aggregate is probably 

largely allanite that for the most part is amorphous 

from metamictization and chemical alteration but 

which locally is sufficiently crystalline to produce weak 

X-ray diffraction lines. 

It is concluded from the mode of occurrence of the 

bastnaesite in tlre Pikes Peak granite that it was 

formed from allanite by reaction with late-stage magmatic solutions. These solutions, containing fluorine 

nnd carbon dioxide, were sufficiently reactive to attack 

the earlier formed allanite and partly replace it by the 

fluocarbonate. 

''There t-he bastnaesite-bearing ~tggrega.te occurs in 

granite in which no allanite was found, its origin from 

monazite might be considered-particularly because 

monazite occurs in the allanite-free rocks; and monazite 

lines are present in the X-ray diffraction pattern of 

one such aggregate. In thin section, however, the aggregat-e from these rocks shows relict zonation and general 

appearance similar to that clearly derived from allanite. Also, no megascopic or microscopic relations 

eomparable to those found between the aggregate and 

al1anite have been seen between the aggregate and 

monazite. Although the evidence is still equivocal, it 

appears more probable that in such rocks the bastna.esi te ttggregates are the residuals of complete allanite 

alteration. 

The first reported occurrence of bastnaesite as an 

accessory mineral of granitic rocks was in the Redstone 

granite of Rhode Island (Smith and Cisney, 1956), 

where it is estimated to make up 0.02 percent of the 

rock. There the bastnaesite is fvund as irregular 

aggregates or as prismatic forms, both of which· are 

made up of minute crystallites. W .. L. Smith (oral 

communication, 1960) considers· that the crystal forms 

may be those of an earlier mineral now replaced by 

the bastnaesite. A very small amount of monazite is 

found in the granite, but no allanite. Allanite, however, is reported as an accessory mineral elsewhere in 

the Narragansett Pier granite with which the Redstone 

granite has been correlated (Moore, 1959), so that this 

occurrence may well represent a further example of 

complete allanite alteration. 

Bastnaesite has also been :found in granites of the 

Elberton area of southeast Georgia as a constituent 

of fine-grained aggregates that pseudomorphically 

replace allanite (Silver and Grunen:felder, 1957). The 

allanite, which originally made up 0.3 percent of the 

rock, appears to have been largely' converted to bastnaesite, huttonite ( ~), hematite, and a pale yellow isotropic, or nearly isotropic, mineral. The alteration is 

thought by Silver and Grunen:felder to be the result 

of reactive solutions, probably deuteric, that attacked 

the allanite along crystal and zonal boundaries. 

Sverdrup and others ( 1959) recently described :four 

occurrences of bastnaesite in Norway. In one of these, 

the Lapplaegret pegmatite, the bastnaesite has replaced 

allanite in a nianner that appears identical with that 

in the Pikes Peak granite and shows the same microcrystalline habit and poorly defined optical properties. 

In contrast to what is probably the deuteric alteration of allanite to ba.stnaesite is the weathering alteration of allanite studied by Watson (1917). Using 

material :from pegmatites in Virginia, Watson made 

comparative chemical analyses of relatively unaltered 

allanite and the reddish-brown alteration rinds so 

commonly :found on allanite masses. These analyses 

showed the alteration product to be variable in composition, but to consist in general of hydrated :ferric 

oxides, alumina, and silica. The rare-earth elements 

were essentially absent except :for cerium, which, while 

generally present to a lesser amount than in the allanite, was found in one instance to. be actually enriched 

in the outermost layer of the rind. The persistence of 

cerium in the alteration product may well be due to. 

its ready oxidation to Ce (IV) , a property that allows 

it to be separated :fr<;>m other members of the rare earth 

group in analytical procedures. 

This supergene alteration characterized by oxidation, 

leaching, and hydration differs :from the deuteric 

process by which bastnaesite is formed. The development of bastnaesite :from allanite involves chemically 

active solutions such as might expectably be residual 

in fluorine-rich intrusive rocks. 
C-294 GEOLOGICAL SURVEY RESEARCH 19 61 

The metamict character shown by much of the 

allanite in the Pikes Peak granite is probably entirely 

unrelated to the bastnaesite alteration, which may be 

assumed to have been completed at a time when the 

allanite was entirely crystalline. Supergene alteration, 

on the other hand, would be accelerated by metamictization through radiochemical effects and by the physical disruption of the allanite and the enclosing rock. 

REFERENCES 

Glass, J. J., and Smalley, R. G., 1945, Bastnasite [Gallinas Mts., 

N. Mex.]: Am. Mineralogist, v. 30, p. 601-615. 

Hutchinson, R. M., 1960, Structure and petrology of north end 

of Pikes Peak batholith, Colorado in Guide to the geology 

of Colorado: Geol. Soc. America, Rocky Mtn. Assoc. Geologists, Colo. Sci. Soc., p. 170-180. 

Moore, G. E., Jr., 1959, Bedrock geology of the Carolina and 

Quonochontaug quadrangles, Rhode Island: U.S. Geol. 

Survey Geol. Quad. Map GQ-117. 

Olson, J. C., Shawe, D. R., Pray, L. C., and Sharp, W. N.·, 1954, 

Rare earth mineral deposits of the Mountain Pass District, 

San Bernardino County, California: U.S. Geol. Survey 

Prof. Paper 261, 75 p. 

Silver, !1. T., and Grunenfelder, Marc, 1957, Alteration of 

accessory allanite in granites of the Elberton area, 

Georgia: Geol. Soc. America Bull., v. 68, p. 1796. 

Smith, "r· L., and Cisney, E. A., 1956, Bastnaesite, an accessory 

mineral in the Redstone granite from ·westerly, Rhode 

Island : Am. Mineralogist, v. 41, p. 76-81. 

Sverdrup, T. L., Bryn, K. 0., and Saeba, P. C., 1959, Bastnasite 

a new mineral for Norway.: Norsk geol. tidsskr., v. 39, p. 

237-247. 

Watson, T. L., 1917, Weathering of allanite: Geol. Soc. America 

Brill., v. 28, p. 463-500. 

255. TUNELLITE, A NEW HYDROUS STRONTIUM BORATE FROM THE KRAMER BORATE DISTRICT, CALIFORNIA 

By RICHARD C. ERn, VINCENT MoRGAN, and JoAN R. CLARK, 

~1enlo Park, Calif.; U. S. Borax & Chemical Corporation, Boron, Calif.; and Washington, D. C. 

Tunellite was first noted by Erd in some samples 

collected in 1957 from a ventilating shaft in the J enifer 

mine, !{ramer borate district, California, by Daniel M. 

Cooper of the U. S. Borax & Chemical Corporation. 

Initial mineralogical determinations showed that the 

optical properties of tunellite nearly matched those 

of hydroboracite, MgO•Ca0•3B20a•6H20, but its . 

X-ray powder pattern could not be identified. Later 

Morgan analyzed material collected from the newly 

opened pit of the company and es~ablished the composition of tunellite, Sr0•3B20a•4H20. In 1959 the mineral was discovered in the Furnace Creek borate area, 

Death Valley region, California, by Jarries F. McAllister, U.S. Geological Survey, who kindly supplied material for comparison. Goniometric and X-ray crystallographic studies by Clark corroborated the chemical 

analysis and confirmed tunellite as a new species 

isostructural with nobleite (tables 255.1 and 255.2). 

The name tunellite (pronounced tun nel' it) is in 

honor of Dr. George Turrell, Professor of Geology, 

University of California, Los Angeles. 

The geology of the Kramer borate district has been 

described by Schaller ( 1930) and Gale ( 1946) ; more 

recent data are given by Smith (1960). In the western 

part of the deposit, where the initial open pit was 

excavated, a prominent fault has displaced the borate 

beds. Near this fault there is an angular discordance 

between the sodium borate ore and overlying boratebearing mudstone beds; this dis.cordance may have been 

the result of subsurface solution (Smith, 1960, p. 113). 

A 6-foot zone above the sodium borate-mudstone conTABLE 255.1.-Crystallographic data for t~mellite, Sr0-3B20a·4H20 

1 Space Group 

P2t/a-C2hs 

a______________________ 14.36 ± 0.05 A 

b__ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8.198 ± 0.02 c _______________________ 9.93o±0.02 

a: b : c_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1. 7 52: 1 : 1. 211 

{L _ _ _ ____ _ _ _ _ _ _ _ _ _ _ __ _ _ 113°55' ± 10' 

12 

Space Group 

P2t/n-C2hs 

13.75 A 

8.19s 

9.93o 

1.677: 1: 1.211 

107°23' 

Cell volume _____________________________ 1068 A3 

Cell contents ____________________________ 4[Sr0·3B20a·4H20] 

Density (calculated) _____________________ 2.39,gcm-3 

Specific gravity (measured, D 204) ___________ 2 2.40±0.01 

t Transformation, P2.!a to P2tfn: IOI/010/001. 2 Determined using the sink-float method with a mixture of bromoform and carbon 

tetrachloride. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-295 

TABLE 255.2.-Comparison of crystallographic, optical, and physical 

data for t1mellite and nobleite 

Cell contents _______ _ Crystnl system _____ _ Spttce group ________ _ a _________________ _ b __________________ _ 

C-------------------

~------------------ Cell volume ________ _ 

Density (mtlculnted). _ Specific gmvity 

(metts., D.20) 

Indices of refraction, 

sodium light: a _________________ _ 

~-----------------­

~------------------ 2V (cttlculnted) _____ _ Dispersion _________ _ 

Opticnl orientation __ _ 

Cleavage ___________ _ 

Hardness ____ - _____ _ 

Tunclllte 

4[Sr0·3B~Oa·4H20] 

Monoclinic 

P2tfa 

14.36 ± 0.05A 

8.198 ± 0.02 

9.93o±0.02 

113°55' ± 10' 

1068 A3 

2.39tgcm-3 

2.40±0.01 

1.519 ± 0.003 

1.534 ± 0.002 

1.569 ± 0.002 

68° 

r>v, weak 

XAa=29° 

Y=b 

ZAc= -5° 

1

100 I perfect 

0011 distinct 

2% 

1 Data from Erd ond others, 1961. 

Noblelte 1 

4[ CaO· 3B20a· 4H20] 

Monoclinic · P2t!a 

14.56 ± 0.05A 

8.016± 0.02 

9.83a±0.02 

111 °45' ± 10' 

1066 A3 

2.09gcm-3 

2.09±0.01 

1.500 ± 0.003 

1.520±0.002 

1.554 ± 0.002 

76° 

r>v, wenk 

XAa=29° 

Y=b 

ZAc= -7° 

1100 I perfect I 0011 indistinct 

3 

tact is disturbed and within this zone tunellite formed 

as a disseminated secondary mineral. 

The first rnaterih.l found consisted of white compact 

fine-grained nodules associated with lenses' of inderite 

and k.urm1kovite (the monoclinic and triclinic polymorphs of 2l\1g0·3B20 3·15H20; Schaller and Mrose, 

1960) a.nd nodular ulexite in a greenish to black montmorillonitic clay. Subsequently individual long prismatic [001] and flat tt1bular {100} crystals of tunellite 

up to 1.5 em in length were found in the clay. As the 

open pit was developed, Morgan discovered a large 

vuggy mass of hydroboracite lined with splendid equant 

crystals of tunellite up to 1 em in diameter. Figure 

255.1 shows idealized prismatic nnd equant habits, 

common forms, and optical orientation of the tunellite 

crystals from .the open pit. Other minernls associated 

wiU1 tunellite in these occurrences are renlgar, stibnite, 

several undescribed iron sulfides, adulnria, nnd annlcime. 

1\l[ost of the physical and opticnl properties of tunellite t1re summarized in tnble 255.2. It is colorless, 

transparent, nonfluorescent, tlnd has a subvitreous 

luster, except that the {100} nnd clcavnge surfaces 

parallel to {100} are pearly. Thin crystals are flexible, 

inelastic, nnd sectile. Fnces of the forn1 {Okl} are 

strit1tecl pt1I't1llel to [001], notab-ly so in speci1nens from 

the Furnace Creek area. Faces of {100} are relatively 

smooth, lustrous, and soft, whereas {110} and {001} 

f11ces are rough, pitted, and hard. X-ray powder diffraetion data for tunellite t1re given in table 255.3. 

Det.ermin11tions of SrO and B203 were made using 

separate 0.5-gnun samples. 'I'he SrO sample was dissolved in dilute HCl, neutralized with NH40H, and 

combined with sufficient dilute H2S04 to precipitate 

all of the strontium. An equal volume of nlethanol 

was added, the solution was mixed, and was allowed to 

stand overnight. The SrS04 precipitate was filtered 

into a dried and tared Gooch crucible and weighed after 

washing and drying. B263 was detern1ined by titration 

with N aOH and manito!. Water was determined by 

loss on ignition of l-gran1 snmples. Redeterminntion 

of B20 3 on the residue proved that there was no loss 

of B20 3 due to volatilization during ignition. Calciunt 

was not detected. The results of the analysis are given 

in table 255.4. 

The synthetic Sr0·3B20 3·4H20 was prepared by 

adding 3 g H3B03 in 50 ml of water to a solution of 10 g 

recrystallized borax in 100 ml of water at 80° C. 

Three-fourths of a gram of SrC03 was ndded and the 

solution was stirred for one day. After six da.ys, when 

most of the precipitate was found to be SrC03, 10 g 

more H3B03 in 50 ml of water was added .. An extremely fine-grained precipitate of Sr0·3B20 3·4H20 had 

formed after two days, and rhon1b- an.d octagonalshaped plates 0.02 nun in dianteter developed after 

standing for one nwnth at room ten1perature. (See 

analysis, table 255.4.) We found no previous report 

,, 

:I 

:j 

I. 

~ I 

A. 

\ 

---- y ·-·--;·-

B. 

FIGURE 255.1.-Prismatic (A) and equant (B) habits and 

optical orientation of tunellite crystals from the Kramer 

borate district. 
C-296 GEOLOGICAL SURVEY RESEARCH 19 61 

TABLE 255.3.-X-ray diffraction data tor tunellite 

Measured 1 Calculated 2 

Mineral3 

Synthetic com- Indexing for space pound 4 group P2da (table 

Boron, Calif. Death Valley region, 255.I) 

California 

I du1 I du1 I du1 du1 hkl 

I 9.10 9.078 001 3 6.97 4 6.97 24 6.97 6.954 110 4 6. 79 7 6. 78 11 6. i9 6. 783 ~01 

100 6. 58 100 6. 57 IOO 6. 57 6. 564 200 2 6. 22 3 6. 21 I5 6. 2I 6. 200 In 6.084 011 1 5.23I 2 5. 215 2 5. 231 5. 226 ~11 

6 5.138 8 5.138 32 5.135 5.124 210 5.024 111 1 4. 750 1 4. 745 11 4. 750 4. 738 2o2 6 4. 531 11 4. 525 18 4. 529 4. 539 002 4. 520 201 4. 240 Il2 4.123 311 4.102 ~12 

<1 4.112 -------- ------------ 3 4.112 4.099 020 <I 3.972 <I 3.969 3 3.969 3.971 012 3.958 211 I 3.924 I 3.9I4 8 3.922 3.913 I20 7 3.872 9 3.867 21 3.867 3.860 310 3. 762 I21 <I 3. 741 <1 3. 743 8 3. 743. 3. 736 021 3. 656 3I2 4 ;J. 597 .8 3. 592 9 3. 596 3. 586 401 1 3. 513 1 3. 513 17. 3. 517 3. 508 ~21 

2 3.486 2 3.484 I6 3.484 { 3.477. 220 3.475 112 3.445 I2I 1 3.399 1 :1.399 3 3.399 3. 39I 402 3.304 ~03 

3. 285 411 2 3.290 5 3.286 2 3. 288 3. 282 400 2 3. 17.5 2 3.175 8 3.175 3.179 202 14 3.163 3. HiS 311 3.158 122 3.I34 412 <I 3.110 <1 3.113 } 9 3.106 { 3.109 321 <I 3.100 <I 3.099 3.100 ~22 

3. 064 213 

4 3.052 7 3.045 I9 3. 046 { 3.047 410 3.042 022 3.036 221 2 3.028 5 3. 028 I8 3.025 3. 026 003 3.022 Il3 I 3.001 2 2.993 IO 2.996 2.99I 320 2.964 212 I 2.955 I 2.954 7 2.952 2.948 3I3 I 2.898 1 2.898 9 2.898 2.893 322 1 2.889 1 2.887 11 2.887 2.882 403 1 2. 841 1 2.840 11 2.840 2.839 013 <1 2.805 -------- ------------ 6 2.804 2. 801 I22 1 2. 755 3 2. 75I 3 2. 751 2. 750 40I <I 2. 724 -------- ------------ 4 2. 722 2. 719 4I3 

3 2. 700 4 2. 696 8 2. 697 { 2.'699 421 2.691 511 

<1 2. 673 3 2.673 { 2.675 I30 2.668 5I2 2.633 321 

{ 2.626 I31 1 2.622 -------- ------------ I3 2.619 2. 617 03I 2. 6I3 422 1 2. 609 -------- ------------ 2.607 411 2. 579 113 

1 2. 568 1 2. 565 7 2. 566 { 2. 572 ~23 

2. 562 420 2. 547 I23 

<I 2. 536 <1 2. 536 6 2. 536 { 2. 535 ~3I 

2. 528 3I2 2. 523 230 

6 2. 514 { 2. 5I2 222 2. 511 I31 

4 2. 507 8 2. 503 11 2. 505 { 2. 502 3~J 

2. 500 5IO <1 2. 481 <I 2. 479 4 2.479 ------------ -------- <I 2.438 -------- ------------ 3 2.436 ------------ -------- 2 2.390 3 2. 388 4 2. 390 ------------ -------- <I 2. 378 -------- ------------ 3 2. 375 ------------ -------- 2 2.362 5 2. 359 5 2. 361 ------------ -------- 1 2.322 -------- ------------ 6 2. 320 ------------ -------- 4 2.268 6 2. 266 13 2. 266 ------------ -------- 3 2.207 7 2.202 8 2. 204 ------------ -------- <1 2.192 2 2.190 2 2.I91 ------------ -------- <1 2.178 -------- ------------ 4 2.176 ------------ -------- 1 2.145 <1 2.141 7 2.143 ------------ -------- 2 2.122 2 2.119 19 2.I20 ------------ -------- 1 2.106 1 2.101 11 2.102 ------------ -------- 1 2.076 <I 2.071 11 2.073 ------------ -------- 1 2.053 2 2. 051 11 2.051 ------------ -------- 1 2. 032 2 2. 024 13 2. 026 ------------ _ _. ______ 

See footnotes at end of table. 

TABLE 255.3.-X-ray diffraotion data fm- htnellit~-Continued 

Measured 1 

Mineral a 

Boron, Calif. 

du1 

<1 1.985 2 1.949 1 1.936 1 1.904 

<I 1.885 

<1 1. 822 1 1.805 

<1 1. 765 

<1 1. 748 

<I 1. 710 

Death Valley region, 

California 

du1 

<1 1. 981 4 1.948 2 1. 931 2 1. 903 

-------- ------------

<I 1.819 1 1. 802 

------------ 1 1. 744 

-------- ------------

Synthetic com- pound 4 

4 1.983 7 1.948 6 1.931 6 1.896 4 1. 885 1 1.858 3 1. 821 4 1.804 2 1. 789 1 1. 772 1 1. 76I 3 1. 745 2 1. 708 

(;alculated 2 

Indexing for space group P2tla (table 

255.1) 

hkl 

------------- -------- ------------ -------- -----·------ -------- ------------ -------- ---·---------- -------- -----·------ -------- -----·------ -------- ------------ -------- ------------ -------- ------------ -------- ------------ -------- ------------ -------- ------------ --------

+--plus additional Jines 

all with 151 all with !52 all with 153 

I X-ray diffractometer data; Cu/Ni radiation, X CuKa=l.5418 A. Aluminum pow- der used as internal standard. Scanned at .H0 per minute from 8°-55°28; at 1 per minute from 55°-101°28. 2 All calculated spacings listed for du,~2.500 A. Indexing assigned on basis of comparison with single-crystal precession photographs. Computation. of the dspacin!!S by Daniel L. Appleman. 3 Diffractometer charts X-I935 (Boron, Calif.) and X-1934 (Death Valley region, 

California) of the mineral show strong preferred orientation effects. 4 Synthetic material prepared by R. C. Erd; analyzed by V. Morgan. Diffractom- eter chart X-1929. 

TAFLE 255.4.-Chemical analyses of tunellite 

Weight Molecular Ratios Calculated 

percent 1 proportions composition for ------ Sr0·3B203·4H20 Min- Syn- Min- Syn- Min- Syn- (percent) eral2 thetic 3 eral the tic eral the tic 

------------ SrO ____________ 27.71 27.02 0. 2674 0. 2607 1.023 0. 988 26.94 

B20a----------- 53.70 52.88 . 7711 . 7593 2. 951 2. 877 54.32 

H20----------- 18. 71 20.04 1. 0385 1.1123 3. 974 4. 214 18.74 ------ TotaL ___ IOO. I2 99.94 -------- -------- -------- -------- 100.00 

1 Analyst, Vincent Morgan, U.S. Borax & Chemical Corporation. 2 Material from U.S. Borax & Chemical Corporation open pit, Boron, Calif. Figure for SrO includes approx. 0.3 percent BaO determined using X-ray spectrochemical 

analysis. a Material synthesized by R. C. Erd (Expt. 58-3). 

of t.his cornpound, although the con1pound 

Sr0·3B20 3·5H20 was synthesized by Gode and Kesans 

(1953, p. 36). 

Tunellite is soluble in cold dilute acid or strong 

alkaline solutions, but is unaffected by treatn1ent with 

glycerol or methanol; a coating_ of SrS04 impedes 

further solution in H2S04. 

The differential thermal analysis curve of the mineral 

shows two endothermic troughs with initial temperatures of 200° 0 and 405° 0 and trough ten1peratures of 

255° 0 and· 430° 0. An exothermic peak with initial 

temperature of 625° C and peak temperature of 670° C 

appeared near the end of the run which was discontinued at 700° C to prevent fusion of the sample in the 

block. 

Heated in a closed tube tunellite exfoliates perpendicular to the cleavage, turns silvery white (resembling 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-297 

muscovite), then turns chalky white. Water driven 

off hns a pl-I of 4 ttnd probably indicates some loss of 

B20 3 due to rapid heating. On prolonged heating a 

clem· glass forms from which an anhydrous strontium 

born,te crystallizes. The melting point of tunellite 

luts not been determined. 

In late 1960, large crystals (some nearly 4 cn1 in 

length) were found in the open pit by ~L L. Speckels, 

who kindly gave them to us for study. Some of these 

crystals have a specific gravity of 2.46 and contain up to 

15.0 percent BaO. The presence of barium in tunellite 

suggests the possibility that Ba0·3B20 3 ·4H20, synthesized by Gode and Kesttns (1953, p. 36), may be 

isostructural with tunellite but dttttt for this compound 

are not ttvttil11ble. 'runellite is isostructural with nobleite (t.11ble 255.2) but the extent of any solid solution 

is unknown. 'l'here is no simple dehydnttion-hydration 

rehttion between tunellite, veatchite (Sr0·3B20 3·2H20), 

lLlld the Sr0·3B20 3·5H20 of Gode ttnd Kesttns. Tunellite and ve1ttchite lutve not been found as associated 

1ninerals, although both have been found in the Kramer 

area (Bendtt nnd others, 1960, p. 330). 

REFERENCES 

Benda, W. K., Erd, R. C., and Smith, W. C., 1960, Core logs 

from five test holes near Kramer, California: U.S. Geol. 

Survey Bull. 1045-F, p. 319-393. 

Erd, R. C., McAllister, J. F., and Vlisidis, A. C., 1961, Nobleite, 

another new hydrous calcium borate from the Death Valley 

.region, California : Am. Mineralogist, v. 46, p. 560--571. 

Gale, H. S., 1946, Geology of the Kramer Borate District, 

Kern County, California: California Jour. Mines and 

Geology, v. 42, p._ 325-378. 

Gode, H. K., and Kesans, A. D., 1953, Sintezy boratov v vodnykh 

rastvorakh (Syntheses of borates in aqueous solutions), in 

Khimiia boratov (Chemistry of the borates) : Akad. Nauk 

Latv. SSR, Izdatelstvo, p. 29-43, Riga. 

Schaller, W. T., 1930, Borate minerals from the Kramer district, Mohave Desert, California: U.S. Geol. Survey Prof. 

Paper 158, p. 137-170. 

Schaller, W. T., and Mrose, M. E., 1960, The naming of the 

hydrous magnesium borate minerals from Boron, California-a preliminary note: Am. Mineralogist, v .. 45, p. 732-

734. 

Smith, W. C., 1960, Borax· and borates, in Industrial minerals 

and rocks: New York, Am. Inst. Mining Metall. Petroleum 

Engineers, 3d ed., p. 1.03-122. 

256. HYDROZIRCON FROM THE WIND RIVER FORMATION, WYOMING 

By R.. G. CoLEMAN and R. C. Eno, Menlo Park, Calif. 

Wo1·k done partly in cooperation with the 

U. S. Ato,mic Energy Cotnmission 

A high concentration of zirconium ( 1 to 5 weight 

percent) was discovered in a uranium-bearing arkose 

submitted for spectrographic analysis and uranium 

assay (table 256.1). This sample was collected as part 

of a geologic study of the Gas Hills uranium district 

in 'V'yoming (Zeller, 1957) and represented the mineralized zone within a nonproductive ura:Qium prospect 

n long the eastern border of the district ( S"T1/4SE1/4 

S"TJ./4 sec. 15, T. 35 N., R. 89 ,V., A.rminta S'V 

quadrangle, Ntttrona County, 'V'yoming). 

Zircon ium-ura11 ium min era.] ization is restricted to 

an area of less than 300 square yards within a small 

bench rising several feet above the nearly flat terrain 

and occurs below an iron gossan caprock within a 

coarse-grained arkose of the Wind River formation 

of early Eocene age. A series of sam pies was obtained 

in vertical sequence from the face of the prospect pit 

601.530 0-61--20 

TAFLE 256.1.-Chemical and spectrographic analyses of hydrozircon-bearing arkose, Wind River formation, Wyoming 

[Analysts: J. C. Hamilton (spectrographic); Lorraine M. Lee, E. J. Fennelly, G. T. 

u 

As 

Se 

>10 

5-10 

1-5 

0.5-1.0 

0.1-0.5 

0.05-0.1 

0.01-0.05 

0.005-0.01 

0.001-0.005 

0.0005-0.001 

Burrow (chemical)] 

ZW-120 ZW-121 

Chemical analyses (weight percent) 

I 

0.16 

0.052 

0.0005 I 

0.11 

0.12 

<0.0005 I 

0.25 

Not determined 

Not determined 

Semiquantitative spectrographic analyses (weight percent) 

Si 

Al 

KNaZr 

Fe 

CaMg 

Ti As Ba 

Mn Mo Sc 

Sr CrY : GaB V La Cu 

PbYb 

Si 

AlK 

Na Fe Zr 

. ·xs-·-----------------

ca Mg Ba 

Ti 

MnMo Sr Y 

Ga Sc Cr V La Pb 

Yb 

-------------------- Cu 

Si 

AlNa 

Zr Fe K 

CaP 

As 

BaMg 

B Ti Mn Sr 

Pb La Ni Y 

Ge Cr Mo Cu Ga 

Sc V 

Be Yb 
C-298 GEOLOGICAL SURVEY RESEARCH 19 61 

10 feet deep (fig. 256.1). The arkose sampled contains 

from 60 to 80 percent quartz, 20 to 40 percent feldspar 

(perthite and microcline), and minor amounts of 

plagioclase and mica. These clastic grains are angular 

nnd poorly sorted, and the potassium feldspar shows 

only minor alteration. The sampled section was 

divided into zones according to the dominant intergranular cement within the arkose (fig. 256.1). 

X-ray determinations on the purified hydrozircon 

(fig. 256.2) shows that its diffraction pattern is similar 

to that of zircon, but considerable water and minor 

amounts of arsenic, uranium, and iron were found by 

chemical analysis (table 256.2). The hydrozircon is 

transparent and nearly isotropic with only a faint 

aggregate birefringence and is characterized Ly a 

complete lack of crystalline form. The X-ray pattern 

demonstrates the similarity to zircon; however, the 

]ow density and index of refraction combined with a 

high water content clearly show hydration. R.azumnaya and others (1958) have described a metacolloid 

ROCK 

DESCRIPTION 

FEET 

____ .Q 

Red arkose 

with goethite 

cement 

___ 1 

White arkose 

with pale- 2 green scorodiTe 

Abundant opal 

) 

Cap-rock 

Scorodite 

'zone 

_c_e_m_e_nt_ 3 

~ 

Buff arkose 4. with jarosite 

cement 

----~ 

Chocolate 

brown arkose 

with 2. 

h'ydrozircon 

and jarosite 

cement 

l 

Buff arkose with jarosite 

cement .S 

( Jarosite 

zone 

- -

Hydrozircon 

zone 

Jarosite 

zone 

.... ~./ -- ,.,' -' .. .,"' 

Zr 

ELEMENTS IN ARKOSE CEMENT 

As Fe 

Arbitrary scale based on X-ray 

spectrochemical analysis 

u 

FIGURE 256.1.-Mineralogic and chemical variations in the 

zirconium-bearing arkose of the ·wind River formation, Gas 

Hills uranium district, Wyoming. 

TABLE 256.2.-Some chemical and physical properties cf hydrozircon from lV yoming 

Partial analysis (weight percent) lptcnsity Mean index Density ratio 

of refraction Zr/Si • Sil Zr 1 Fe2 As2 ua H203 

--------- -- >10 >10 1.1 0. 68 0.11 16.6 1. 70-1. 72 3. 0-3.2 2. 68 

I Semiquantitative spectrographic analysis, by K. V. Hazel. 2 X-ray spectrochemical analysis using GeO as ipternal standard, by J. M. Axelrod. 3 Estimated -by loss on ignition at 950° C for two hours. 

··Determined by X-ray spectrochemicfll methods u.~ing the ZrLa/SiKa peaks, by 

Harry J. Rose and Francis J. Flanagan. 

variety of zircon from the U.S.S.R.. similar in many 

respects to the vVyoming hydrozircon, except that the 

Russian variety is soluble in dilute HN03 and HCI 

whereas the 'Vyon1ing material studied is resistant 

even to concentrated HN03 and HCI. 

Prior to the discovery of hydrozircon from Wyoming 

and the U.S.S.R., metamict zircons derived from igneous and metamorphic rocks. were the. only natural 

zircons known to contain minor amounts of water. 

Fronde! (1953) has proposed the general formula 

Zr(Si04) 1_x(OH)4x for hydrozircons, but Mumpton and 

Roy (1961) present experimental evidence, combined 

with 43 analyses of natural metamict zircons, that 

suggests the formula ZrSi04 ·xH20. As the Zr/Si 

intensity ratio of the Wyoming hydrozircon (table 

256.2) is similar to that of normal zircon, it is possible 

that its formula is more nearly like that suggested by 

Mumpton and Roy. The X-ray pattern of the Wyoming hydrozircon is diffuse with a0 larger and c0 smaller 

than zircon; however on heating the hydrozircon for 

two hours at 950° C the pattern is identical with that 

of well crystallized zircon and neither Zr02 nor Si02 

were detec.ted (fig. 256.2). The arsenic, iron, a.nd 

uranium revealed by analysis must be part of the 

compound. If we assume iron is prest:-n t as Fe+3 

(ionic radius 0.67 A) and arsenic as (As04)-3 then it is 

possible to substitute Fe+3 for Zr+4 (ionic radius 0.87 A) 

and (As04)-3 for (Si04)-4• Maintaining a 1:1 ratio for 

(As04)-3 and Fe+3 would satisfy the valence requirements and a possible formula for the Wyoming hydrozircon would then be as follows: · 

[ (ZrH, U+4)t-xFe+3x] [ (Si04)-\-x(As04)-3x] · 2H20. 

Further complete analyses will be needed to confirm 

this tentative formula. 

Hydrozircon deposited as a secondary intergranular 

cement in an unaltered arkose and lacking crystalline 

form is clear evidence that this material was formed at 

low temperatures and transported to the point of 

deposition as a soluble zirconium compound. Experimental work on the stability of zircon demonstrates 

that corrosion may take place in alkaline environments, 

and that a stable zirconium carbonate complex can 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-299 

N 

;; 

.... 

g 

ss· so· 45° 40° 35° 30° 25° 20° 

Degrees 29 copper K a radiation 

Fxoum~ 256.2.-Diffractometer traces for natural hydrozircon (lower trace) and for hydrozircon heated two hours at 950°0 (upper 

trace). 

exist in solutions whose pH is not excessively alkaline 

(Blumenthal, 1958, p. 210-213, p. 37~39). Zircons 

from the granite in the vicinity of the Sweetwater 

River, source rock for the arkosic facies of the Wind 

River formation, are partly metamict, and a lead-alpha 

age determination on these same zircons shows them 

to be Precambrian in age. 1 Detrital zircons, within the 

arkose and derived from these granites, are also partially 

o1· completely metamict and show evidences of corrosion. Evidence for alkaline leaching of the alkalisoluble constituents in the Wind River formation has 

been given by Coleman (1957), and the well-known 

fact that metamict zircons are susceptible to corrosion 

(Pabst, 1952) leads to the conclusion that zirconium 

• Snmplo ZW-263 shows tho following: a/mg-hr 816, Pb 800 ppm, and an ago or 

2000:1:225 my. I-oml-nlpha detorminntlon by 'I'. W. Stern, lead determination by 

H. J. Rose, Jr., nnd H. W. Worthing. Ago calculntlon by methods similar to those 

given hy Oottrrlocl and others (Hl59). 

could have been mobilized by. these same alkaline 

solutions. The association of uranium with the 

secondary zirconium indicates that leaching of the 

detrital zircon was contemporaneous with the leaching 

that gave rise to the high-grade uranium deposits of 

the Gas Hills district. Precipitation of the zirconium 

as Zr(OH) 4 may have been concomitant with the 

deposition of iron sulfides in an alkaline reducing 

environment. Later surface oxidation of the pyrite 

produced the oxide, arsenate, and sulfate zones of iron. 

and the silica released in this acid environment may 

have reacted with the zirconium hydrate to form the 

hydrozircon. 

Radiochemical studies by Rosholt ( 1958; 1959) on 

the Gas l-Iills uranium ores and the hydrozircon-bearing arkose disclose a Pleistocene ( ~) age for the mineralization with some ores giving ages of 12,000 years. 

TABLE 256.3.-Radiochemical analyses of hydrozircon-bearing arkose, Wyoming 

[Annlyst: J. N. Rosholt, Jr. Analyses made according to methods described by Rosholt (1959)) 

Percent Percent equivalent Radioisotope ratios 

.Snmplo eU u Th232 Pa231 Rn222 Pb21o eU/U ePa231/U eRn222/U ePb2IO/U 

--- ZW-120 ________ 0. 12 0. 16 0. 015 0. 12 0.09 0. 10 0. 75 0. 75 0. 56 0. 62 ZW-121_ _______ . 083 .11 . 003 . 080 . 06 . 046 . 75 . 72 . 55 . 42 
C-300 GEOLOGICAL SURVEY RESEARCH 19 61 

The hydrozircon samples have a time-related daughterproduct deficiency suggesting that the zirconium and 

uranium are of Recent origin (table 256.3). If this 

zirconium has been derived by leaching of Precambrian metamict zircons, it has to be in the soluble form 

and transported to allow a separation fron1 the 

daughter products contained in the metamict zircon. 

This unusual concentration of zirconium as a 

secondary cement in sedimentary rocks reveals that, 

under certain conditions, zirconium deposits may form 

by processes hitherto unrecognized. 

REFERENCES 

Blumenthal, W. B., 1958, The chemical behavior of zirconium: 

New York, Van Nostrand, 398 p. 

Coleman, R. G., 1957, Mineralogy and geochemistry of uranium 

deposits in the Gas Hills district, Wyoming, in Geologic 

investigations of radioactive deposits-Semiannual progress report, Dec. 1, 1956 to May 31, 1957 : U. S. Geol. 

Survey TEI-690, book 2, p. 508-512, issued by U. S. Atomic 

Energy Comm. Tech. Inf. Service Ext., Oak Ridge, Tenn. 

Fronde!, C., 1953, Hydroxyl substitution in thorite and zircon: 

Am. Mineralogist, v. 38, p. 1007-1018. 

Gottfried, D., Jaffe, H. W., and Senftle, F. E., 1959, The leadalpha (Larsen) method of determining the age of igneous 

rocks from their accessory minerals: U. S. Geol. Survey 

Bull. 1097-A, 64 p. 

Mumpton, F. A., and Roy, R., 1961, Hydrothermal stability 

studies of the zircon-thorite group : Geochim. et Cosmochim. Acta, v. 21, p. 217-238. 

Pabst, A., 1952, The metamict state: Am. Mineralogist, v. 37, p. 

137-157. 

Razumanya, E. G., Smolianskaya, K. G., Korolev, K. G., and 

Pakulpis, G. V., 1958, Arshinovite as a metacolloid variety 

of uranium-containing zircon: United Nations Internat. 

Conf. on Peaceful Uses of Atomic Energy, 2d. Geneva, 

1958, Proc., v. 2, Survey of Raw Materials, p. 307-308. 

Rosholt, J. N., Jr., 1958, Radioactive disequilibrium studies as 

an aid in understanding the natural migration of uranium 

and its decay products: United Nations Internat. Conf. on 

Peaceful Uses of Atomic Energy, 2d. Geneva, 1958, Proc., 

v. 2, Survey of Raw Materials, p. 230-236. 

--- 1959, Natural radioactive, disequilibrium of the uranium 

series: U. S. Geol. Survey Bull. 1084-A, 30 p. 

Zeller, H. D., 1957, The Gas Hills uranium district and some 

probable controls for ore deposition: 'Vyoming Geol. Assoc. 

Guidebook, 12th Ann. Field Conf., p. 156-160. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-301 

257. MICROTEXTURE OF ARTIFICIALLY CONSOLIDATED ARAGONITIC MUD 

By JoHN C. HATHAWAY and EuGENE C. RoBERTSON, 

Denver, Colo., and Silver Spring, Md. 

The aragonitic muds of the Bahama Banks have 

long been considered to be one type of sediment from 

which aphanitic limestones, so widespread in the 

geologic column, may have formed. Our laboratory 

experiments on the diagenesis of this carbonate mud 

show that aphanitic limestone can indeed be formed 

from such mud. Previous investigations of the 

Bahama. muds; for example, those by Smith ( 1940), 

Black ( 1933), and Illing ( 1954), ·were field studies 

concerned primarily with the origin of the sediment 

itself and only secondarily with diagenesis. 

'Ve have examined replicas of fractured surfaces of 

experimentally consolidated products and of natural 

aphanitic limestone with the electron microscope to 

corn pare clutracteristics of the two. Our observations 

confirm suggestions by Black (I-Iatch, Rastall, and 

Black, 1938, p. 173-174), and by Bramlette (1958, p. 

125) that the fine mosaic texture of tiny interlocking 

crystals in very fine grained limestones, as seen in thin 

sections, was })l'Ob~bly formed by recrystallization of 

originnJ particles of all shapes. · 

In the electron microscope technique that is used, 

a piece of each sample is broken into small fragments 

a few millimeters across, and each is cemented. to a 

glass slide with a nearly flat surface facing upward. A 

replica of the surface of each fragment is formed in an 

evacuated chamber: the surface is first shadowed with 

platinum at a high angle (about 60°), and carbon is 

then evaporated vertically onto it. Next, the replicated 

surf~tces are coated with household cement to protect 

and support the carbon-platinum film while the 

original carbonate is dissolved away by HCI. After 

washing, each replica is placed gently on a copper 

electron-microscope grid, and its cement coating removed with acetone. After it is dry, electron microcrraphs, usually at a magnification of about 30,000 

diameters; are taken of representative areas of the 

replica for closer examination. 

More than 200 consolidation experime,1ts on mud 

from the Bahama Banks have been performed under 

various conditions of temperature, pressure, and time, 

but only pertinent ones will be described here; the 

experimental work will be discussed more completely 

later. Briefly, mud in very nearly its natural state is 

compressed under a constant load in a cylinder, fitted 

so as to permit escape of the water, and the cylinder 

nnd mud are heated at n controlled temperature; 

lengths of most runs were from 1 day to 4 weeks. 

In one type of apparatus, a large porous alundum 

sleeve was used as a cylinder, although its low tensile 

strength placed a limit of 1,000 psi on pressure; densities of the consolidated mud of about 1.9 g per cm3 

were obtained. In a second type of apparatus, a steel 

cylinder was used, so that apparent pressures up to 

50,000 psi could be obtained. Probably owing to friction of the piston and the mud against the wall, .the 

pressure inside the mud was reduced by as much as 

20 percent from the nominal value so that the highest 

density obtained in the products was only about 2.1 g 

per cm3 • I-Iydrostatic pressures up to 50,000 psi were 

applied in a third apparatus to mud samples contained 

in gold tubing, and densities up to 2.4 g per cm3 were 

obtained. 

As neither the chemical composition of the sea water 

in the mud nor that of the vapor driven off was analyzed, there was no control af the chen1ical environm€mt of the mud; this important variable is not accounted for in any of the experiments. Furthermore, 

the fact that the arae-onite seems to be stable as deposited but 1netastable under our experimental conditions introduces another intangible in detern1ining 

how 1nuch recrystallization occurred upon inversion to 

calcite. (X-ray diffraction patterns were made to 

determine the. degree of inversion.) Due to these 

uncertainties, the experiments were controlled only 

roughly; the accuracies are pressure ± 20 percent, 

temperature ± 10° C, and time ± 2 hours. 

The needle shape of the original unconso]idated 

grains, 1 to 3 p, long, is depicted in an electron micrograph on figure 257.1. The needles are broken up at 

pressures above 10,000 psi, as shown on figure 257.2. 

The effect of increasing time of experiment on 

samples under low pressure and at a temperature n_ear 

400°C is shown by the micrographs on figures 257.3-5. 

(The effect of pressure is unimportant at 400°C.) In 

all th,ree runs, the aragonite inverted completely to 

calcite; recrystallization is probably speeded up by the 

inversion, but actual grain growth is a rate process, as 

shown by comparison of the textures and times. On 

figure 257.3, the needle shape of the grains is still 

quite evident; but th~ originally square and ragged 

ends of the grains (fig. 257.1) have become rounded, 

and some of the shorter grains have become globular 

as a result of rounding. The sample shows considerable open space, which accounts for its moderately 

low density. On figure 257.4, the remains of one rela-
C-302 GEOLOGICAL SURVEY RESEARCH 1 9 61 

FIGURES 257.1-4.-ELECTRON MICROGRAPI]:_S_OF ARAGONITE NEEDLES AND COMPRESSED ARAGONITIC MUD 

FIGURE 257.1.-Aragonite needles from mud from the Bahama 

Banks before consolidation. 5 to 10 percent calcite. 

FIGURE 257.3.-Sample D103. Aragonitic mud from the Bahama 

Banks compressed for 5 hours at 1,000 psi and 43o•c. 

100 percent calcite. Density-1.6 g per em•. 

FIGURE 257.2.-Sample D169. Aragonitic mud from the Bahama 

Banks compressed for 7 days at 20,000 psi and 2oo•c. 8 percent (original) calcite. Density-2.1 g per cm3

• 

FIGURE 257.4.-Sample D118. Aragonitic mud from the Bahama 

Banks compressed for 1.0 days at 500 psi and 4oo•c. 

100 percent calcite. Density-1.95 g per em•. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-303 

FIGURES 257.5-8.-ELECTRON MICROGRAPHS OF COMPRESSED ARAGONITIC MUD AND SOLENHOFEN 

LIMESTONE. 

FIGURE 257.5.-Sample Dl19. Aragonitic mud from the Bahama 

Banks compressed for 2.6 days at 180 psi and 400°0. 

100 percent calcite. Density-1.35 g per em•. 

FIGURE 257.7.-Sample D162. Aragonitic mud from the Bahama 

Banks compressed for 63 days at 5,000 psi and 200°0. 

100 percent calcite. Density-1.9 g per em•. 

FIGURE 257.6.-Sample D163. Aragonitic mud from the Bahama. 

Banks compressed for 14 days at 5,000 psi and 300°0. 

100 percent calcite. Density-1.85 g per em•. 

FIGURE 257.8.-Solenhofen limestone, Bavaria. 100 percent 

calcite. Density-2.6 g per em•. 
C-304 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

tively large needle can be seen, but the rest of the 

grains are rounded and are beginning to coalesce to 

form larger, continuous masses; considerable open 

space is still visible. On figure 257.5, the grains are 

very rounded, and coalescence is far advanced. Owing 

to the ·relatively low pressure, the density of the sample 

is quite low. 

Longer time and higher pressure than in the preceding experiments offset a lower temperature ·in recrystalling the consolidated product, as figure 257.6 shows. 

The grains have intergrown to give a mosaic texture 

and have ~begun to show rudimentary crystal faces on 

some surfaces. The globular appearance of the grains 

shown on figure 257.5 is modified to more angular outlines in the sample on figure 257.6, and there is no 

suggestion of the original needle shape. Even longer 

time under a moderately high pressure offsets the low 

temperature of 200°C in causing a subhedral mosaic 

texture to be formed in the sample replicated on figure 

257.7. The similarity of the textures of the artificial 

products on figures 257.6 and 257.7 to that of the 

natural limestone from Solenhofen, Bavaria, on figure 

257.8 is striking. · 

The pressures in our experimental conditions are 

probably much the same as those in nature at a depth 

of 5,000 feet or less. On the other hand, the relatively 

high temperatures are not those expected in the earth's 

crust near the surface, and the lengths of the ex periments are very short. However, it seems reasonable 

that, given geologic time, recrystallization of a calcium 

carbonate mud to an aphanitic limestone would occur 

in nature in a manner similar to that described here. 

We are grateful to Preston E. Cloud, Jr., who supplied the aragonite mud samples and who stimulated 

our interest in this problem in conjunction with his 

own studies of calcium carbonate deposition on the 

Bahama Banks. Acknowledgment is due Paul Blackmon for making the X-ray determinations of calcitearagonite ratios in the samples. 

REFERENCES 

Black, Maurice, 1933, The precipitation of calcium carbonate 

on the Great Bahama Bank: Geol. Mag., v. 70, no. 10, 

p. 455-466. 

Bramlette, M. N., 1958, Significance of coccolithophoride in 

calcium carbonate deposition: Geol. Soc. America Bull., 

v. 69, p. 121-126. 

Hatch, F. H., Rastall, R. H., and Black, Maurice, 1938, The 

petrology of the sedimentary rocks : London, Thomas 

Murby & Co., 383 p. 

Illing, L. V., 1954, Bahaman calcareous sands: Am. Assoc. 

Petroleum Geologists Bull., v. 38, p. 1-95. 

Smith, C. L., 1940, The Great Bahama Banks: Jour. Marine 

Research, pts. 1 and 2, v. 3, no. 2, p. 147-189. 

258. FLUORINE DURING HYDRATION OF RHYOLITIC GLASS 

By IRVING FRIEDMAN and JosEPH HARRIS, vVashington, D. c. 

During a study of the amount of. water bound in 

glassy rhyolites and their relative deuterium-hydrogen 

concentrations, the authors became curious as to the 

role of fluorine in such glasses. Harris made determinations of fluorine of glasses whose water contents had 

been determined by Friedman. 

The fluorine content was determined colorimetrically 

after fusion of the sample in a flux and distillation of 

the SiF4. The method has been described by Grimaldi 

and others ( 1955). 

Water content was determined by heating the rock 

in a vacuum, converting the extracted water to hydrogen gas, and measuring the quantity of hydrogen 

gas volumetrically. The technique was described by 

Friedman and Smith (1958). 

Most of the samples of rhyolitic glasses include both 

obsidian and perlite that were separated from the 

same hand sample. The perlite in these samples is believed to have been formed by hydration of obsidian 

under surficial conditions (Ross and Smith, 1955). 

Thus, the only alteration has been the addition of 

water to the glass. The paper of Friedman and Smith 

(1958) discusses the formation of such perlite in more 

detail. 

Table 258.1 lists the water and fluorine content of 

the samples analyzed. The data show a remarkable 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-305 

TARLE 258.1.-H20 and F analyses of rhyolitic glass samples 

(Precision or analyses Is ±5 percent or the amount present) 

H20 F, 

Location Sample Description (per- (per- cent) cent) 

----------

Our data show that during hydration the fluorine 

content of the glass remains relatively constant in the 

samples that we analyzed. From this it may be inferred 

that the amount of fluorine found in the hydrated 

glass shards of a bed of volcanic ash represents the 

Canovtts Canyon, 2Q-2 obsidian _____ 

Valles Mts., N. Mex. 20-1 perlite ______ 

Bland Canyon, Valles 67-8 black perlite 

0. 21. 0.02 

2. 9 . 02 

2. 5 . 03 

1 original fluorine content of the material and not an 

3 accidental fraction that remains after variable degrees 5 

Mt.s., N. Mex. ·of hydration. The constancy of the fluorine content I>o _______________ 65-7A gray perlite __ 

65-7B blue perlite __ I>o _______________ 65-6A gmy perlite __ 

65-6B black perlite_ Superior, Ariz _________ 3024-7 obsidian _____ 

3024-6 perlite ______ 

91n.nclm, Cn.lif _________ I 53-'J obsidian _____ 

53-11 pumice ______ 

Mono Cmters, Calif ____ 52-23 gray glass ___ 

53-7 obsidian _____ I>o _______________ 39-3 pumice ______ 

Clen.r Ln.ke, Lake 52-21 obsidian _____ 

County, Cn.lif. 52-22 perlite ______ 

Bi~ Glass Mountain, 2-5 obsidian _____ 

Calif. 47-14 puinice ______ Pueblo, Mex_ _________ 67-5 obsidian _____ 

67-6 perlite ______ 

Prestahnukur, Iceland __ 3023-3 obsidian _____ 

3023-2 perlite ______ 

Mayor Isln.nd~ New 70-9 obsidian _____ 

Zen.land. 70-10 perlite _______ 

Ongarn.to, New 70-11 obsidian _____ 

Zealand. 70-12 perlite _______ 

t From single outcrop; nil others arc single specimens. 

2.9 

2. 9 

3. 6 

4. 4 

. 23 

3. 4 

. 95 

3. 5 

. 31 

. 36 

1.9 

. 09 

3. 1 

. 10 

. 26 

. 98 

3. 1 

. 17 

3. 7 

. 10 

3. 7 

. 10 

2. 6'. 

. 02 

. 03 

. 03 

. 02 

. 03 

. 04 

. 07 

. 07 

. 06 

. 06 

. 06 

. 05 

. 06 

. 02 

. 03 

9 

4 

6 

3 

7 

1 

2 

2 

0 

5 

0 

6 

0 

8 

1 . 081 

. 07 5 

.11 

. 07 9 . 13 

. 11 

. 02 8 . 025 

constancy to the weight percent fluorine in a given 

igneous provilice. This fact was noted by R. R. Coats 

(1956). I-Ioward Powers (Art.111, Prof. Paper 424-B) 

has found that most samples from the same bed of 

volcanic ash have a similar content of fluorine, regardless of the water content of the shards. 

This suggestion differs from the view expressed by 

Ross and Smith (1955) on the basis of the work of 

Shepherd (1938). Ross and Smith stated that "hydration has had the effect of flushing C02, Clz, and F z 

from the system and replacing them by HzO in the 

hydrated glasses." However, careful consideration of 

Shepherd's results shows the fallacy of this interpretation. Shepherd reported the constituents of the gases 

extracted from his samples in volume percent. If the 

fluorine content of the glass remains constant, but the 

water content increases, the relative volume percent of 

fluorine in the extracted gas will be decreased. This 

is demonstrated in table III in ·Shepherd's paper, 

where the analyses of the rocks, both fresh and hydrated, are reported in weight percent. 

during hydration then permits the fluorine content of 

hydrated glasses to be used as an index of place of 

origin of volcanic ash . 

"Te do not wish to give the impression that fluorine 

ca~u1ot be released during extensive alteration of 

rhyolitic ash. 'iV e prefer to divide the alteration process 

into two steps. The first step discussed in this paper 

is the diffusion of \Vater into the glass. This water can 

come from groundwater, meteoric water, or atmospheric water vapor. The diffusion is fairly rapid and 

results in a glass containing about 3.5 percent water 

by weight from glass usually containing originally less 

than 0.35 percent water (Friedman and Smith, 1960) . 

During this process, fluorine is not lost from the glass . 

The next step in the alteration of the glass is probably the devitrification of the hydrated glass, during 

which clay minerals are formed and fluorine may be 

lost. As yet, we have no data on the movement of 

fluorine during devitrification, but it is probably during this process that many elements present in the glass 

are released to the groundwater. 

REFERENCES 

Coats, R. R., 1956, Uranium and certain other trace elements in 

felsic volcanic rocks· of Cenozoic age in western United 

States: U.S. Geol. Survey Prof. ·Paper 300, p. 75-78. 

Friedman, Irving, and Smith, R. L., 1958, The deuterium content of water in some volcanic glasses : Geochim et Cosmochim. Acta, v. 15, p. 218-228. 

-- 1960, A new dating method using obsidian, Pt. I, The 

development of the method: Am: Antiquity, v. 25, p. 476-

522. 

Grimaldi, F. S., Ingram, Blanche, and Cuttitta, Frank, 1955, 

Determination of small and large amounts of fluorine in 

rocks: Anal. Chemistry, v. 27, p. 918-921. 

Ross, C. S., and Smith, R. L., 1955, 'Vater and other volatiles 

in volcanic glasses: Am. Mineralogist, v. 40, p. 1071-1089. 

Shepherd, E. S., 1938, The gases in rocks and some related 

problems: Am. Jour. Sci., 5th ser., v. 35A, p. 311-351. 
C-306 GEOLOGICAL SURVEY RESEARCH 19 61 

259. A CRITICAL REVIEW OF ANALYSES OF CHLORITOID 

By MARGARET D. FosTER, Washington, D. C. 

Chloritoid, so named by G. Rose (in Dana, 189.2, p. 

642) from its superficial similarity to chlorite, closely 

resembles the mica minerals physically and chemically. 

It is commonly included in the, group of brittle micas, 

which are generally presumed to be similar to the true 

micas in structure but to have greater substitution of 

AI for Si in the tetrahedral layers, and, in margarite 

and xanthophyllite, to have Ca instead of K in interlayer positions. In chloritoid, as generally formalized, 

4[ (Fe+2,Mg) 2(Al,Fe+3) 2(Si2Al2) Olo(OH) 4], 

the deficiency in charge in the tetrahedral group is 

balanced by an excess of charge in the octahedral group 

because of the trivalent cations present. The unit 

layers neutralize each other and there is no need for 

interlayer cations as in the true micas, and in margarites and xanthophyllites. 

Machatschki n.nd Mussgnug (1942) proposed a 

structure for chloritoid based on that of muscovite, 

with K being replaced by 1 (Fe+2,Mg) and 2(0H) 

forming a close-packed arrangen1ent between the 

silicate layers. The remaining Fe+2,Mg, and FeH, 

u.nd any Al not required to cmnplete the tetrahedral 

layers, occupy octahedral positions. Octahedral Al 

and FeH are together close to 2.00, as is also tetrahedral Al; consequently the silicate layers are neutral, 

as is also the interlayer (Fe+2,Mg) (0H)2, and there is 

no charge binding the silicate layers and the interlayer (Fe+2,Mg) (0H)2, as in the true micas. ~Iachatschki and Mussgnug expressed. their structure by the 

formula 

!Fe+2(0H)2 {(OH)z(Fe,Al,Mg)3 [(Si,Al)4010J}. 

Presumably Fe in the octahedral group in this formula 

represents both Fe+a and Fe+2• In this formula and 

that previously given for chloritoid, (Si,Al) occupy 

four positions, with Si and AI usually occupying about 

two positions each, with some variation in the relative 

amounts of Si and AI permissible. Thus Milne (1949) 

found (Si + Al)4 ranging from (Sit.93Ab m) to (Si2 .27 

+Alt.73). 

More recent work by Brindley and Harrison (1954) 

indicates, however, that chloritoid does not have a 

mica-like structure but a type of layer lattice structure 

not reported heretofore. They found that in a Fourier 

synthesis the electron content of the "Si" peak is 

only half the usual value, 2Si in place of the usual 

4(Si,Al) at this level in the structure. The peak heights 

also suggested 2(Fe+2,Mg)+ 1Al within the silicate 

sheets, in the octahedral positions, and 3Al between 

the sheets, where K occurs in muscovite. The Si 

atoms do not form continuous silicate sheets as in 

the micas, but occur within distinct (Si04) groups. 

Brindley and IIarrison expressed this structure in the 

formula, [ (Fe+2Mg)2Al] (OH)4Ala[02 (Si04)z]. In this 

structure there are only 2 Si ions. Thus, the upper 

limit of the number of Si ions in a chloritoid is strictly 

defined. This limitation on the numqer of Si ions, 

and the other atomic proportions indicated for chloritoid by Brindley and Harrison, suggested the desirability of a review of published analyses of chloritoid. 

ATOMIC PROPORTIONS IN CHLORITOID ANALYSES 

CITED BY DANA 

Some of the chloritoid analyses cited by Dana (1892) 

with their calculated atomic proportions, are given 

in table 259.1 The atomic proportions were calculated 

on the basis of the theoretical O(OH) content, 0 10 (0H)4, 

by a method adapted from that used for calculating 

the formulas of micas (Foster, 1960) by using the 

number 48 instead of 44 to convert gram-equivalents 

of cationic constituents to cationic valences per unit 

cell. In the allocation of AI, which occupies two 

different sites in the Brindley and Harrison structure 1 

three AI ions were assigned to positions between the 

silicate groups and the remainder was assigned to 

octahedral positions. The atomic proportions for a 

few of the analyses, particularly analyses 10 and 3, 

agree quite satisfactorily with Brindley and Harrison's 

suggested proportions of 2Si :1 octahedral (AI+ Fe H): 

2R+2

, but those of most of the others do not agree as 

well. 

In five analyses, (10, 6, 3, 8, and 4) the number of 

positions occupied by Si is 2.00±0.04, but in the others 

Si is either deficient by 0.10 or more positions (as in 

2, 11, and 9), or is excessive by 0.06 to 0.24 positions 

(as in 13, 9, 12 a~d 1). In those in which Si is excessive, the high Si is probably due to occluded quartz. 

Brindley and Harrison (1954) did not state whether 

Al can substitute for Si if Si is somewhat deficient, as 

in analyses 2, 11, and 7. In analyses 2 and 11, in which 

Si is only 1.89., octahedral RH is also low, 0.90 and 0.68, 

respectively, and allocation of some AI ions to tetrahedral positions only increases the deficiency in RH ions. 

In no. 7, however, octahedral RH is high, 1.18, and 

allocation of 0.10 AI to tetrahedral positions to bring 
.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-307 

T A ~LE 259.1.-A. nalyses of chloritoids cited by Dana (1892) 1 and atomic proportions 

[Numbers of analyses are those of Dana (1892, p, 641)] 

Virginia 13 I St. Marcel 9 I Leeds, 12 I Ko~ibrod Canada 

Chemical analyses 

Si02---- _______ 23.01 23. 91 22. 52 24.40 24. 47 24. 90 26. 03 24. 90 25. 03 25. 50 26. 30 .27. 48 

A bOa- - - - -- --- 40. 26 39. 52 39. 60 42. 80 41. 34 40. 99 42. 33 40. 36 39. 75 38. 13 37. 10 35. 57 Fe20s- ________ -------- -------- 3. 97 -------- . 38 . 55 4. 09 -------- -------- -------- -------- -------- FeO __________ 27.40 28. 05 15. 35 19. 17 18. 52 24. 28 14. 32 26. 17 22. 92 23 .. 1)8 25. 92 27. 05 MgQ __________ 3. 97 -------- 2. 10 6. 17 6. 80 3. 33 7. 30 2. 54 3. 32 5. 19 3. 66 4. 29 MnQ _________ -------- -------- 8. 40 -------- . 91 -------- -------- -------- 1. 30 -------- . 93 . 30 CaO __________ -------- -------- . 35 -------- . 30 -------- . 35 -------- . 21 -------- -------- -------- H20 _______ - __ 6. 34 7. 08 7. 44 6. 90 6. 98 7. 82 6. 56 6. 23 6. 64 6. 90 6. 10 6. 95 

Total ___ 100. 98 98. 56 I 99. 78 99. 44 99. 70 101. 87 100. 98 100. 20 2 99. 31 99. 30 100. 01 101. 64 

Atomic proportions 

Si ____________ 1. 89 1. 89 1. 90 1. 96 1. 97 R+a ___________ . 90 . 68 1. 18 1. 04 . 95 Al __________ . 90 . 68 . 93 1. 04 . 93 

Fe+a_ ------- -------- -------- . 25 -------- . 02 

R +2- - - - - - - - - - - 2. 37 2. 69 1. 94 1. 98 2. 13 F e+2 ________ l. 88 1. 86 1. 08 1. 24 1. 25 Mg _________ . 49 . 83 . 26 . 74 . 82 Mn _________ -------- -------- . 60 -·------- . 06 

R +a+ R +2- - - - - - 3. 27 3. 26 3. 02 3. 02 3.08 

AI (interlayer) __ 3. 00 3. 00 3. 00 3. 00 3. 00 

• Includes 0.05 percent CoO. 2 Includes 0.14 percent alkalies. 

the totnJ to 2.00, would reduce the number of R+a ions 

to 1.08. In this nnnlysis the number of R+2 ions is only 

1.94, slightly deficient of the 2.00 R+2 ions indicn,ted by 

Brindley nnd Harrison. The slightly high octahedral 

R+3 n.nd slightly low R+2 in the atomic proportions of 

this ann.lysis m.n,y be due to error in the relative amounts 

of Fe203 n.nd FeO reported. 

A correct determinn.tion of the ferrous iron content 

of rocks nnd m.inernls is generally beset with grent 

difficulties, of which one of the gren,test is preparation of 

the sample. Grinding the Sttmple in nir tends to lower 

the FeO nnd to incren.se the Fe20 3 in a rock or minern1 

thnt contn.ins FeO. This oxidizing effect was not 

realized until after about 1900; consequently, nearly 

n.ll n1inerni ann.lyses mttde prior to that date are npt to 

contnin more or less serious errors with respect to the 

relative nm.ounts of Fe20 3 nnd FeO reported. For 

example, a chlorite was reported by Clarke (1910) to 

contttin 2.86 percent Fe20 3 nnd 17.77 percent FeO. 

Recent values for Fe203 ttnd FeO on n sample from the 

snn1e hnnd specimen nrc 0. 72 nnd 20.25 percent, respectively. Totnl iron as ~"'e 3 nrc 22.61 and 23.23, respectively. Thus, the slightly high octtthedral R+a and 

slightly low R+2 content of n.mtlysis 7 mny well be due 

to error in the reln.tive proportions of Fe20 3• and FeO 

reported in the nrmlysis. This m.ny nlso be the reason 

for the high octn,hedrnl R+a nnd low R+2 content of 

n.nnlysis 8. · 

In eight of the tLnttlyses in tttble 259.1 no value is 

2.02 2. 02 2. 04 2. 06 . 94 1. 12 . 89 . 86 . 91 . 88 . 89 . 86 . 03 . 24 -------- -------- 2. 04 1. 77 2. 10 2. 08 

l. 64 . 93 1. 79 1. 58 . 40 . 84 . 31 . 41 

-------- -------- -------- . 09 

2. 98 2. 89 2. 99 2. 94 

3. 00 3. 00 3. 00 3. 00 

2. 10 2. 16 . 70 . 59 . 70 . 59 

-------- -------- 2. 26 2. 29 

1. 62 1. 78 . 64 . 45 

-------- . 06 

2. 96 2. 88 

3. 00 3. 00 

2. 2 

.4 

.4 

4 

2 

2 

-------- 2. 3 

1.8 

.5 

.0 

9 

5 

2 

2 

2. 81 

3. 0 0 

given for Fe20 3 ; only FeO is reported. This suggests 

tlutt the total iron in these snrn.ples was reported as 

FeO, and tlutt FeO wtts not determined as such; it wn.s 

sirr.ply ttssumed that nil the iron wns present tts ferrous 

iron. However, the low octahedral R+3 ttnd high R+2 

contents of seven of these analyses (2, 11, 4, 13, 9, 12 

tLnd 1) suggest thttt the samples rn.ust have contu.ined 

more or less Fe203• If it is assum.ed, for exarn.ple, thnt 

5 percent of the FeO reported (23.58 percent) was 

actunlly present as Fe20 3, nnd the atomic proportions 

recnlculnted on thnt bttsis, Si decrenses from 2.10 to 

2.07 positions, octahedral R+3 increttses from 0. 70 to 

0.98 positions, ·R+2 decreases from. 2.08 to 1.89 positions 

nnd octahedntl (R+3 nnd R+2) decreases from 2.94 to 

2.87 positions- tt considernbly better agreern.ent with 

the atomic proportions suggested for chloritoid by 

Brindley and Harrison (1954). In only one analysis 

(10) in which FeO only is reported do the atomic proportions of octahedral R+3 nnd .R+2 indicttte thnt nil 

the iron was probttbly present ns ferrous iron. 

From this review of 12 of the analyses of chloritoid 

cited by Dana it may be concluded that error in the 

relative amounts of Fe20 3 and FeO reported, and 

failure to differentiate Fe203 and FeO (reporting all 

iron as FeO), which are characteristic of many analyses of rocks and minerals made before the beginning 

of the twentieth century, are important reasons for 

lack of agreement between the atomic proportions calculated from these analyses and those indicated for 
C-308 GEOLOGICAL SURVEY RESEARCH 19 61 

chloritoid by Brindley and Harrison. Another reason 

for lack of agreement in those analyses in which Si 

occupies an excessive number of positions is probably 

faihute to remove -impurities, especially quartz, before 

analysis, or to adjust the analysis to allow for such 

impurities. 

ATOMIC PROPORTIONS OF SELECTED RECENT 

ANALYSES OF CHLORITOID 

Selected analyses of chloritoid published since 1925 

and the calculated atomic proportions are given in 

table 259.2. In calculating the atomic proportions for 

analyses 1, 2, and 7, the CaO reported is considered 

extraneous to the chloritoid structure, in which there is 

no likely place for an ion as large as Ca. The atomic 

proportions of these analyses, with the exception of 

those of analysis 7, agree very well with those suggested 

for chloritoid by Brindley and Harrison; Si 2.00, 

octahedral R+3 1.00, RH 2.00, with 3 AI ions between 

the silicate sheets. Analysis 1 is slightly low in Si, 

1.92. However, octahedral RH and (R+3+ R+2) are 

both slightly .high, 1.07 and 3.12, respectively, and 

allocation of 0.08 AI to tetrahedral positions, if permissible, would bring these values close to the ideal. 

Analysis 7 is high in Si, and low in octahedral RH and 

(R +a+ R +2), suggesting incom.plete separation of the 

analyzed sample from occluded impurities such as 

quartz. 

The analyses in table 259.2 were made after the oxidizing effect of fine grinding on FeO was· realized, and 

after more refined methods for determining FeO had 

been developed. The good agreement of the atomic 

proportions of analyses 1 to 6 with those indicated by 

the new structure for chlofitoid, compared with the 

poor agreement of the atomic proportions calculated 

from the older analyses, especially in octahedral R +a 

and R+2, demonstrates the importance of correct values 

for Fe203 and FeO in caleulating atomic proportions 

not only for chloritoid but also for all other minerals 

containing Fe203 and FeO. Nearly all mineral analyses 

that were· made before the effect of fine grinding was 

considered are affected by more or less serious errors 

in respect to the oxides of iron. 

The analyses in table 259.2 also demonstrate the extremely narrow limits permitted for Si02 in the new 

structure. In analysis 1 with 22.67 percent Si02 , the 

number of Si ions is low, only 1.92, in analysis 5, with 

less than 2.5 percent more Si02 , the number of Si ions 

is slightly high, ~.04, and in analysis 7, with only 2.31 

percent more Si02 than analysis 1; the number of Si 

positions is 2.12. These two analyses ( 5 and 7), illustrate the effect of other constituents present in calculating the number of positions occupied by Si. 

TABLE 259.2.-Selected analyses of chloritoids published since · 1925, and atomic proportions I 

2 a 4 5 6 

Chemical analyses 

Si02-------- 22. 67 23. 74 24. 31 24. 20 25. 12 24. 4 24.98 

Al20a------- 38.86 39. 01 39. 18 40. 46 40. 25 39. 6 35.07 

Fe20a ______ 2. 98 3. 04 3. 56 ------ 3. 22 2. 4 4. 81 FeO ________ 25 .. 46 23. 98 22. 64 24. 24 19. 62 23. 0 26. 84 MgO _______ 1. 96 1. 61 2. 70 2. 60 3. 89 1.8 . 67 

MnO _______ ------ . 4Y 1. 51 ------ 1. 05 .2 . 79 CaO _______ . 93 1. 02 Tr ------ none Tr . 58 

H20 _____ - - - 7. 14 7. 72 6. 65 7. 30 6. 76 7. 3 6. 34 --------------------- TotaL_ 100. 00 100. 61 100. 55 98. 80 99. 91 98. 7 100. 08 

Atomic proportions 

SL _________ 1. 92 2. 00 2. 00 2. 02 2. 04 2. 04 2. 12 

R+a-------- 1. 07 1. 04 1. 01 . 97 1. 04 1. 05 . 82 AL ______ . 88 . 87 . 79 . 97 . 84 . 90 . 51 

Fe+3 ____ "" . 19 . 17 . 22 ------ . 20 . 15 . 31 

R +2 - - - - - - - - 2. 05 1. 93 1. 99 2. 01 1. 87 1. 85 2. 04 Fe+2 _____ 1. 80 1. 69 1. 55 1. 69 1. 33 1. 61 1. 90 

Mg ______ . 25 . 20 . 33 . 32 . 47 . 22 . 08 

Mn ______ ------ . 04 .11 ------ . 07 . 02 . 06 

R+3+R+2 ___ 3. 12 2. 97 3. 00 2: 98 2. 91 2. 90 2. 86 

Al (interlayer) 3. 00 3. 00 3. 00 3. 00 3. 00 3. 00 3. 00 

1 Analyses as follows: 

1, Lemhi. County, Idaho, Shannon, 1926; analysis adjusted for about a percent cobaltiferous arsenopyrite; 2, Kalgoorie, Western Australia, Simpson, 19a1; 

analysis corrected for occluded quartz; a, Varnpi., Western Australia, Simp- son, 19a1; 4, El Cardosa (Sornosierra) Guadalajara, Spain, Recarte, 1951; 

5, Rawlinsville, Lancaster County, Pa., Hietanen, Anna, 1951; also 

reported 0.09 percent K20; analysis adjusted for 0.63 percent Ti02 (rutile); 

6, Clove Valley, Dutchess County, N.Y., Barth and Balk, 19a4; also reported 1.3 percent Ti02; analysis adjusted for impurities; 7, Rhode Island, Koch, 19a5. 

Analyses 5 and 7 have almost the same SiOz content, 

25.12 and 24.98 respectively. Yet the calculated number of Si positions is 0.08 greater in the analysis having the lower Si02 content because of its higher FeO 

and lower Alz03 and MgO content. It is for this reason that precise limits cannot be set on the amount of 

SiOz to be found in chloritoid. However, it ·would be 

expected that in analyses reporting less than 22.0 or 

more than 26.0 percent Si02 , Si would occupy either 

too few or too many positions to fit the new structure 

for chloritoid. · 

REFERENCES 

Barth, T. F. W., and Balk, Robert, 1934, Chloritoid from 

Dutchess County, New York: Am. Mineralogist, v. 19, p. 

348. 

Brindley, G. W., and Harrison, F. W., 1954, The structure of 

chloritoid, in Swineford and Plummer, eds., Clays and 

clay minerals, Natl. Research Council Pub. 327, p. 360-363. 

Clarke, F. W., 1910, Analyses of rocks and minerals from the 

• Laboratories of the United States Geological Survey, 18RO 

to 1903: U.S. Geol. Survey Bull. 419, p. 294. 

Dana, E. S., 1892, The system of mineralogy, 6th ed., New 

York, p. 641. 

Foster, Margaret D., 1960, Interpretation of the composition of 

trioctahedral niicas: U.S. Geol. Survey Prof. Paper 354-B, 

p. 13. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-309 

Hietanen, Anna, 1951, Chloritoid from Rawlinsville, Lancaster 

County, Pennsylvania: Am. Mineralogist, v. 36 p. 867. 

Koch, Gottfried, 1935, Chemische und physikalisch-optische 

Zusanunenhange innerhalb der Sprodglimmergruppe: 

Chemie der Erde, v. 9, p. 460-461. 

Machatschld, F., and Mussgnug, F., 1942, Uber die Kristallstruktur des Chloritoids: Naturwissenschaften, v. 30, p. 

106. 

Milne, I. H., 1949, Chloritoid from Megan tic County, Quebec: 

Am. Mineralogist, v. 34, p. 422-434. 

Recarti, A. B., 1951, Nota acerca del mineral clasiftcado como 

"diasporo" de El Cardosa ( Somosierra) Guadalajara : Inst. 

Geol. Espana, Notas Comun., no. 23, p. 66. 

Shannon, E. V., 1926, The minerals of Idaho: U.S. Natl. 

Museum Bull. 131, p. 378. 

Simpson, E. S., 1931, Contributions to the mineralogy of Western Australia, Series V: Royal Soc. Western Australia 

Jour., v. 16, p. 29. 

260. X-RAY CRYSTAI~LOGRAPHY AND OPTICAL PROPERTIES OF SYNTHETIC MONOCLINIC KFeSi30 8 IRON· 

SANIDINE 

By DAVID R. "VoN:~<:s and DANIEL E. APPLEl\fAN, Washington, D.C. 

In a study of the phase equilibria involving the mica 

KFe3FeSi30 10 (0H)z, Wones (1959) found one of the 

reactants to be potassium-iron feldspar, KFeSi30 8. 

Single-crystal techniques lutve shown that this· monoclinic feldspftr forms in the system KzO-Si02-Fe-O-HzO 

from the reaction of mien. with gas to form feldspar, 

hematite, and magnetite: 

2 KFe3FeSi3010(0H)z+5/4 Oz~ 

mica oxygen 

2KFeSi30s+Fe:~04+3/2 Fez03+2Hz0. 

feldspar magnetite hematite steam 

The best crystals of the monoclinic polymorph formed 

from an aggregate of mica held at 750° C, 2000 bars total 

pressure nnd 10-10 bars oxygen :fugacity for 4 hours, 

then held at 650° C, 2000 bars total pressure and- 10-12 

bars oxygen fugacity for 48 hours. The ru!ls were made 

in standard hydrothermal apparatus using the oxygei)-

buffer technique described by Eugster (1957). Theresultant feldspar crystals are thin and tabular, ranging 

up to 0.5 mm in diameter, with well-developed { 010} 

forms; carlsbad-type twins are frequent. 

A comparison of the X-ray powder diffraction pattern 

of the monoclinic feldspar with those of feldspars obtained in other runs in the same study shows that n. 

triclinic polymC>rph can be synthesized under different 

experimental conditions. The crystals formed are very 

small, exhibit some "triclinicity", and show the "gridiron" twinning characteristic of microcline. 

The space group and unit-cell parameters of the 

monoclinic potassium-iron feldspar were determined 

from nn untwinned crystal with approximate dimensions 

of 0.2 X0.2 X0.05 mm. Zero- and first-level photogrnphs were taken of the hOl and Okl zones, using a 

quartz-calibrated Buerger precession camera with 

l\1oKa radiation; zero- and first-level· photographs of 

the hkO zone, taken on a Weissenberg camera using 

MoKa and FeKa radiations, were used only to check 

the space group. The values found from precession 

photographs are as follows: monoclinic, 02/m; a= 

8.689±0.01A; b=l3.12±0.02; c=7.319 ±0.01; ~= 

116°06' ± 5'; cell contents: 4[KFeSi30 8j; cell volume: 

749.3 ± 2.0 A3; specific gravity (calculated): 2. 72. Using 

these cell parameters, the values of the d-spacings were 

computed; they are con1pared in table 260.1 with the 

observed d-spacings, measured from a.n X-ray powderdiffraction film taken with a Debye-Scherrer camera 

(114.59 mm diameter) using the Straumanis technique 

with manganese-filtered FeKa radiation (:,= 1.9373A). 

The agreement is considered adequate. 

TABLE 260.1.-X-ray powder data for synthetic monoclinic 

K F eSiaOa, iron-sanidine 

[Monocllnlc, C2/m•; a=8.68g±O.Ol A; b=13.12±0.02; c=7.3h±O.Ol; ~=116°06'±5'1 

Measured 1 Calculated 

"u• "u• Ul 

6. 706 110 

6. 57a 001 

10 6 .• 5sB 6. 561 020 <I 5. 94 5. 952 Ill 

4. 64a 021 

30 4. 282 4. 282 201 

15 3. 994 3. 99g 111 

3. 901 200 

40 3. 81s 3. 81s 130 

3. 65g T31 

3. 586 221 

20 3. 52a 3. 524 Tl2 

3. 37} r 35, 220 

60 to B 

3. 34 3. 340 202 

See footnotes at end of table. 
C-310 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TABLE 260.1.- X -ray powder data for synthetic monoclinic KFeSia08, 

iron-sanidine-Continued 

100 

30 

l.lj 

30 

13 

20 

8 

5 

IS 

I5 

5 

<I 

<I 

8 

2 

8 

<1 

1.1j 

Measured 2 

3. 27g 

3. 026 

2. 978 

2. 934 

2. 803 

2. 6.1j3 

2. 60} to B 

2. 58 

2. 463D 

2. 4II 

2. 289 

2. 183 

2. 148 

2. I17 

2. 076D 

2. 033 

1. 995D 

l. 880 

1. 866D 

1. 823 

Calculated 

duz hkl r 28, 002 

3. 28o 040 

3. 02g 13I 

2. 976 222 

2. 938 022 

2. 935 041 

2. 850 201 

2. 825 311 

2. 806 I32 

2. 642 312 

2. 6I4 221 J2· 604 241 

l2. 589 112 

2. 551 310 

2. 5I1 240 

f2. 487 I 50 

l2. 442 I 51 

2. 4I8 203 

2. 4I3 33I 

2. 363 Il3 

2. 340 242 

2. 322 042 

2. 296 332 

2. 268 223 

2. 26I I32 

2. 236 330 

2. 225 3 I5I 

2. I87 060 J2· I5I 24I 

l2. I45 40I 

2. I06 I33 r- 078 023 

2. 075 06I 

2. 035 422 

1. 999 222 

1. 88I 352 

1. 870 420 

1. 823 I70 

• Space group assumed to be centrosymmctric because of the 'crystal morphology, lack of piezoelectric properties, and analogy with sanidine. 2 Films corrected for expansion. Camera diarr.eter 114.59'mm. Manganese-filtered iron radiation. (X=l.9373A). Lower limit of 29 measurable: approximately 7° 

(15.9A). B=broad. D=diffusc. a All smaller d-spacings not corresponding with observed reflections were omitted 

beyond this arbitrarily chosen d-spacing. 

The optical data of the monoclinic potassium-iron 

feldspar are as follows: a=l.584±0.001, ,8=1.595± 

0.001, ')'=1.605±0.001, 2Va"'85° (observed), 2Va= 

86.5° (calculated); Y =b, ZAc=16°±4°. Optical measurements w~re made with a sodium light source, using 

immersion oils calibrated on an Abbe refractometer at 

the time of .measurement. The orientation of the indicatrix is comparable to that found for "high sanidine" 

(Tuttle, 1952). These values differ from those quoted 

by Faust (1936) for the measurements by Hautefeuille 

and Perrey, Niggli, and Gaubert on synthetic iron 

feldspar prepared by Hautefeuille and Perrey, using a 

potassium vanadate flux. The discrepancy is not unex-

. pected, considering the vanadium content of their 

material. Faust reported that the material he prepared 

was unsuited for precise optical measurements. The 

data presented in this paper strengthen the view that 

the· phase referred to as "Fe-sanidine" by Wones 

(1959) is structurally analogous to monoclinic potassium-aluminum feldspar (high sanidine). 

The authors thank H. T. Evans, Jr., for preliminary 

single-crystal measurements, and Mary E. Mrose, for 

preparing the X-ray powder-diffraction film. 

REFERENCES 

Eugster, H. P., 1957, Heterogeneous reactions involving oxidation and reduction at high pressures and temperatures: 

Jour. Chern. Physics, v. 26, no. 6, p. 1760-1761. 

Faust, G. T., 1936, The fusion relations of iron orthoclase: Am. 

Mineralogist, v. 21, p. '735-763. 

Tuttle, 0. F., 1952, Optical studies on alkali feldspars: Am. 

Jour. Sci., Bowen volume, p. 553-567. 

Wones, D. R., 1959, Biotites, Phase relations of the K20•6FeO• 

Fe20a•6Si02•2H20 end member [abs.] : Jour. Geophys. 

Research, v. 64, no. 8, p. 1131. 
·SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-311 

261. A REVIEW OF THE CHEMICAL COMPOSITION OF GASES FROM VOLCANIC FUMAROLES AND 

IGNEOUS ROCKS 

By DoNALD E. WHITE and G. A. V\TARING, Menlo Park, Calif., and Palo Alto, Calif. 

VOLCANIC GASES 

Careful systematic work on the composition of volcn.nic gases has been attempted at only a few volcanoes 

and generally for short periods of time; nevertheless, 

some conclusions can be reached from a review of the 

geologic literature. The extensive studies of ICamchatkan volcanoes hn.ve been reviewed by Naboko (1959a; 

1959b). Other recent studies have been made at ShowaShinzan, Jn,pan (Nemoto, Hayakawa, Takahashi, and 

Oann., 1957, p. 121-123); Nasu, Japan (IC Hayase, 

written communication, 1957); O-shima, Japan (Iwasaki, 1951, p. 140-143); Vulcn.no, Italy (Sicardi, 1956); 

''Thite Isln.nd, New Zealand ('Vilson, 1959, p. 42, 45); 

and I-Iekla, Iceland (Baldur Lindal, written communication, 1.957). 

The principal generalizations that can be made for 

cl1emical ann.lyses of gases from volcanic fumaroles 

are: 

1. Steam, where determined, is with few exceptions the 

greatly dominant gas, generally exceeding 90 percent of 

the total in volume percent. 

2. Total air, when reported, commonly exceeds the "active-" 

gases and may be greatly dominant even when much 

effort is made to exclude it (the "active" gases are considered to include all gases other than H20, air, excess 

N~, and the inert gases, and are here recomputed to 

equal 100 percent). 

3. COu is generally the dominant "active" gas, particularly at 

low temperatures. 

4. Hu is highly erratic in amount; it is commonly absent but 

exceeds 40 percent in some analyses. CH, and NHa are 

erratic in amount, but seldom exceed 1 percent. 

5. HOI commonly increases with increasing temperature, but 

some high-temperature fumaroles contain little HOI, and 

some low-temperature fumaroles contain much. 

6. HF, seldom determined, is generally less than 10 percent of 

reported HOI but may be higher in silicic volcanism. 

7. HDS seldom exceeds 20 percent of the "active" gases, and 

its proportion is commonly not clearly related to temperature. 

8. SOu is nearly always the dominant oxidized sulfur gas; 

it exceeds 20 percent of total "active" gases in nearly 

one-third of the samples in which it was determined, but 

is commonly not clearly related to temperature. 

0. SOa has seldom been determined in addition to S02 in whole 

gases. In fumarolic condensates, SOa dissolves as H2SO,, 

which commonly exceeds HCI in weight percent. 

10. The content of HaBOa generally ranges from 1/1,000 to 1/20 

that of HOI. 

11. Bromine has been determined in only a few fumarolic 

condensates; the Br/Cl ratio generally ranges from 

about that of sea water ( 0.0034) to less than one-tenth 

that of sea water. 

12. Components of low volatility ( Si02, Na, Ca, Mg, and 

others) have bee-n found in condensates from low-temperature fumaroles in much larger quantities that can 

be accounted for by their volatilities. Transport in 

droplets of water or aerosols in wet steam is suspected 

( N aboko, 1959, p. 127). 

13. The same low-volatile components as well as significant 

quantities of minor metals also occur in high-temperature fumarolic vapors. 

Zn, As, Sn, and Ag are present in especially large 

quantities at Showa-Shinzan (table 261.1). These 

analyses constitute the most extensive search that has 

been made for minor compol).ents in fumarolic gases. 

TABLE 261.1.- "Complete" chemical analyses of gas from volcanic 

fumaroles Showa-Shinzan, Japan 

[From Nemoto, Hayakawa, Takahashi, and Oana, 1957, p. 122-123, recomputed to parts per million; fumaroles associated with eruption of extrusive dome or hypersthene dacite) 

Sample 9081 Sample 9051 Sample 9063 

Temperature Temperature Temperature 

760° c 525° c 220° c 

Si 02 _________ 253 289 48 

AL ___ - __ - - - - 15 14 1.3 Fe ___________ 1.3 1.2 5. 9 Ca __________ 4. 6 4. 3 21 Mg __________ 32 14 7. 9 Na __________ 22 22 13 K ___________ 15 11 1.7 

C02- _------ _ 29, 200 25,800 13,000 

co-- -------- 50 34 -------------- 802---------- 1,490 716 716 

SOa-- _----- __ 21 11 2. 7 

H2S ____ ------ 8. 0 42 1, 080 s ____________ 3. 7 1.8 CL -------------- __________ 728 420 433 

F ----------- 238 169 35 Br ___________ 1. 1 .9 1.2 B ____________ 39 21 5. 6 

P04---- ______ 2. 8 3. 0 .8 No~ _________ . 01 . 001 . 008 

02----------- 51 47 23 

H2----------- 685 381 20 

NHa __ - ______ 1.3 .8 17 

N2----------- 567 676 1, 250 A4o ___________ .6 -------------- 1. 5 CH4 __________ 1.5 18 -------------- I Ni_ _________ <. 01 . 0007 . 0007 1 Cu __________ . 03 . 03 . 004 1 Zn __________ .5 .4 . 02 1 Ge __________ <. 01 . 003 . 0007 1 As __________ .7 .3 . 007 1 Mo _________ Trace Trace Trace 

~ ~~t = = = = = = = ~ = 

. 003 . 0007 <. 0001 . 03 . 006 . 001 I Sb __________ <.1 <. 01 <. 005 I Pb----- - ---- . 03 . 03 . 005 

I BL- - ------- <.05 < .. 005 <. 002 2 Rn _________ 1. 3X 10-7 2. 1 X 10-7 12. 6X 10-7 

1 Semiquantitative spectrographic analysis of solids in condensate 

computed to ppm in total gases; inte.rmediate value of range. II Curies. · 
C-312 GEOLOGICAL SURVEY RESEARCH 19 61 

GASES IN ROCKS 

Recent analyses of gases in rocks have been published by Nikogosyan (1940) and Iwasaki, Katsura, 

and Sakato (1955, p. 70). Special studies have been 

made of specific components, the principal one of 

which is water, which is absorbed by natural glass with 

time (Friedman and Smith, 1960). 

Shepherd's summary ( 1938) of his careful work 

on gases in rocks contains few general conclusions. 

Selected analyses that contain all major components 

and that are apparently of gases from fresh unaltered 

rocks (Shepherd, 1938, p. 326-337, analyses, 1-6, 8, 10-

12, 16-19, 22-27) have been recomputed on a water-free 

basis, greatly decreasing the percentage variations. 

Generalizations for gases other than water that are 

suggested from these few recomputed analyses are: 

1. The gases other than water are rather consistent in quantity, ranging from a little more than 0.1 to 6 cc per gram. 

Rhyolitic obsidians seem to have the lowest contents and 

granites the highest; basaltic lavas are relatively consistent, generally with a little more than 1 cc per gram. 

2. C02 is generally near 50 percent of total gases other than 

H20 in. basalts, but is generally low in rhyolites and intermediate in granites and andesites. 

3. H2 is the dominant gas of the granites, but is highly 

variable in other rocks; CO, N2, and Ar do not show 

systematic differences. 

4. Sulfur, reported as S2, is generally 2 to 9 percent of "other" 

gases in basalts, is also high in some andesites, but is 

generally low in obsidians and granites. 

5. Cb is commonly 10 to 30 percent in rhyolites and some 

andesites, is less than 10 percent in basalts and less than 

1 percent in the two granites. 

6. F2 is the dominant gas in most obsidians and in some 

basalts, and ranges from 10 to 30 percent in most other 

rocks. 

The data suggest that more interest should be shown 

in the gases contained in rocks. Extensive geochronologic and isotope studies now being made on specific 

volatile elements in rocks could be broadened with 

relatively little effort to include quantitative study of 

other gases driven off in the extraction process. The 

data also indicate that gases are consistently retained 

during extrusion of volcanic rocks, and that l{/ Ar age 

determinations of whole rocks should be corrected for 

Ar40 that was retained. 

REFERENCES 

Friedman, 1., and Smith., R. I..., 1960, A new dating method 

using obsidian-Pt. 1, The development of the method : 

Am. Antiquity, v. 25, p. 476-522. 

Iwasaki, lwaji, 1951, The 1950-51 eruption of Mihara-yama, 

Geochemical investigation of the volcano: Jour. Geology 

[Japan], v. 60, p. 140-143. 

Iwasaki, Iwaji; Katsura, Takashi; and Sakato, Naoyuki, 1955, 

Geochemical investigations of volcanoes in Japan, 30, 

Volatile components of igneous rocks: Chem. Soc. Japan 

Jour., Pure Chem. Sec., v. 76, p. 778-782. 

Naboko, S. 1., 1959a, Volcanic exhalations and the products of 

their reactions: Akad. Nauk SSSR, Vulkanol. Trudy I..ab., 

v. 16, p. 1-301. 

--- 1959b, Volcanic exhalations and products of their reactions as exemplified by Kamchatka-Kuriles volcanoes: 

Bull. Volcanol., v. 20, p. 121-136. 

Nemoto, Tadahiro; Hayakawa, Masami; Takahashi, Kiyoshi; 

and Oana, Shinya, 1957, Report on the geological, geophysical, and geochemical studies of Usu volcano ( ShowaShinzan) : Japan Geol. Survey Rept. 170, 149 p. 

Nikogosyan, K. S., 1940, Investigation of gaseous components of 

rocks: Akad. Nauk SSSR, Inst. Geol. Nauk, Trudy Tret'ego 

Soveshchaniya Eksptl. Min. i Petrog., p. 55-64. 

Sheperd, E. S., 1938, The gases in rocks and some related problems: Am. Jour. Sci., ser. 5, v. 35a, p. 311-351. 

Sicardi, I..udovico, 1956, Dell'esalazione solfidrico-sofforosa nella 

attvale face solfatarica dell'attivita dell'isla di Vulcano e 

di alcune questioni ad essa increnti : Bull. Vulcanol. ser. 

2, v. 18, p. 159-168. 

Wilson, S. H., 1959, Physical and chemical investigations 1939-

1955 (of White Island, New Zealand): New. Zealand Dept. 

Sci. and Indust. Research Bull. 127, p. 32-50 . 

. ~ 
.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-2 9 2 C-313 

262. VARIATIONS IN PROPERTIES OF HORNBLENDES FORMED DURING PROGRESSIVE METAMORPHISM OF 

AMPHIBOLITES, NORTHWEST ADIRONDACK MOUNTAINS, NEW YORK 

By A. E. J. ENGEL, CELE.STE G. ENGEL, and R. G. l-IAVENS, 

La Jolla, Calif., and Denver, Colo. 

Work done in cooperation with the Un·iversity of California, La Jolla, Calif., 

and. the National Science Fottndation. 

liornblendes :in amphibolite rocks of the northwest 

A.dironda.pks show systematic variations in cmnposition and color cleal'ly related to the progressive metamorphism of the rock system. Other properties of 

the hornblendes such as density, and dimensions of 

unit cell do not show measurable, systematic changes. 

1\{n.x.imum temperatures of reconstitution of the 

hornblende-bearing nmphibolites have increased unik~7'/.'1 

Group 1 (Emeryville) 

lOmi. 

T= 00~+) 

EXPLANATION 

Mig matitic 

para gneiss 

_.,._ 

Foliation 

,.,...----, 

formly from at least 525°C or higher at Emeryville, 

N. Y., to 625°C or higher near Colton, N. Y., at the 

edge of the central Adirondack massif (fig. 262.1). 

The chemical composition of the amphibolite rock 

clutnges with increasing temperature and pressure 

from that of a typical saturated basalt to olivine basalt 

or pyroxene granulite (table 262.1). The mineralogy 

of the rock also shows systematic changes. At EmeryA 

9~........_ .. ~....~ . ...~.1_--~..1 __ ?.L...-,.-l~ Miles 

Mostly igneous A ----....__ __ _ granite and granitic 

gneiss 

I:\ :.~ii::·?:::.::,:: .. /:·.1 ( ' ' _; 

Mostly metasomatic granite Metasediment 

other than gneiss 

...... __ Outline of area 

(Source of samples) Vertical 

l!.,IGUIU!: 262.1.-Sl\:etch nwy of the northwest Adirondack Mountains showing the relations of the several major rock types. ~rhe 

hornblendes described in the text occur in amphibolites within the paragneiss complex. The lines drawn approximately 

normul to the verimetet· of the massif indicate the relative distances of the Emeryville and Colton areas from the massif. 

001530 0-(11--21 
C-314 GEOLOGICAL SURVEY RESEARCH 19 61 

vi1le (almandite-amphibolite facies) bluish-green 

hornblende is the dominant mineral, averaging about 

60 volume percent of the rock. Associated minerals 

are (in order of abundance) andesine, quartz, and 

accessory ilmenite and sphene. At Colton (hornblendegranulite facies) near the perimeter of the Adirondack 

massif, the hornblende is brownish green in body 

color and decreases in abundance to about 25 volume 

percent of the rock. Sodic labradorite, clinopyroxene, 

and orthopyroxene are coexisting phases (Engel and 

Engel, 1960b, p. B467, fig. 212.3). Sphene is absent 

and ilmenite is the only significant accessory mineral. 

The average composition and mean deviations of 

the hornblendes in amphibolites at opposed ends of 

the belt of progressive metamorphism are shown in 

table 262.2 along with the structural formulae. Inspection of table 262.2 and figure 262.2 shows that with 

increasing temperature and pressure the variations in 

chemical composition of the hornblendes include a 

very marked increase in amounts of Ti, and lesser 

increases in N a, l{, and F. There are also increases in· 

the concentrations of the trace elements Cr, V, Sc, 

and probably Co and Ni (table 262.3). The concentrations of l\fn, Zn, OH + F + Cl, as well as the ratios 

Fe20a/Fe0 and Fe/Mg decrease with increasing grade 

of metamorphism. 

TABLE 262.1.-Chemical composition and C.I.P. W. norms of 

average amphibolite rock in the Emeryville and Colton areas, 

New York 

I Emeryvllle area (almandite- I Colton area (hornblende- amphibolite facies, 7 samples) granulite facies, 9 samples) 

Si 02- _-- ~ ______ _ Ti 02 __________ _ 

AhOa----------- Fe20a---- ______ _ FeQ ___________ _ MnQ __________ _ 

MgQ ___ -------- cao ___________ _ Na20-----------

K20------------ H 20+ _- _ - ______ _ H2o-__________ _ 

P20s------------

TotaL ___ _ 

Chemicaleomposition (pereent) 

48. 20 

1. 89 

14. 45 

3. 50 

10. 53 

. 25 

6. 62 

10. 25 

1. 94 

. 96 

1. 31 

. 01 

. 18 

100.09 

C.I.P.W. Norm 

Quarlz_________ .38 

Orthoclase _____ ·_ 5. 67 

Albite__________ 16. 40 

Anorthite_______ 27. 88 

Diopside__ _ _ _ _ _ _ 17. 87 

Hypersthene____ 2l. 38 Olivine ____________________________ _ 

Magnetite______ 5. 08 

Ilmenite_ _ _ _ _ _ _ _ 3. 65 

Apatite_________ . 44 

47.89 

1. 56 

14. 63 

1. 85 

11. 20 

. 25 

7. 41 

11. 54 

2. 19 

. 58 

. 72 

. 03 

. 14 

99.99 

3. 45 

18. 50 

28. 36 

23.03 

8. 54 

11. 29 

2. 69 

3.01 

. 34 

TABLE 262.4.-Chemical composition ana structural formu-lae of 

hornblendes from amphibolite rocks in the Emeryville ana 

Colton areas, N.Y. 

Si02-----------

Ti 02..: ____ - - - __ 

Al20a-------- __ 

FezOa------- --- FeO ___________ 

Mno __________ 

MgO _____ - - - __ CaO __ _: ___ - _- __ 

N azO ___ - _- _- __ 

HK zO- - - - - - - - - - - 20+ __________ 

F _____________ 

Cl _____________ 

FezOa/FeO _____ Fe/Mg 1 ________ 

Mg/Mg+ Fe 1 __ 

K 

(W) Na 

Ca 

Mg 

(X) Fe++ 

Mn 

AI 

(Y) Fe+++ 

Ti 

Si 

(Z) AI 

OH 

F 

Cl 

I 

Emeryville area, almandite-] Colton area, hornblendeamphibolite facies, 7 samples granulite facies, 9 samples 

Chemiealeomposition (weight pereent) 

Mean Mean devla- Mean Mean devlatlon tlon 

42. 46 0. 56 42. 16 0. 40 

1. 32 . 05 2. 40 . 15 

12. 53 . 51 12. 19 . 39 

4. 94 . 22 3. 36 . 45 

13. 71 . 47 14. 36 . 53 . 31 . 009 . 17 . 014 

9. 04 . 59 9. 42 . 20 

11. 64 . 17 11. 49 . 05 

1. 33 . 04 1. 51 . 09 

1. 03 . 08 1. 39 . 16 

1. 83 . 03 1. 50 . 08 

.11 . 04 . 18 . 03 

. 03 . 002 . 03 . 02 

. 36 . 014 . 23 . 040 

2. 59 ---------- 2. 38 ---------- . 278 ---------- . 295 ----------

Structural formulae 2 

. 20) . 27) . 38 2. 45 . 43 2. 56 

1. 87 1. 86 

2. 01) 2. 12} 1. 72 3. 77 1. 78 3. 92 

. 04 . 02 

57) . 52) . 56 11. 28 . 42 1. 21 

. 15 • . 27 

t ~~}8. oo t ~~}s. oo 

1. 83) I. 50} . 05 1. 89 . 08 1. 59 

. 01 . 01 

• Atomic weight percent ratios. ~The structural type Is taken as W2-3(XY)5(Z4011h(OH,F,Cl)2 

Total Si, Ca, and AI in the hornblendes remain 

essentially constant throughout the probable difference 

in temperature of metamorphism of 100°C or more 

(Engel and Engel, 1958). The ratio l\1g/Mg+Fe 

increases only slightly between Emeryville and Colton 

(table 262.2) . 

"The increase in N a, J{, and Ti in solid solution in 

the hornblendes formed at the highest measured temperature and pressure must be near the mn.ximum 

possible under the prevailing physical conditions. This 

interpretation for Ti follows from the facts that 

FIGURE 262.2.-Variations in chemical composition of hornblendes plotted as a function of increasing grade of metamorphism between Emeryville and Colton, N. Y. Total 

analyses of the average hornblendes are listed in tables 

262.2 and 262.3. 
:SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-315 

2.0 2.0 800 

(J) 

~ 750 750 

...... 

~ 1.5 Nazo ___ _. 1.5 700 /' 700 ........ 

c:: -- 0 / Q) --- ~ ~ ·- ,.,.. / 

' Co0/10 ~ / 650 

Q) + + p ~ 'f..rz,o . ..,........ ~ / I 

I ........ o·~ 1.0 600 / I ~ 1.0 600 / I 

.~ ...... I / ~ I 

c:: / I 550 / I C) 

...... .... I ......... I ~ I 0.5 ...... 500 E:: I 

~0 I 

I €Jr ' I .Yv;l. Q) I 1$ ~ I 450 I 

(J) cj-1 ........ I 

4 A H 4 ' 

~ I 400 

--~ -+-c,+ I 

I 

!:"$ ~ ~="x 2 I 

+, ~ --....:::.. I 350 . ,t::; ~ I 

'·$0 . ----- (J) '-':. ..r 'o I 

I 

~ ' I 

3 ........... 3 300 I ...... 300 ........... I ~ ........... I C) I 

........ ........... + I 

t::: 250 cf 250 

Q) 

~ +-. .._. ' Q) 2 ,,.. 2 200 ·--·-- Zn 200 ~ ~\O'Z..,.,,.. 

........ ·--·-- ,.,.. • 

·--.. __ ~ ,.,.. . .._+ .~ / 150 ,.,. ...... 0""/ 

~ 100 X 

X 

Co .. 50 • 50 

0 0 0 0 

10 5 Miles 10 5 Miles 

' ' ' I ' ' ' I 

~0 Colto4-toss. ~0 Colt~Os . $/'" $/'" .Yv,i. 'I) If" Yv1i. 'I) S;;c 

1$ 1$ 
C-316 GEOLOGICAL SURVEY RE:SEARCH 19 61 

TABLE 262.3.-Trace-element analyses and mean deviations of 

hornblendes from amphibolite rocks, Emeryville and Colton 

areas, N.Y. 

(In parts per million; analyses of Pb are colorimetric analyses by N. L. Nieman 

al other analyses are quantitative spectrographic analyses by R. G. Havens] 

B _____________ 

Ba ____________ Co ____________ Cr ____________ Cu ____________ Ga. ___________ Ni ____________ Pb ____________ Sc _____________ Sr _____________ 

v _____________ y _____________ 

Yb ____________ Zn ____________ 

Zr _____________ 

Emeryville area, almandite- Colton area, hornblendeamphibolite facies, 7 samples granulite facies, 9 samples 

Mean 

<40 

86 

47 

249 

17 

18 

57 

6 

77 

46 

527 

72 

9 

216 

97 

Mean deviation 

---------- 32 

3 

95 

6 

2 

11 

1 

2 

12 

66 

22 

2 

32 

26 

Mean 

<40 

106 

60 

737 

7 

19 

76 

7 

109 

42 

811 

118 

13 

163 

75 

Mean deviation 

----------40 

2 

131 

4 

2 

13 

3 

8 

12 

81 

22 

2 

21 

9 

ilmenite is invariably present in the rock as a common 

accessory mineral, and Ti, in addition, tends to be 

emitted from the amphibolite rock system as it is 

reconstituted at Colton (Engel and Engel, 1960b). 

Potassium is also emitted and this emission undoubtedly is because there is no other phase capable of 

incorporating more than a few tenths of one percent 

of J{ except the rapidly diminishing amounts of hornblende. 

The · ~ecrease in OH + F + Cl in the hornblendes 

with increasing temperature and pressure is accompanied by a decrease in the ratio Fe~Oa/FeO in both 

hornblendes and total rock. An analogous relation 

exists in the enclosing paragneiss. There the decrease 

in OH+F+Cl in biotites (with increasing temperature and pressure) is also accompanied by a decrease 

in the ratio Fe 20,JFeO in both biotite and total rock 

(Engel and Engel, 1960a). In addition, both rocks 

are profoundly dehydrated. The paragneiss commonly 

contains magnetite. Magnetite and other iron oxides 

are, however, ui1common constituents of the amphibolite rocks due to the abundance of ferrophile hornblende. The combined reduction and dehydration of 

constituent ·mafic minerals and total rock systems 

needs further study to evaluate the mobility of 0 and 

H in progressive metamorphism. 

The lack of significant variations in concentrations 

of Si, Al, in the ratio Al/ AI+ Si and hence in amounts 

of Al in the Y structural site (table 262.2) is in contradiction to most published generalizations and 

predictions. Considering the range of temperature and 

pressure involved, the increases in the ratio 

Mg/Mg+ Fe also seem remarkably small. 

The near constancy of CaO content in the hornblendes at about 11.5 weight percent appears to be 

consistent with concentrations of CaO in carefully 

analyzed hornblendes from many mafic igneous and 

metamorphic rocks. Inasmuch as both Na and J{ increase with increasing temperature and pressure, the 

total value for the W structural site ( Ca,N a,l{) Jncreases at Colton (table 262.2). 

The systematic variations in minor elements in the 

hornblendes, especially Co, Ni, Sc, V, and Zn, do not 

appear to bear simple relations to the variations in the 

presumed chemical cogeners such as Fe and Mg, which 

have high concentrations in the hornblendes but show 

relatively small variations with temperature and 

pressure (tables 262.2 and 262.3, fig. 262.2). Chromium 

seems to be the trace element most responsive to the 

changes in the ratio Fe/Mg. 

The average density of hornblendes at both Emeryville· and Colton is about 3.26 .to 3.27. As might be 

predicted, the most obvious fluctuations in density are 

induced by the largest variations in Fe/Mg. A hornblende from a slightly granitized amphibolite at Emeryville shows an Fe/Mg ratio some 50 percent higher than 

the average and has a density of 3.32. This increase in 

the ratio Fe/Mg and in density is accompanied by a 

tenfold decrease in the amount of Cr in the hornblende. 

Unit cell parameters a sin {3, b, c sin {3 were determined for all 16 hornblendes. Any systematic variations which may result from changes in composition, 

temperature, and pressure are within the limits of the 

errors of the measurements. 

REFERENCES 

Engel, A. E. J., and Engel, Celeste G., 1958, Progressive metamorphism and granitization of the major paragneiss, northwest Adirondack Mountains, New York, part 1, total rock: 

Geol. Soc. America Bull., v. 69, p. 1369-1414. 

-- 1960a, Progressive metamorphism and granitization of 

the major paragneiss, Northwest Adirondack Mountains, 

New York, part 2, mineralogy: Geol. Soc. ·America Bull., 

v. 71, p. 1-58. 

-- 1960b, Migration of elements during metamorphism in 

the northwest Adirondack Mountains, New York, in Short 

papers in the geological sciences: U.S. Geol. Survey Prof. 

Paper 400-B, p. B465-B470. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-317 

263. DISTRIBUTION OF CLAY-SIZED SEDIMENTS IN THE COASTAL PLAIN FORMATIONS NEAR TRENTON, 

NEW JERSEY 

By ,JAl\IES P. OwJ<~Ns, tTAl\fES P. ~iiNARD, and PAuL D. BLACKl\fON, 

~r ashington, D.C., and Denver, Colo. 

A general relation between environment of deposition nnd rock type has been observed in formations of 

the Coastal Plnin near Trenton, N .• T. The clay-sized 

pnrticles in these formations are particularly sensitive 

indicators of depositionnl co~1ditions. 

Three major environments of deposition are recognized on the basis of lithology, bedding, shape of 

deposit, and fossil content (table 263.1). These are 

marine, depth generally less than 100 fathoms; transitiona] between marine and nonmarine; and nonmarine, 

including fluvial, lacustrine, paludal, and beach 

environments. A charncteristic assemblage of claysized minerrds typifies each environment, although 

there are some exceptions. 

The marine formations are composed of dark unconsolidated quartz sand containing 5 to 15 percent 

feldspar; green glauconit:e-benring sand; or mixtures 

of both types. The clny-sized sediment in these formations occurs as finely dispersed cement, except in the 

"Voodbury clay-in which clay is a major constituent. 

In most of the marine formations, the clay-sized fraction is a complex mixture of many clastic and authigenic minerals (table 263.2). Each formation generally 

has its own diagnostic suite. Detrital minerals identiTAOLE 263.1.-Characteristics of pre-Quaternary formations near T1·enton, N.J. 

Characteristics 

Ago Formation Depositional environment 

Bedding Fossils Rock type 

Miocene(?) Cohnnsey sand Transitional (beach) "r ell-stratified. None. Quartz sand (orthoquartzite). 

Miocene Kirkwood Marine (inner neritic) Massive. None. Feldspathic quartz sand 

(subgraywacke). 

Marine (inner to outer neritic) Rare. Glauconite sand. 

Eocene Mnnnsqunn ---------------------------- Massive. ---------------- -------------------------- Marine (inner neritic) Common. Feldspathic quartz sand. 

Marine (inner neritic) Stratified. V cry abundant. Calcarenite (spergenite). 

Vincentown ---------------------------- ---------------- ------------------------------------------ Paleocene Mnrine (inner neritic) Massive. Rare. Feldspathic quartz sand. 

Hornerstowu Marine (inner neritic?) Massive. Rare. Glauconite sand. 

snnd 

- Marine (inner neritic) Massive. Feldspathic quartz sand. 

Red Bank sand ---------------------------- ---------------- ---------------- -------------------------- Marine (inner neritic) Massive. Rare. Glauconite sand. 

Nnvesink Marine (outer neritic) Massive. Very abundant. Glauconite sand. 

Mount J,aurel Marine (outer neritic?) Massive. J,ocally Feldspathic quartz sand. 

sand abundant. 

gj Wenonah Marine (inner neritic) Massive. Rare. Feldspathic quartz sand. 

0 

Marshalltown Q) 

C) Marine (outer neritic) Massive. Rare. Glauconite sand. oS 

~ 

Englishtown Q) 

.... Transitional (beach, lagoon) Well-stratified. Very rare. Interbedded sand and clay 

0 (feldspathic quartz sand). Q) 

.,.:> 

Woodbury clay Marine (inner neritic-lagoon) Massive. Common to rare. Clay. oS 

....:l 

Merchu.ntville Marine (outer to inner neritic) Massive. Common to Glauconitic quartz silt to rare. sand. 

Magothy Transitional (beach, lagoon) Well-stratified. Rare. Interbedded sand and clay 

(orthoquartzite). 

Rnritnn Nonmarine (fluvial, beach(?), Well-stratified. None. Interbedded gravel, sand and 

paludal, lacustrine) clay; mainly quartz sands 

(orthoquartzite). 
TABLE 263.2.-Composition of clay-sized sediment concentrated by water elutriation from pre-Quaternary formations near Trenton, N.J. 

[M, major constituent; C, common; R, rare; Tr, trace. Constituents identified by X-ray analysis, P. D. Blackmon, analyst) 

Glauco- MicaGlauco- nite- chlo- MicaMloa I I I Mloa-~ nilo- chlo- rite- mont- MicaKaolin- Mont- (mostly Glauco- Chlo- glauco- mont- rite- mont- moril- chlo- I Fi>ld- I I Cal-, Carbo- Sample No. I Quartz I ite I moril- I musco- nite rite nite moril- mont- moril- lonite rite spar Pyrite cite naceous lonite vite) mix- lonite moril- lonite mixed mixed matter ture mixed lonite mixed layer layer 

Formation Remarks 

layer mixed layer 

__________ layer , _______ , ____ , ___ , ____ , ____ , ___ , ___ , ___ , ___ , ____ , ____ , ____ , ____ , ____ , ___ , __ , ___ , ________ _ 

Cohansey sand ____ l Bm 34 

Bm 39 

c 

c 

c 

c -----

______ -~----- C -~--- ______ ---~----- -------~--__________________________________________ --- -~- ---- -~-- ----~------I c 1----- -~----- -~- R ---- -~--- ____ -~------ C 

Kirkwood _______ _ Bm Co178 9 M C M ~~-c--~~~~~=-==~~~~=------ ______ C ______ C ____________________________________________________ C 

I Manasquan______ NE 67 C ----------------1 

------ C C M ---- ______ - _ C? _ _ _ _ _ _ _ _ _ _ _ _ C? _ _ _ _ _ _ _ _ _ _ _ _ C _________ _ PEm 35 C C __________________ C M ______ C? C? __________________ Tr _________ _ 

Light. 

Dark. 

Light. 

Dark. 

Quartz sand. 

Vincentown _____ _I !!: :: -~--- -1-~~--- ~ :::::: :::::: :::::: -~--- -~-:--- :::::: :::::: ·_ ~-:--- :::::: :::::: :::::: :::: -~-- --~ Quartz sand 

Co 196 

NE 59 

PEm 28 

c Tr Tr ------·------·------· M C? ------.-- ---, C? ------·------·------·----· c 

C 1---- _ _I _____ _I _____ _I _____ _I ___ ---'--- __ -'- ____ _I _____ _I _____ _I _____ _I _____ _I _____ _I _____ _I M 

c Tr -- ----·------·-- ----·----- _,_---- _, __ -- __ ,_---- -·----- _,_ ---- _,_---- _,_- ----·----- _, M 

member. 

Quartz sand 

member. 

Calcarenite 

member. 

Calcarenite 

member. 

:::~:~:::~~-; ~~~~~: -~~--- -=-~-=-=-= -=~-~=-=-=-= :~::: :~::: =~.::: ~~:~~ ~~~~~= ~~:~~~ ~~~~~~ ~~~~.~~ ~~=~~~ :~r::: -=~--=-=-=-= ~]=~===~-G-la_u_c_o_n-it_e __ _ 

NE 29 

NE 56 

M 

c 

Tr 

c 

------· Tr --- ___ ,_--- __ ,_-- ___ , __ -___ ,_ ---- _, __ -- __ , ____ -_,_--- __ ,_--- __ ,_ ---- _, __ -_, c 

c ------·------·------· c ------·-- ----,_---- _,_- --- _,_---- _,_---- _,_- --- _,_-- _, R 

member. 

Glauconite 

member. 

Quartz sand 

member. 

Navesink _______ _! PEm57~-c ~-c ~~~~~~~-c ~~~~~~~-c ~~~=-==~~~-c 1=1 c 

C

N

0

E

1

13B ~ TCr _ _ _ _ _ _ C _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ C + _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ C 

----=----I 81 Tr __ ::..:...:...:....:....:....:.. ~.:...:...:...:...:....:....:..::..:...:...:..::..:...:...:...:..:...:..:..:..:....:....:....:....:....:...:...:...:...:. _!:..___ ~ _c __ 1 _____ _ 

Mount Laurel 

sand __________ _l PEm 9 c' 

Wenonah ________ ~ Co 182 c NE 18B c 

Marshalltown_____ Co 74 c 

Englishtown ______ ! Co 22 M 

Co 34 M 

BR 24A M 

Woodbury clay __ -1 Co 1 c Co 53 c 

_, 1 g ~~~~~~ _c ____ ~~~~~~ -~: ___ -~--- -~-? ___ ~~~~~~ -T-r=R -~-? ___ ~~~~~~ -Tr ___ ~~~~~~ ~~~~ _g-, ______ _ . . ~r ~~ ~ ~~~~~~ -g- ~~~~~~ ~~~~~~ ~~~~~~ -g-~~~~~~ ~~~~~~ -~: ___ -g- ~~~~ -g-1-D=---ar-=-k-.----

11--=::----,----_,_c ___ c __ -c--~ ~ ~ ~ ~~---rr;- ~~ ~ = c Dark. 

C ______ C ______________________________________________________________________ Light. 

C C C ________________________________________________________________ C Dark. 

-c-- ~-c-- ~~ ~~~ ~-c-- ~ ~ ~ = ______ 1-=L-ig_h_t_b=-r_o_w_n ___ _ 

C C M _ _ _ _ _ _ C _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ C _ _ _ _ _ _ _ _ _ _ _ _ Tr C _ _ _ _ C 

TE 22 M 

Merchantville ___ -1 Co 25 c 

Magothy _________ TE 20 M 

BC 1 M 

CB 1 M 

Raritan _________ _! TE 21 M 

-g- -~: ___ · ~ ~~~~~~ _c ____ ~~~~~~ ~~~~~~ ~~~~~~ ~~~~~~ -~: ___ _ c _____ T_r ___ -c;--- ~~~~ _g-, ______ _ 

-1 I-_-,_R ___ I'======I'g ====== ====== ====== ====== ====== -~--- _R ___ ====== ====== ====== ==== g _g- ~ ~ ~ ~ ~ ~ _g- ~ ~ ~ ~ ~ ~ _ ~- _ _ _ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -;,~- --~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ _ ~- ___ 11------'--

0 

~ ~ 

00 

0 

t_".l 

0 

t"l 

0 

0 

~ 

0 

> t"4 

UJ 

0 

=:tl 

< t_".l 

~ 

=:tl 

t_:j 

UJ 

t_".l 

> 

~ () 

~ 

.... 

co 

0) 

.... 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-319 

fled include kaolinite, montmorillonite, and mixedlayered clays having montmorillonite or chlorite as 

one layer. Qunrtz and muscovite also are abundant, 

ttnd small amounts of feldspar are locally present. 

Abundant authigenic minernls, mainly glauconite and 

chlorite, ch:Lract:erize the marine formations. Authigenic :Lpatite, pyrite, siderite, and vivianite also have 

been found in small amounts. Finely comminuted carbonaceous matter amounts to as much as 7 percent by 

weight in some units, but whether it is authigenic or 

detrital is not known. It is the major coloring agent 

in tLlmost all the marine formations. 

Probably the most diagnostic mineral in the marine 

formations of the New ,Jersey Coastal Plain, as compared with most other marine formations, is glauconite, which occurs abundantly either as discrete grains 

or interlnyered with other minerals (table 263.2). It 

is most abundant in the Hornerstown sand, in which 

both the sand and clay fractions are almost totally 

glauconite. A large qu:wtit.y of authigenic glauconite 

in the marine beds indicates that a high degree of 

chemical alteration has taken place in the marine environment. 

Other particularly prominent minerals are kaolinite 

in the older marine formations and montmorillonite in 

the younger ones. Some writers suggest that the relat.i vely con.rse grained kaolinite is deposited in shallow 

water and the finer grained montmorillonite in deep 

water. Others, including us, regard the difference in 

mineralogy as the result of a change with time in the 

t'.ype of sediment supplied from the source area. 

Carbonate cement in the calcarenite rnember of the 

Vincentown formation is unusual in this sequence of 

formlltions, which is largely characterized by siliceous 

cements. Appn.rently the Vincentown represents the 

only time from the lower Upper Cretaceous to the 

middle Miocene dur.ing which environmental conditions favored the accumulation of clay-sized calcite. 

The transitim1al formations are beach-lagoon 

deposits and include the ~1agothy, Englishtown, and 

Cohansey formations. These formations can be 

distinguished from the marine formations by their 

more common intercalation of thin beds of sand and 

clay. The .composition of the sand in these units is 

variable; the ~iagothy and Cohansey are chiefly quartz 

sands, and the Englishtown a quartz sand or subgraywacke containing 10 or 15 percent feldspar. The clay 

beds are dark. Carbonn.cem~s matter is not everywhere 

as finely dispersed as in the marine deposits; locally 

it occurs. n.s large woody pieces as much as several feet 

long, particula.rly in the ~1agothy formation. The 

clay-sized minern.l assemblage is relatively simple, 

consisting of quartz, kaolinite, and mic!t. :Mixedlayered mica montmorillonite and(or) chlorite are 

present in small amounts, except in some of the beds 

in the Englishto"'n, which have complex assemblages 

resembling those in the marine formations. Glauconite 

is absent, and the amount of authigenic minerals, except for pyrite, is sharply reduced. 

The only known nonmarine formation on the 

Coastal Plain near Trenton is the Raritan, the oldest 

and thickest. Coast:d Plain formation. The Raritan 

has the same bedding characteristics as the transitional 

beds; hmYever, the clayey beds are typically llghter 

colored, mainly red and white, and considerably 

thicker. The clay-sized mineral assemblage is quartz, 

kaolinite, and mica; authigenic minerals, except for 

local concentrations of siderite, are virtually absent. 

The associated sand is mainly quartz sand. 
C-320 GEOLOGICAL SURVEY RESEARCH 1 9 61 

264. A HEULANDITE-LIKE MINERAL ASSOCIATED WITH CLINOPTILOLITE IN TUFFS OF OAK SPRING 

FORMATION, NEVADA TEST SITE, NYE COUNTY, NEVADA 

By A. 0. SHEPARD, Denver, Colo. 

Wm·k done in cooper,ation with the U.S. A.tomic Energy Commission 

Zeolites which make up as much as 45 percent of 

some of the tuffs of the Oak Spring formation 

(Miocene(?) or younger) at the Nevada Test Site 

have been studied extensively using thermal and 

X-ray diffractori1eter metho.ds. Botinelly and I-Iinrichs 

(1959, p. 20) reported the principal zeolite in. the tuff 

as heulandite but later reclassified it as clinoptilolite 

(Wilmarth, Botinelly, and vVilcox; 1960, p. 150). 

These two minerals have virtually the same X-ray 

diffraction pattern, but l\1umpton (1960, p. 368) 

pointed out they can be distinguished by a simple 

thermal test. Heulandite is decomposed on long heating at 450°C, whereas clinoptilolite is stable to temperatures of 750°C or above. This difference in 

thermal stability affords~a simple means of distinguishing the two minerals, but special heat. treatment is 

required to detect either heulandite or a heulanditelike mineral in mixtures of the heulandite-clinoptilolite type of zeolites. 

The criterion used in this study for identifying the 

heulandite or heulandite-like zeolites is a phase change· 

which occurs in heulandite but not in clinoptilolite 

when the minerals are heated to certain critical temperatures. The higher temperature form of heulandite 

(the "B" modification mentioned by Mumpton ( 1960, 

p. 367) as characterizing heulandite) appears at- about 

250°C, and the X-ray pattern is so distinctly different 

from that of heulandite that a fundamental change 

in structure is indicated (fig. 264.1). The X-ray 

diffraction pattern obtained from a mixture of heulandite and clinoptilolite which has been heated tp 

critical temperatures shows the heulandite "B" pattern 

together with the persistent clinoptilolite pattern. 

Most of the zeolites in the tuff of the Oak Spring 

formation are clinoptilolite, although mixtures of 

clinoptilolite and heulandite-like mineral have been 

found in a tuffaceous sandstone bed. by X-ray diffractometer analysis of samples subjected t~ special heat 

treatment (fig. 264.2). This treatment consists of heating a sample for 10 minutes at 250°C and at 50°C 

increments until the heulandite-like mineral is destroyed. After each heating, the sample is analyzed 

·by X-ray diffractometer methods as soon as it is cool 

enough to handle, because the critical phase change is 

not permanent when produced by short heating at low 

temperatures. In some of the samples a sluggish phase 

change indicated by peak asymmetry is often found. 

If upon heating at next 50°C temperature increase, the 

phase change is not complete, another sample is heated 

at the lower temperature for a longer period. In 

general, the zeolites of the Oak Spring formation required additional heat treatment at 350cC. 

The heulandite-like mineral in the tuffaceous sandstone can be distinguished from heulandite by its 

slower phase change and by the higher tern peratures 

required for phase change and destruction (table 

264.1). Moreover, before the temperature at which the 

mineral is destroyed is reached, the strongest reflection 

undergoes an additional change in d spacing not observed in heulandite. The heulandite-like mineral has 

an average refractive index that varies from 1.483 to 

1.486 (heulandite near 1.500; clinoptilolite, 1.480), and 

its birefringence is lower than that of heulandite. 

Thin sections of the tuffaceous sandstone show that 

the heulandite-like mineral fills the interstitial spaces 

of the rock, and rims or fills vesicles in the pumice 

lapilli. X-ray difl'raction analysis reveals the presence 

of the heulandite-like mineral in both the sandstone 

cement and the pumice lapilli. Silt and less than two 

micron fractions were compared for differences in the 

amounts of clinoptilolite and heulandite-like mineral. 

TARLE 264.1.-Thermal behavior and optical properties of 

heulandite- and clinoptilolite-type minerals after heating for 10 

minutes 

Changes in the 020 peak I Heulandite 1 I Heulandite-like 

mineral' 

Temperature, in degrees centigrade 

First appearance of 

8.35A peak_______ 250 

Change to 8.35A 

complete_________ 300 

Maximum intensity 

at 8.35A__________ 350 

Change to 8.19A_ _ _ _ 400 

Change to 7.9.0-

7.76A ____________ ------------ _ Destruction_________ 500 

Optical properties 

350-400 

400 

400 

400 

·550-700 

500-750 

Clinoptilo- lite 2 

850-200 

Refractive index _____ ] near 1. 500 I 

Birefringence.______ near 0. 005 

1. 483-1. 486 1 · 1. 480 

low I very low 

1 Berufiord, Iceland. 2 Oak Spring formation, Nevada Test Si~e, Nye County, Nev. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-321 

Heated to 500° C 

Heated to 300° C 

3.0 4.0 5.0 10 15 20 .25 50 

d, IN ANGSTROMS 

FwuRJ~ 264.1.-X-my diffractograms of heulandite from Berufiord, Iceland, after heating to various temperatures. 
C-322 GEOLOGICAL SURVEY RE:SEARCH 1961 

3 4 5 

d, IN ANGSTROMS 

-~ 

:2 

·.g 

0 

c 

Heated to 650° C 

Heated to 450° C 

~ 

Heated to 400° C 

10 15 20 25 50 

FIGURE 264.2.-X-ray diffractograms of a mixture of heulandite-like mineral and clinoptilolite heated to various temperatures. 

Samples from Nevada Test Site, Nye County, Nev. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-323 

Although clinoptilolite is typically finer grained than 

the heulandite-like mineral, analysis of the two fractions showed the two minerals in approximately the 

same proportions. No evidence was found to indicate 

the two minerals are of different generations. 

The heulandite-like zeolite in the Oak Spring formation is not unique. Similar mixtures of clinoptilolite 

and a heulandite-like mineral have been identified in 

volcanic rocks from Arizona and Oregon. This mineral 

may be more common than would be inferred from the 

absence of any published reference to it because evidence of it is destroyed by the usual thermal tests. 

REFERENCES 

Botinelly, Theodore, and Hinrichs, E. N., 1959, Part 3, 

Petrology, in Diment, W. H. and others, Geological Survey 

investigations in the U12b.Ol tunnel, Nevada Test Site: 

U. S. Geol. Survey TEM-998, open-file report. 

Mumpton, F. A., 1960, Clinoptilolite redefined: Am. 1\Iineralogist, v. 45, p. 35~-369. 

Wilmarth, V. R., Botinelly, Theodore, and ·wilcox, R. E, 1960, 

Alteration of tuffs by Rainier underground nuclear explosion, Nevada Test Site, Nye County, Nevada, in Short 

papers in the geological sciences : U. S. Geol. Survey Prof. 

Paper 400-B, p. B149-B151. . 

265. PARTICLE-SIZE DISTRIBUTION OF STREAM BED MATERIAL IN THE MIDDLE RIO GRANDE BASIN, 

NEW MEXICO 

By CARL F. NoRDIN, JR., and JAMES IC CuLBERTSON, Albuquerque, N. Mex. 

Samples of channel-bed material at eight sites on 

the Rio Grande between Otowi Brjdge near San Ildefonso and San Marcial, N. ~:1ex., a reach of about 190 

miles, were used to prepare average particle-size distribu6on curves for sediment transport studies. All 

samples of bed material are from the top inch or two 

of the bed. Three to fifteen samples were collected 

nlong a cross section at equal centroids of flow and 

were analyzed separately by sieves or by the visual accumulation tube method. The results of the individual 

samples were averaged to obtain the size-distribution 

curve for the cross section. · 

Two parameters describe particle-size distribution in 

this discussion, the median diameter, d, and the geometric standard deviation, u. The median diameter is the 

midpoint in the size distribution of a sample of which 

one half of the sample weight is composed of particles 

larger in diarneter than the 1nedian, and one half of 

particles smaller in diameter. The slope of the lognormal plot of the cmnulative size distribution is a 

measure of the geometric standard deviation, and is 

approximated as follows: 

u= 1/2(d/d16+ds4/d) 

where the subscript indicates percentage finer. 

Table 265.1 sununarizes the statistical analysis of 

bed material. The analysis indicates the dispersion 

of the observed values of d and u for individual observations about 1nean values. For exa1nple, between 

discharges of 4 and 10,100 cfs at the Rio Grande near 

BernaliJlo station, the average median diameter of bed 

material for 139 observations is 0.29 mm, and 68 

percent of the values fall between 0.27 and 0.31 1nm. 

Similarly, the average slope of the log-norma] plots of 

size distribution is 1.68, and 68 percent of the values 

fal1 between 1.39 and 1.97. 

The 3 upstream stations show large variations in 

bed-material characteristics when cornpared to the 

other 5 stations, and there is a syste1natic change in 

bed-material characteristics in a downstrean1 direction. 

The arithmetic averages of all observations for each 

station were used to determine average size-distribution 

curves (fig. 265.1). All of the curves approxintate a 

log-normal distribution. However, the c.urves for three 

upstream stations, Otowi, Cochiti, and San Felipe, 

indicate a skewed distribution toward the coarser 

material, whereas the curve for San Marcial shows a 

skewed distribution toward the finer 1naterial. The 

curves for Bernalillo, Belen, Socorro, and San Antonio 

most closely approach a log-normal distribution. 

The values of d and u frmn the .curves of figure 

265.1 do not agree with the average values listed in 

table 265.1 In preparing the average curves, values 

of percentages finer than a given size were averaged; 

whereas in the table, values of diameters that represent 

a specific percentage were averaged. The values in 
C-324 GEOLOGICAL SURVEY RESEARCH 19 61 

TABLE 265.1.-Statistical analyses of bed material, Middle Rio Grande basin, New Mexico 

[Upstream stations listed at top] 

Median diameter, d Geometric standard deviation, rr 

Num- Range of discharge CoefH- Rio Grande station ber of rate (cubic feet per Minimum Maximum Mean Standard Coeffi- Stand- cient of obser- second) value value value deviation cient of Minimum ·Maximum Mean ard varia- vations (milli- (milli- (milli- (milli- varia- value value value de via- tion meters) meters) meters) meters) tion tion (per- (percent) cent) -------

At Otowi_ _______ 11 1, 130-10, 100 0. 20 10. 4 1. 45 3. 00 207 1. 50 14. 7 3. 97 3. 82 96 

At Cochiti_ ______ 102 24-9, 810 . 18 3. 10 

At San Felipe ____ 102 71-9, 720 . 17 5 .. 10 

Nenr Bernalillo ___ 139 4-10, 100 .11 . 45 

Nenr Belen ______ 85 520-8, 270 . 08 . 37 

Near Socorro ____ 10 697-3, 600 . 15 . 25 

At San Antonio __ 14 368-8, 500 . 15 . 25 

At San MarciaL __ 9 1, 990-8, 680 . 13 . 16 

table 265.1 and the average curves in figure 265.1 show 

that the median particle size and the standard deviation 

both tend to decrease downstream. 

The changes that occur in the characteristics of the 

bed material in the reach between Otowi and San 

Marcial may be seen more readily by plotting d and u 

against distance downstream from Otowi (fig. 265.2). 

The values of d and u were taken from the average 

curves. The elevations of channels are also plotted. 

There is a discontinuity in the slope of the channel 

profile between the San Felipe and Bernalillo stations. · 

Downstream from this discontinuity the channel eleva-

. tion, the average water-surface slope, and the median 

diameter of bed material decrease systematically. The 

geometric standard deviation attains a near-constant 

value of about 1.6. 

Culbertson and Dawdy (written communication, 

1961) indicate that downstream from the discontinuity 

In channel slope resulting from the steep reach of 

~ 60 

At Otowi 

~ 

AtSanrelipe 

-

N~lo 

Near Belen 

--o--

NellrSocorro 

At San Antonio 

-+-

AtSanMarcial 

~ 5or------------~-~~-r~-----+----------­

~ 40 

It 

FIGURE 265.1.-Average particle-size distribution of bed material for eight localities in the Middle Rio Grande basin, 

New Mexico. 

'#.L ·-~.t; ... :· .•. :: -· ·~ ~. . .~: : 

... '~· 

. 44 . 32 . 45 . 48 . 29 . 02 . 23 . 06 . 19 . 03 . 20 . 03 . 14 . 01 

·~ 

0 

0 5 

73 

107 

7 

26 

16 

15 

7 

Q) 

.9-

;ea> 

.c: u.. u c: o ro ()(f) 

1. 23 25. 8 

1. 36 42.0 

1. 37 3. 44 

1. 38 2. 10 

1. 36 1. 65 

1. 38 1. 64 

1. 32 1. 55 

.2 

-

ro 

c: 

Q; 

Ill 

2. 71 3. 07 113 

3. 24 4. 90 151 

1. 68 . 29 17 

1. 55 . 16 10 

1. 52 . 09 6 

1. 48 . 08 5 

1. 43 . 08 6 

0 (ij ·c: 

.B -~ 

e c: ro 

c: 0 <( ~ Q) 

Q) u c: c: 0 ro ro Ill en en en 

~8 r I ~co~:Q ~Q_i~ ~~-+-+---+----. " 

(/) z ~ :g 3.0 " 

5:::? Q LJ.J ::::i " C::t-1-._J ~ 

ti ~ ~ ~ 2.0 X '-X 8 ~ ' --.}C;X---------~X--- )( X ---X-

(!) 1.0 ..___ _________________________ __J 

4000'o 1 oo 200 

DISTANCE, IN RIVER MILES, DOWNSTREAM FROM OTOWI 

FIGURE 265.2.-Variations in elevation and bed-material 

characteristics for the Middle Rio Grande basin, New 

Mexico. 

White Rock Canyon, the Rio Grande is a sand-channel 

stream; that is, an unlimited supply of sand-size particles in the bed is available for transport. They also . 

show that the water-surface slope remains approximately constant at a station over a wide range of discharge and may be assumed equal to the slope of the 

energy gradient for most purposes. 

The sand-bed channel of the l\1iddle Rio Grande has 

media.!). diameters of bed material between 0.14 and 

0.30 mm, geometric standard deviations between 1.49 
.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-325 

(/) 

(/) 

60 

40 

20 

d 0 

~ 

fz 

LLJ 

u 60 0::: 

LLJ 

a.. 

(/) 

(/) 

s 

u 

~ 

fz 

40 

20 

0 

60 

40 

20 

0 

~ 6T 

·+ 

20 

0 Ln 0 N Ln .... N 

c::i c::i I I 

N Ln 1.0 

0 ~ 

c::i c::i 

Surface samples 

Core samples 

Surface samples 

Rio Grande at San Felipe 

Core samples 

8 0 0 0 0 0 0 0 

C! 0 0 0 :£ N ..t Ln "j' N ..t ex) (\') 1.0 c::i I I I I I I 

I 0 0 0 0 0 0 0 0 0 C! 0 0 0 \£) N Ln Ln .... N ..t ex) .... (\') N c::i c::i 

SIZE CLASS, IN MILLIMETERS 

FIGURE 265.3.-Comparison of particle-size distribution between 

core samples and surface samples of bed material for the 

Rio Grande near Bernalillo and at San Felipe, N . .Mex. 

and 1.66, and slopes ranging from 0.0004 to about 0.001. 

On the other hand, the channel bed of the three upstream stations is composed of material ranging in size 

from fine sand to gravel. The water-surface slope 

varies appreciably with rate of discharge, apparently 

due to a pool-and-riffle condition which is flooded out 

at high rates of discharge. The characteristics of bed 

material show a 'vide range of values as indicated in 

the statistical analysis. 

The median diameter of bed material at the three 

upstream stations shown on figures 265.1 and 265.2 is 

in the sand -size range, and is only slightly coarser than 

the medians for the sand-bed channels. The values, 

however, represent the average of only the top few 

inches of the bed material. Figure 265.3 shows histograms of the size distribution of the surface samples ~ 

from the average curves of figure 265.1 and of core 

samples furnished by the 1J. S. Bureau of Reclamation 

for two of the stations. The histogram for Bernalillo 

represents the average of 17 cores, average depth 6.4 

feet; for San Felipe, 3 cores, average depth 4.0 feet. 

The particle-size distributions in surface and core 

samples for the Rio Grande near Bernalillo are similar, 

but for the Rio Grande at San Felipe, the core samples 

exhibit a definite bimodal distribution. 

The significance of bimodal distributions of sediments has been discussed in detail by Pettijohn ( 1949). 

Relations similar to those shown in figure 265.2 between the channel-profile d~scontinuity (fig. 265.2) and 

an abrupt change in channel bed material from sand 

to gravel, or to the bimodal distribution with a deficiency of material in the size range from 1 to 8 mm, 

have been investigated by Yatsu ( 1955) and Sundborg 

(1956). It is significant that the surface samples, 

which represent the material available for transport, 

show a log-normal distribution as an average condition even though the material at greater depths in the 

bed has a bimodal distribution. 

A basic difference in behavior between the sand-bed 

channe]s and the sand-gravel channels of the Rio 

Grande is illustrated in figure 265.4 For the range of 

discharge shown, which represents a frequency of 

discharge rates equalled or exceeded between about 

95 percent and 2 percent of the.tin1e, the characteristics 

of .the bed material at all the sand-bed channels show 

no rela'tion to discharge. The values plotted for San 

Felipe are typical of the three stations upstream from 

the discontinuity in channel profiles. Above a certain· 

discharge rate (about 2,000 cubic feet per second for 

all three sand-gravel stations), the median diameter 

and the geometric standard deviation of the bed 

material increase with discharge; in general, the 

highest values are associated with falling stages. It 
C-326 GEOLOGICAL SURVEY RE,SEARCH 19 61 

Rio Grande near Bernalillo, N. Mex. 

0.40 ~---1---lf...--1--1-~-l-!-+--=---~-+--1--+--t-.-H-+-l 

. . . . -· ~... . .. ·.' .· . • • • .. '· • • ·~ • "· t- • lt. 1- • • I • • ••. • ""• 0.20 f---¥---~!-~-~{--l--l-1~· ---!--t--t--l-t-t-H--1 

.. . 

. 

ffi 0.00 L__ __ j_--l_..l_..J_.l_L....L...l_!_ __ _l_ _ _j___j _ _J__l_l__j_.l_j 

1-

~ 

~ 

~ 

?: 

Rio Grande at San Felipe, N. Mex. 

5.10 

~ . 5 1.00 f---+-----l--1--1-{--l--l-!--t-----+--+--1--+--l-H--!- 1-

LLJ 

:2 

<{ 

C:i 0.80 1----t----1!-+-+-i-+-H-1----+---l--1--1--1-t-t--H 

z 

<{ 

C:i 

~ 0.60 1----t----11---l---1-.J-+.-l-l-+----j.ei---J.--t-+-l-1-+~ 

.. II • :• '"•~e I '"• • •• I'" 

:: -~ ; . 0.40 • 

. . . : .... .. 0.20 l----t----11-7~-te...:.-f-t--H-1----+---l--l--l--1-t-t--t0.00 L.._ __ ..l.___l___j_...J.__..L_l_l_LJ.__ __ _!_ _ _!___J___J__J_..L....L.J_ 

100 1000 10,000 

WATER DISCHARGE, IN CUBIC FEET PE~ SECOND 

FIGURE 265.4.-Relation of median diameter of bed material to 

water discharge for the Rio Grande near Bernalillo and 

at San Felipe, N. Mex. 

may be assumed that at these higher stages, the 

capacity of the stream to transport sand-size particles 

exceeds the supply of these ·particles. Below this 

discharge rate the sections behave as sand-bed channels. 

The rate of sediment supply to the sections approximately equals the rate of sediment transport, and the 

d and u of the bed material show no relation to discharge, 

but vary aro\}nd a mean value with approximately the 

same degree of dispersion as the sand-bed channels. 

The coefficient of variation at San Felipe for the median 

diameters of bed material below the discharge of 2,000 

cubic feet per second is 25 percent, about the same as 

at Belen. 

The changing characteristics of the bed material for 

the sand-gravel channels are reflected in the resistance 

to flow at these sections, which tends to increase with 

increasing discharge above 2,000 cubic feet per second. 

For the sand-bed channels, the resistance to flow remains about constant or decreases with increasing 

discharge rate. 

It may be concluded that the characteristics of the 

. bed material for sand-bed channels show no change 

with change of discharge rate,· and that an average 

bed-material size distribution may be assumed subject 

to the random deviations indicated in table 265.1. Below a certain definable stage, the sand-gravel channels 

behave essentially as sand-bed channels; above this 

stage, the characteristics of the bed material change 

appreciably with rate of discharge. 

REFERENCES 

Pettijohn, F. J., 1949, Sedimentary rocks: New York, Harper 

& Brothers, 526 p. 

Sundborg, A., 1956, The river Klaralven, a study of ft.uvial 

processes: Stockholm, Geogr. Ann., v. 38, p. 191-195. 

Yatsu, E., 1955, On the longitudinal profile of the graded 

river: Am. Geophys. Union Trans., v. 36, p. 655-663. 

266. WOR_LDWIDE RUNOFF OF DISSOLVED SOLIDS 

By W. H. J)URuM, S. G. HEIDEL, and L. J. TisoN, 

Washington, D. C. and University of Ghent, Belgium 

A study of the size and nature of the load of dissolved solids carried by the large rivers of the world 

is in progress by the Geological Survey and the International Union of Geodesy and Geophysics. (See 

Durum, Heidel, and 'Tison, 1960). Measurements of 

dissolved solids in waters of major rivers of the world 

reveal gross lo:tds discharged to the oceans range from 

about 17 tons per square mile per year for the arid 

Colorado River basin to about 695 tons per square mile 

per year for the humid Rhine River basin. Some of the 

results obtained for individual countries or continents 

are summarized below. 

The rivers of conterminous United States drain 

about 3.02 million square miles and discharge water to 

the oceans at a rate of. about 1.8 million cfs (cubic feet 

per second). For this study, 2.75 million square miles 

of drainage area was included, for which streamflow 

averages 1.73 million cfs. Table 266.1 summarizes some 
TABLE 266.1-Summary of rates of dissolved solids runoff and water discharge in conterminous United States 

Runoff Drainage area covered 

Gross yield of dissolved solids 

Basin 

Area drained 1 

(sqmi) 

Gross dissolved 

solids (ppm) 

Thousand tons per year 'Tons per square mile 

Precipi-, 

(inches) ~ Discharge Mean Weight I . Mean annual (cfs per discharge Cfs per- average Entire Dole and 

discharge (cfs) sq mi) Inches Area (sq mi) (cfs) sq mi in area basin Stabler (1909) Present study covered 

(1) (2) (3) I (4) (5) (6) (7) (8) (9) (10) <n> 02) I (13) 

North Atlantic slope ___ _ South Atlantic slope ____ _ Eastern Gulf of Mexico __ Mississippi River _______ _ Western Gulf of Mexico __ Colorado River ________ _ 

Pacific Slope in Cali- fornia ______________ _ 

Columbia River and 

North Pacific Slope ___ _ 

148,000 

144,000 

140,000 

'1, 244,000 

413,000 

246,000 

117, 000 

302,000 

40. 2 

49 

52 

29 

24. 6 

12. 6 

26. 7 

31. 6 

TotaL ___________ ! 2, 754,000 

Average_________ I 30 

210,000 

143,000 

182,000 

634,000 

56,000 

5,500 

~0,000 

419,000 

1, 729,500 

1. 42 

. 99 

1. 30 

. 51 

. 14 

. 02 

. 68 

1. 39 

. 63 

19. 3 

13. 4 

17. 7 

6. 9 

1.9 

. 30 

9. 2 

18. 9 

8. 6 

88, 100 

72,900 

80,000 

1,244,000 

307, 600 

243,000 

57, 700 

252,000 

134,000 

61, 700 

104,000 

634,000 

36,800 

5,500 

66,900 

248,000 

2,345,000 !1,291,000 

1. 52 

. 85 

1. 30 

. 51 

. 12 

. 02 

1. 16 

. 90 

. 55 

89 

56 

83 

196 

240 

750 

95 

99 

149 

90 

55 

83 

196 

235 

750 

120 

82 

131 

1 Excludes area of Great Basin, St. Lawrence River basin, and Hudson Bay, and includes Columbia River basin in Canada and Rio Grande basin in Mexico. 

2 Value computed by Dole and Stabler (1909) adjusted to comparable area 2 ::~00 000 tons.1 94 tons per square mile. , , square rm es 3 Col. 13 225,000,000 tons . Col. 2 2, 754,

000 square miles 82 tons per square m1le. 

20,800 

11, 700 

16,600 

136,400 

14,900 

11, 700 

12,800 

30,200 

2 255, 100 

18,600 

7, 760 

14,900 

123,000 

13,000 

4,070 

9,470 

33,900 

3 224, 700 

Dole and 

Stabler 

(1909) -

(14) 

130 

94 

117 

108 

36 

51 

177 

100 

2 94 

Present 

study 

(15) 

126 

54 

106 

99 

31 

17 

81 

112 

3 82 

~ ::0 

~ 

~ 

> 

~ 

t".l 

::0 

UJ 

1-4 

z 

~ t".l 

0 

t".l 

0 

t"4 

0 

0 

1-4 

Q 

~ t::;j 

~ 

~ 

t::;j 

::0 

0 

t"4 

0 

0 

1-4 

Q 

UJ 

("') 

1-4 

t".l 

z 

("') 

t".l 

!fl 

> ::0 

~ 

~ t".l 

UJ 

.... 

""" ~ 

I 

~ 

fD 

~ 

0 

~ t-.J 

'-1 
GEOLOGICAL SURVEY RE:SEARCH 19 61 

of the hydrologic and chemical load data for eight 

basins in the United States. The total annual yield 

of dissolved solids in streams draining these basins is 

about 224.7 million tons, ranging from about 4.0 to 

123 million tons for individual basins. The largest 

yields are in streams from the North Atlantic f:;lope 

basins, where 19.3 inches of runoff to the Atlantic 

Ocean annually contains about 126 tons o:f dissolved 

solids for each square mile of drainage area. The 

humid Eastern Gulf o:f Mexico basin, with 17.7 inches 

of runoff, yields annually about 106 tons per square 

mile. The Mississippi River basin, intermediate between the arid regions. o:f the west and the· humid regions o:f the east, yields 99 tons per square mile per 

year to the Gulf of Mexico. The bulk of the dissolved 

solids transported from the United States (about 55 

percent) is discharged by the Mississippi River. Thus 

the Gulf of Mexico receives annually about 151 million 

tons or 67 percent o:f the total 225 million tons average 

annual chemical load from conterminous United States. 

About 4 7 million tons, or 21 percent of the total, 

reaches the Pacific Ocean, and the remainder, about 26 

500 

-

1-

a:: 

<( 

UJ 

>-

ffi 200 1- a.. 

UJ 

-' 

~ 

UJ 

a:: 

<( 

::::> 

g100 

a:: . UJ 

a.. 

en 

z 

0 

1-

~ 

0 

<( 

0 

-' 

en 

0 

::J 

g 

0 

UJ 

> -' 0 

en 

en 

0 

1-

1-

1-

1-

50 1-

40 1-

30 1-

20 -

10 

0.1 

I 

............ / 

0.2 

I I I T I I ! 

/ 

/ 

/ ,.,.,"" / 

/ 

• '/ 

/ 

/ 

_l I I I I I I 

0.3 0.4 0.5 

million tons, or 12 percent of the total, reaches the 

Atlantic Ocean. 

The entire North Arnerican Continent, covering 

8.24 million square miles and discharging 5.35 million 

cfs of river· water, yields about 611 n1illion tons of 

dissolved solids annually. This is equivalent to about 

116 parts per million or 7 4 tons per square mile of 

drainage. Other gross values (uncorrected for salts 

in precipitation) in North America are as follows: 

Area 

Alaska 

Canada 

Annual runoff 

(inches) 

. 8. 9 

8. 5 

nross yield of dissolved solids 

(ppm) 

94 

91 

(tons per square mile per year) 

68 

57 

The weighted-mean loads of dissolved solids for 

major North American rivers generally .is related to the 

modulus of runoff. For exainple, a log-log plot of 

annual runoff in inches versus annual load in tons per 

square mile for rivers and principal drainage basins of 

North America (fig. 266.1) shows a direct increase in 

load with increase in runoff up to the 1naxirnum observed-about 21 inches runoff and 199 tons per square 

mile per year (Hudson River). There is considerable 

I I I I I I I I I I 

-

-

• -

• ......... "" / .. ,., . ,.,.: ./ . v...,.... - .. • 

/· - .. / -

/ - /. 

• • ......... - / 

/ - • / 

• -

- • 

_l I I I I I I I _l I 

2 3 4 5 10 20 30 40 

RUNOFF, IN INCHES 

FIGURE 266.1.-Runoff an~ loads of dissolved solids at mouths of large rivers and drainage basins, North America. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-329 

scatter about the curve of relationship, which has a 

slope of n.bout 0.5. 

The excellent work of Alekin and Brazhnikova (1957) 

has enabled us to compute the ionic (principal cations 

and anions) discharge from the territory of the USSR. 

For u.n area of 6.4 million square miles of drainage, 

having an twerage stream fiow of about 4.0 million cfs, 

about 287 million tons of dissolved solids are discharged 

annun.lly to the oceans. Thus, for all the territory of 

the USSR, the annual discharge of ionic substance is 

about 44.5 tons per square 1nile. The largest load, 

n.bout 205 rnillion tons, is carried to the Arctic Ocean. 

Aickin and Brn.zhnikova (1957) report that about 25.5 

million tons u.nd 78.5 million tons of nonionic and 

organic substances, respectively, drain from the USSR, 

giving a totn.l of about 390.9 million tons annually or 

about 61 tons per squn.re mile. 

The following examples of hydrologic data for 

selected rivers show the wide rn.nge of observed conditions thn.t enter in to con tin en tn.l averages: 

Drainage area Annual f:ross yield of dissol11ed solids 

(l.honsands of rnnoff (tonsfsqnare 

Ri11er sqttare miles) (inches) (P1>m) mile/year) 

Rhim:, Holland 56 19. 0 503 6U5 

Olomma, Norway 15 21. 7 30 47 

Mekong, Thailand 310 17. 1 124 154 

Congo, Congo 1, 550 12. 4 50 45 

The load of dissolved solids includes small quantities 

of many minor elements of which iron, aluminum, 

strontium, barium, manganese, boron, titanium, copper, 

ehromium, nickel, and phosphorus are the most abundant".. Lesser amounts of about 15 other minor elements 

n.re also present. Quantitative data on most of these 

minor elements can be obtained through use of emmission spectrography techniques described by Haffty 

(1960). 

Of the alkaline earth metals, barium occurs in all 

waters examined in concentrations of as much as 150 

micrograms per liter, and, strontium occurs in concentrations of as much as 800 micrograms per liter. Undoubtedly these values are exceeded at very lmv flows, 

although barium concentrations seem to be independent 

of the rate of streamflow. 

Generally, there is no well-defined relation between 

strontium content. and streamflow, except for samples 

from the ".Mississippi and Atchafalaya R.ivers. In these 

streams strontium content and the ratio of strontium 

to barium deerease when streamflow inereases. Also, 

ratios of calcium to strontium and calcium to barium 

in samples from these bYo streams tend to be high at 

high flow stages and low at low flow. 

REFERENCES 

Alekin, 0. A., and Brazhnikova, r_.. V., 1957, New data on the 

discharge of dissolved substances from the Territory of 

the USSR: USSR Acad. Sci. Proc .. v. 114, no. 1-6. 

Dole, R. B., and Stabler, Herman, 1!)09, Denudation, in Papers 

on the conservation of water resources: U. S. Geol. Survey 

Water-Supply Paper 234, p. 78-93. 

Durum, ,V. H., Heidel, S. G., and Tison, L .• J., 1960, 'Vorld-wide 

. runoff of dissolved solids: Internat. Assoc. Hydrology, 

Surface 'Vaters Comm. Pub. 51, Gen. Assembly of Helsinki, 

p. 618-628. 

Haffty, .Joseph, 1960, Residue method for common minor 

elements: U. S. Geol. Survey "rater-Supply Paper lfi40-

A, p. 1-9. 

267. METAL CONTENT OF SOME BLACK SHALES OF THE WESTERN UNITED STATES 

By D. F. DAVIDSON and H. vV. LAKIN, Denver, Colo. 

The high metal content of black shale beds in the 

Permian Phosphoria. formation in western 'Vyoming 

a.nd southeastern Idaho, and in an unnamed Paleozoic 

formation exposed in the Fish Creek R.ange near 

Eureka, Nev., has led to a search for, and study of, 

other similar rocks in the western United States. The 

metal concentrations in some of these rocks probably 

will be considered ore deposits in the relatively near 

:future. 

6()1530 0-61--22 

In this paper are presented partial analyses for some 

samples from the Phosplioria formation, the unnamed 

Paleozoic formation referred to above, and from four 

other stratigraphic units: the Comus formation (Ordovician) exposed in the Edna ~1ountains, Nev.; the 

Chainman shale (Mississippian) exposed in the Schell 

Creek R.ange, Nev.; the Deseret limestone (~1i!;?sissippia.n) at ~1ercur Dome, Utah; and the ~1innelusa formation (Pennsylvanian) exposed in I-Iot Brook 
C-330 GEOLOGICAL SURVEY RE,SEARCH 19 61 

TABLE 267.1-Analyses of carbonaceous marine shale samples from six geologic formations of the western United States 

[Semiquantitative spectrographic analyses by R. G. Havens, Uteana Oda, and E. F. Cooley; chemical analyses by H. L. Neiman; X=1 to 9) 

Semiquantitative spectrographic analyses 

Num- (parts per million) 

No. ber of on Collector Sample Nos. Source of samples sam- Pb Mn Cu Zn Nt map pies 

Range Aver- Range Aver- Range Aver- Range Aver- Range Aver- age age age age age 

----- -------- -----

1 C. C. Hawley _____ D-78831 to Minnelusa 4 xo ------- xo ------- 70-1,500 ------- <500 ------- 70-1, 500 ------ D-7883·1 formation, Hot Brook Canyon, 

S.Dak. 2 D. F. Davidson 60-4581 to 60-4003 Phosphoria 23 10-50 20 100-300 180 100-300 150 700-10,000 2,800 150-1,500 roo and H. W. formation, 

Lakin. Dry Creek 

Canyon 

Wyo. ~ 

3 T. S. Lovering ____ 52517, 52520 to Deserct 7 0 0 xo-xoo xoo xo xo XOO-XOOO xoo XO-XOO xoo 52521, 52527- limestone. .~2530. Mercur 

60-5087S ____ ----~- Dome, Utah. 4 Harald Drewes. __ Chainman shale, 1 30 ------- 300 ------- 200 ------- 2,000 ------- 100 ------ Schell Creek 

Range, Nev. s D. F. Davidson .. 60-3416 to 60-3441. Unnamed 26 <10-20 10 20-500 180 15-100 40 <150-5,000 1,430 10-100 .'5.'5 Paleozoic formation,F-ish Creek 

Range, Nev. 6 _____ do._--- _______ 60-3445 and Comus 2 30 ------- 100-150 ------- 200-500 ------- 2. 000-3. 000 ------- 150-700 ------ 60-3543. formation, 

Edna 

Mountains, 

Nev. 

Chemical 

Semiquantitative spectrographic analyses analysis 

Num- (parts per million) (parts per million) No. Source of of on Collector Sample Nos. samples ber of map sam- v Mo Ag Cr Fe Se 

pies 

Range Aver-. Range Aver- Range Aver- Range Aver- Range Aver- Range Aver- age age age age age age 

--------------- ----- 1 c. c. D-78831 to Minnelusa 4 1, 500-3, 000 ------ Hawley. D-78834. formation, 

Hot Brook 

Canyon, 

S.Dak. 2 D. F. fl0-4581 to .Phosphoria 23 500-7,000 2,500 

Davidson 60-4603. formation, 

and H. W. Dry Creek 

Lakin. C.anyon, 

Wyo. 

3 T. S. 52517, 52520 to Desf'ret 7 xooo xooo Lovering 52521, limestone, 

52527- Mercur 52530. Dome, 

Utah. 4 Harald 60-5087S _______ Chainman 1 1,000 ------ Drewes. shale, 

Schell 

Creek 

Range, 

Nev. 5 D. F. 60-3416 to Unnamed 26 200-2,000 1, 000 

Davidson. 60-3441. Paleozoic 

formation, 

Fish Creek 

Range, 

Nev. 6 _____ do ________ 60-3445 and Comus 2 3,000 ------ 60-3543. formation, 

Edna 

Mountains, 

Nev. 

Canyon, S. Da.k. The locations of the sample sites are 

shown on figure 267.1, and the collector, description, 

and analyses are listed in table 267.1. 

All samples are of carbonac~ous marine "shales." 

l\1ost are from beds intercalated in thick sequences of 

carbonate rocks, and probably represent a part of a 

"shelf facies" of marine sediments. 

70-3,000 ------ 0-XOO ------ 150-300 ------ XOOO-XOOOO ------- 130-150 ------

50-500 150 2-30 7 500-5,000 2,000 10, 000-20, 000 17,000 100-675 277 

X-XO xo xo xo xoo xoo xooo xooo 24-110 6.'5 

50 ------ 20 ------ 1,000 ------ 30,000 ------- 20 ------

5-50 28 <1-2 1.5 50-150 90 5, 000-20, 000 8,000 7-290 79 

<2-10 ------ 5-30 ------ 200-300 ------ 15,000 ------- <1-1 ------

The thicknesses of rock represented by these samples 

vary greatly. The samples from the unnamed shale in 

the Fish Creek Range represent a thickness of 135 feet, 

but the samples from the ~iinnelusa formation represent thicknesses of only 0.5, 0.6, 1.25, and 3.3 feet of 

rock, and are from different stratigraphic horizons. 

The 2 samples from the Cmnus formation each repre-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-2 9 2 C-331 

FIGURE 267.1.-Locations at which samples were collected. 1, 

Hot Brook Canyon, S. Dak. ; 2, Dry Creek Canyon, 'Vyo. ; 3, 

l\fercur Dome, Utah; 4, Schell Creek Range, Nev.; 5, Fish 

Creek Runge, Nev.; 6, Edna Mountains, Nev. 

sent a thickness of 5.0 feet and are from different horizons, as are the 3 from the Deser·et limestone, which 

represent thicknesses of 2.6, 6.1, and 15.5 feet. The 

samples from the Phosphoria formation are from the 

same stratigraphic horizon at three different localities 

in. Dry Creek Canyon and are of thicknesses of rock 

of 3.6, 4.8, and 5.0 feet. (See J. D. Love, Art. 250). 

The sample of Chainman shale is a grab sample. 

The metal contents of these shales tend to be as high 

as or higher than those reported by I\:rauskopf ( 1955, 

p. 417) as shown by table 267.2. 

H.econcentration of metals may have occurred locally 

during diagenesis or structural deformation of the 

rocks, which presents the possibility that shales contabling even larger amounts of metals may be discovered. 

TABLE 267.2.-Comparison of m€tal contents, in_ parts per million, 

of shales discussed, with content in black shales re7Jorted by 

K rwuskopf (1955) 

Metal 

[X=1-9] . 

Metal content in black 

shales according to Krauskopf 

Metal content of black 

shales discussed in this 

paper 

Average Maximum Average Maximum 

Lead_··---------------------- 20-400 700 Manganese __________ --_-- ___________ ------ --- _-- ------ Copper______________________ 20-300 1, 000 

Zinc __ ----------------------- 100-1,000 IO, 000 NickeL_____________________ 20-300 2, 400 Vanadium___________________ 50-2,000 I4, 000 Molybdenum________________ 10-300 I, 000 Silver________________________ 5-50 800 Chromium___________________ I0-500 5, 000 Iron __________________________________________________ _ Selenium _____________________________________________ _ 

REFERENCE 

0-30 X0-180 

X0-540 X00-2,800 55-540 I, 000-3, 000 

5-840 

1. 5-15 90-2,000 

X000-17, 000 <I-277 

50 

.500 1, 500 10,000 

1, .500 

7,000 

3,000 30 .5,000 

30,000 67.5 

Krauskopf, K. B:, 1955, Sedimentary deposits of rare metals: 

Econ. Geology, 50th Anniv. Volume, pt. 1, p. 411-463. 

268. CORDIERITE HORNFELS FROM LITCHFIELD, CONNECTICUT 

By FRED BARKER, Washington, D. C. 

Cordierite hornfels of argillaceous composition is 

found at the northwest margin of the Mount Prospect 

igneous complex in Litchfield, Conn. This hornfels has 

formed from regionally metamorphosed Berkshire 

schist of 1\1iddle Ordovician age. Its mineral assemblage is biotite, cordierite, garnet (metastable), 

magnetite, orthoclase, plagiochl.se, quartz, sillimanite. 

Pleonaste is present with cordierite and sillimanite in 

pseudomorphs that have formed from staurolite. This 

is a new occurrence of cordierite in Connecticut. 

The .Berkshire schist consists of intensely folded interlayered mica schist, gneiss, and quartzite of middle 

to high metamorphic grade (Agar, 1927, p. 26-28; 

Cameron, 1951, p. 8-9). The igneous rocks adjacent 

to the cordierite hornfels are quartz norite, biotitehornblende diorite, and other rocks (Cameron, 1951, p. 

31-33, pl. 2). 

The hornfels lies about 1.6 miles northwest of Bantam, Conn., at the sharp bend where Prospect Road 

changes direction from northwesterly to northeasterly. 
C-332 GEOLOGICAL SURVEY RE:SEARCH 1 9 61 

The locality is 1.55 miles S. 54.5° W. from the northeast corner of the New Preston quadrangle, Connecticut. Blocks of hornfels lie about 10 feet east of the 

sharp bend in Prospect R.oad, and about 10 feet farther 

east is a small outcrop of hornblendite of the Mount 

Prospect complex. Exposures of the hornfels are 

scarce, and the thickness of hornfelsed schist is· only 

about 10 or 15 feet. There are no exposures here of 

schist unaffected by thermal metamorphism. 

PETROGRAPHY 

The hornfels is bluish gray and is fine grained in 

hand specimen, except for easily visible garnet, biotite, and orthoclase. The rock is not fissile, although 

original laminae of the schist are well preserved. In 

thin section one sees t\vo types of laminae: one of 

red-brown biotite, equant cordierite, felted masses of 

si11imanite, irregular grains of magnetite, scattered 

garnet, and occasional quartz and feldspar; and 

another of quartz, orthoclase, and andesine, and small 

quantities of biotite, cordierite, and sillimanite. The 

first type of laminae are 1 to several mm thick, the 

second mostly 5 to 25 mm thick. Most of the minerals 

have maximum dimensions of 14, to ·~'2 mm. The 

orthoclase is partly perthitic, and myrmekite is often 

found between it and the plagioclase. Pleochroic haloes 

around the zircons in cordierite are exceptionally conspicuous. ':(he rock is fresh, and the only retrograde 

minerals are in a fine felt of sillimanite and biotite 

that rims many of the grains of cordierite. Andalusite 

and muscovite were not seen in 14 thin sections. 

In one thin section a rectangular pseudomorph, 8 

by 25 mm in size, contains about 75 percent of sillimanite, 15 percent of biotite, 5 percent of cordierite, 

and the remainder magnetite, pleonaste, and plagioclase; pleonaste is in contact with only sillimanite and 

cordierite. This is a local assemblage free of l\:20. 

The composition of the pseuclomorph suggests that the 

original mineral "·as staurolite. l\1inor exchange of 

alkalies, lime, and silica between the original constituents of the staurolite and the surrounding rock 

resulted in the formation of biotite, orthoclase, and 

plagioclase. The infiltration ot'ICO, however, "·as not 

complete, as evidenced by the presence of pleonaste. 

Other sillimanite-rich pseudomorphs are present, but 

have less regular outlines. 

Garnet is veined by biotite and magnetite (both 

singly and together), is deeply embayed by these 

minerals and also by cordierite, and commonly shows 

very ragged boundaries where in contact with aggregates of biotite, cordierite, and magnetite. These 

features imply that it is metastable. 

Compositions of the biotite, cordierite, and garnet 

may be estimated approximately from their indices 

of refraction. These minerals are too impure to be 

easily separated for chemical analysis. Biotite, like 

plagioclase, is slightly zoned; the 'Y index in sodium 

light ranges from 1.637 to 1.642. suggesting roughly 

equal amounts of ferrous and magnesian end members. 

Cordierite has relatively high indices; a, 1.547; {3, 

1.552; and 'Y, 1.557. Leake's graph (1960, p. 289) 

indicates a composition of about half Mg-cordierite 

and half Fe-cordierite. The index of garnet is 1. 793, 

which is in the usual range of garnet of regionally 

metamorphosed rocks; it is mainly almandine, perhaps 

15 or 20 percent is pyrope, and only small amounts 

are lime-bearing end members. Plagioclase is mostly 

sodic andesine; some grains are zoned outward from 

sodic oligoclase, left from the original schist, to calcic 

andesine, which formed during thermal metamorphism. 

PHASE RELATIONS 

The hornfels formed during thermal metamorphism 

consists of an assemblage of 7 minerals-bi~tite, 

cordierite, magnetite,. orthoclase, plagioclase, quartz, 

and sillimanite. The breakdown of staurolite alone 

yielded cordierite, pleonaste, and sillimanite, and expelled water. Components of the rock may be chosen 

as Alz03, CaO, Fe, H20, KzO, MgO, NazO, Oz, and 

Si02• The fugacity of ll20 probably was uniform 

throughout the hornfels. Magnetite formed from 

ferrous silicates indicates relative variations in FeO 

and Fe203, so Fe and 02 are taken as components. 

The fugacity of 0 2 may have been defined internally 

in the hornfels by temperature, total pressure, fugacity of water, and the mineral assemblage ('Vones and 

Eugster, 1959, p. 130-132), or it· may have been set 

externally by the fugacity of 02 in the adjacent 

magma. One cannot tell from the assemblage whether 

0 2 is an inert component or has its fugacity externally 

determined. The remaining 7 components are inert; 

that is, their activities are determined by their relative 

amounts. The phase rule allows at least 7 and perhaps 

8 phases to coexist stably for a given total pressure 

· and temperature (Thon1pson, 1955, p. 81). The hornfels consists of 7 phases and so does not violate the 

phase rule, which suggests (but does not prove) that 

equilibrium was reached. The phase pleonaste is stable 

only with cordierite and sillimanite, and this mineral 

is not a part of the 7-phase assemblage that forms 

most of the hornfels. 

Formation of the hornfels from the original garnetstaurolite schist involved several related reactions. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-333 

The n1ost probable ones are, written without stoichiometric coefficients: 

(1) Muscovite + quartz - Sillimanite + Orthoclase + H20 

(2) Staurolite + orthoclase + quartz + H 20 - biotite + 

cordierite + magnetite + sillimanite + H2 

(3) Gu.rnet + orthoclase + HzO - biotite + cordierite + 

mngnetite + quartz + H 2 

(4) orthoclase + oligocla.se + andesine - orthoclase perthite + labradorite. 

The simple breakdown of stn.urotite is the reaction: 

(5) staurolite- cordierite + pleonaste + sillimanite + H 20, 

where the ratio FeO/(FeO + l\1g0) in the staurolite 

probably is less than thn.t in the pleonaste and greater 

than tht1t in the cordierite. Staurolite may be considered as a system of 4 inert components, Al203, 

FeO, MgO, and Si02• The coexistenee of only these 3 

phases, cordierite, pleonn.ste, and sillin1anite, n.t given 

total pressure, temperature, n.nd fugacity of water, 

necessitates thn.t the rn.tios FeO/(FeO + .l\t[g0) of the 

cordierite and pleonaste be fixed. 

The formation of similar cordierite-bearing hornfels 

from schist has been described by IIarker ( 1939, p. 

324-329). 

REFERENCES 

Agar, W. M., 1927, The geology of the Shepaug Aqueduct 

Tunnel, Litchfield County, Connecticut: Connecticut Geol. 

Nat. History Survey Bull. 40, 38 p. 

Cameron, E. N., 1951, The geology of the Mount Prospect complex: Connecticut Geol. Nat. History Survey Bull. 76, 44 p. 

Harker, A., 1939, Metamorphism: New York, E. P. Dutton and 

Co., 362 p. 

Leake, B. E., 1960, Compilation of chemical analyses and 

physical constants of natural cordierites: Am. 1\fineralogist, v. 45, p. 282-298. 

Thompson, J. B., 1955, The thermodynamic basis for the 

mineral facies concept: Am. Jour. Sci., v. 253, p. 65-103. 

Wones, D. R., and Eugster, H. P., 1959, Biotites on the joins 

phlogopite (KMga AlSia01o (OH)2)-annite (KFeaAlSia01o 

(0H)2) : Carnegie lnst. Washington Yearbook 58, p. 127-

132. 

269. FIELD MEASUREMENTS OF SILICA IN WATER FROM HOT SPRINGS AND GEYSERS _IN 

YELLOWSTONE NATIONAL PARK 

By G. 1V. MoREY, R. 0. FouRNIER, J. J. HEMLEY, and J. J. RowE, 1Vashington, D. C. 

The geochemistry of the hot springs and geysers of 

Yellowstone Park has been of interest ever since their 

discovery. The first study "·as that of Gooch and 

'Vhitfield (1888) on a series of 4:3 water samples 

collected during the field seasons of 188:-1 to 1886 under 

the direction of ~{r. Arnold lln.gue (189!)). Allen and 

Dn.y ( 1935.) published an exhn.ust-i ve monograph 

describing the physical and chemical nature of many 

of the hot springs in the area. In all the above work, 

the analyses were made on samples colleeted some time 

previous to a.nalysis and accordingly any changes 

which could take place \Yith time had ta.ken place. 

1Vhite, Brannock, and l\1urata ( 1956) found that 

the dissolved silica. content of waters from hot springs 

may change with the age of the sample-the dissolved, 

presumably monomeric, silica changing to polymerized 

and colloidal silica. In YellO\YStone, 'Vhite measured 

t'.he dissolved silica contents of several springs at the 

time of sample collection, using the colorimetric silicomolybdate method. The analytical uncertainty ranged 

from ±10 to +30 ppm (parts per million). 

For our investigation, water sa.mples were collected 

in 500 ml polyethylene bottles from the hottest regions 

of pools and as near the vents as possible. Immediately after each sample was collected, the dissolved 

silica content was measured in the field by means o:f 

the colorimetric molybdenum blue method, using a 

portable photoelectric colorimeter. l\lany samples ";ere 

analyzed a second time the day after collection and 

some samples were analyzed a third time on the third 

or fourth day after collection. Several weeks later, 

. all the samples were again analyzed for dissolved silica 

and also for total silica. The results are tabulated in 

table 269.1. To determine total silica, it was necessary 

to evaporate a measured amount of the sample to 

dryness, fuse the residue with N aOH, leach with 

water, and acidify to assure the complete conversion 

of highly polymerized silica to the monomeric form. 

The precision of the field analyses ranged from 

about +1 ppm for the most dilute silica-bearing 

waters to about +5 ppm for the more concentrated 

waters. 
C-334 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TARLE 269.1.-Silica content of water of Yellowstone Park springs 

and geysers, 1960 

[Samples collected September 1960 by G. W. Morey and others. R. 0. Fournier 

made field analyses (0 to 2 days elapsed); J. J. Rowe made laboratory analyses 

(more than 2 days elapsed)] 

Ternpera- Locality ture pH (OC) 

Mammoth Hot Springs 

Jupiter Terrace ______ ------- _______ ------ 72 6. 7 

Opal Spring ____________________________ _ 69 6. 5 

New spring, north of OpaL _____________ -------- --------

Norris Basin 

pinder PooL ___________________________ 86 3. 8 

Echinus Geyser~------------------------ 87 3. 4 

Green Dragon ___________________________ 71 2. 9 

"Little Scald", SW side of Porcelain Terrace __ --_---_-- ____________________ 91 7. 7 

Opalescent PooL _______________________ 40 7. 7 

Pinwheel Geyser------------------------ 85 2. 9 

Porcelain Terrace, near road _____________ 91 2. 3 

"Pork Chop" Pool, 200' SW of PearL ___ 71 7.5 

Steamboat Geyser 1 ___ ------------------ 81 7. 7 

West of Norris drlll hole _________________ 66 2. 3 

Beryl Pool 

B"yl PooL_----------------------------~ 

Lower Basin 

Black Warrior--------------------------- 92 8.1 

Great Fountain Geyser _________________ _ 95 8. 7 

Narcissus Geyser~---------------------- 90 6. 8 

Midway Basin 

Excelsior Geyser ___ --------------------- 76 8. 4 

See footnotes at end of table. 

Appro xi- mate 

time 

elapsed 

(days) 

0 

26 

88 

0 

1 

26 

88 

88 

0 

36 

73 

88 

0 

36 

73 

88 

0 

1 

25 

73 

87 

0 

35 

87 

0 

1 

25 

. 73 

87 

0 

35 

87 

0 

35 

73 

87 

0 

36 

73 

88 

0 

1 

36 

73 

88 

0 

36 

73 

88 

Dissolved Total 

silica silica 

(ppm) (ppm) 

52 --------

52 --------51 

50 --------

52 -------- 51 --------

316 

322 

322 

280 

283 

286 

428 

422 

430 

420 

573 

126 

358 

262 

142 

118 

456 

460 

179 

184 

191 

428 

131 

114 

550 

155 

129 

115 

204 

202 

198 

51 

55 

348 

--------

--------

287 

--------

--------

441 

--------

608 

--------

--------

492 

....................... 

460 

..................... 

--------

189 

--------

--------

-----435 

--------

·-------

570 

--------

....................... 

205 

. 0 I 269

1 

_______ _ 

33 149 --------

85 -------- 268 

0 209 --------

33 145 --------

85 -------- 211 

0 324 --------

33 160 --------

85 -------- 325 

0 331 -------- 33 160 -------- 85 354 

0 

1 

28 

90 

I 

283 --------

207 -------- 145· -------- 303 

TARLE 269.1.-Silica content of water of Yellowstone Park springs 

and geysers, 1960-Continued 

Tern- Ap- Dis- per a- pro xi- solved Total mate Locality ture pH time silica silica 

(oC) elapsed (ppm) (ppm) 

(days) 

Upper Basin 

Artemisia Geyser 1 __ -------------------- 95 3. 45 0 267 

1 234 

2 185 

29 147 

91 275 

Daisy Geyser~-------------------------- 91 7. 8 0 306 

1 247 ....................... 2 179 -------- 29 131 -----ao4 91 Pool SW of Daisy and Splendid Geysers_ 71 4. 3 0 270 

1 272 -------- 2 271 -------- 29 272 -----278 91 Giantess Geyser _________________________ 95 8. 9 0 384 -------- 1 163 ................... 28 145 

90 417 

Hillside spring ___ ----------------------- 86 7.0 0 222 -------- 1 179 -------- 28 132 

90 190 Iron Spring _____________________________ 95 3. 5 0 45.5 -------- 29 463 

91 456 Old Faithful2 ___________________________ 90 9. 3 0 356 -------- 33 205 -----381 85 Small ----313- spring N of Old FaithfuL ________ 78 8. 9 0 .................... 33 167 -----318 85 

Riverside Geyser 1_ --------------------- 95 8. 9 0 226 

1 190 ..................... 2 152 -------- 28 150 -----288 90 Sapphire PooL _________________________ 92 9. 2 0 348 

1 233 -------- 2 179 ................... 28 175 

90 352 Turban I ________________________________ 89 8.5 0 315 --·----- 32 184 -----318 84 Pool near Upper Basin drill hole ________ 93 9. 7 0 361 

1 316 -------- 2 282 -------- 29 251 -----374 91 

At Continental Divide 7 miles west of Old Faithful 

"Contrary Spring" in stream gully ______ 91 6. 9 

Cloudy spring in stream gully ___________ 82 6. 3 

Boiling poolS ottran ___________________ 92 2. 3 

West Thumb 

Abyss PooL____________________________ 91 8. 5 

Occasional geyser~---------------------- 94 8. 6 

Mud Volcano area 

Churning Cauldron ____________________ _ 55 2.0 

I Sampled before eruption, during preliminary overflow. 2 Sai¥pled during eruption. 

1 

2 

27 

89 

1 

27 

89 

.1 

27 

89 

0 

1 

28 

90 

0 

1 

28 

90 

0 

1 

28 

90 

246 

240 

252 

254 

259 

262 

302 

282 

152 

139 

252 

--------

-----264 

..................... 

300 

297 

262 -------- 163 --------

139 --------

297 

300 

327 

283 

32f 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-335 

Only one sample, from IIillside, showed evidence of 

flocculation and settling of silica to the bottom of the 

container between the time of field analysis and the 

laboratory analysis because the total silica measured in 

the laboratory was 32 ppm less than the dissolved 

silica measured at poolside. For most of the samples, 

dissolved silica determined immediately after collection and total silica values are identical, within the 

limits of accuracy of the method. Analyses from 14 

pools showed 10 to 35 ppm more total silica than initially dissolved silica,. These differe~ces may be the 

result of polymerization taking place in the few minutes between the sample collection and the completion 

of analyses, or they may even be due to the presence 

of a few small solid particles swept up in the "·aters 

from the bottom of the pool. The only large discrepancy between total silica and dissolved silica was 

registered for water taken from an opalescent pool in 

Norris Basin. The opalescence of the water, at the 

time of collection, was due to dispersed colloidal silica. 

I-Iowever, even though colloidal silica was forming, 

this pool was still grently supersaturated with dissolved silica in respect to silica gel. The hottest part. 

of the pool· was 40°C. At this temperature the solubility of silica gel is about 175 ppm, while the water in 

the pool contained 358 ppm. The pool had a slow but 

continuous overflow, and water coming up from hotter 

regions presumably was adding dissolved silica at too 

fast a rate for equilibrium between dissolved and 

colloidal silica to be attained. 

'Vhite and others (1956, p. 42-43) observed that 

acid waters tend to maintain high degrees of sup~rsaturation of dissolved silica at room temperature and 

pressure for long periods of time. On the other hand, 

in alkaline waters dissolved silica tends to convert. 

rapidly to po]ymerized silica unt.il the equilibrium 

solubility with silica gel is approximated. This effect 

may be seen in table 269.1, where for given springs the 

pl-I and dissolved and total silica values are compared. 

Of the springs annJyzed, Little Scald contains the 

most disso]ved si.lica. It lies on the southwest side of 

Porcelain Terrace, in the Norris Basin. The dissolved 

silica content was 573 ppm and the total silica 608 

ppm. If the solubility of quartz or chalcedony in hot 

regions at depth controls the quantity of silica in the 

waters issuing from rapidly discharging springs and 

geysers, then, using data from J(ennedy (1950), the 

temperature at which equilibrium between dissoh·ed 

silica and quartz was last attained in the water of 

Little Scald was about 275°C. l\{ore commonly, springs 

and geysers in Yellowstone contain 250 to 350 ppm 

dissolved and total silica. At pool temperatures of 

uooc. such solutions are unsaturated in respect to 

silica gel. They are saturated, however, with respect 

to quartz at temperatures ranging from 175°C to 

225°C, assuming pressures equal to the vapor pressure 

of water (Fournier, 1960). Indeed, it is likely that 

quartz and chalcedony deposit in hot spring areas at 

relatively shallow depths and at temperatures ranging 

from 175°C to 275°C. Secondary quartz has been reported by Fenner (1936) in drill core from both 

Norris Basin ai1d the Upper Basin. The m:tximum 

temperature encountered in the Norris drill hole was 

205°C at a depth of 2461;2 feet and in the Upper Basin 

drill hole 180°C at a depth of 406 feet. Also, in experimental work at 1,000 bars I-I:!O pressure, quartz 

was precipitated from initially supersaturated solutions within three days at 125°C. 

In stagnant and slowly discharging springs, the dissolved si]ica content of the water may be fixed in great 

part by the formation of colloidal and gelatinous silica, 

or. even by silica dissolving from the immediate borders 

of the spring pools, as suggested for acid sulfate pools 

by 1Vhite and others ( 1956, p. 43). 

One of the objectives of this study is to determine 

what chemical changes, if any, have taken place in 

the waters from springs and geysers previously analyzed. Of the 36 springs reported here, waters from 

21 had been sampled one or more times and analyzed 

by other workers. ''T aters from 8 springs show no 

change in silica content, within the limits of accuracy 

of the measurements. Four previous analyses are 

higher in silica and 15 are lower in silica. 

Abnormally intense discharge was reported for 

many of the springs and geysers of Yellowstone Park 

the night of the 1959 Hebgen Lake earthquake (Marler, 1960; and personal communication, 1960). Other 

springs became markedly less active. Some of these 

changes have persisted up to the present (spring 1961). 

The frequencies of eruption of both Artemisia and 

Great Fountain geysers have greatly increased since 

the earthquake, yet their silica and chlorine contents 

remain practically unchanged. Sapphire Pool changed 

from a minor to a major geyser with all aspects of its 

former function greatly altered. The silica content of 

its water has also increased from 320 ppm in 1947 to 

350 ppm now. 

The greatest change in the chemical nature of a 

spring was found at Porcelain Terrace in Norris Basin. 

There, one spring, known to have been an alkaline 

chloride type, had changed to an acid sulfate type 

with a pH of 2.3. The total silica has decreased from 

about 700 ppm measured both in 1930 and 1947 to 189 

ppm now. Chlorine has dropped from 7 48 ppm to 20 

ppm. Since the Hebgen Lake earthquake, the spring 

has ceased overflowing and the water level has ebbed. 
C-336 GEOLOGICAL SURVEY RESEARCH 1 9 61 

The old water supply to the spring was probably 

diverted to other channels as ground shifted during 

the earthquake. In agreement with the views of vVhite, 

Sandberg, and Brannock ( 1953, p. 493) for the origin 

of acid sulfate pools, it is probable that now only 

steam, rich in acid-forming gases, rises to the vicinity 

of the spring, there condensing and mixing with 

ground waters already presei1t to produce an acid sulfate pool. Steam at 108°C perpetually roars from a 

small vent adjacent to the pool. 

·unfortunately, at most places it cannot be determined with certainty what chemical changes have been 

brought about in various spring waters due to the 

catastrophic effects of the earthquake and what 

changes we now see were due to slow continuous 

processes operative before the earthquake. Five years 

elapsed between the time of the last collection of samples for analys~s (vVhite and o~,hers, 1956, p. 34) and 

the time of the earthquake. There is a definite need to 

obtain more chemical data at Yellowstone to achieve 

a better understanding of the extent of chemical variat.ions in thermal waters in one area and to provide a 

broader base to judge when, why, and how chemical 

changes take place. 

REFERENCES 

Allen, E. T., and Day, A. L., 1935, Hot springs of the Yellow-

.stone Park: Carnegie Inst. Washington Pub. 466, 524 p. 

Fenner, C. N., 1936, Bore-hole investigations in the Yellowstone Park: Jour. Geology, v. 44, p. 282-310. 

Fournier, R. 0., 1960, The solubility of quartz in water in 

the temperature interval 25°C to 300°C [abs.] : Geol. 

Soc. America Bull., v. 70, p. 1604. 

Gooch, F. A., and ·whitfield, .J. E., 1888. Analyses of waters of 

the Yellowstone National Park: U.S. Geol. Survey Bull. 

47. 

Hague, Arnold, and others, 1899, Geology of the Yellowstone 

Park : U. S. Geol. Survey Mon. 32, pt. 2, 893 p. 

Kennedy, G. C., 1950, A portion of the system silica-water: 

Econ. Geology, v. 45, p. 629-653. 

Marler, G. D., 1960, The 1959 Hebgen Lake earthquake alters 

Yellowstone's hot springs, in Billings Geol. Soc. Guidebook 

11th Ann. Field Conf., 1960: p. 61-66. 

White, D. E., Brannock, W. '\V., and Murata, K. .J., 1956, 

Silica in hot spring waters: Geochim. et Cosmochim. Acta, 

v. 10, p. 27-59. 

White, D. E., Sandberg, C. H., and Brannock, ,V, '\V., 1953, 

Geochemical and geophysical approaches to the problems 

of utilization of hot-spring water and heat: Pacific Sci. 

Cong., 7th, New Zealand, 1949, Proc., v. 2, p. 491-493. 

270. ANTHOPHYLLITE-BIOTITE-HYPERSTHENE-RHODOLITE ASSEMBLAGE, MASON MOUNTAIN, 

NORTH CAROLINA 

By FRED BARKER, vVashington, D. c. 

Rhodolite, a pyrope-rich variety of garnet, is associated with aluminous anthophyllite, hypersthene, 

biotite, quartz, and sillimanite at Mason Mountain, 

Macon County, N. C., about 6 miles north of Franklin. 

The rhodolite locality is a small quarry 1.18 miles N. 

82° W .. of the southeastern corner of the Alarka quadrangle, as shown on figure 270.1. 

RHODOLITE-BEARING ROCK 

Rhodolite garnet was described and named by Hidden and Pratt (1898a). Henderson (1931) described 

the quarry where fresh rhodolite-rich rock crops out. 

He gave analyses of the anthophyllite and hypersthene, 

checked Pratt's determination of FeO in rhodolite, and 

analyzed biotite for FeO and Fez03 • The quarry was 

later enlarged, and Heinrich ( 1950) made a detailed 

petrographic study of the rhodolite-bearing rocks. 

The body of rhodolite-bearing rock is exposed only 

in the quarry. It is about 15 to 40 feet in width, is at 

least 100 feet long, and has steep contacts with the 

wallrocks. An abundance of rhodolite in the gravels 

of the lower part of Mason Branch suggests that the 

body is much longer than 100 feet. It ·probably is a 

dike. Decomposed gneiss and schist are exposed along 

both sides of the rhodolite-bearing rock; their foliation 

is truncated by the dike. 

The rhodolite-bearing rock is coarsely crystalline, 

mostly rudely banded, and composed of variable proportions of anthophyllite, biotite, rhodolite, hypersthene, quartz, sillimanite, ferriferous rutile, and 

graphite. Henderson (1931, p. 564) pointed out that 

anthophyllite formed from an original rhodolite-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-2 9 2 C-337 

hypersthene rock. Heinrich (1950) gave a detailed 

sequence of mineral growth, which is confirmed by 

my own petrographic work. R.hodolite and hypersthene 

are the earliest minerals. They are corroded and veined 

by anthophyllite, biotite, and quartz. These minerals 

1000 0 1000 2000 3000 FEET I II II I I I I 

lf'wum~ 270.1.-Mason Mountain and vicinity, showing locations 

of rhodolite qunrry, nnd outcrops of biotite-garnet schist and 

twice-metamorphosed sillimanite schist. 

T A RLI<J 270 . .l .-Chemical analyses of minerals, rhodolite deposit, 

·Mason Mountain, Macon County, N.C. 

[In percent) 

Rhodolite 1 Antho- Hyper- Biotite a phyllite 2 sthene 2 

-------1---......-----:----1·---------

Sl02----------------- 41.54 41.65 ---------- 44.22 52.36 38.9 

~1'102---------------- ·--------- ---------- ---------· ---------- ---------- 2. 9 AhOa ............... ---------- 23.26 23.10 23.79 4. 29 17.7 J~e203 .. -............ 1.88 1.92---------- .20 .72 FeO................ 15.48 15.63 ---------- 9. 21 16.00 6. 2 l\1n0 ............... ·--------- ---------- __________ . 16 ---------- _________ _ M~tO ............... ---------- 16.00 17.48 20.69 25.89 20.2 cao .. ______________ 1.02 .86 ---------- .62 .44 ---------- NI\20-................................... ---------- ---------- .... ______ . 54 

K20 .......................... ---------- ---------·- ---------- ---------- 8. 7 lhO ................ ··-------- --------·- ---------- 1. 42 . 34 3. 5 F ......................... ---- ---------- ---------- ---------- ---------- . 54 

------11---.;__-~..L_---1---- ------ 'l'otal ........ . 100.22 100. 31 100. 22 !19. 90 

I Annlyst: .l. H. Pratt. (Hidden and Pratt, 1898a, p. 295). 2 Annl~st.: E. P. Henderson (1931, p. 566 and 568). , a Aunlyst: B. L. Ingram. Spectrochemical analysis or the biotite shows: Ca 0.003 pcrcPnt, ond Mn 0.015 percent. 

are transected by veinlets of sillimanite and quartz. 

Anthophyllite and sillimanite are rarely associated. 

The rutile contains patches of ilmenite. Flakes of 

graphite are associated with biotite, rhodolite, and 

rutile. Analyses of the mafic minerals are given in 

table 270.1. 

Henderson (1931, p. 565, 568) obtained an average 

of 16.06 percent of FeO in rhodolite from two deterininations, and· 5. 78 percent of FeO and 0. 72 percent of 

Fe203 in biotite. He n1easured (1931, p. 565-568) the 

indices of refraction of the mafic n1aterials as follows: 

n 'Y Limit of error 

-----------!---------------

Rhodolite_____________________ 1.758 -------------------- .......... ---------- Anthophyllite .. ____ ........ ___ .. ---.--.. 

11 ypersthene. __ .. _.- ... -----... ---.----. Biotite •.. ___ . __ .. __ ._ .. _______ . _ .. __ . __ . 

1. 642 

1. 658 1. 565 

l\1easurements by the author agree. 

I. 1355 1. 696 1. fl()7 1. 661 ±0. 003 1.1399 ± .003 1. 607 ± .003 

The molar ratios l\1g0: (l\1gO+Fe0) of these minerals are: rhodolite 0.66, hypersthene 0. 73, anthophyllite 

0.81, and biotite 0.85. The formula of biotite nlay be 

written: 

[ Sis .57] [02o .44 J 

Al2 .43 • (OH)a .32 

Fo.24 

ADJACENT SCHIST 

Hidden and Pratt (1898b, p. 468) found a garnet that 

they cal1ecl impure rhodolite that occurs with biotite 

near the summit of Mason l\1ountain. About 1,600 

feet southwest of the western summit of the n1ountain 

a small pit exposes weathered biotite-garnet-oligoclasequartz-sil1imanite schist. The garnet in this rock is 

violet as is rhodolite; however, as its index ranges from 

1. 793 to 1. 798, ± 0.004, it is an almandine-rich variety. 

The (3 and 'Y indices of the biotite are 1.635, ± 0.003, 

which is much higher than those of the biotite found 

with rhodolite. This rock is a typical regionally metaInorphosed argillaceous schist. 

Twice-metamorphosed schist crops out south of the 

saddle that lies 14 mile east of the eastern summi_t of 

l\1ason l\·fountain. This rock consists of ·corroded 

garnets and tabular pseudomorphic masses of intergrown sillimanite in a matrix of sillimanite, biotite, 

quartz, perthitic microcline, cordierite, magnetite, and 

leucoxene. The original elongated tabular mineral, 

in crystals as large as 1 inch in length, is judged to 

have been kyanite. Garnet has partly reacted to biotite, 

cordierite, sillimanite, and iron oxides. Fine-grained 

microcline and sillimanite in the matrix probably 

formed from muscovite and quartz. An initial metamorphism apparently produced the garnet, kyanite, 

muscovite, and the staurolite found in placer deposits 
C-338 GEOLOGICAL SURVEY RESEARCH 1961 

(Hidden and Pratt, 1898a, p. 294). These minerals 

are typical of middle-rank regional metamorphism. 

The second metamorphism produced biotite-cordieriteoligoclase-quartz-sillimanite-Fe, Ti oxides. Garnet may 

be unstable in this environment, or the original garnet 

may have reacted to form a mineral that contains more 

magnesium and is stable with cordierite; the petrographic relations do not indicate which alternative is 

correct. The second metamorphism was either the result of very high rank regional metamorphism or of 

thermal metamorphism by plutonic intrusives. 

ORIGIN 

The mineral pair rhodolite-hypersthene is an unusual one; its origin is unknown. These minerals may 

have been part of a rare igneous rock, such as a pyrope-· 

bearing peridotite, or the hypersthene may be a relict 

from a normal ultramafic igneous body, and the 

rhodolite may have formed in the initial, middle-rank 

metamorphism. Anthophyllite, biotite, and quartz, and 

the younger veinlets of sillimanite and quartz as w~ll, 

probably formed during the second, high-rank metamorphism. 

Compositions of the mafic minerals and sillimanite 

are shown on figure 270.2. Alteration of hypersthene 

and rhodolite to anthophyllite and biotite involved 

addition of H:!O and 1{20 and probably Al20a. Breakdown of muscovite during the second metam·orphism 

of the adjacent schist may have forced a solution of 

KAl02, saturated with Si02, into the rhodolite rock. 

Anthophyllite and biotite have higher ratios of 

MgO: (l\1g0 + FeO) than the hypersthene and rhodolite; this could be the result either of addition of MgO 

to the system, or of subtraction of FeO. The proportions of ferrous iron in anthophyllite and biotite were 

complex functions· of fugacities of oxygen and water, 

pressure, and temperature, as well as composition of 

the original rock. Thus, exact equations for the transformation of hypersthene and rhodolite to anthophylAnthophyllite 

/LRhodolite Biotite 

Hypersthene 

MgO .__------------------~ FeO 

FIGURE 270.2.-Compositional plot of AbOa-FeO-MgO in moles 

of mafic silicates from Mason Mountain, N. C. Composition 

of cordierite is not known. 

lite and biotite cannot be written, even though the compositions of these minerals are known. 

Sillimanite in the late veinlets may be due to leaching by hot water that percolated along fractures. Solution of the more soluble constituents of the four mafic 

silicates would leave Al20 3 , which, with the excess SiO, 

would crystallize as sillimanite. This mode of origin 

was suggested to the author by vVerner Schreyer (oral 

communication, 1961). 

REFERENCES 

Heinrich, E. W., 1950, Paragenesis of the rhodolite deposit, 

Mason Mountain, North Carolina: Am. Mineralogist, v. 

35, p. 764-771. 

Henderson, E. P., 1931, Notes on some minerals from the 

rhodolite quarry near Franklin, North Carolina : Am. 

Mineralogist, v. 16, p. 563-568. 

Hidden, ,V. E., and Pratt, J. H., 1898a, On rhodolite, a new 

variety of garnet: Am. Jour. Sci., v. 5, p. 294-296. 

--1898b, On the associated minerals of rhodolite: Am. 

Jour. Sci., v. 6, p. 463-468. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-339 

271. TWO OCCURRENCES OF THORIUM-BEARING MINERALS WITH RHABDOPHANE-LIKE STRUCI'URE 

By J. R. DooLEY, JR., and JouN C. HATHAWAY, Denver, Colo. 

Recently Bowie (1959, p. 306) reported a thoriumbearing phosphate with a rhabdophanelike structure 

from the l\Itoko district of Southern Rhodesia independently, Fisher (in McKelvey, 1960, p. A60) and 

Phair (written communication, 1960) found similar 

material in a sample from the \Vet Mountains of Colorado. Two additional occurrences of similar material, 

one from Wyoming and one from near Gunnison, Colo., 

are here described. 

We wish to acknowledge the initial work and analyses of the material from Gunnison, Colo., by J . \V. 

Adams and R. P. Marquiss. F. H. Hildebrand furnished the X-ray pattern of rhabdophane from Salisbury, Conn. 

WYOMING OCCURRENCE 

Radioactive samples of the limestone member of the 

Pliocene Moonstone formation were found in Fremont 

County, Wyo. (sec. 25, T. 30 N., R. 90 W.) by J . D. 

Love in 1951 and H. D. Zeller and J. D. Love in 1955. 

Autoradiographs of polished specimens of limestone 

sho"·ed the radioactive material to be distributed 

throughout the limestone, but the highest concentrations were in crack fillings. Formic acid was used to 

w 

() 

z 

<( 

0 

z 

:::> 

CD 

<( 

w 

> 

10 .0 ,---

f= -l 

:s 

w 

0:: 

1.0 

0. 1 1.0 10.0 100.0 

PARTICLE SIZE, IN MICRONS 

FIGURE 271.1.-Schematic diagram showing the distribution of 

insoluble minerals as a function of particle size. Samples 

265110A and 265112. 

FIGURE 271.2.-X-ray powder diffraction patterns of the thorium-bearing minerals and rhabdophane. A, thorium-bearing 

mineral. Fremont County, Wyo. ; B , rhabdophane. Salisbury, 

Conn. ; C, thorium-bearing mineral, Gunnison, Colo. 

concentrate the insoluble residue from the limestone, 

as hydrochloric acid tended to dissolve a considerable 

amount of thorium from the sample. 

The highest concentrations of thorium were in the 

finer sized materials; these fractions were concentrated 

by wet sieving and centrifuging, then analyzed by Xray powder diffraction techniques. Disordered cristohalite (Florke, 1955a, 1955b), quartz, montmorillonite, 

and the thorium-bearing mineral, in order of decreasing abundance, "·ere identified. A schematic representation of the mineral distribution versus particle size 

that \Yas compiled from both X-ray and radioactivity 

measurements of the various size fractions is presented 

on figure 271.1. 

A particle size of about 1 micron showed the greatest 

concentration of the thorium mineral and the smallest 

amount of impurities. A few milligrams of the 

thorium-bearing mineral were obtained from this size 

fraction by solution of the disordered cristobalite in 

strong NaOH. It was not possible to determine physical or optical properties on so small an amount of very 

fine grained material, but X-ray powder photographs 

and diffraction data showed the material to have a 

structure closely resembling that of rhabdophane (fig. 

271.2 and table 271.1) . 

Further similarity of the mineral to rhabdophane 

was noted on ignition of the sample at 800° to 900°C. 

The ignited material gave an X-ray pattern closely resembling that of monazite (fig. 271.3) as does rhabdophane after igni6on (Muto and others, 1959, p. 648) . 
C-340 GEOLOGICAL SURVEY RESEARCH 1 9 61 

TABLE 271.1.- X-my powder diffraction data for two thoriumbearing minemls and for rhabdophane 

[CuKo radiation; 114.59 mm powder camera; din Angstrom units] 

Material from Wyoming before heating. Film 457 

d I I 

7. H f2 

6. 04 "' 4. 47 V\Y 3 

4. 35 "' 4. 26 V\Y 4 

3. 90 f6 

3. 56 f2 . 

3. 4"1 "' 3. 33 m• 

3. 21 I". 3. 0-1 vs 5 

2. 96 VII" 

2. 82 

2. 71 " f 

2. 56 f 

2. 45 f 4 

2. 37 "' 2. 2g \\" 

2. 21 f 

2. 14 s 2. JO V\Y 6 

1. 914 w 

1. 85fi m 

1. 821 " l. 788 V\Y 

I. 749 w 

1. 6'l7 w 

1. 667 vw 

M aterial from Gunnison 

before heating. Film D-2449 

d 

6. 05 

4. 35 

4. 26 

3. 46 

3. 33 

3. 03 

2. 82 

2. 45 

2. 36 

2. 27 

2. 15 

------ --- 1. 91-1 

l. 856 

m 

f 4 

I I 

V"' 

VI\- 4 

vs 

s 

f. 

V\Y 

f 

s 

----

vw 

m 

1. 748 vw 

1. 704 vw 

1. 667 vw 

Rhabdophane . Salisbury, Conn. (Muto and others, 

1959, p. 644) 

d I I 

6. 07 m 

4. 40 s 

3. 49 m 

3. 02 vsb 

2. 83 s 

2. 36 w 

2. 28 ,-w 

2. 15 s 2. 02 f 

1. 920 \\' 

1. 85!) m 

1. 743 vwb 

l. 704 vw 

1. 675 V\1" 

1 vs. very Rtrong: s, strong: m , medium ; w, weak; vw. T'er~r weak : f,, faint; b. broad. "Ka olini te( ?) . a l\fon tmorilloni te. 4 Quartz. 6 Include~ trace of calcitP. • Calcite. 

Semiquantitative spectrographic analysis of the 

same fraction that ·was analyzed by X-rays is shown 

in table 271.2. It is noteworthy that the material contains less than 0.5 percent rare earths. The silicon, 

aluminum, iron, and magnesium among the major 

constituents are probably the result of failure to 

remove all the montmorillonite and quartz from the 

fraction, although it. is possible that some silicon may 

substitute for phosphorus in the rhabdophane structure. The calcium shown may occur in the rhabdophanelike structure but some is undoubtedly the result 

of failure to remove all the calcite from the sample by 

acid treatment. 

GUNNISON, COLO., OCCURRENCE 

A second occurrence of a thorium-bearing material 

having a rhabdophane structure was found in a small 

vein in Precambrian rocks southwest of Gunnison, 

Colo. (sec. 24, T. 49 N., R. 2 W.) in 1955 by R. C. 

Derzay and R. C. Maylan. Both the vein material and 

the surrounding rock are oxidized and friable. The 

FIGURE 271.3.-X-ray powder diffraction patterns of the 

thorium-bearing minerals after heating at 800° to 900°C 

and monazite, unheated. A, thorium-bearing mineral, Fremont County, Wyo.; B, monazite, locality unknown; 0, 

thorium-bearing mineral, Gunnison, Colo. 

original sample of relatively fresh material consisted 

principally of potassium feldspar, chiefly microcline, 

and subordinate quartz. Analyses sho,Yed thorium to 

be the principal source of the radioactivity; uranium 

was present only in minor amounts. The same structure was observed in the X-ray po\Yder patterns 

of both the Wyoming and Gunnison material. 

TABLE 271.2.- Semiquantitative spectrographic data on concentrate containing thorium-bearing mineral 

[Analyst: N. ;\[. Conklin; in percent to nearest number in the series 7, 3, 1.5, 0.7' 

0.3, 0.15, and so forth] 

Percent ~ron p 

> 10. 0 

7. 

0. 7 

.3 

3. 

1.5 

. 15 

. 07 

. 03 

. 015 t < .OJ 

. 007 

. 003 

. 0015 

. 0007 

. 0003 

(2) 

(2) 

·wyoming occurrence. Mineral concentrate 0.5-1.0 micron size. 

Sample 265110A-plate II-1986 

Gunnison occurrence. Mineral concentrated 

from heavy fraction . Sample 231219- plate 1348 

M.:tjor constituents and contaminants 

Si, Th 

Ca 

P, AI 

Ft', Mg 

Th 

P Si F e c~ , Ti 

Minor impurities and trace elements 

Na, Pb 

Ba, Cu, Sr 

Ti, Y 

Ni, V 

Rn, Zr, Yb 

l\1n 

Bi 

Co, Cr 

B 

AI, Ba, Ce 

La, Nd, Y, Zr 

Cu 

Mg, Dy, Gd 

Mn 

Yb 

Bi, Co, Cr 

_ _ _ _ _ _ _ _ _ _ _ _ Be 

Ag, Ga 

Be 

J ight rare earths 

II cavv rar<' earths ex- ccp't Yb anrl Y 

Light rare earths except 

La, Ce, and Nd 

Heavy rare earths except Gd, Dy, Yh, and Y 

u 

'Lower limit of detection is 0.01 percent. " 'l'h ~ lo""er limits of det ection from 10 ppm to 500 ppm depending 

upon ~acb particular element. 3 The lower limit of detection is 0.05 percent. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-341 

A heavy-mineral fraction of the sample contained the 

thorium-bearing mineral together with iron-bearin~ 

opaque minerals, and minor amphibole and rutile. 

A few milligrams of. the thorium mineral were concentrated by hand picking. The rnineral was dark 

reddish brown and occurred in cryptocrystalline aggregn.tes. J...~ighter colored material grading into red and 

redclish-oran~e grains was abundant but optical and 

X-ray analyses of these grains showed considerable 

amounts of intimately admixed quartz. 

Some physical and optical properties of the mineral, 

as detennined from the hand-picked grains, are as 

follows: 

Physical and optical properties 

Color_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Reddish brown 

Fracture ______________________ ·- Conchoidal 

Luster_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Resinous 

Hard ness_____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 to 4 

Specific gravity _________________ 3.7 to 4.3 

Average index of refraction ______ 1.66 to 1.69 

Birefringence ___________________ Moderate 

The similarity of this mineral t,o the vVyoming 

material described above and to rhabdophane can be 

seen in the X-ray data given in table 271.1 and figure 

271..2. The Gunnison mineral also shows a monazite-

. like structure on ignition at 800° to 900° 0 (fig. 271.3). 

A semiquantitative spectrographic analysis of the 

heavy-mineral concentrate is compared in table 271.2 

with that of the Wyoming material; in the Gunnison 

miner.al the rare-earth content is relatively higher but 

is nevertheless below 2 percent. Some silicon, iron, 

calcium, and titanium in the analysis undoubtedly are 

due to amphibole, rutile, and iron-bearing opaque 

minerals that were not removed during concentration 

of the samples. It is possible that some of the silicon 

may substitt1te for phosphorus in the rhabdophane-like 

structure. 

·In both the occurrences rare-earth elements are 

minor as compared to thorium and calcium. This low 

rare-earth content contrasts with the usually moderate 

and high rare-earth content of rhabdophane and 

monazite. 

Pho~phorus appears among the major elements in 

samples from both occurrences but the material available 'yas insufficient for complete chemical analysis. 

Presumably the thorium-bearing minerals, like rhabdophn.ne and ningyoite (~futo and others, 1959), are 

fundamentally hydrated phosphates and like rhr~bdophn.ne and ningyoite, they alter to a monazite structure 

through dehydration upon ignition. 

REFERENCES 

Bowie, S. H. U., 1959, Note on uranium and thorium occurrences in the Federation of Rhodesia and Nyasaland: 

Chronique des Mines d'Outre-l\ier de la Recherche Miniere, 

no. 279, p. 304-309. 

Florke, 0. ,V., 1955a, Zur Frage des "Hoch"-Cristobalit in· 

Opa·len, Bentoniten und GHlsern: Neues Jarhb. l\fineralogie 

l\fon'atsh., no. 10, p. 217-223 . 

--1955b, Structuranomalien bei Tridimyt und Cristobalit: 

Deutschen Keramischen Gesell. Ber., v. 32, p. 364-381. 

McKelvey, V. E., compiler, 1960, Geological Survey research, 

1960, synopsis of geologic results: U.S. Geol. Survey Prof. 

Paper 400-A, 136 p. 

Muto, Tadashi, l\feyrowitz, Robert, Pommer, A. M., and 

Murano, Torn, 1959, Ningyoite, a new uranous phosphate 

mineral from .Japan: Am. Mineralogist, v. 44, nos. 5 and 6, 

p. 633-650. 
C-342 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

272. EFFECTS OF IMPACT ON THERMOLUMINESCENCE OF YULE MARBLE 

By C. H. RoAcH, G. R. JoHNSON, J. G. McGRATH, and F. H. SPENCE, Denver, Colo. 

Impact experiments are being made on various rock 

types as a part of a general study of the physical 

effects of high energy shock in rocks. Yule marble 

from ~1arble, Colo., was selected for investigation because of the large amount of physical, chemical, and 

petrofabric data available for this rock (Balsley; 1941; 

Griggs and Miller, 1951; Griggs and others, 1951; 

IIandin and Griggs, 1951; l(nopf, 1949; Lepper, 1941; 

Turner, 1949; Turner and Ch'ih, 1950; Turner and 

Ch'ih, 1951; and Turner and others, 1950). 

A sa wed block of unfractured Yule marble about 

6 inches thick and with a target surface area· of about 

1 square foot was used for an experiment. A 30-

caliber armor-.piercing bullet was fired into the block 

of marble in a direction normal to the target surface. 

The point of impact ·was 46.0 feet from the gun 

muzzle, impact velocity of the projectile was estimated 

at 2,700 feet per second, and the bullet ·weighed 10.92 

grams. 

The impact formed a crater having an average 

diameter of about 5 inches and a depth at the center of 

about 1 inch (fig. 272.1). A well-defined radial fracture system intersects the crater. l\1arble in the central 

part of the crater has a white opaque appearance 

apparently related to intense microbrecciation caused 

by shock produced by the impacting projectile. The 

intensity of microbrecciation decreases progressively 

with distance from the center of the crater. Along the 

rim of the crater, single pieces of marble up to 1 

square inch in area and about 0.1 inch thick spalled 

loose but :were not ejected from the crater. Apparently 

the marble failed mainly by shear in the zone of 

microbrecciation, whereas tensional failure was more 

important along the rim of the crater. 

Shock produced by the impact caused significant 

changes in" thermoluminescence characteristics of the 

marble (fig. 272.1). Comparison of glow curves (fig. 

272.1) of samples CS-1, CS-2, CS-3, CS-4, S-4"', and 

S-6" taken :from the target surface and crater surface 

after the impact with a sample taken before impact 

shows that the total thermoluminescence of the marble 

was increased. The amount of shock-induced thermoluminescence is greatest at the center of the crater and 

generally decreases with distance outward. Glow 

curves of pre-impact samples of Yule marble have a 

lower peak amplitude at 270°C than at 325°C. The 

effect of the shock in the intensely microbrecciated 

region was to reverse the relative heights of the 270°C 

and 325°C peaks in san1ples CS-1 and CS-2. This 

"reversed peak" relation has been observed in shocked 

carbonate rocks from other impact experiments and 

in rocks associated with meteorite craters, and may 

be a common characteristic of intensely shocked rocks. 

The block of marble was sawe~ perpendicular to the 

target ·surface and one-quarter of an inch from the 

projectile hole in order to evaluate the effect of shock 

below the crater (fig. 272.2). The top of the steel 

projectile penetrated to a depth coinciding with the 

horizontal fracture shown in figure 272.2, and is about 

one-quarter of an inch behind the sa wed surface. The 

fracture system is roughly symmetrical with respect 

to the crater axis. Fractures above the projectile are 

concave upward, whereas fractures below the projectile 

are concave down\Yard. Other cross sections show that 

the fracture surfaces are approximately paraboloids. 

The impact increased the total thermoluminescence 

of the marble below the crater; the greatest increase 

occurred in sample V-1 and the sample that formed a 

coating on the bullet (fig. 272.2). The amount of 

shock-produced thermoluminescence decreases \Yith increasing distance below the crater. Glow curves of 

sample V-1 and the bullet coating do not have the 

"reversed peaks" expected in the intensely brecciated 

zone. The lack of "reversed peaks" in these samples 

might be attributed to thermal decay of the 270°C 

peak as a result of frictional heating close to the path 

of penetration of the projectile. 

Splits of snmple V-2 n,nd .the pre-impact sample were 

prehen,ted at 400° C for 16 hours and subsequently 

exposed to short-wave (A=2537 A) ultraviolet radiation for 4 hours. Significant low temperature thermo· 

luininescence was induced in the post-impact sample 

but not in the pre-impact sample (fig. 272.3). The 

two ultraviolet-induced peaks of sample V-2 decay 

rapidly at roon1 temperature (fig. 272.4); the 70° C 

peak has the fastest rate of decay. The 70° C peak 

decayed approximately according to the equation 

log Y=-0.92 log X+L719 (where Y is the peak 

height in relative thermoluminescence units and .. X is 

the time, in minutes, elapsed since the sample Wtts 

removed from the radiation source). The 140° C peak 

decayed approximately according to the equation 

log Y=-0.38log X+2.054. 
100 

0 

(/) 

t::: 

z 

:::> 

UJ 100 > 

>= 

< __, 

UJ 

0:: 

~ 

ui 

'-' 

z 

UJ 

'-' (/) 

UJ 

~ 

::E 

:::> 0 __, 

0 

::E 

0: 

UJ 

:>: 

I- 100 

0 

PRE-IMPACT SAMPLE 

/ ' / 

/ 

/ 

100" 400" 

S-4~~ 

'\ I ·. 

('- \. 

I 

I 

J I I I 

100" 400" 

S-6" --

(' ;'\ 

I \ 

I 

/ 

100" 400" 

TEMPERATURE. IN 

DEGREES CENTIGRADE 

' 

S·4" 

• 

100 

0 

10 ) 

) 

100 

0 

100 

EXPLANATION 

~- --1:10 

- ··-1:3 

Scale factor 

Room temperature 

• 

Sample location 

) 

Fw URE '27'2.l.- Etfccts of impact on t.hermolumincscPncc of Yule marble along crater urfacc and original s urface. 

CS-1 ...... - ... 

100" 

CS-2 

-- " 

"--

I 

I 

100" 

CS-3 

-- v 

I 

/ 

100" 

CS-4 

100" 

400" 

--1 

r\ 

\f\ -

\...' 

T 

Ul 

P1 

0 

:::0 

..., 

"'d 

> "'d 

M 

:::0 

Ul 

z 

~ M 

0 

M 

0 

t" 

0 

0 

H 

() 

400" > 

(-" 

/ 

/ 

/ 

400" 

r . 

.,..--........---""' 

400" 

z 

t:l 

~ t:l 

:::0 

0 

t" 

0 

0 

H 

() 

Ul 

() 

H 

M 

z 

() 

M 

_UJ 

> :::0 

..., 

H 

() 

t" 

M 

Ul 

>-' 

""' _, 

I 

~ "" 

"" 

(") 

I 

w 

*"" w 
100 PRE-IMPACT SAMPLE 

(/) 

t: 

z 

::::> 

"' i= 

< 

> 

__, ,b/ 

"' "' 

~ i 100" 

..; 

u 

z BULLET COATING 100 "' u 

(/) 

"' z 

::;: 

::::> 

__, 

0 

::;: 

"' "' :I: 

..... 

0 

100" 

TEMPERATURE, IN 

DEGREES CENTIGRADE 

EXPLANATION 

1:30 

----1:10 Scale factor 

- -- - · - 1:3 

Room temperature 

• 

Sample location 

400" 

400" 

100 

0 

10 ) 

100 

0 

100 

0 1 INCH 

0 

FIGURE 272.2.-Effects of impact on thermoluminescence of Yule marble in the direction of penetration of projectile. 

V-1 

100" 400" 

V-2 . -

100" 400" 

V-3 ---

.---I 

j_ -

I ---:::1 

/"/ 

.· / -

100" 400" 

V-4 

·-~ 

/ 

I 

/ 

i 

I 

~~~-' 

100" 400" 

? 

C/.:) 

~ 

~ 

0 

M 

0 

t-< 

0 

0 

..... 

0 

> t-< 

U1 

q 

~ M 

~ 

;l:l 

M 

U1 

M 

> 

;l:l 

0 

~ 

..... 

co 

Cl 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-2 9 2 C-345 

The thermoluminescence was not completely 

destroyed :in either the pre-impact sample or sample 

V-2 by preheating the samples to 400°C for 16 hours 

before obtaining t.hei r glow curves (fig. 272.3). This 

persistence of thermoluminescence is o:f interest because heating of samples at 400°C for less time has 

been considered sht.ndard trenJment·. for eornplet'ely 

dest-roying t-l1e thermoluminescence of any sample 

( J\ ngino, 1959). 

0 

"' ... 

z 100 ::> 

~ 

~ IX 

!: 

..; 

(.J 

z 

g 

z 

i 

:3 

0 

:IE 

IX 

~ 

PRE-IMPACT SAMPLE 

I 

: 

I 

/ / I T T 100' c 

L"'/ 

: 

400' c 

100 ~~P~O~ST~-I=MP=A~CT~S=A~M~PL=E~V~-2~~ 

I 100' c I I 

/ 

400' c 

GLOW CURVES OF YULE MARBLE OBTAINED AFTER PREHEATING 

SAMPLES AT 400' C FOR 16 HOURS 

PRE·IMPACT SAMPLE 

I 

I 

/ 

/ I T I 

100' c 

T""" 

400' c 

100 r-~PO~S~T-=IM~PA~C~T~SA~M~PL~E~V~-2~~ 

I 

100' c 

'-. / ....... / 

I I 400'-C 

GLOW CURVES OF YULE MARBLE OBTAINED AFTER PREHEATING SAMPLES AT 400' C FOR 16 HOURS 

AND SUBSEQUENT EXPOSURE TO ULTRAVIOLET IRRADIATION (>. =2537 A) FOR4 HOURS 

t Room temperature 

F't:r.u1u~ 272.3.-IDffects of prehe'ating and short-wave ultraviolet 

irradiation on thermoluminescence of pre- and post-impact 

:;;amples of Ynle marble. 

A cmnparison of selected calcite X--ray diffraction 

peaks of the bullet· coat·ing and pre-impact samples 

shows t·hat t"l1e impact-produced shock caused changes 

.in lattice structure of the calcite coating the bullet 

(fig. 272.5). The effect of the impact was to decrease 

t·he amplitude of the peaks and to dull or chop off some 

peaks. The shock produced by impact of the bullet in 

the Yule mn.rble thus caused chttnges in the crystal 

structure of the calcite that may account for some of 

the observed changes in the thermoluminescence. 

601530 o~-61--23 

§ 

2.50.-------------------------, 

1.25-

I 

LEAST SQUARES LINE OF LOG Y ON LOG X FOR 

·140• PEAK (LOG Y =- 0.38 LOG X+ 2.0543 OR 

Y = 113/X0 ·

38 ) 

LEAST SQUARES LINE OF LOG Y ON LOG X FOR 

70' PEAK (LOG Y=-0.92 LOG X+ 1.7188 OR 

Y= 52.3/X0 ·

92 ) 

v Intensity of peak in relative 

thermoluminescence units 

LOG X 

X 

Minutes elapsed after removal 

from radiation source 

2.00 

FIGURE 272.4.-Decay rate of ultraviolet-induced thermoluminescence peaks of post-impact sample V-2. 

l"rA 

lJ \: 1-v62' 28 59' 

v '"' \. 1--

62' 28 59' 

I 

I f 

J J ll\ ~ 

44' 28 35' 

SCALE FACTOR (SF) IS 32 UNLESS NOTED 

' r 

1 

44' 

n 

fl 

u -

·28 

CuK Q 

~n 

7IT -........ "" 

35' 

_./ 

s F64 

SF ·~ 

~ ~ 

31' 28 28' 

./ 

SF ~ 

~ ~ 

31' 28 28' 

Fwmm 272.5.-Effects of impact on X-ray diffraction patterns 

of Yule marble. 
C-346 GEOLOGICAL SURVEY RESEARCH 1961 

REFERENCES 

Angino, E. E., 1959, Pressure effects on thermoluminescence 

of limestone relative to geologic age: Jour. Geophys. 

Research, v. 64, no. 5, p. 569-573. 

Balsley, J. R., 1941, Deformation of marble under tension at 

high pressure: Am. Geophys. Union Trans., v. 22, }). 519-

525. 

Griggs, D. T., and Miller, ,V. B., 1951, Compression and extension experiments on dry Yule marble at 10,000 atmospheres confining pressure, room temperature, pt. 1 of 

Deformation of Yule [Colo.] marble: Geol. Soc. America 

Bull., v. 62, p. 853-862. 

Griggs, D. T., Turner, F. J., Borg, Iris, and Sosoka, .John, 

1951, Effe,cts at 150°C, pt. 4 of Deformation of Yule 

[Colo.] marble: Geol. Soc. America Bull., v. 62, nQ. 12, 

p. 1385-1405. 

Handin, .J. ·w., and Griggs, D. T., 1951, Predieted fabric 

changes, pt. 2 ot Deformation of Yule [Colo.] marble: 

qeol. Soc. America Bull., v. 62, no. 8, p. 863-885. 

Knopf, E. F. B., 1949, Fabric changes in Yule marble after 

deformation in compression: Am. .Jour. Sci., v. 247, 

p. 433-461, 537-569. 

Lepper, H. A., Jr., 1941, Compression tests on oriented specimens of Yule marble: Am . .Jour. Sci., v. 2-:1:7, no. 8, p. 

570-574. 

Turner, F. J., 1949, Preferred orientation of calcite in Yule 

marble: Am . .Jour. Sci., v. 247, no. 9, p. 593-621. 

~rurner, F. J., and Ch'ih, C. S., 1950, Note on survival of 

fabric characters in Yule marble after heating at 700°C: 

Am . .Jour. Sci., v. 248, no. 5, p. 347-352. 

---1951, Observed fabric changes due to deformation at 

10,000 atmospheres confining pressure, room temperature, 

dry, pt. 3 of Deformation of Yule [Colo.] marble: 

Geol. Soc. America Bull., v. 62, no. 8, p. 887-905. 

Turner, F. J., Griggs, D. T., and Ch'ih, C. S., 1950, Fabric 

of Yule marble deformed experimentally at ordinary 

temperatures in absence of water [abs.] : Geol. Soc. 

America Bull., v. 61, no. 12, pt. 2, p. 1512. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-347' 

273. X-RAY POWDER DATA FOR HERZENBERGITE, TEALLITE, AND TIN TRISULFIDE 

By SHIRLEY Mosnuno, DAPHNE R. Ross, PHILIP M. BETHKE, and PRIESTLEY ToULMIN 3d, vVashington, D.C. 

As a preliminary step in an investigation of the 

phase relations and crystallographic properties of 

phases in the system Pb-Sn-S, the X-ray powder 

diffraction data for synthetic SnS (herzenbergite), 

PbSnS2 ( teal1i te) , and Sn2S3 (tin trisu lfide) have been 

indexed. 'rhe three phases were prepared from the 

elements by heating in evacuated sealed silica tubes 

for several days. Synthesis temperatures were 600°0 

for SnS, 750°0 for PbSnS2, and 700°0 for Sn2S3. 

Analyses of the lead and sulfur used are reported by 

Bethke and .Barton (Art. 114, Prof. Paper 424-B). 

The tin used is standard sample 42e of the National 

·Bureau of Standards; semiquantitative spectrographic 

analysis by .IC V. Hazel revealed· only the following 

impurities (in weight precent) : iron, 0.003; silver, 

0.001; copper, 0.001; nickel, 0.001; and vanadium, 

0.0001. 

The crystals of SnS and PbSnS2 are platy and the 

cr·ystals of Sn2S3 are acicular. Both of these habits 

cause preferred orientation of the materials on a 

diffractometer slide. No attempt wn.s made to decrease 

preferred orientn,tion as it does not affect the problem 

of indexing the materials. Because it does affect peak 

intensity, however, the intensities can be reported only 

approximately. All three materials, but particularly 

SnS nnd PbSnS2, are malleable and have a tendency 

to s1near when ground, resulting in poor resolution of 

the pen,ks. Therefore, SnS and PbSnS2 were first 

ground to 11 size suitable for X-ray diffraction and then 

annen.led in evacuated sealed silica tubes at 600° C 

for 2 hours and 24 hours, respectively, in order to 

improve their crystallinity. The diffractometer slides 

were then prepared without further grinding. 

The indexing was accomplished by comparing observed and calculated sin2 8 values for the· reflections. 

The lower limit of observed 28 was 5°. Observed sin2 

8 values were determined from reflections measured 

from tt diffractometer chnrt made on a N orelco wide 

ninge diffrnctometer, using Ni-filtered CuK radiation 

(X= l.54050A). Scanning speed was Xo (28) per 

minute; chart speed was 30 inches per hour. The 

difrerence between observed and calculated sin2 8 was 

then minimized by successive lenst squares npproximations on well-resolved low-angle peaks, most of 

which had been measured against either fluorite or 

silicon as an internal standard. The uncertainty 

reported for the cell edge is the root mean square 

percentage deviation calculated from observed 

d-spacings of the peaks used in the final least squal·es 

analysis. 

From Buerger precession photographs, D. R. Ross 

determined the unit cell of Sn2S3 to be orthorhmnbic 

with space group Pnam and approximate axes a=8.84A, 

b= 14.02A, and c=3.71A. These vn.lues have been 

refined by powder measurements to a=8.79± .03A, 

b=14.02±.05A, c=3.74±.01A. 

All reflections of SnS and PbSnS2 cn.n be indexed on 

the basis of Hofmann's earlier work (1935). Hofmann 

TABLE 273.1.-Indexed powder pattern of herzenbergite (SnS) 

[Spacings dur ralculated for unit cell In space group Pbnm with a=4.328±0.002A, 

b= 11.190±0.004A, c=3.978±0.001A. Intensity ratio based on measurements of 

height above background] 

durA IX 100 

I mal• Observed 

5 4. 036 

10 3. 421 

15 3. 243 

5 2. 929 

25 2. 831 { 

100 2. 793 

15 2. 305 

1 2. 123 

10 2. 024 

10 1. 988 

5 1. 874 { 

5 1. 778 

1 1. 721 

5 1. 713 

1 1. 694 

5 1. 689 

5 1. 622 

5 1. 454 

5 1. 451 

1 1. 403 

70 1. 399 

1 1. 320 

1 1. 286 

5 1. 262 

5 1. 195 

5 1. 14;5 

1 1. 084 

5 1. 081 

5 1. 078 { 

1 1. 041 

1 1. 025 

1 . 9741 { 

1 . 9613 

1 . 9521 

15 . 9326 

1 . 9238 

1 . 9212 

1 . 9082 

1 . 8892 

1 . 8887 

5 . 8792 

5 . 8444 { 

Calculated 

4. 037 

3. 425 

3. 243 

2. 929 

2. 834 

2. 826 

2. 798 

2. 304 

2. 125 

2. 023 

1. 988 

1. 874 

1. 874 

1. 779 

1. 720 

1. 712 

1. 694 

1. 689 

1. 621 

1. 452 

1. 449 

1. 403 

1. 399 

1. 320 

1. 286 

1. 262 

1. 195 

1. 145 

1. 084 

1. 081 

1. 078 

1. 078 

1'. 041 

1. 024 

. 9741 

. 9738 

. 9610 

. 9514 

. 9326 

. 9231 

. 9207 

. 9080 

. 8894 

. 889 

. 8793 

. 8444 

. 8443 

hkl 

110 

120 

021 

101 

111 

130 

040 

I 131 

210 

I 141 

I 150 

022 

211 

I 151 

122 

I 240 

231 

I 061 

I 042 

212 

251 

171 

I 080 

1 081 

1 270 

I 181 

I 190 

I 191 

1·10·0 

063 

342 

290 

I 291 

192 

450 

381 

1·11·1 

1·10·2 

I 0·12·0 

273 

2·11·0 

0·12·1 

154 

2·10· 1 283 

2 

2 

0 

0·12· 

1·13· 

1 Reflections measured against fluorite Internal standard and used In final least 

squares computation. 
C-348 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

TABLE 273.2.-lndexed powder pattern of tealli(e (PbSnS2). 

[Spacings du1 calculated for unit cell in space group (Pbnm with a=4.266±0.003A, 

b=ll.419±0.007A, c=4.090±0.002A. Intensity ratio based on measurements of 

height above background] 

IXJOO du1A 

Imu. 

Observed Calculated 

----

5 3. 993 3. 999 

10 3. 416 3. 417 

V> 3. 327 3. 324 

!) 2. 952 2. 951 

100 2. 856 { 2. 859 

2. 855 

10 2. 334 2. 333 

1 2. 096 2. 097 

10 2. 052 2. 052 

5 2. 014 2. 011 

5 1. 861 1. 861 

5 1. 8077 1. 8064 

1 1. 75f)1 1. 7546 

5 1. 7390 1. 7379 

5 1. 7250 1. 7254 

1 1. 6926 1. 6936. 

,1) 1..6620 1. 6622 

1 

1. 4293 

10 1. 4282 1. 4280 

1. 4274 

2 1. .2161 1. 2162 

1 1.1719 'l. 1704 

5 1. 1663 { 1. 1665 

1. 1656 

1 1. 1031 1. 1030 

5 1. 1004 { 1. 0999 

1. 0997 

1 1. 0536 1. 0537 

1 1. 0457 1. 0453 

1 0. 9793 { 0. 9796 

0. 9793 

1 . 9707 { . 9709 

. 9706 

1 . 9520 . 9516 

1 . 9340 . 9334 

1 . 9271 . 9269 

1 . 9060 . 9057 

1 . 8630 . 8627 

1 . 8606 . 8603 

1 . 8421 { . 8426 

. 8419 

I Reflections measured against fluorite internal standard. 2 Reflections used in final least squares computation. 

hkl 

12 110 

1 2 120 12 021 1 2 101 

1 111 

040 1 2 131 

210 I 2 141 

I 150 

2 230 I 2 151 

122 

2 160 

2 061 

231 

2 042 

222 

171 

080 

2 190 

082 

191 

262 

1. 10. 0 

0. 10. 1 

233 

291 

192 

124 

1. 11. l 

1. 10. 2 

441 

0. 12. 0 

2. 11. 0 

0. 12. 1 

1. 12. 1 

0. 12. 2 

1. 13. 0 

373 

1. 13. 1 

detenninecl .the space group as Pmcn; we have chosen 

the alternate setting Pbnm, in agreement with the 

isostructural GeS (Sn1ithells, 1955, p. 216-217). The 

axes have been refined as follows: SnS a=4.328± .002A, 

b= 11.190± .004A, c=3.978± .001A; PbSnS2 a=4.266± 

.003A, b=11.419±.007A, c=4.090±.002A. 

Tables 273.1, 273.2, and 273.3 present the indexed 

powder patterns. For SnS, there are 143_ additional 

pennissible reflections in the range 5° to 140° 20, 

98 of which are above 80° 20. For PbSnS2 there are 

TABLE 273.3.-lndexed powder pattern of tin trisulfide (Sn283). 

[Spacings du1 calcnlatcd for unit cell in space group Pnam with a=8.79±0.03A, 

li=l4.02±0.05A, c=3.74±0.01A. Intensity ratio based on measurements of height above background] · 

IXlOO du1A 

I;;.:; 

Observed Calculated 

40 7. 003 7. 011 

75 5. 495 5. 481 

10 4. 433 4. 394 

100 4. 131 4. 126 

35 3. 740 3. 723 

15 3. 346 3. 344 

30 3. 257 3. 256 

25 3. 215 3. 201 

5 3. 095 3. 091 

25 2. 890 2. 921 

5 2. 859 { 2. 868 

2. 849 

15 2. 801 2. 792 

35 2. 747 2. 740 

45 2. 670 2. 672 

5 2. 646 2. 640 

5 2. 495 2. 482 

5 2. 460 2. 455 

20 2. 368 2. 364 

5 2. 334 2. 337 

25 2. 257 2. 259 

10 2. 244 { 2. 248 

2. 244 

5 2. 215 2. 211 

10 2. 112 2. 097 

10 2. 065 { 2. 069 

2. 063 

10 2. 002 l. 999 

10 1. 952 l. 953 

10 1. 933 { l. 934 

1. 927 

5 1. 873 { 1. 878 

1. 871 

5 l. 841 l. 827 

{ l. 756 

5 l. 751 l. 753 

l. 744 

5 1. 6568 1. 6535 

10 1. 5813 1. 5808 

5 1. 5616 l. 5620 

10 1. 4771 l. 4802 

1 

l. 3765 

10 1. 3772 l. 3755 

l. 3746 

1 Reflections measured against silicon internal standard. 2 Rcficctions used for final least squares computation. 

hkl 

12 020 12 120 l2 200 

I 2 130 !2 220 I 2 111 

I 2 140 12 230 I 2 121 

I 2 031 I 2 310 

201 

2 211 

2 240 

2 150 

2 221 

2 330 

2 141 

2 250 

2 060 

2 160 

I 340 

051 

2 241 

420 

331 

260 

2 251 

2 170 

2 161 

341 

411 

002 

360 

431 

080 

510 

2 370 

2 511 

181 

2 470 

471 

390 

352 

159 additional perm.issible reflections in the range 5° to 

140° 20, 105 of w·hich are above 80° 20. For Sn2S3, 

there are 77 additional permissible reflections in the 

range 5° to 70° 20. 

REFERENCES 

Hofmann, Wilhelm, 1935, Ergebnisse der Strukturbestimnnmg 

komplexer sulfide: Zeit;schr. fiir Kri'stallographie, v. !)2, 

p. 161-185. 

Smitbells, C. J., 1955, Metals reference book, v. 1: London, 

Butterwortbs Scientific Pub., 531 p. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14,7-2 9 2 

GEOLOGY AND HYDROLOGY APPLIED TO ENGINEERING AND PUBLIC HEALTH 

274. DEFORMATION AND STRESS DISTRIBUTION AROUND COAL MINE WORKINGS IN SUNNYSIDE 

NO. 1 MINE, UTAH 

By FRANK ,V. OsTERWALD, Denver, Colo. 

Work done in coo1wra.tion with the U.S. B1trea1t of Mines 

Ribs, floors, and roofs in the Sunnyside No. 1 mine, 

Utah, show evidence of premining and post-mining 

deformation indicating that the coal and surrounding 

rocks are highly stressed. 

Small deformationn.I features in the mine, and the 

distribution and intensity of rock failures provide an 

insight into the stress distribution aronnd the mine 

workings. These small features include fracture zones, 

joints, cleavage, curved shear fractures and faults in 

coal, faults and joints in rock, and deformed roof 

bolts, bent landing mats, broken crossbars, bent, 

broken, and tilted timbers, and bent trade Although 

the surface topography is rugged and coal is mined 

from depths as great as 2,500 feet, deformation 

(structural) features in the mine indicate that compressionn.l deformation resulting from lateral stress 

components is greater than deformation from vertical 

stress (load). T'ensional deformation of mine workings .is clearly superficial and appears to result- from 

components of the predominantly compressional stress. 

Deformation of workings strongly indicates high 

lateral stress, and the strong deformation of southeast · 

ribs of slopes n,nd northeast ribs of entries (fig. 274.1) 

indicates asymmetric stress distribution. 

l\1ost of the joints, cleavage, fracture zones, and 

faults in the ribs are of premining age because their 

orientation :is closely parallel to that of the regional 

joint and fault pattern at the surface. Curved shear 

fractures commonly observed in ribs :tre of post-mining 

age. Ribs are also deformed by movement of coal into 

the "·orkings, commonly along contacts "·ith shale . 

above and coal below. Such contacts become shear 

pln,nes along which coal is "underthrust" into openings. The top of the coal commonly is in contact "·ith 

shale and other argillaceous rocks and slips much more 

ren,dily than the bottom, '\vhich commonly is in contact 

with coarse-grained siltstone. Slight expansion of coal 

that is thrust into openings causes numerous tension 

fractures to form. If fracture zones are present, the 

expansion causes individual fractures to open slightly. 

'I'he slow movement of coal, which is loosened because 

of expansion, produces rnany slivers and columns of 

coal that separate from ribs and fa.H into workings 

(fig. 274.2). Coal also moves into some workings by 

creep, which amounted to as much as 2 feet in lJ: years 

as measured from roof bolts that are now covered by 

coal from the ribs (fig. 274.3). Some ribs bulge outward into the workings and buckle nea,r the middle. 

Bulged and buckled ribs apparently result from friction bet,Yeen siltstone roofs and coal (fig. 27 4.6). 

Deformation of fioors commonly produces domes 

and anticlines in siltstone below the coal beds. Anticlines are as much as 100 feet long. and have a structural relief of as much as 1 foot. Tension along the 

crests of some anticlines produced sm:tll cross fractures, some of which have as much as 2 inches vertical 

displacement (fig. 274.4) because of gravitational 

collapse of the crests. Cores of the domes and anticlines are commonly ho1low, suggesting that the folds 

formed by slipping along bedding planes or along thin 

coal splits within the siltstones. I-Iigh vertic:tl compressional stress in pillars adjacent to workings probably produces lateral stress in the uppermost bed of 

the floor that causes upward folding. 

Deformation of unsupported roofs, or of roofs supported lightly, commonly produces "synclines~: that 

are parallel to the mine openings. Such "synclines~~ 

result from lateral components of compressi\re stress in 

the lowermost beds of the .roof. Tensional components 

of stress along the troughs of the "synclines" commonly produce smaH fractures parallel to the mine 

workings. The fractures allow blocks of rock to loosen 

and to fall into the workings. 

Deformation of roofs that are strongly supported 

by timber, crossbars, and roof bolts is different from 

that of lightly supported roofs. Such crossbars are 

commonly bent downward and snapped off (fig. 274.5). 

The bending and breaking are not the result of clownward pressure, but of horizontal stress against the 

ends of the crossbars and against the rocks above 

them, thus forcing the timber and rocks downward into 

the openings. The breaks in some crossbars can be 

traced upward into shear frn,ctures in the roof. 
C-350 GEOLOGICAL SURVEY RESEARCH 19 6 1 

N 

1 

0 40 FEET 

EXPLANATION 

D 

Coal 

Siltstone 

Contact 

Outline of mine workings 

Cross-bar and dashes indicate caved workings 

Concrete stopping 

zzzzzr;z;zz; t 

81 

Fault, with dip where shown Dashed where inferred; cross-hatched where broad zone 

D 3 in 

Fault, with downthrown side and 

displacement, where shown 

---,- Strike and dip of beds 

Strike and dip of joint 

1\ 1\ 

Bedding-plane shear 

Arrows indicate direction of movement of lower plate 

• Deformed roof bolt 

\\ 

Deformed landing mat 

Bi Tilted timber, with plunge, 

where shown 

Broken ' timber 

Geology by F. W. Osterwald and 

R. E. Eggleton, August 1958 

FIGUHE 274.1.-Undergroun'd geologic map of righ't-hand air course at Sunnyside fault zone, main slopes, Sunnyside No. 1 mine, 

Utah. Plane mapped is roof. 

'\Vhenever an opening is made in a rock, the vertical 

load formerly supported by the remo\'ed rock is added 

to the adjacent rocks. Lateral stress formerly transmitted by the removed rock ''"ill be added to the rocks 

above and below the opening, and, in addition, lateral 

stress components of vertical stress cause strong deformation of ribs. The tensional deformation of \Yorkings in the Sunnyside No. 1 mine resulting. from 

strong lateral and vertical compressive stress produces a narrow zone of reduced stress around nunc 

workings similar to "yielded" or "destressed:: zones 

observed in other mines (I-Io11ancl and Thomas, 1Df>4, 

p. 7-15; Spackeler, 1958, p. 316; Serata and Gloyna, 

1960, p. 2081-2986). Ann.lysis of observed directions 

of movement along shear planes indicates that inclinations of principal stress directions range from vertical 

in the roof to near 45° in the ribs (fig. 274.6). Although differing degrees of adhesion between coal and 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-351 

FIGURE 274.2.-Arcuate slabs of coal in rib resulting from 

movement along curved shear fractures that flatten iu clip 

upward and probably downward. Fracture zone striking 

into rib at high angle causes splinters, slabs, and columns 

of coal to separate and fall into working. Photograph by 

J. C. Witt. 

FIGURE 274.4.-Floor anticline (hea,·e) in thin-bedded siltstone 

in left-hand air course near main parting. Smm~-;:;ide Xo. 1 

mine, Utah. Crest of anticline, marked by irregular longitudinal fault, trends obliquely to direction of mine working. 

Cross faults with as much as 2 inches of displacement cut 

crest. Photograph by J. C. Witt. 

FIGURE 274.3.-Rib coal mo,·ing b:> creep into right-hand manway at first right entry, Sunnyside No. 1 mine, Utah. Coal 

is deforming and covering roof bolt to left of scale. Photograph by J. C. Witt. 

FIGnm 274.ii.-Broken timber crossbars, in incoming air course, 

main slopes above main parting, Sunnyside No. 1 mine. 

Utah. Horizontal stress from ribs has broken timbers, and 

horizontal stress in roof created shear fracture in rockR 

above break in timbers. Another shear fracture extends 

upward in roof from intersection with left rib. 
C-352 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

Coal Min~ working Coal 

Medium- to finegrained siltstone 

·:: ::· . . .·..... . .. ·· ... ·:::>·:··:: .. ··:·::::::: .. :.:.:.:·:·.·: ..... :·.:-.::·:· ........... ·.· . .'. · ... . :-:.-... :.:.::-.: .. ·.:·:.-.::: ... :: . . ·.· ::""····=:·::·~:·:::;:.::·:·=::' .... -;;; ............ : .. · .. :· :.;/ 

:: . ··. .. .... :~.:.: .. : .. :.: .. : ·. :··... ·. : :'. :. . ............ ; .:·:: · ... : : .· :·.'_.·.:::::: ... :: · ...... ::. :. ·. :::. :. ···: ·: .. : ..... : .. ': ·:.: ·:.·::.'..:":.; .. :· .. ·.:- ...... ::·:::: ..... ,: 

Small she~,~ fractures-?~ j 

Coal I 

I 

/J 

Mine working Coal 

I) 

B 

FIGURE 274.6.-Diagrammatic sections showing deformation and stress distribution around worldngs in Sunnyside 

No. 1 mine, Utah. Diagonally lined areas are hollow. A, Roof synclines, floor anticlines, curved shear fractures, and resolution of principal stress components ( ua, where coal slips along clayey roof but adheres to 

coarse-grained siltstone floor. B, Bulged and buckled ribs where coal adheres to roof and floor. 

floor causes differences in the type of deformation observed in ribs, orientations of stress components are 

the same (fig. 27 4.6). Because lateral stress causes 

roofs to act as prestressed beams (Corlett and Emery, 

1959), roof control measures should be adequate to 

resist both the movement of coal and rock il'tto mine 

openings and the superficial tensional deformation due 

to bending in order to preserve the beams. Thus the 

rocks themselves can support much of the supernlcumbent load. 

Geologic examination of small deformational features in mines will reveal what types of deformation 

are present and will permit the stress distribution 

around openings to be predicted. ~1ining engineer~ 

can take advantage of such geologic features for more 

effective design of mine layouts and artificial supports. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 9 2 C-353 

Studies of deformation in salt mines enabled Dellwig 

(1958) to suggest remedial measures for buckling of 

floors. Studies o:f postmining deformation should aid 

similarly in the designing of many other kinds o:f 

underground openings. 

REFERENCES 

Corlett, A. V., and Emery, C. L., 1959, Prestress and stress 

redistribution in rocl\:S around a mine opening: Canadian 

Mining Metall. Bull., v. 52, p. 37.2-384. 

Dellwig, L. F., 1958, Flowage in rock salt at Lyons, Kansas: 

Kansas Geol. Survey Bull. 130, p. 166-175. 

Holland, C. T., and Thomas, Edward, 1954, Coal-mine bumps; 

some aspects of occurrence, cause and control: U. S. Bur. 

Mines Bull. 535; 37 p. 

Serata, Shosei, and Gloyna, E. F., 1960, Principles of structural 

stability, of underground salt cavities: Geophys. Research Jour., v. 65, p. 2979-2987. 

Spackeler, Georg., 1958, Observations on the distribution of 

stress around coal and salt workings : Akad. "'iss., Berlin, 

Section fiir Bergbau, [Internat. Strata Control Cong., 

1958, Leipzig, English translation p. 305-319]. 

275. HYDROLOGIC EFFECTS OF URBAN GROWTH-SOME CHARACTERISTICS OF URBAN RUNOFF 

By ARvi 0. WAANANEN, Menlo Park, Calif. 

The concentration of two-thirds of our population in 

urban and suburban areas, and the accelerated development of suburban centers and strip cities with 

associated improvement in highways gives rise to 

growing concern about storm drainage from those 

areas. 

I-Iydrographs of runoff from natural areas reflect the 

influence of topographic characteristics, geology, vegetation, infiltration and percolation, evaporation and 

transpiration, land use, and related hydrologic and 

meteorologic factors. The physical changes associated 

with urban growth modify the surface characteristics 

and drainage patterns. As a result, the timing, intensity, and distribution of runoff, and the shape of the 

flood hydrograph are affected. The effects on individual storm-drainage systems may be evaluated using 

procedures and data now available. Few data aFe 

available, however, to define cumulative impact of 

urban growth on downstream receiving channels and 

streams. 

The impact of urban development on streamflow is 

demonstrated in figure 275.1, which presents runoff 

hydrographs of Onondaga Creek at two locations in 

Syracuse, N. Y. These hydrographs demonstrate runoff characteristics evident in records for many streams 

flowing through developed areas. Records for the 

Dorwin A venue gage (drainage area, 88.9 square 

miles) at the southern edge of the city define characteristics of runoff from a predominantly rural area. 

Runoff at the Temple Street gage 4.9 miles downstream (from stage records collected by the Syracuse 

City Engineer's Office) is affected by drainage from 

substantial areas of development in the city. The 

drainage area at the Temple Street gage is approximately 103 square miles, but the actual area contributing storm runoff is not known. I-Iigh flows from 68.1 

square miles of the drainage basin have been regulated 

since 1949 by Onondaga Reservoir (18,200 acre-feet 

capacity) on Onondaga Creek at Nedrow, N.Y. 

The sharp peak at the Temple Street gage preceding 

the usual flood peak from upstream illustrates a significant characteristic of urban runoff. Short-duration, 

high-intensity summer storms (such as those that occur 

in central New York), may in urban areas cause sharp 

flood peaks that are considerably higher than flood 

peaks generally in the basin. The hydrograph of the 

flood of August 1953, for example, indicates an urban 

flood peak of 860 cfs, as contrasted to only 132 cfs 

from upstream flows. Although individual flood peaks 

vary in magnitude, the average of 16 peaks representing urban runoff in Syracuse was nearly three times 

greater than the average of corresponding peaks 

representing regulated flow from Onondaga Reservoir 

plus natural storm runoff between the reservoir and 

Syracuse. These runoff events were the result of summer storms during the period 1952-1958. The increase 

\n runoff at the Temple Street gage during the storm 

periods appeared to be greater than the amount 

normally attributable to the intervening area and reflects differences in overland flow, retardation, de pres-
C-354 GEOLOGICAL SURVEY RESEARCH 19 61 

500 

...... , 

I ' I -...... ~--Onondaga Creek at Temple Street, f ' 

Cl Syracuse, N.Y. I \\ z 

0 

() 

I.LJ 

en 

a:: 

I.LJ 

a_ 

fI.LJ 

I.LJ 

LL. 

I 

I 

i' ,-J 

I \ 

I \ 

I \ 

I \ 

I \ 

I \\ 

I ' 

I ' I ', 

I 

I 

I 

I 

I 

~ 

w 

(.!) 

a:: 

<( 

G 5o 

,_ I I \ I 

I \ I 

I \ / 

en 

a 

I 

I \j 

) 

I 

I 

I - I 

I 

I 

I 

I 

I 

I Onondaga Creek at Dorwin Avenue,___,_j 

I Syracuse, N.Y. ·1 

I -, I 

\,_/,.-./ 

I 

I ,........-,I // 1/ 

IJ 

I 

, 

I 

) 

QL---~----,8,----J----~9~--~----~1~0-----L----------L---~3~0~---L----3~1~--~---~1~--~---~ 

AUGUST 1953 AUGUST-SEPTEMBER 1954 

FIGURE 275.1.-Hydrographs of storm runoff in Onondaga Creek basin, Syracuse, N.Y., comparing flows at the Dorwin Avenue 

nnd 'l'emvle Street gages during storms of August 8 to 10, 1953, and August 30 to. September 1, 1954. 

sion and subsurface storage, and seepage, a result of 

urbanization. 

The principal floods in Onondaga Creek usually 

result from substantial and sustained basin-wide 

rainfall. Urban runoff from such storms usually is 

nearly proportional to basin runoff. 1\l[aximum discharge at the Dorwin Avenue gage during the 

period 1951 to 1959, for example, was 1,960 cfs on 

,January 22, 1959 (probably about two-thirds of 

the unregulated peak). An unregulated peak flmy 

of 3,980 cfs occurred December 30, 1942 at a former 

gage on Onondaga Creek (drainage area, 98.2 

square miles) 2.2 miles downstream. Although these 

peaks exceed those from local runoff, the accelerated 

and rapid runoff from urban areas following 

thunderstorms creates significantly large peaks and 

raises the n1agnitude of floods of a given frequency. 

Available records for streams that drain natural 

and urbanized areas in northern New Jersey, ~1:ichigan, Pennsylvania, and Virginia indicate that peak 

runoff from developed areas on the average is three 

to four times those from upstream or adjaeent 

natural areas. 

The degree of change may be illustrated further 

by several examples. Tholin and IGefer (1950), in 

their computation of urban runoff at Chicago using 

the "Chicago Hyclrograph ~1ethocl", show that industrial and commercial areas may produce flood peaks up 

to 3lj2 to 4 tin1es greater than those from single-family 

residential suburban areas. Ramey (1959), in his 
tLI,J 

LI,J 

u.. 

uJ 

a: 

u 

<( 

0 

z 

<t 

C/) 

::> 

0 

:I: 

t-

~ 

~-

0 

....J 

1..1.. 

t-

::> 

0 

L.IJ 

> 

t= 

<( 

....J 

::> 

~ 

::> 

u 

60 

50 

40 

30 

20 

10 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14t7-292 C-355 

/ 

/ 

1955 

./ 

/ 

Inflow: sum of flows of Permanente Creek at Holly 

Ranch, Los Altos, and Magdalena Creek near Magdalena Road, Los Altos 

Outflow: flow of Permanente Creek at California 

Street, Mountain View 

Q~---------1~0----------~20-----------3~0----------4~0----------~5-0----------6LO--------~ 

CUMULATIVE INFLOW, IN THOUSAND ACRE-FEET 

Jrnnmt~ 27fi.2.-Douhle-mass curve of inflow and outflow, Permanente Creek basin, Los Altos and Mountain View, Cal'if., 1939-58, 

<:ompariug- iuflow (the smn of flows of Permanente Creek at Holly Ranch, Los Altos, and Magdalena Creek near Magdalena 

Rond, Los Altos) with the outftow, Permanente Creek at California S'treet, Mountain View. 
C-356 GEOLOGICAL SURVEY RESEARCH 19 61 

analysis of flows in the Chicago Drainage Canal states, 

"* * * in the Chicago area, within the past 30 years 

the runoff, from one cause or another, has increased 

two and a half times", and reports that several floods 

exceeding 25,000 cfs occurred since 1948 in a canal 

originally designed to carry 10,000 cfs. The Bigwood 

and Thomas ( 1955) formula for determination of 

mean annual discharge of floods in Connecticut is 

QM=OJJAS in which A is the effective area, S the basin 

slope, and 0 B the watershed coefficient. 0 B is only 0.85 

for the state as a whole, but it is 3.0 for urban-residential areas. 

Urban development thus may affect flood flows substantially. It has been postulated that the annual runoff from developed areas should not differ materially 

fron1 that occurring before development. The timetable for runoff, however, differs significantly. A substantial part of the flow from urban areas will occur 

during a short period follo-wing the storm, primarily 

as overland flow to streets, gutters and sewers that 

discharge promptly into the receiving channels and 

streams. The quick runoff reduces evaporation and 

transpiration opportunity, as well as infiltration and 

percolation. 

Figure 275.2 illustrates a change in runoff characteristics following urban development. A double-mass 

curve of inflow and outflow in a portion of the 

Permanente Creek basin in Los Altos and l\1ountain 

View, Calif., in which ground-water recharge occurs, 

based on records obtained by the Santa Clara Valley 

Water Conservation District during the period 1939-

1958, shows a sharp change in the relationship in 1955. 

Intensive urban residential development took place 

in the intervening area between 1953 and 1955 and is 

continuing. The physical changes include installation· 

of streets, gutters, other paved areas, and short storm 

sewers discharging into Permanente Creek. Outflow 

from this recharge reach was only 76 percent of the 

inflow during the period 1939-1955, but increased to 

123 percent of the inflow during 1956-1958, thus 

demonstrating the change in the relationship of infiltration, recharge, and local runoff since 1955. 

A few other appropriate streamflow records.indicate 

increases in total runoff from developed areas. 

Analysis of mean annual flows in Connecticut, using 

the same parameters as for the flood-flow formula, 

indicates coefficients of 0.017 for normal and 0.036 

for urban areas in the formula QA=O(AS)1. 2 , or a 

twofold increase. 

There is a paucity of information about urban runoff characteristics. A few studies by federal, state, and 

local agencies of urban flood hydrology are underway, 

including the project of the Geological Survey in San 

Francisquito Creek basin at Menlo Park, Calif., for 

evaluation of hydrologic changes as lands are converted from rural to urban residential use. 

REFERENCES 

Bigwood, B. L., and Thomas, M. P., 1955, A flood flow formula 

for Connecticut: U.S. Geol. Survey Circ. 365, 16 p. 

Ramey, H. P., 1959, Storm water drainage in the Chicago 

area: Am. Soc. Civil Engineers Proc., v. 85, HY4, Paper 

1995. 

Tholin, A. L., and Kiefer, C. J., 1959, The hydrology of urban 

runoff: Am. Soc. Civil Engineers Proc., v. 85, SA2, Paper 

1984. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14r7-292 C-357 

276. ENGINEERING GEOLOGY AND THE CHILEAN EARTHQUAKES OF 1960 

By EnNEST DonnovoLNY and RrCI-IARD ,¥. LEl\IKE, Ashland, 1\:y., and Denver, Colo. 

W01·Tc llonc in coope1·ation with the Chilean Institnto de Investigaciones Geologico 

The authors spent most of the month of ,July 1960 

doing geologic investigations of the cities of Concepcion, Valdivia, and Puerto l\1ontt. During this time 

they worked closely with geologists of the Chilean 

Instituto de Investigaciones Geologico and with other 

geologists of the U.S. Geological Survey stationed in 

Chile. This paper incorporates the work of all these 

geologists. 

REGIONAL EARTHQUAKE EFFECTS 

Earthquakes of high mag-nitudes shook southern 

Chile in l\1ay and .June 1960. The first shock, of magnitude 7.5 (Richter scale), occurred l\1ay 21. The main 

shock, of magnitude approximately 8.5 (Duke, 1960) 

and epicenter south of Lebu (Pierre St. Amand, written communication), came l\1ay 22 at 3 :15 p.m. local 

time. Other significant shocks occurred as late as June 

20. Depth of focus of the shoc}\:s was about 50 km 

(Duke, 1960). I-Iighest intensities, reaching XI on the 

l\1ercalli scale, were along the coast from Lebu to 

south of Ancud (St.. Amand, 1960). 

Surface faulting attributable to the earthquakes was 

not observed, although altitude changes, probably due 

to movement along a north-trending pre-existing fault 

zone, occurred along the coast. In the vicinity of Lebu 

the land rose 1112 m; from Puerto Saavedra to south 

of Ancud (fig. 276.1) the coast sank 1 to 2 m (St. 

Amand, 1960). Landslides, debris flows, fissures caused 

by lateral displacement, liquification of deposits, and 

subsidence resulting from compaction "-rere common. 

Large landslides of glaciofluvial and lacustrine deposits dammed the outlet of Lake Rinihue. 

A tsunami followed the major shock;· waves 10 m 

high (St. Amand, 1960) swept the shoreline in the 

vicinity of Ancud causing great loss of life. The 

tsunami traveled n,cross the Pacific Ocean at nearly 500 

mph reaching I-Iilo, I-Iawaii about 14 hours later where 

it caused much loss of life and property (l\1urata, 

1961). Disastrous effects reached as far as ,Japan. 

Volcano Puyehue started a flank eruption on l\1ay 

24. It threw cinders, ash, vapor, and gas for several 

weeks, terminating in an eruption of a small quantity 

of viscous lava (Pierre St.. Amand, oral communication). 

About 4,000 people were killed by the earthquakes 

and tsunami (Duke, 1960). Property damage, estimated at about $400 million, was particularly high in 

the cities of Concepcion, Valdivia, and Puerto l\1ontt. 

EARTHQUAKE EFFECTS IN CONCEPCION 

Concepcion, a city of about 40,000 people on the 

north side of the Bio Bio River, is built mostly on 

Quaternary alluvium about 30 m thick (Galli 0. and 

Sanchez R., 1960), on terraces of sand, clay, silt and 

gravel, and on artificial fill. Hills composed of marine 

and continental sediments of Cretaceous or Tertiary 

age locally project through the alluvium. Granitic 

rocks of tTurassic or Cretaceous age and metamorphic 

rocks of Paleozoic age underlie low hills along the edge 

of the city. 

Earthquake intensities were between VIII and IX 

on the l\1ercalli scale (Duke, 1960; '¥ atanabe and 

1\:arzulovic, 1960). Ground motion of the l\1ay 21 

shock was north-south; the l\1ay 22 shock movement 

was first north-south and then east-west (Fred IC 

Coleman, oral communication). 

A direct relation between ground conditions and 

amount of damage to buildings was not demonstrable 

from field studies in this city. There is, however, a 

direct relation between damage and the kind of material that "·as used in construction. This relation was 

scaled for mnny types of building materials (Galli 0. 

and Sanchez R., 1960). Reinforced concrete buildings 

generally sustained little or no damage whereas adobe 

buildings or brick buildings with mud mortar and tile 

roofs sustained almost complete to complete damage. 

''Tooden buildings sustained little damage even \Yhere 

located on alluvium or artificial fill. Concrete roadbeds on artificial fill, such as the approach to the bridge 

over the Bio Bio River, however, were fractured and 

differentially displaced. 

The earthquake shocks caused landslides in surficial 

materials, differential compaction in alluvial deposits 

and artificial fill, and eruption of water, sand, and mud 

from fissures. The landslides were generally small. 

Local differential compaction in alluvial deposits and 

in artificial fill was estimated to be as much as 40 em; 

however, the total regional amount of settlement of 

the alluvium clue to compaction is unknown (Galli 0. 

and Sanchez R., 1960). "Tater, sand, and mud erupted 

from fissures in tidal flats and cultivated fields near 

the mouth of the Bio Bio River; ridges and cones of 
. C-358 GEOLOGICAL SURVEY RESEARCH 19 61 

sand as much as 10 em high and 5 to 70 em across were 

formed (Segerstrom, 1960). 

EARTHQUAKE EFFECTS IN VALDIVIA 

Valdivia, a city of about 60,000 persons, lies on both 

sides of the estuary of the Rio Calle Calle, which has 

its principal source in Lake Rinihue. The city is built 

on alluvium and eolian deposits of Tertiary and 

Quaternary age as much as 150 m thick. Metamorphic 

74" 

34" 

36" 

38" 

Ill 

\.:> 

..... 

k, 

..... 

\.:> 

40" "t: 

0.. 

42" 

0 

FIGURE 276.1.-Index 

70" 

SANTIAGOt * I 

J 

I , 

I 

s ... § l 

.\ 

.. ' 

J··· , (J 

., , 

, 

( 

I 

' 

.. J .:'$ 

~ 

~ \ ~ & 0 I 1<: 

"' , 

rJ 

Q , 

o. 

~ ~ ' Mt Puyehue 

' ' 

\ 

' l 

J 

I 

100 200 KILOMETERS 

map of southern Chile. 

FIGURE 276.2.-Street in Valdivia showing destruction of houses 

built on artificial fill and alluvium. 

rocks of undetermined age underlie these deposits 

(Watanabe and Karzulovic, 1960, p. 52). 

Highest shock intensity in the city was X on the 

Mercalli scale on May 22 (Duke, 1960). Ground motion 

was undulatory and slow; there ''as no unanimity of 

opinion as to the direction of the movement (Doyel, 

Moraga B., and Falcon M., 1960). 

Principal effects and resulting damage to man-made 

structures of the earrl1quake shocks were settlement of 

the land surface as much as 2 m below mean sea level 

along the estuary of the river in the city, fracturing 

and differential settlement in Quaternary deposits and 

artificial fill, and slumping. Settlement and resulting 

damage caused by compaction of artificial fill and 

alluvium in an abandoned watercourse are illustrated 

on figure 276.2. Slumping and associated fracturing 

of Quaternary deposits and artificial fill occurred along 

the banks of the Rio Calle Calle (fig. 276.3). Evidence 

of faulting was not observed. Subsidence appears to 

be due to both tectonic down-warping and to compaction of unconsolidated materials. The amount attributable to either cause cannot be determined until firstorder levels are rerun. 

EARTHQUAKE EFFECTS IN PUERTO MONTT 

Puerto Montt, a city of approximately 33,000 persons, lies on the north edge of the Bay of Reloncavi. 

No bedrock is exposed in the city. Stratified glacial 

deposits of sand and gravel, more than 30 m thick, 

form steep cliffs and well-defined terraces that flank 

the bay in most places. 

The residential part of the city lies mostly on hYo 

terraces at altitudes of 45 m and 107m; the business 

district is built mostly on alluYium, debris fiO\YS, and 

artificial fill along the bay shoreline. Thinly stratified 

glaciolacustrine silt and clay are locally exposed un-
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 1417-292 C-359 

FIGURE 276.3.-Street in Valdivia showing results of slumping 

and fracturing in underlying Quaternary deposits and 

artificial fill. 

derlying the glaciofluvial deposits in the soutlnYest 

part of the dock area. End moraines roughly rim the 

city. 

Maximum shock intensities in the city ranged from 

VII on the two terrace levels to XI in areas underlain 

by artificial fill (Pierre St. Amand, oral communication). Ground motion reportedly was a slow rocking 

movement. No tsunami was produced in the bay. 

Ground effects of the earthquakes "·ere expressed 

by surficial fractures, landslides and debris flo"·s, and 

slumping on steep hillsides. Man-made structures 

built on artificial fill, allu\·ium, and colluYium were 

most heavily damaged. Those built on ouh1ash in 

broad terraces and on till in end moraines '"ere least 

damaged. 

The dock area, underlain by artificial fill consisting 

of gravel, sand, brick, wood, and muck, possibly as 

much as 4 m thick, was heaxily damaged. Here 

numerous fractures and scarps, with vertical displacements of as much as 1 m, were formed by subsidence 

due to differential compaction and to lateral displacement. 

Three conspicuous landslides and debris flows ''ere 

triggered by the earthquakes in the city. The largest, 

im-olving mostly fi'ne to medium sand, moved rapidly 

down a steep slope of a terrace 45 meters high and 

formed a toe of debris several meters thick. A second 

debris or mud fto,,, originating in a debris flow actiYe 

in 1957, swept across two city blocks and destroyed all 

houses in its path \\'ith loss of life. Open fractures in 

the deposits at the head of the slide scarp indicate 

that additional sliding can be expected. The third and 

smallest slide originated in colluvial material along a 

steep terrace scarp. 

Many small fractures showing displacement of 

material do,Ynslope \Yere formed along colluvial coYered terrace scarps. Had the ground been saturnJed at 

the time of the major earthquake, as it is during the 

rainy season, these incipient slides might· well have 

become destructive landslides or mudflows. 

REFERENCES 

Doyel, "r· ,V., Moraga B., A., and Falcon l\i., E., 1960, Relaciones entre la geologia de Valdivia (Chile) y los danos 

ca usados por los terremotos del 22 de Mayo de 1960 [informe preliminar] : Santiago de Chile, Inst. de Inv. 

Geologicas, 15 p. 

Dnke, C. l\I., 1960, The Chilean earthquakes of May 1960: 

Science, v. 107, p. 1797-1802. 

Galli 0., C., and Sanchez R., J., 1960, La geologia y los effectos 

de los terremotos de Mayo de 1960 en Concepcion y alrededores [informe preliminar] : Santiago de Chile, Inst. de 

Inv. Geologicas, 22 p. 

Murata, K. J., 1961, Vigil for disaster: GeoTimes, v. 5, no. 5, 

p. 12-13. 

St. Amand, Pierre, 1960, South Chile earthquake swarm of 

1960 [abs.] : Geol. Soc. America Bull., v. 71, no. 12, pt. 2, 

p. 1964. 

Segerstrom, Kenneth, 1960, Eruption of water, sand, and clay 

resulting from the earthquake of May 21, 1960, near 

Concepcion, Chile [abs.] : Geol. Soc. America Bull., v. 

71, no. 12, pt. 2, p. 1972. 

Watanabe, Takeo and Karzulovic, Ivan K., 1960, Los moYimientos sismicos del mes de l\layo de 1960 en Chile in 

Anales de la Facultad de Ciencias Fisicas y l\Iatematicas: 

Univ. de Chile, Pub. 14, v. 17. 
C~360 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

277. EFFECT OF TUNNEL CONSTRUCTION ON FLOW OF SPRINGS AND SMALL STREAMS IN THE TECOLOTE 

TUNNEL AREA OF SANTA BARBARA COUNTY, CALIFORNIA 

By S. E. RANTz, Menlo Park, Calif. 

Work done in cooperation with.Santa Barbm·a County Water Agency 

The effect of the construction of Tecolote Tunnel in 

southern Sanbt Barbara County, Calif., on the flow 

of springs and spring-fed streams in: the vicinity of 

the tunnel has been evaluated by monthly measurements of discharge at 125 places in the area from late 

1948 to 1961. Construction of the tunnel began in 

~1arch 1950 and was completed in January 1956. By 

late 1951 \vater was seeping into the tunnel at a rate 

of 9 cubic feet per second. An analysis of the effect of 

tunnel construction on discharge is complicated by the 

occurrence of the Arvin-Tehachapi earthquake on July 

21, 1952, and the Refugio brush fire in early September 1955. 

The earthquake, whose epicenter "\vas located 65 

miles northwest of Tecolote Tunnel, abruptly increased . the flow at 18 measuring sites. Because the 

earthquake occurred in July during the usual summer 

drought, the increase in discharge 'nls strikingly 

noticeable. At 15 of the 18 sites, the increased discharge continued for several months, and at the other 

3 sites it continued for several years. It is doubtful 

that the· earthquake had any permanent effe.ct on recharge areas or on the permeability of any of the 

aquifers. Th~ increase in discharge 'vas most likely 

due to disturbance of the unconsolidated material in 

the discharge areas, resulting in the clearing of existing ground-water outlets and the opening of new ones. 

The Refugio brush fire of September 1955 m_ay have 

caused an increase in the summer· flow of springs and 

streams because of decreased evapotranspiration, but 

the evidence is inconclusive. The possibility of such an 

increase, however, adds a complication to the task of 

interpreting the discharge data. 

~1any complex and interrelated factors influence the 

discharge of springs and spring-fed streams and make 

it diflicult to isolate the effect of the tunnel on the 

flow. A complicating element, also, is the short period 

of record before construction of the tunnel. This 

calibration period was only 3 years, 1948 to 1951, during all 3 of which the precipitation was deficient. ..c\..t 

all but one spring, discharge "\Yas greater in the years 

after 1951 than in the preceding 3 years. .Available 

data concerning water quality and water temperature, 

.c ~ 20 S!~ ~ ~~ 

uc 30 ~ i ~~ 15 0: a: 

~~ ~w ~~ ~~ 

~a: 10 20 .... ~ ww Oz w~ wO 

~t;j 5 10 ~ ~ ~~ ~~ 

z 0 ~~ ~ 0 0 ~ 1950, 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 

FIGURE 277.1.-Hydrographs of seepage into Tecolote Tunnel 

and discharge of spring 110b. 

however, are helpful in evaluating the effect of tunnel 

construction. 

Seepage appeared in the tunnel a month after excavation began. 'Vhen the tunneling progressed into 

areas of faults, inflow into the tunnel increased 

sharply and reached a peak of 16.7 cfs in September 

1954. Seepage has more or less steadily declined ever 

since. Figure 277.1 shmYs the discharge hydrograph 

of seepage; the irregular shape of the graph indicates 

the effect of grouting, which was used in an effort to 

control the seepage. The tunnel inflows 'vere under a 

static head of about 500 feet, and water temperatures 

were as high as 113°F. These high temperatures m1ty 

be a result of heating along active faults in the a.rea, 

or may be an indication that the flows originate at 

considerable depth. The great volume of "\Vater discharged seems to indicate that a 1arge underground 

"\Vater reservoir had been tapped. The chemical quality 

of the "\Yater and the decline of inflow into the tunnel 

strongly suggest that the ground "\Vater is meteoric in 

origin. 

For the flow of a spring to be adversely affected by 

the tunnel, both the spring discharge and the tunnel 

inflow would have to be supplied from the same 

aquifer. To determine positiYely the existence of a 

common aquifer for both flmvs is very difficult, but 

sufficient evidence shows that one spring, designated 

as spring 110b, was affected by construction of the 

tunnel. Spring 110b, now dry, is about 1.8 miles east 

of the tunnel. Its "\Vater "·as chemically similar to 

water that seeped into the tunnel and dissimi1ar to 

water discharged from the other springs in the area. 

The tunnel seepages are predominantly sodium "\Yaters, 

whereas the springs other than spring 110b, discharge 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14,7-292 C-361 

calcium waters. IIardness, fluoride concentration, and. 

the presence of sulfides were also similar in the waters 

discharged by spring 110b and the seepage into the 

tunnel. 'Vater temperatures at spring 110b ranged 

from 105°F to 112°F, equaling the water temperatures 

observed in the tunnel; at the other springs and 

streams the temperature ranged from 45°F to 75°F. 

Although the elevation of spring 110b is 400 feet 

above the tunnel, tunnel inflows were under a static 

head of about 500 feet, thus making it possible that 

both spring and tunnel are supplied from the same 

aquifer. 

The flow of spring 110b was first measured in July 

1954 and a discharge of 29 gallons per minute was 

observed. The discharge receded rapidly, as shown on 

figure 277.1, and by 1\iarch 1955 the spring was dry. 

Although springs and streams in the area normally 

show little time lag between precipitation and discharge, spring 110b was not recharged by precipitation in the following years. All evidence indicates 

that the failure of spring 110b was a result of seepage 

into Tecolote .Tunnel. Construction of the tunnel 

seems not to have affected the flow of any other spring 

or stream. 

278. INFLUENCE OF NATURAL FRACTURES ON THE SHAPE OF EXPLOSION-PRODUCED CRATERS 

By D. D. DrcKEY and Ross B. JoHNSON, Denver, Colo. 

Work done in cooperation with the U.S. Atomic Energy Ootnmission 

Explosion-produced craters in basalt and alluvium 

at the Nevada Test Site, Nye County, Nev., show that 

natural (preexplosion) fractures in the rock influence 

the shape of the craters and the pattern of ejecta. Five 

small craters in basalt., each made by the detonation 

o:f 1,000 pounds of high explosive, and three large 

craters in basalt, each made by the detonation of 40,000 

pounds of high explosive, were mapped to determine 

the geologic factors affecting the size and shape of the 

craters and ejecta patterns. Control of the crater shape 

and the pattern of ejecta by preexplosion fractures are 

especially evident in the small craters. The cratering 

experiments were performed by the Sandia Corp. on 

Buckboard ~~esa in the northwestern part of the test 

site. · 

Buckboard Mesa is capped by 50 to 200 feet of 

nearly f1at lying olivine basalt of probable Quaternary 

age. Although the basalt is cut by only one fault, it 

is extensively jointed. The joints seem to be randomly 

oriented at most places on the mesa. Many joints are 

arcuate or wavy. Dip of the joints ranges from horizontal to vertical, but straight and slightly arcuate 

joints less than 50 feet long that dip from 75° to 90° 

are most common. The basalt is black and dense, and 

hn.s n. uniform chemicn.l composition. Vesicles rrmke 

601530 0-.61--24 

up as much as 20 percent by volume of the upper 2 or 3 

feet of the rock but generally make up less than 2 percent below 3 feet. Locally some of the vesicles are 

partly or completely filled by calcite. 

The influence of fractures on cratering is clearly 

shown in craters 8 and 11 (fig. 278.1). The craters 

were formed by detonation of spherical charges of high 

explosive weighing 1,000 and 40,000 pounds, and centered at depths of 15 and 25.5 feet, respectively. 

· The maximum depth of crater 8 below the original 

surface is 9.4 feet, and maximum width is 45 feet. 

Conspicuous nearly vertical joints that form much of 

the north and south edges of the crater are coated with 

caliche and obviously existed before the explosion. The 

long dimension <;>f the crater roughly parallels the 

direction of these joints, and ejecta are sparse in the 

directions parallel to the joints. The long narrow area 

covered by ejecta north of the crater is oriented nearly 

normal to the strike of the joint along the south rim. 

The size and shape of the ejecta-covered area that extends north of the crater apparently were controlled 

by the joint on the south rim, and by the spatial relation of the joint to the explosive charge. 

Crater 11 (fig. 278.1) has a maximum width of 115 

feet and a maximum depth of 24.8 feet helm~ the 
C-362 

595,000 

0 

OS\ 

c:> 

0 

s0o 

0 

595,050 

GEOLOGICAL SURVEY RESEARCH 19 61 

0 0 

0 C) 

130 ft 595,100 

5310 \ J r:; ~t~~· 

0 0 

0 C) 

0 0 

I 

I 

\ 

\ 

0 

\j 

0 

\) 

oa 

00. 

EXPLANATION 

Dominant pre-explosion joints 

mapped in drill hole 

Squ<tre shows direction of dip; circle shows 

position of drill hole 

Post explosion surface joints 

......._ ___ __ Crest of crater rim 

~---------~130ft 

Outer limit of area mostly covered by ejecta 

Number indicntes distnnce in feet 

to fnrthe.~t li·mit 

c=-53107) 

Topographic contours 

Contour intervnl 2 feet for Cra.ter 8 wnd 4 feet 

fm· Crnter 11. Da.tum is .~en level. Ha.chu.res 

show depression 

0 ;g 

~ --~--~~~-~-----------------------+--------------~---------4--------~------

~ 

0 

A. Crater 8 

B. Crater 11 

N 

1 

I 

0 

0 

0 

ft 

50 FEET 

0 100 200 -FEET 

FIGURE 278.1.-Maps of craters 8 and 11, Nevada Test Site. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14 7-2 92 C-363 

FIGURE 278.2.-Meteor Crater, Ariz. Photograph by Army Air 

Service. 

original surface of the mesa. The overall shape of 

crater 11 is more circular than that of crater 8. The 

crater rim locally parallels preexplosion joints for as 

much as 10 feet. The ejecta pattern, as shown on figure 

278.1, is elongate to the northwest; however, the pattern is more nearly circular than the ejecta pattern 

for crater 8 and suggests less control by joints. Crater 

11 is so large and encompasses so many randomly 

oriented joints that a nearly circular crater formed. 

The influence of fractures on crater shape and ejecta 

distribution is also apparent at Meteor Crater, Ariz. 

(fig. 278.2). This crater is about 400 feet deep, 4,000 

feet across, and is "square" in plan. The shape apparently was controlled by two strong regional joint 

sets (Shoemaker, 1959) that are oriented parallel to 

the diagonals of the "square". 

Presumably a crater produced by an explosion in 

homogeneous material would be circular and have a 

circular distribution of ejecta. Explosion-produced 

craters in unjointed alluvium are circular. In structurally anisotropic rocks, however, the distribution of 

energy from an explosion is controlled by physical 

discontinuities such as fractures. Fractures act as reflectors and attenuators of kinetic energy, and therefore the greatest amount of energy is transmitted in 

those directions which intersect the fewest fractures. 

This results in removal of more material in these directions. The "square" shape of Meteor Crater can be 

explained by this process. The shape of crater 8 on the 

other hand was largely controlled by a few large 

fractures limited to the ·immediate crater area. 

In large-scale excavations produced by explosion 

cratering, the structural anisotropy of the rocks may 

be an economically important factor. Adequate knowledge of the natural fractures could aid in predicting 

the shape of the crater and the distribution of ejecta, 

or artificially crested fractures could be used to control 

these efi'ects of cratering. 

REFERENCE 

Shoemaker, E. M., 1959, Impact mechanics at Meteor Crater, 

Arizona: U.S. Geol. Survey open-file report. 

EXPLORATION AND MAPPING TECHNIQUES 

279. NEW EQUIPMENT FOR MEASUREMENTS IN THE UNSATURATED ZONE 

By R. W. STALLMAN and R. P. MosToN, Denver, Colo. 

Field applications of even the simpler equations of 

isothermal liquid flow in the unsaturated zone 

(Richards, 1931) have not been made on any significant scale. This lack of application may be ascribed 

partly to a lack of instrumentation for field measurement of the flow variables. Most instruments now in 

field use have been developed through agricultural 

research wherein interest has been centered on qualitative measurements to depths of only a few feet. Of 

the equipment now available, only the nuclear probe 

devices (Stone and others, 1955) for measuring 

moisture content and bulk soil density, and thermistors 

or thermocouples for measuring temperature, seem to 

fit the broader requirements in hydrology for reasonably accurate measurement at greater depths. Standard laboratory techniques, such as the use of the 

manometer for measuring liquid head (a tensiometer 

in soils parlance), have very limited application be-
C-364 GEOLOGICAL SURVEY RESEARCH 1 9 61 

F.IGURE 279.1.-Schematic diagram of an electrical tensiometer. 

A, sensor; B, transducer; 0 , flexible wi('k; and, D , rigid 

support frame. 

cause of placement or reading difficulties under field 

conditions. 

Liquid heads in the unsaturated zone ran{)"e from b 

zero to several atmospheres and are negative with 

respect to atmospheric pressure. Measurements o:f 

negative heads with a liquid column are impossible 

above one atmosphere, and generally are impracticable 

above 0.5 atmosphere. Use o:f heacl-inclicatinO" devices 

based on other than manometric principles is ~equirecl. In a search :for a suitable device, preliminary tests 

have been made using the concept illustrated in fiO"ure 

279.1. The liquid phase comes into equilibrium ~ith a sensor material, A, through a flexible porous wick C. 

Mat~rial A _is ~n annulus o:f wood which swells ~p­ p~emably with mcreasecl content o:f liquid, and causes 

displacement o:f the sensing ~rm o:f transducer B. The 

:form o:f electrical measurement depends upon the type 

o:f transducer used; :for example, one mia-ht measure 

a change in resistance or a change in ~apsecl time 

between pulses. 

A system like the one shown in figure 279.1 would 

ha:re the advantage o:f easy installation at great depths. 

'VIth the use o:f available transducers, however, the 

FIGURE 279.2.- Test strip using Celab: a, first conductor; b, 

Oelab ; ('. second conductor. 

overall accuracy will be limited to less than 1 percent 

o:f :full range. Hysteresis effects clue to the sensor 

material A have not yet been evaluated. 

Pronounced hysteresis effects in standard transducers, which are clue largely to loose mechanical 

coupling between the sensed and sensin{)" elements 0 ' 

have prompted a search :for materials which \Youlcl 

reduce or eliminate defective coupling. A "paint" 

that changes resistance as pressure is applied is now 

being studied :for possible use as the transducer of 

figure 279.1. A test strip, made :for observing the 

electrical characteristics of the paint, is shown in 

figure 279.2. 

The pressure-sensitive paint used is sold by Clark 

Electronic Laboratories, Palm Springs, Calif., under 

the registered trade name Celab. The test strip shown 

was prepared by painting Celab on one conductor 

bonded to phenolic, drying at room temperature :for 

48 hours, wetting with a second coat o:f Celab over 

which the second conductor was pressed liO"htly and • b ' 

curmg at room temperature :for about 30 days. 

Changes in resistance of the test strip observed in the 

laboratory under atmospheric conditions over a short 

period o:f time are shown at the top o:f figure 279.3. 

The sensitivity to pressure chanO"eS was not O"reat b b 

enough to ascribe the resistance fluctuations noted to 

atmospheric-pressure fluctuations; and because the . ' perwcl o:f observation "-as short, effects clue to temperature changes were small. The results :from this 

test. strip indicate that the Celab paint has an inherent 

instability over short periods of time. However, other 

t~sts have shown that stability can be improved by 

]ugh-temperature cures at a cost o:f decreased sensitivity. Short-period fluctuations o:f resistance can be 

smoothed by adding electrical capacity in parallel with 

the resistive paint. Figure 279.3 also shows that Celab 

cured at room temperatures has resistance versus current characteristics nearly identical with those of 

commercial elements commonly referred to as varistors. 

Resistance increases markedly with decreased current. 

'\h.is relation in re~ses the problem o:f attaining stability and reproducible measurements in the field . 

. Direct measurement o:f vapor content in comparatively dry soils is a prerequisite to evaluation o:f the 

role o:f vapor movement in the unsaturated zone. 

Electrical hygrometers, "borrowed" :from climatology b ' 

have been used :for this purpose (Fukuda, 1955). 

However, after a :few hours in the highly humid pore 

space, they become ineffective because the thin element 

film is contaminated or partly washed off (Wexler and 

others, 1955) . The thermocouple described by Monteith and O'ven (1958) :for measuring clewpoint depression seems more promising :for vapor-content 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-365 

determinations. The Humistor, produced by ConradCarson, Inc., San Diego, Calif., is a device which 

changes resistance markedly in a changing environment of any gas or vapor having a strong dipole 

moment. The Humistor is reported to have a temperature coefficient of zero· over the range 0-100° C and, 

according to the manufacturer, can be cleaned without 

affecting its calibration by heating to a cherry red in 

a clean flame. A sample Humistor is shown in figure 

279.4, and a characteristic curve of humidity versus 

electrical resistance is shown in figure 279.5. Its small 

size, purported durability and stability, and high 

sensitivity qualify the Humistor element as a prospect 

for extensive application in unsaturated zone measurements; particularly because the usual soil gases, with 

the exception of water vapor, have a very weak or no FIGURE 279.4.-The Humistor. 

dipole moment. The Humistor could easily be installed 

underground because of its small size, and its present 

cost is only $10. Preliminary tests indicate that each 

element will require individual calibration. Detailed 

and closely controlled tests of these elements are being 

2 .7 

E 

.c 

0 4.1 c 

L 

.T. ~ ~ ~ ... ,.~ 

I ...::.I ....... ..::.... iLIJ """ ~ c 

"' ' -:;; ' v; 

"' 6.2 0: 

10 

(/) 9 :2 

I 

0 

z 

w· 

() 

z 

<( 

I-

(/) 

(/) 

w 

a:: 

<.!) 

0 

_J 

5 

0 25 50 75 

RELATIVE HUMIDITY, IN PERCENT 

100 

9.4xiO FIGURE 279.5.-Resistance of the Humistor versus relative 

= 2 112 mmutes 

glo•.------.-------.-------.-------.-------,10 ,_: ~ z ~ w I ~ 

0 w 

...J z w 

~ 107 I~> z a~ 

w 0:~ 

~ u~ 

~ ~~ w ~> 

~ 0 

o 10• .I ~ ~ 

w w u ~ z ~ 

~ ~ ~ ...J 

~ ~ 

~ ~n -. 10-· 10-' 10-· lQ-5 10 :.~1 

CURRENT THROUGH ELEMENT, IN AMPERES (I) 

FIGURE 279.3.-Electrical characteristics of Celab. Top, resistance versus time ; bottom, resistance and YOltage Yersus 

current. 

humidity in dean air. 

set up currently by "\Y. N. Palmquist and the junior 

author in the U.S. Geological Survey's Hydrologic 

Laboratory, Denver, Colo. 

REFERENCES 

Fukuda, Hitosbi, 1955, Air and vapor movement in soil due 

to wind gustiness: Soil Sci. v. 79, p. 249-256. 

:.\Ionteith, J. L., and Owen, P. C., 1938, A thermocouple method 

for measuring relative humidity in the range 95-100% : 

Jour. Sci. Instr., v. 35, p. 443-446. 

Richards, L. A., 1931, Capillary conduction of liquids through 

porous mediums: Physics, v. 1, p. 318-333. 

Stone, J. F., Kirkham, Don, and Read, A. A., 1955, Soil moisture determination by a portable neutron scattering 

moisture meter: Soil Sci. Soc. Am. Proc., v. 19, p. 419-423. 

Wexler, Arnold, and others, 1955, A fast responding electric 

hygrometer: Jour. Res., Natl. Bur. Standards, v. 55, no. 

2, p. 71-78. 
· C-366 GEOLOGICAL SURVEY RESEARCH 1961 

280. EQUIPMENT FOR FIELD MEASUREMENT OF ELECTROCHEMICAL POTENTIALS 

By WILLIAJVI BACK and IvAN BARNEs, "\V'ashington, D. C. 

Equipment and techniques have been developed to 

deter.mine in the field certain electrochemical variables 

in ground water. 

Sources of error in ·electrochemical studies can be 

classified in 4 groups: (a) electrical interference, either 

in the measuring system or in the sampling device; 

(b) mechanical work, either done on the solution 

(electrokinetic effects) or on the electrodes (analogous 

to work of expansion) ; (c) temperature differences 

among reference samples, study samples, and electrode; and (d) contamination of reference solutions, 

study solutions, or electrodes. 

These possible errors and ways to prevent or assess 

them are listed in table 280.1. 

Ground water studied in the present investigation 

was obtained at the well heads of wells of large discharge (200 to 1,200 gpm) where the cone of depression was known not to reach the water intake area. 

The travel time of the water in all the wells was less 

than 8 minutes. The water was withdrawn through 

plastic tubing into a sealed sample jar containing 

electrodes (fig. 280.1) and discharged through 15 feet 

of plastic tubing. The plastic tubing and sample jar 

were water tight at pressures of 15 psi, and the sample 

jar was water tight at 100 psi; thus the samples probably were not contaminated by the air. The tubing 

and sample jar were flushed until a constant or slowly 

changing potential was reached while water flowed 

TARLE 280.1.- Sources of error in electrochemical studies 

Nature of error 

Stati c cha rge _____ _ 

E lectric current ___ _ 

Electric current 

(AC pickup). Electrokinesis ____ _ 0 . motic work ___ _ 

Contamination ___ _ 

Contamina tion ___ _ 

Thermal differ- ences. 

Source of error 

Proximity of 

personnel. 

Wind, friction ____ _ 

Power lines and 

motors. Motion of sample_ 

Sample pressure higher t han a tmospheri c. From previous sample, washing, and stagnant water in 

the casing. 

From the atmos- phere. T emperature of 

electrodes not 

the same as th e sampl e. 

Prevention 

E lectrical shielding. 

Do. Do. 

Static measure mentR. 

Sample pre ure brought to atmos- pheric pressure. High capacity pumps. Long flow period for 

complele flu Rhing 

of sample jar and casing. 

Closed sample ja r. 

Long flow period , sampling when ambient temper- ature is that. of 

ground water; 

heating and cooling 

of reference solutions. 

FIGURE 280.1.-Equipment used to measure electrochemical 

potentials in the field. Shielded plastic intake and discharge 

tubing and three electrodes (reference, platinum, and a third 

electrode of any material such as glass or gold) are 

mounted in a brass lid for a jar, which is enclosed in a 

copper-clad box. The electrodes are wired to a potentiometer 

(pH meter) which is shielded. 

in the system (3/4 hour to 8 hours). A constant potential was assumed to mean that all the oxyp:en and 

all traces of earlier samples were flushed from the 

system, and that the system was filled with uncontaminated ground water. 

Time-potential curves for three wells are shown in 

figure 280.2. These examples are representative of 

curves plotted for 42 wells. The potential measured 

in the field between the platinum and saturated calomel electrodes is plotted against time of sampling. 

Zero time is "·hen the water began flowing through 

the system. 

After a reasonably steady potential was obtained in 

flowing samples, the flow was stopped and the potential in the static samples was recorded as a function 

of time. The \Yater level in the discharge tube was 

brought to the level of the top of the sample jar to 

avoid pressure on the saturated calomel electrode. 

Owing to electrokinetic effects a potential difference 

was always observed between flo\Ving and static samples (fig. 280.2). The lo,-vest (or in a few tests the 

highesL), constant static potential \Yas presumably the 

potential of the gronnd-\Yater sample. The curves for 

most samples that had a final potential lower than 

about 100 millivolts had a downward trend, whereas 

l!'IOURE 280.2.- Time-potential curves for three wells in the 

Atlantic Coastal Plain. 
LIJ 

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w 

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w 

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:::::> 

f-

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:::::> 

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SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-367 

480 

'--- Flow stopped 

/" 1.t 

( v 

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440 

400 

360 

320 

280 

240 

200 "' 

160 

120 

80 

40 

0 

-40 

-80 

0 

\ 

""' \ ' ~-- ~ 

\ ~ ~~ Platinum 1\ - electrode 

cleaned 

\ \ "--~ Flow stopped 

\ 1-" Ja. taken apart ~ " \ 

~ ~ !-----.. 

~If Flow stopped 

• 

20 40 60 80 100 120 140 160 180 200 

TIME, SINCE START OF SAMPLING, IN MINUTES 
C-368 GEOLOGICAL SURVEY RESEARCH 1961 

curves for samples having a potential of more than 

about 400 mv generally had an upward trend, as shown 

in the top curve, figure 280.2. The middle curve shows 

the effect of cleaning the electrode with washed sea 

sand and the contamination of the sample with air 

when the jar was later taken apart for a minor repair. 

After the electrode was cleaned the potential decreased 

at a more rapid rate. Later with the admittance of 

air the potential increased as shown (fig. 280.2). 

In the calibration of the electrodes for pH determination, the temperature of the reference solutions 

(standard buffers) were brought to within 2°C of the 

temperature of the electrodes, which were brought to 

the temperature of ground-water sample by immersion 

in the discharge water. 

To avoid electrical interference, the meter, sample 

jar, electrodes, electrode leads, inlet and discharge 

tubes were electrically shielded. Two copper shields 

were added outside the built-in shield of the meter. 

The outside shields were connected in series and 

grounded to a stake, the well casing, or some other 

true earth ground. No difference was observed among 

any of these ground connections. The shielding and 

grounding assured that potentials where unaffected by 

blowing wind, movement of people in the vicinity of 

the meters, transporting the equipment, a physical 

connection of the water inlet tube to the water main, 

and 60 horsepmver motors and pumps operating in the 

vicinity. It was observed that without the shielding 

any of the disturbances listed above could cause 

rapidly fluctuating erratic measurements or significant 

errors in sluggishly changing measurements. 

The techniques outlined here have permitted a maximum precision of measurement of pH to + 0.03 pH 

unit and Eh to:+ 10 mv in waters that are essentially 

unbuffered and unpoised, and that contained total 

dissolved solids of 50 to 200 ppm. 

281. TRANSFER OF GEOLOGIC DATA FROM AERIAL PHOTOGRAPHS TO TOPOGRAPHIC MAPS BY 

DIRECT TRACING 

By RussELL H. CAl\IPBELL, Menlo Park, Calif. 

Direct tracing of geologic data from vertical aerial 

photographs to a transparent topographic map prepared at an average of the scales of a set of aerial 

photographs covering the same area can provide a 

rapid ·and accurate method of field compilation. Tracing requires no cumbersome plotting instruments and 

can be done in even the most primitive field camp. 

Except in areas of high ground relief, tracing offers 

greater accuracy than transfer by inspection, particularly where relatively featureless plains are cut by 

enough drainage lines for good registry. In addition, 

many features in areas of poor tone contrast on the 

photographs are more clearly visible and sharply defined than are their images as projected through an 

optical system. 

The fit between the transparent base map and individual photographs of the set depends on the amount 

by which the scales of the photos differ from their 

average, which is determined by the uniformity of the 

flying height above the ground surface. For most 

modern aerial photographs the plotting error introduced by these scale variations is small. The chief 

sources of error in the tracing method are those common to any method of transfer from a single nonorthographic photo print. Ray (1956, p. 15-16) discusses the sources of error in methods using reflecting 

projectors and the vertical sketchmaster. For modern 

commercial photographs the source of greatest plotting 

error is the radial displacement of photographic 

images imposed by the ground relief. Of particular 

advantage is ~he ease with which the map can be 

shifted to register with specific parts of a photograph 

such as stream intersections and hill and ridge tops to 

adjust for scale variations. 

A few simple preliminary computations will determine the maximum plotting errors to be expected due 
SHOR'l' PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14,7-292 C-369 

to scale variations and local relief for a particular set 

of photos and maps. 'iVith these various sources of 

error in mind, a sample area in northwestern Alaska 

ha,~ing generally low ground relief and a large number 

of recognizable points for local registry was studied 

to determine the practical problems involved in the 

application of the direct tracing method. Preliminary 

computn,tions indicated that the maximum expectable 

errors were small. In addition, experience showed that 

virtually all plotting errors caused by scale variations 

between photo prints and map, and much of the error 

within individual prints caused by radial displ~cement 

due to relief, can be eliminated in tracing by adjusting 

to local points of registry within segments of a photograph. l\1oreover, as pointed out by C. L; Pillmore 

(oral communication, 1961), the stereo model may be 

observed in relation to the topography by using one 

print o:f a stereoscopic pair above the transparent map 

and the other below it. By this technique photographic 

distortions of the form of lines on hillsides were found 

to be easily adjustable to their correct map expression. 

In the sample area the fit between the photographs 

and an enlarged topographic base map was found to 

be very good. In only a few small areas did plotting 

errors approach the computed maxima. Contacts and 

fault traces could be traced directly from the photogr:1phs with confidence, and map symbols could be 

accurately located. · 

DETERMINING SCALE FOR TRANSPARENT BASE 

MAPS 

Where It known distn,nce is represented on the original 

mftp by D inches ftnd on a photograph by d inches, n,nd 

the nmp settle is ;

1 1u1d the photo scale is Jj then since 

Pd=lYID=the distttnce on the ground, then 

P=MD. (1) rl 

For CILCh photograph determine P for two lines dittgonn,l 

to the :flight line n,pproximtttely through the photo 

eentcr tts defined by four points of registry at ttbout the 

sn,rne ground elevation. The mean of these two settles 

is used for the scale of the photograph. (Vtuiations in 

the scales of the two di~tgonals ~tre due chiefly to tilt, 

ttnd itre commonly small.) The mttp is then photogrnphically enlttrged on n, trn,nsparent medium to a 

scale of ~, the ttveru.ge settle of the individual photos. 

DETERMINING EXPECTABLE ERRORS 

To determine the plotting error, ~x, in tracing from a 

photo of scn,le ~ to a map of scale ~'let Xm be the dis-

"' .... 

X 

0 

z 

:!:O.lr---·-------------~-----, 

~ :!:0.05 

~ 

0 

Xp, IN INCHES 

FIGURE 281.1.-Family of lines showing plotting error Llx as a 

function of the distance xv of the point to be plotted from a 

point of registry and the constant K= p S S for an individual 

h · 1 · · 1 d 1 

p oto pnnt, where pIS pnnt . I sea e an S IS map sea e. 

tttnce on the mttp from a point of registry to a point to 

be plotted, and Xv be the distance on the photo between 

the same two points. Then the error is represented by 

(2) 

XvP d b . . . Now, using equation (1), Xm=s an su st1tutmg m 

equatiOn . ( h . 2), cP-S) F h t e error IS ~x=xv -s . or eac 

P-S individual photograph -s is a constant, K, and a 

family of lines can be drawn for different K's along 

which the maximum expected plotting error due to 

seale variation can be determined as a function of the 

distance from a point of registry (fig. 281.1). In the 

sample area the average photo scale,~' is 41 50 ttnd the 

' 

consttmt K was found to be 0.010 or less for most of the 

photographs of the covering set and exceeded 0.012 for 

only two photo prints. In practice, the distance from 

a point of registry did not exceed 2 inchec:;; therefore, 

the plotting error resulting fron1 the difference in scale 

between the map and photogrnphs may be expected to 

be less than 0.025 inch (fig. 281.1). 

A complete evu1uation of the effects of radin1 displacement caused by ground relief is beyond the scope 

of this paper. Seventl textbooks concerning the applicntions of aerittl photographs cover their characteristics in detail (for exan1ple, Smith, 1943, p. 36-39). 

The general formuhL for computntion of this displacement is ~r= 1; where ~r is the radin1 displacement, his 
C-370 GEOLOGICAL SURVEY RESEARCH 1 9 61 

the difference in ground elevation between the center of 

a 8trictly vertical photograph and a point at a distance r 

from the photo center, and His the altitude above the 

mean ground surfa,ce from which the photo was taken. 

The flying height, H, and the contact, print scale, 

l, are related by the formula P=!!.f· where j is the focal 

p . 

. h rh length of the cn,mera, t us Ar= P/ Figure 281.2 shows 

a fam.ily of lines thn,t mn.y be conveniently cornpared 

with those on figure 281.1. They show the expectable 

displacement due to relief of points at a distance of 3 

inches from a photo center for several common scales 

as con1puted for a ca1nera focal length (6 inches) in 

common use. In the sample area in northwe"tern 

Alaska the n,pproximate photo scale is 1:40,000 and the 

local relief n, vern,ges 500 to 700 feet with one hill rising 

to 1,500 feet. The ground re]ief between photo 

centers and peripheral points is commonly less than 

500 feet and the resulting rttdial di"phwement is commonly less than 0.1 inch (fig. 281.2). 

g ±0.5.----------~--------::::;:-::-------, 

~ ±0.4 (,JCI) 

C"' i 5±0.3 CI)Z 

~~±0.2 

c 

~ 

0 500 1000 1500 2000 

LOCAL RELIEF. IN FEET 

FIGURE 281.2.-Family of lines showing maximum radial displacement due to relief of a peripheral point 3 inches from 

the center of a vertical photograph. Displacement is a function of the contact print scale (in this example computed for 

a camera focal length of 6 inches) and the difference in 

altitude between the photo center and the peripheral point. 

REFERENCES 

Ray, Richard G., 1956, Photogeologic procedures in geologic 

interpretation and mapping: U. S. Geol. Survey Bull. 

1043-A, p. 1-21. 

Smith, H. T. U., 1943, Aerial photographs and their applications: New York, Appleton-Century-Crofts, Inc., 372 p. 

282. A REMANENT MAGNETOMETER AND MAGNETIC SUSCEPTIBILITY BRIDGE 

By LENNART A. ANDERSON, Denver, Colo. 

A dual-purpose instrument, using separate detecting 

and common amplifying systems, precisely measures 

remanent magnetism and magnetic susceptibility of 

rock samples. The instrument was developed ·with the 

assistance of J. A. Graham and P. F. Michelsen of the 

Department of Terrestrial l\fagnetism of the Carnegie 

Institution of 'Vashington from unpublished designs 

of equipment of that organization. 

REMANENT MAGNETOMETER 

Remanent magnetization is magnetization that exists 

within a material independent of any external magnetic field. The remanent magnetization of a rock 

sample is given in terms of intensity and its orientation with respect to magnetic north and the horizontal 

plane. 

A functional diagram of the remanent magnetometer 

is shown on figure 282.1. A cylindrical core, one inch 

in diameter and length, is cut from a rock sample 

marked to indicate its orientation. The sample is 

placed in an air-driven, cylindrical, Incite turbine and 

rotated within a vertically mounted pickup coil at 280 

cycles per second. The horizontal component of the 

alternating magnetic field generated by the rotating 
·SHORT PAPEHS IN 'l.'HE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14.7-292 C-371 

Signal 

"pick·up" coil 

Signal channel 

FIGURE 282.1.-Fnnctional diagram of the remanent magnetometer. . 

sample induces a small alternating voltage in the 

coil ''7 inclings. This voltage is amplified and measured, 

and its phase is compared with a synchronous referenye 

voltage. · 

The reference signal is produced by focusing a light 

beam on n. photoelectric cell and interrupting the beam 

with an opaque 105-degree sector of the rotating sample holder. The phase angle between the reference 

signal and the induced signal depends on the angular 

displacement between the leading edge of the opaque 

sector o:f the turbine and the component of magnetization o:f the sample in the ho:r:izontal plane. The speed 

of the turbine is adjnsted by varying the air pressure 

until a null reading is obtained at the output of the 

frequency discriminator. 

The values for intensity and phase determine the 

lengt·h and direction of one particular component of 

the remanent magnetization vector. The sample is 

spun on three mutually perpendicular axes in order to 

determine three components of the total vector. By 

plotting these components on an equal area projection 

net, the direction of the remanent magnetization of the 

sample is determined. Its total intensity is found by 

htking the square root of one-half the sum of the 

squares of the three average intensities. 

MAGNETIC SUSCEPTIBILITY BRIDGE 

~1agnetic susceptibility is the ratio between the intensity of the induced magnetization of a substance 

in an external magnetic field and the intensity of the 

field. 

The magnetic susceptibility bridge utilizes the same 

amplificat.ion channels as the remanent magnetometer 

,.----:::--Re_fe_,rence,_ch_an_ne_l ----., 

Pre·amplifier 

[Qj AttS?ator 

Amplifiers 

and 

Phase shifter bandpass filter 

GJ Attenuator 

Amplifiers 

and 

bandpass filter 

FIGURE 282.2.-Functional diagram of the magnetic susceptibil'ity bridge. 

but differs in the system of detection. As indicated 

on figure 282.2, two sets of .identical coils and resistances are arranged to form a Campbell inductance 

bridge. An additional inductance and resistance arm, 

called a "T agner ground, is used to bring the signal 

output side of the bridge to ground potential. The 

resistance arms are made of coiled manganin wire. 

An oscillator set for 280 cps (cycles per second) drives 

the bridge and also feeds a signal into the reference 

channel through an isolation. transformer. The reference signal is amplified and sent through a phase 

shifting circuit which is adjusted so that the. phase 

detector will be sensitive to only the induetive component of the bridge unbalanced voltage. 

Initial balance of the bridge inductance is obtained 

by moving a ferrite slug near the balancing coil. The 

effective resistance of the reference coil, and hence the 

resistive balance, is adjusted by changing the position 

of a closed loop of manganin wire that acts as a 

resistance-loaded secondary transformer winding. The 

Wagner ground arm is balanced in the same manner. 

In addition to the balancing controls, the reference 

coil has a control using a slug of ferrite with enough 

permalloy to match the resistive unbalanced component due to the conductivity of magnetite. This control varies the resistive and inductive components as 

seen by the reference coil. The slug is mounted on a 

screw and enters the core of the coil. It is in the 

shape of a long cone so that the susceptibility can be 

measured to two significant figures from 10-6 to 0.5 cgs 

units per cc. 

The mode of operation requires that the sample coil 

be balanced first with respect to the ';Vagner ground 

and then with respect to the reference arm with the 
C--372 GEOLOGICAL SURVEY RESEARCH 1 9 61 

screw control set at zero. A rough balance is achieved 

by obtaining a horizontal line on the oscilloscope. The 

phase shifter is adjusted so that a small change of the 

resistive control will not unbalance the bridge. Fine 

balance is achieved by adjusting the controls for zero 

output of the phase detector. 

When a rock is inserted into the sample coil its 

inductance will become greater if the rock is paramagnetic, and smaller if the rock is diamagnetic. The 

resulting off bala.nce is compensated for by varying 

the reference coil screw control until the phase meter 

reads zero. The position of the screw control is read 

on a scale that has been calibrated previously by using 

as standards ferric chloride solutions of various susceptibilities, and cores of magnetite and plaster whose 

susceptibilities were determined by measuring the 

anomaly they produce in a known field. 

REFERENCE AND SIGNAL AMPLIFICATION 

CHANNELS 

The reference and signal channels are common to 

the remanent magnetometer and the magnetic susceptibility bridge. The reference channel consists of a 

pre-amplifier, an attenuator, a phase shifter, two a-c 

amplifiers, and a narrow bandpass filter. The output 

of the reference channel feeds a phase detection circuit 

and the horizontal input of an oscilloscope. The signal 

channel has essentially the same components without 

a phase shifter. The outputs feed the vertical input 

of the oscilloscope, the phase detector, and an a-c voltmeter. 

The outputs of the signal and reference channels 

are fed into an oscilloscope to form a single-loop 

Lissajous figure. When used with the susceptibility 

bridge, the oscilloscope is useful in making rapid 

course balances of the bridge because a relatively small 

unbalance will cause the phase meter to go off scale. 

The oscilloscope also serves to detect saturation of the 

amplifier. 

The limit of reliable sensitivity is of the order of 

1x10-6 cgs m1its per cc, although sensitivities of 

1x1o-s cgs units per cc are possible for the susceptibility 

bridge when the external noise level is sufficiently low. 

The signal channel has an overall gain of 1x108 and 

has a noise level of a):>proximately 1.2x1o-s volts. 

ANALYTICAL AND PETROGRAPHIC METHODS 

283. A METHOD FOR DETERMINING THE SPECIFIC GRAVITY OF SAND AND GROUND ROCK OR MINERALS 

By JosEPH J. FAHEY, 'Vashington,,D. C. 

The· determination· of the specific gravity of sand, 

or samples of rock or minerals ground to pass a 100 

mesh sieve and to be retained on a 200 mesh sieve is 

usually made by one of several pycnometer methods. 

Each of these procedures entails successive weighing 

on the analytical balance of the pycnometer, the 

pycnometer plus the sample, the pycnometer plus the 

liquid (usually \Yater), and the pycnometer plus sample plus liquid. From these data the specific gravity 

of the sample at the temperature of the room is computed. By applying a suitable factor the specific 

gravity at 4°C can be obtained. , 

Appreciable errors may occur in the pycnometer 

method due to the difficulty encountered in weighing 

the pycnometer plus liquid, and the pycnometer plus 

sample plus liquid. Duplicate determinations may 

differ by as much as 10 mg due to variations in temperature, humidity, time on the balance pan, and the 

adjustment of the stopper of either the truncated cone 

with a capillary, or the plane surface top of the 

Adams-,Johnston pycnometer. These errors are eliminated in the procedure described in this paper. 

Suspend an unstoppered Erlenmeyer flash of about 

5 ml capacity or a 5 ml pycnometer with truncated 

stopper removed, on about 10 cn1 of fine platinum wire 

from the arm of the analytical balance. Record the 

weight in air and also the weight in water, which is 

obtained by immersing the suspended flask in a beaker 
.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 1417-292 ·c-373 

o:f water that rests on a bridge over the balance pa~. 

The height of the watei· in the beaker should be marked 

to assure constant depth of immersion in successive 

determinations. This is necessary to avoid a small error 

that would result from the immersion of varying 

lengths of the fine platinum wire. The weight in air 

and the weight in water of the flask are constants for 

a given f-lask and need not be repeated when determining the specific gravity of a sample. 

After drying the flask well, place about 0.5 to 1.5 

grams of the sample into the flask. The weight of the 

f-lask plus the sample is recorded. , Remove the suspended flask plus sample from the balance arm and 

add watet until it is about three-fourths full. Tap the 

flask until all bubbles are exhausted. Fill the flask 

with water and suspend it from the balance arm in a 

beaker of water as described above. The weight in 

water of the flask plus sample is recorded~ 

The specific gravity is computed from the following relation: 

Specific ~t'avi'ty 'Vt. of sample in air 

"rt. of sample in nir-wt. of sample in H20 

The weight of the sample in air equals the combined 

weight of flask and sample in air less the weight of. 

flask in air, and the weight of the sample in water is 

determined similarly from corresponding measurements in water. 

A sample of quartz (Ottawa sand) was ground to 

pass a 100-mesh sieve. That portion retained on a 

200-mesh sieve was allowed to remain in ( 1 + 1) HCl 

on the steam bath over night. After washing and 

drying, this sample of quartz was used to check the 

accuracy and precision of the results obtained by this 

method for the determination of specific gravity. 

Four determinations were made, each requiring 

about 15 minutes. The results recorded were: 2.649, 

2.652, 2.654, 2.654. 

Tiny liquid inclusions, readily visible under the 

microscope, may account for the slightly lower figures 

than the 2.653 to 2.660 given by Dana and Ford (1945, 

p. 471). 

The specific gravity of water-soluble minerals can 

be determined by this method using toluene that has 

been saturated with the mineral being examined. The 

specific gravity of the mineral-saturated toluene can 

be determined easily by weighing in a 50 ml volumetric 

flask on the analytical balance. 

REFERENCE 

Dana, E. S., and Ford, W. E., 1945, A textbook of mineralogy: 

New York, John Wiley and Sons, 851 p. 

284. MEASUREMENT OF SODIUM ACTIVITIES IN CLAY SUSPENSIONS WITH 

CATIONIC-SENSITIVE ELECTRODES 

By ALFRED M. Pol\ll\IER, Washington, D. C. 

Work done in cooperation with the U.S. Atomic Energy Commission 

~1illivolt readings obtained with sodium-sensitive 

glass electrodes are useful in clay titrations (Pommer, 

1960). Such electrodes measure activities rather than 

concentrations. The difficulties of measuring pH in 

clay suspensions (Jenny and others, 1950; Marshall, 

1951; Eriksson, 1951; Mysels, 1951; Overbeek, 1953; 

Low, 1954) apply equally to measurements with 

cationic-sensitive glass electrodes in such suspensions 

(Bower, 1961). It is essential, therefore, to consider 

the difficulties involved. Although the work of Low 

( 1954) vitiates the statement by Feldman ( 1956) that 

"pH measurements on suspensions of highly charged 

particles are meaningless," many of Feldman's comments pertaining to the "use and abuse of pH measurements" may be applied profitably to sodium 

determinations with sodium-sensitive glass electrodes. 

To visualize the dangers inherent in an uncritical 

utilization of sodium electrode readings as a measure 
C-374 GEOLOGICAL SURVEY RESEARCH 19 61 

uJ 

g -160 Q: 

1-

u 

uJ 

..J 

UJ -140 w 

> 

~ .. u; 

z ., . .. UJ -120 en 

:::!!: 

:::J .. 0 

0 

en -100 

:I: 

1-

~ 

0 

w -80 z 

<i 

1-

CD 

0 

(.!) -60 z 

0 

<( 

UJ 

Q: 

1- -40 ..J 

0 

~ 

..J 

..J : 

:::!!: -20 

.:: .. 

I 

0 -I 

LOGARITHM OF SODIUM CONCENTRATION IN ppm 

FIGURE 284.1.-A comparison of sodium values in 143 unselected 

determinations W'ith sodium electrode readings. 

of sodium content, the first 143 sodium electrode readings obtained in this laboratory were plotted against 

sodium content. Electrode readings were obtained 

from a single Beckman cationic-sensitive glass electrode (Spec. Electrode No: 78137V) using either a 

Beckman ~fodel · GS or Zeromatic pH meter. Analytical sodium values were obtained either with a BeckJn~n ~1odel DU spectrophotometer with fla.me photometer a.ttaclunent and photomul>tiplier a.ttachment or 

(in the ease of pure NaCl solutions) were computed 

from the nominal composition of the solutions. As 

the sodium-sensitive glasses yield electrode potentials 

"·hich are a linear function of the logaritlun of the 

cation activity (Eisenman, Rudin, and Casby, 1958), 

the logarithm of the sodium concentration ''"as plotted 

against the millivolt readings obtained with the electrode. Figure 284.1 clearly shows that an uncritical 

substitution of electrode readings for analytical values 

gives unsnJisfactory results. 

Eisenman, Rudin, and Casby (1957) give the 

following e1npirical equation for the performance of a 

glass electrode in a mixture of any two univalent 

cations: 

RT 1Hll nAB n.tB nAB 

[ 

!_ ] ..!.] 

E=E0+F ln (A+). +KAu (B+) (1) 

wherein: 

E=measured emf 

E 0 =standarcl potential 

R=ideal gas equation constant 

T=Temperature 

F=Faraclay constant 

(A+) and (B+) =activity of the ionic species A+ 

and B+ 

nAB and KAB=empirical constants for a given glass 

composition 

and ionic pair A+ and B+ 

It should be noted that E 0 , the "standard potentiAl," 

is not the potential of the electrode if all activities are 

unity, and the term "standard" does not carry the 

customary thermodynamic connotation. It is sin1ply 

the measured emf whenever the logarithmic term drops 

out, and depends on all the sources contributing to this 

emf in the cell chain, such as the potential of the 

reference electrode, the potential contributed by the 

silver-silver chloride wire clipping into a sodimn 

acetate-hydrochloric acid solution inside the glass 

electrode (Isard, 1959), and asymmetry, conta.ct, and 

liquid junction potentials (Bates, 1954). 

In the case of a solution containing H+ and .Na+ 

ions only, nHNa is unity (Eisenman, Rudin, and Casby, 

1957), and equation (1) reduces to 

RT· 

E=E0+i_t;- ln [(H+)+KHNa(Na+)] (2) 

an eq uat.ion· which indicates that in a plot of log (N a+) 

against E, a straight line is possible only if (N a+)>> 

H+ /KHNa· Figure 284.2 shows millivolt readings 

obtained with a sodium-sensitive glass electrode at 

22° C plotted against sodium activities of sodium 

chloride solutions. These were prepared by dissolving 

in distilled water N aCl dried in an oven and diluting 

to yield a series of solutions ranging in molarity from 

0.05 to 0.000165. Sodium ion activities were calculated 

using the Debye-Hiickel formula. The straightness 

of the line indicates that H+jKHNa<<Na+. Figure 

284.2 clearly shows the applicability of the method to 

sodium solutions under carefully controlled conditions. 

Figure 284.3 relates the millivolt readings obtained 

with a sodium-sensitive glass electrode (Pommer, 1960) 

during the titration of a hydrogen montmorillonite 

with sodium hydroxide to the sodium values deter- . 

mined with a flame photometer (Dorothy Carroll, 

analyst). As the ionic strength o:f the solution was 

not uniquely defined by the conditions o:f the experiment and could not be determined experimentally, the 

activity corrections required by the Debye-Hiickel 

theory could not be made. In spite o:f this, the plot 

gives a rather straight line in the region where the 

sodium concentration exceeds 2.5 millimoles per liter. 
SHORT PAPER~ .. IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14·7-292 C-375 

ILl 

0 

0 

a: 

1-

u 

w 

..J 

w 

w 

> 

i= 

iii 

z 

w 

IJ) 

~ 

:::1 

0 

0 

IJ) 

:I: 

1-

i 

0 

w 

z 

<i 

1-

CD 

0 

C) 

z 

0 

<t 

w 

0: 

!:i 

~ 

::i 

+50 

+25 

0 

-25 

-50 

-75 

..J -100 

~ 

1.0 1.5 2.0 2.5 3.0 3.5 4.0 

-LOG aNa+ 

FioUJm 284.2.-Relntion between sodium-electrode emf and 

cnlculnted sodium activity in sodium chloride solutions. Data 

by M. M. Schnepfe. 

The dev.in,tion of the slope from unity can be explained 

by the fa,ilure to make corrections for 11ctivity coefficients. The bulge in the graph at a concentration of 

less than 2.5 millimoles indicates that the electrometric 

sodium values 11re lower than those obtained by flame 

photometry. The reason for the discrepancy between 

the f-lame photometry and electrometric sodium values 

:is not yet known. It is generally accepted that the 

analysis o:f: n,]kali metals tends to give high values, 

and this may be the reason. The possibility of colloidal 

clay p11rt.icles passing through the filter paper and, 

during fbme photometry, being aspirated and vaporized, thus contributing excess sodium, must be borne 

in mind. ~1icroscopic examination of a clay suspension 

filt-rate (by E. Zen) indicated the presence of some 

clay particles, though aspiration of the filtrate through 

a. flame photometer capillary failed to deposit particles 

on a slide which could be detected on microscopic 

examination. This is not necessarily conclusive, since 

the extremely small amount of particulate matter necessary to give discrepant results may be missed on 

microscopic examination. Since the clay suspensions 

containing higher sodium concentrations were better 

coagulated, it is still tempting to ascribe the deviations 

in the low-sodium region to this effect. 

1.2 

1.1 

1.0 

.9 

5 .8 

1-

:::::i .7 ti' 

z 

IJ) .6 w 

..J 

0 .5 :::!: 

:::i 

..J.4 

~ 

C) .3 

0 

..J :2 

.I 

0 

-0.1 

-0.2 

-20 -40 -60 -80 -100 -J20 -140 

MILLIVOLTS 

FIGURE 284.3.-Relation betwen flame photometric and potentiometric sodium values in a discontinuous montmorillonite 

titration. 

It is also possible that the deviations result from the 

presence of sodimn in a form other than Na+. Gregor 

(1951) has reported on ion-pair formation in ionexchange systems, and it is conceivable that this 

phenomenon may account for the apparent lowering 

of sodium activity. Another possibility is uptake of 

carbon dioxide from the atmosphere which may result 

in the formation of N aC03- ion (Garrels, Thompson, 

and Siever, 1961), thus lowering the amount of sodium 

available for formation of Na+. However, insufficient 

information is available at this time to settle the point. 

REFERENCES 

Bates, R. G., 1954, Electrometric pH determinations: New 

York, John Wiley and Sons, 330 p. 

Bower, C. A., 1961, Studies on the suspension effect with a 

sodium electrode: Soil Science Soc. America Proc., v. 

25, p. 18-21. 

Eisenman, George, Rudin, D. 0., and Casby, J. U., 1957, Glass 

electrode for measuring sodium ion: Science, v. 126, p. 

831-834. 

--1958, Glass electrode for measuring sodium ion: U.S. 

Patent No. 2,829,090. 

Eriksson, Erik, 1951, The significance of pH, ion activities, 

and membrane potentials in colloidal systems : Science, 

v. 113, p. 418-420. 

Feldman, Isaac, 1956, Use and abuse of pH measurements: 

Anal. Chemistry, v. 28, p. 1859-1866. 
C-376 GEOLOGICAL SURVEY RESEARCH 1 9 61 

Garrels, R. M., Thompson, M. E., and Siever, Raymond, 1961, 

Control of carbonate solubility by carbonate complexes: 

Am. Jour. Sci., v. 259, p. 24-45. 

Gregor, H. P., 1951, Ion-pair formation in ion exchange systems: Am. Chem. Soc. Jour., v. 73, p. 3537-3538. 

Isard, J. D., 1959, Alkali ion determinations by means of glass 

electrodes: Nature, v. 184, p. 1616-1618. 

Jenny, Hans, Nielsen, T. R., and Coleman, N. T., 1950, Concerning the measurement of pH, ion activities, and membrane potentials in colloidal systems: Science, v. 112, p. 

164-167. 

Low, P. F., 1954, Ion activity measurements in heterogeneous 

systems: Soil Science, v. 77, p. 29-41. 

Marshall, C. E., 1951, Measurements in colloidal systems: 

Science, v. 113, p. 43-44. 

Mysels, K. J., 1951, , (Potentiometric) measurements in (some) 

colloidal systems: Science, v. 114, p. 424-425. 

Overbeek, J. T. G., 1953, Donnan-emf and suspension effect: 

Jour. Colloid Science, v. 8, p. 593-605. 

Pommer, A. M., 1960, Sodium-sensitive glass electrodes in 

clay titrations in Short papers in the geological sciences: 

U.S. Geol. Survey Prof. Paper 400-B, p. B502-B504. · 

285. EVALUATION OF THE USE OF DICHROMATE OXIDATION TO ESTIMATE THE ORGANIC CARBON 

CONTENT OF ROCKS 

By I. C. FnosT, Denver, Colo. 

The determination of organic matter in sedimentary 

rocks and associated ores presents some challenging 

and difficult analytical problems. The complex chemical nature of the organic matter and its intimate 

association with inorganic minerals makes separation 

into organic ·and inorganic fractions difficult if at all 

possible. Organic matter in sedimentary rocks may 

range from none to several percent. As contrasted with 

the analysis of samples for their organic matter, the 

determination of organic carbon is much easier to 

obtain and serves well as an index to the amount of 

organic matter. 

The reducing capacity of the organic matter as 

1neasured by the dichromate oxidation is used 

routinely in. many soil studies to approximate soil 

organic matter. The method was originally proposed 

by Schollenberger (1927), and later modified by 'Valkley (1945, 1947). The method used in this study is 

that of 'Valkley as adapted and described by the U.S. 

Dept. of Agriculture ( 1954). A weighed sample not 

exceeding 10 g and containing from 10 to 25 mg of 

organic carbon is treated in a 500-ml Erlenmeyer flask 

with 10 ml of 1 N potassium dichromate and 20 ml of 

concentrated sulfuric acid containing 25 g per liter of 

silver sulfate. The flask is heated gently to a temperature of 150°C in a period of 1 minute, then allowed 

to cool. The excess potassium dichromate is measured 

after dilution by titration with 0.5 N ferrous sulfate 

using orthophenanthroline as an indicator. 

It is recognized that dichromate oxidation cannot 

distinguish reduction due to organic matter from that 

due to sulfides, ferrous iron, or other reducing agents. 

The method was investigated, however, to see if it 

might satisfy the demand for a quick, simple, and 

approximate means for determining the organic carbon 

TABLE 285.1.-Comparative data used to eval·uate a rapid field 

method for organic carbon in Pierre shales 

[In percent] 

Organic carbon CarbonequlvCarbonequiv- alent by 

alent by dichromate 

Sample No. Modlfiod I Gasometric dichromate Sulfur t oxidation 

combustion method oxidation corrected 

method for sulfur 

Range 0.10 to 0.49 percent 

259557 0.10 -------------- 0. 06 0.09 0.02 

528 .12 -------------- .16 :02 .16 

539 .15 -------------- .32 . 23 .19 

542 .16 -------------- . 40 . 39 .17 

583 .18 -------------- .22 .02 . 22 

559 . 21 -------------- .21 . 01 . 21 

534 .23 -------------- .26 2,10 . 21 

536 . 24 -------------- .27 . 01 .27 

550 .24 -------------- . 24 .06 . 21 

598 . 24 -------------- .30 2 .10 . 25 

565 . 25 -------------- . 27 .02 . 27 

600 . 27 -------------- . 2S . 04 . 27 

540 . 28 -------------- . 52 . 27 . 37 

551 .30 -------------- . 29 . 01 . 29 

580 . 32 -------------- . 26 . 01 . 26 

586 .36 -------------- . 30 .02 . 30 

566 .36 -------------- . 43 .02 . 43 

605 .37 -------------- . 54 .01 . 54 

531 .39 -------------- .43 2 .14 . 35 

538 . 41 -------------- .63 . 31 . 45 

584 . 41 -------------- . 38 .14 . 30 

546 . 41 -------------- . 40 .07 .37 

535 . 43 -------------- .46 2 .19 .35 

529 .46 -------------- . 46 .01 . 46 

530 . 48 -------------- . 48 . 09 . 44 

See footnotes at end of table. 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14,7-292 C-377 

T ABI-E 285.1.-Comparative data 1tsed to evaluate a rapid field 

method for organic carbon in Pierre shales-Continued 

[In percent) 

Organic carbon Carbonequiv- Carbonequiv- alent by alent by dichromate 

Sample No. Modified Oasomotrlo dichromate Sulfur 1 oxidation 

combustion method oxidation corrected 

method for sulfur 

Range 0.50 to 0.99 percent 

259576 0. 50 -------------- 0.64 0.17 0.51 

552 . 52 -------------- .60 .02 . 59 

575 . 55 -----------·-- .80 .43 .46 

690 . 67 -------------- .68 .03 .57 

689 . 58 ............................. 1.08 . 45 . 73 

587 . 69 -------------- .65 .02 .64 

633 . 69 -------------- 1.14 .60 .67 597 . 64 -------------- 1.12 . 61 .65 677 . 66 .............................. .63 .09 . 67 669 . 67 -------------- 1.13 . 41 .81 

259560 . 73 -------------- .92 .27 . 72 

581 . 75 ............................. .69 .02 .68 

594 . 75 .............................. .84 3 .11 . 76 564 . 78 -------------- 1. 42 .87 . 7.4 

585 . 78 -------------- .65 .02 .64 

601 . 79 -------------- 1. 23 .42 . 91 

592 .80 -------------· 1.14 2 .14 1.04 

545 .82 -------------- 1. 02 .29 .80 

558 .S'Z ............................ . 76 .02 . 75 

568 . 89 -------------- 1. 05 . 42 . 73 

570 .96 -------------- 1.14 . 40 .83 

532 .96 ............................ 1. 23 . 56 .80 

Range 1.00 to 8.08 percent 

259543 ......................... 1. 00 1.60 0.84 1.15 

555 ------------ 1.10 1. 02 .02 1.15 

547 ------------ 1. 32 2.14 1. 02 1. 56 

574 ........................... 1. 81 2.43 .99 1. 87 

604 ------------ 2.43 4.25 2.00 2.97 

562 ------------ 2.48 3. 61 1. 64 2. 59 

571 ------------ 2.49 3. 42 1. 76 2.31 

553 ------------ . 2.58 4.09 1. 93 2.86 

556 ........................... 2.87 3. 40 .92 2.89 

563 ---------·-- 3.18 3.36 .87 2.88 

526 .......................... 4. 73 4. 76 . 25 4. 72 

595 ........................... 4.93 5. 51 1.17 4.82 

561 ------------ 5.40 5. 75 .45 5.58 

591 ------------ 5. 70 6.28 .85 5.82 

682 ............................... 6. 50 10.15 4.46 7.11 

602 ------------ 7.15 10.53 5. 67 6.63 8 549 .............................. 8.23 14.96 9.83 8.08 

I ~rho dlfToronco between the sulfur oxidizable with (1+3) nitric acid and that 

soluble In dilute (10 percent) hydrochloric acid. 2 ~l'otal sulfur values. a Composite samples. 

content of shaJes and to determine its applicability as 

a field reconnaissance method. 

The reducing capacities of 64 selected samples of 

the Pierre shale were determined by the described 

method and calculated as organic carbon. The samples 

selected had organic carbon contents greater than 0.10 

percent. The values of organic carbon for different 

ranges of concentration are given in tables 285.1 and 

285.2. Organic carbon was determined by methods 

described by Frost (1960). The modified combustion 

method was used for those samples having less than 

601.530 0-6L--25 

TABLE 285.2.-Mean carbon content of 64 samples of Pierre shale 

and their standard deviations before and after sulfur corrections 

Standard deviation between organic 

Organic carbon (percent) carbons and dichromate carbon 

Number or equivalents 

samples 

Range Mean Uncorrected Corrected for 

sulfur 

25 0. 10-0. 49 0. 29 0. 10 0. 06 

22 . 50-0. 99 . 71 . 30 . 10 

17 1. 00-8. 23 3. 76 2. 2 . 27 

1.00 percent organic carbon and a gasometric method 

for those having more . 

The samples are arranged in the tables in three 

groups according to their organic carbon contents . 

The reducing capacities, calculated as organic carbon, 

were mostly greater than the determined carbon values . 

Those samples having the larger amounts of oxidizable 

sulfur show the greatest differences. The effect of the 

oxidizable sulfur was determined for each range of 

organic carbon by the method of least squares. Standard deviations between the corrected values and the 

values determined directly can be obtained by multiplying the oxidizable sulfur by 0.7 and subtracting 

the result from the carbon equivalent of the reducing 

capacities. 

The reducing capacities determined by dichromate 

oxidation are quick and easy to obtain and can be 

carried out. in field reconnaissance studies . 

REFERENCES 

Frost, I. C., . 1960, Comparison of three methods for the 

determination of total and organic carbon in geochemical studies, in Short papers in the geological sciences: U.S. 

Geol. Survey Prof. Paper 400-B, p. B480-B483. 

Schollenberger, C. J., 1927, A rapid approximate method for 

determining soil organic matter: Soil Science, v. 24, p. 

65-68. 

U.S. Department. of Agriculture, 1954, Diagnosis and improvement of saline and alkaline soils : Agriculture Handbook 

No. 60, p. 105-106. 

·walkley, A., 1945, An examination of methods for determining 

organic carbon and nitrogen in soil: Jour. of Agr. Sci. 

(England), v. 25, p. 598-609. 

---l947, A critical examination of a rapid method for 

determining organic carbon in soil-effect of variations 

in digestion conditions and of inorganic soil constituents : 

Soil Science, v. 63, p. 251-264. 
C-378 GEOLOGICAL SURVEY RESEARCH 19 61 

286. DETERMINING THE DISTRIBUTION OF BERYLLIUM IN ROCKS BY A CONTACT-PRINT METHOD 

By WALLACE R. GRIFFITTS and LoRRAINE E. PATTEN, Denver, Colo. 

During a mineralogic study of beryllium ores from 

. Spor Mountain, Utah, we wished to determine the 

distribution of beryllium in siliceous nodules and other 

coherent lumps of rock. Staining with quinalizarin 

(Jedwab, 1957) was unsatisfactory because the reagent 

stained the porous surfaces and because the purple 

fluorite in many specimens made the color distinctions 

difficult. ·we found that beryllium could easily be dissolved from the surfaces of the specimens and transferred to paper, on which it could be rendered visible 

with suitable reagents. This technique has long been 

used in the study of sulfide ores. 

To make the print, a flat, smooth, but not polished, 

rock surface is pressed for about 15 seconds against 

a piece of fine filter paper moistened with 3 normal 

sulfuric acid. The paper is then dried, sprayed with 

a 0.01 percent solution of morin in ethyl alcohol, and 

suspended in a closed container over concentrated ammonium hydroxide. The ammonia fumes neutralize the 

acid that remains in the paper and makes the paper 

alkaline; the beryllium-morin compound then fluoresces under ultraviolet light. The intensity of the 

fluorescence varies with the amount of beryllium. 

For permanent record the fluorescent image can be 

photographed or the areas with different intensity of 

fluorescence can be outlined on the paper with a pencil, 

as was done with the samples shown on figure 286.1. 

Beryllium is dissolved from the Spor Mountain ore 

because of the extremely fine grain size of the bertrandite. Sulfuric acid does not readily dissolve coarse 

beryl or bertrandite unless the specimen is first briefly 

etched with sodium hydroxide. This preliminary treatment consists of clipping the cold specimen into fused 

NaOH for a few seconds, withdrawing it, and washing 

off the coating of solidified hydroxide with water. 

After drying, the specimen can be treated in the same 

manner as the Spor Mountain ore. 

REFERENCE 

Jedwab, J., 1957, Coloration du surface du beryl: Soc. Geol. 

Belgique Bull., v. 66, no. 1, p. 133-136. 

A c 

0 1 inch 

B D 

FIGURE 286.1.-Distribution of beryllium in two specimens 

from Spor Mountain, Utah. A, nodule that contains blades 

of purple fluorite and a white rind; B, outline of smooth 

surface of specimen A (stippled area is strongly fluorescent 

indicating that beryllium is most concentrated in rock with 

medium-sized fluorite blades) ; a, specimen having palepurple center and mottled white ends; D, outline of smooth 

surface of specimen a (stippled area is strongly fluorescent, 

indicating that beryllium is most concentrated in the white 

terminal parts of the specimen). 
.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14t7-292 C-379 

287 SOME FACTORS AFFECTING THE DETERMINATION OF BERYLLIUM BY THE GAMMA-RAY ACTIVATION 

METHOD 

By WAYNE MouNTJOY and H. H. Lrrr, Denver, Colo. 

A gamma-ray activation analysis instrument for 

the detection and deter1nination of beryllium has been 

described by Vaughn and others (1960). This instrmnen t activates a beryl sarnple by exposure to the 

gamma radiation from antimony-124. The activated 

beryllium nuclei emit neutrons according to the reaction: 

Be0 + y~Be8 + n. These neutrons are moderat~d by 

a block of paraffin and counted with a scintillation 

type detector and a scaler. The reaction is specific for 

beryllimn except for deuterium, which has a negligible 

effect in rock san1ples (Bowie and others, 1960). 

The relative efficiency of the instrument using 

sample holders of different sizes and shapes was deternlined for the following types of sample holders: 

(a) half-pint, cylindrical ice cream cartons.. 8. 7 em 

in diameter and 5.5 cn1 high, which are commonly 

used for storing samples, (b) shallow cylindrical plastic 

dishes, 8.7 em in diameter and 2.0 em high, having 

a capacity of about 115 cc, (c) cone shaped dishes, 6 em 

in diameter at the top, 3 em in diameter at the bottom, 

2.0 em high, and having a capacity of about 40 cc. 

Both the cylindrical and conical dishes rest in the 

sample well of the instrument almost in contact with 

the capsule containing the radioactive antimony when 

the capsule is raised for counting. Dishes with low 

sides permit the neutron detector to be lowered quite 

close to the samples. The cartons however, have both 

the top and bottom recessed about 1 em. This spacing 

holds the sample farther away from both the source 

and detector and creates a less efficient counting geometry than that obtained with the other two containers. 

The relation between sample size, sample-container 

shape, and count rate is shown on figure 287.1. ·The 

cone-shaped dish is superior to the cylindrical dish 

and to the paper cartons when less than 100 grams of 

sample are available for analysis. The count rate of 

10 grams of sample in the conical dish is about twice 

tlutt obtained with the cylindrical dishes and nearly 

4lf2 times that obtained with the cartons. An advantage of the conical dishes, not apparent from the 

graph, is the greater accuracy obtained by their use 

because of the difficulty of distributing a small sample 

evenly over the bottom of larger dishes. However, 

when both are filled to capacity, the cylindrical dishes 

give an approximately 45 percent greater count-rate 

than the conical ones. 

6000 

UJ 

~ 4000 

z 

~ 

0:: 

UJ 

0.. 

en 

..... 

z 5 2000 

u 

Cylindrical dishes 

100 

SAMPLE WEIGHT, iN GRAMS 

FIGURE 287.1.-Difference in count rate for different sample 

weights for 3 types of sample containers. 

The radioactive source is.rod shaped, and more efficient counting geometry wouid be obtained on small 

samples if the dishes were elongate. Modeling clay 

containing about 4 percent BeO was molded into various shapes of the same volume as the conical dish 

and were analyzed by the counter. All models were 

flat at top and bottom. The most efficient model tested 

was wedge shaped in section and had rounded ends. 

This model gave an 11-percent greater count-rate than 

the conical one. 

In order to determine the effect of particle size on 

the count rate, a rough crushed sample containing 

about 10.3 percent BeO was split into three parts. One 

part was ground very fine, the second medium fine, 

and the third not ground. . 

The count-rate per gram for a constant weight of 

sample was virtually the same for all three samples. 

The rough crushed sample had a greater apparent 

density than the fine material and therefore gave 

a slightly greater count-rate for an equal volume of 

sample. 

Table 287.1 shows a comparison of the results obtained by activation analysis to those obtained by the 

direct reading spectrograph. Calibration factors were 

calculated for both the conical dishes and the cartons 

as sample holders. These factors, based on the average 

percent BeO obtained by direct reading spectrograph, 

were used to calculate the activation-analysis. percent 

BeO. The average standard deviations between the 

spectrographic analysis and the activation analysis in 
C-380 GEOLOGICAL SURVEY RESEARCH 19 61 

the range from 0.1 to 2.3 percent BeO were found to 

be 0.08 percent BeO for 11 weighed samples in conical 

dishes and 0.04 percent BeO for 7 samples in filled 

paper cartons. It is obvious that these standard deviations are a measure of the precision of the calibration 

rather than the accuracy, which depends on the standard used. 

TABLE 287.1.-Comparison of the activation analysis with the 

direct reading spectrographic determination of beryllium for 12 

samples from Spor Mountain, Utah 

Activation analysis 

counts per minute BeO, percent 

1---,....---l Sample 

weight By activation Laboratory No. in cartons !ly direct analysis 

Conical' Paper (grams) reading I-----.---- dishes cartons spectrograph Conical Paper 

dishes cartons 

-·-----1------------------- 648 ______ - ----------- 684 

643__________________ t 643 

701.. •• -------------- 2 645 623._________________ 2 639 

864 ______ ------------ 2 631 

809 ___ --------------- 461 613. ____ ------------- 358 

649 ___ --------------- 281 737__________________ 141 645__________________ 112 

632 ___________ ------- 37 741...________________ 35 

t Samole weight, 40 grams. 2 Replicate splits. 

718 246 

505 254 365 198 311 256 

129 253 124 256 36 251 28 270 

2.36 

2. 22 2.19 

2.08 

1. 91 1. 66 

1. 25 

.94 

.44 

.42 

. 014 

.11 

2.32 

2.17 

2.17 

2.15 

2.13 

1. 55 1. 21 

. 95 

.47 

.38 

.13 

.12 

2.37 

1. 67 

1. 21 

1. 03 

.43 

. 41 

.12 

.09 

Table 287.1 also shows that the cartons gave results 

in agreement with those obtained with the conical 

dishes even though the sample weights ranged from 

198 grams to 270 grams. An explanation is that samples in cartons may be considered to approach infinite 

size in their effect on count rate. 

It was concluded from this study that full cartons 

of sample material, when available for analysis, give 

reliable results without removing the sample from the 

half-pint storage container. For smaller amounts of 

material, the sample should be weighed in one of the 

plastic sample holders for the most precise determination of beryllium by activation analysis. In this case, 

the cylindrical holder may be used to advantage if the 

sample weight is over 100 grams, but the conical 

holder should be used if less than that amount is 

available. 

REFERENCES 

Bowie, S. H. V., Bisby, H., Burke, K. C., and 'Vale, F. H., 

1960, Electronic instruments for detecting and assaying 

beryllium ores: Inst. Mining Metall. Trans., v. 69, no. 

7, p. 345-359 . 

Vaughn, W. W., Wilson, E. E., and Ohm, J. M., 1960, A field 

instrument for quantitative determination of beryllium by 

activation analysis: U.S. Geol. Survey Circ. 427. 

288. DETERMINATION OF BERYLI.iiUM WITH A DIRECT-READING SPECTROGRAPH 

· By ARMIN W. HELZ and CHARLES S. ANNELL, Washington, D. C. 

A spectrographic method has . been developed for 

determining beryllium quantitatively and rapidly in 

concentrations ranging from a few parts per million 

to ·a few percent in a large variety of silicate rocks 

and beryllium ores without special attention to the 

types of samples being analyzed. A spark-pellet technique is used similar to that described by Tingle and 

Matocha (1958) for the determination of the major 

elements in nonmetallic samples. 

APPARATUS 

A low voltage spark source (Multisource) with a 

mechanical rotary interrupter is used with the following sets of' circuit parameters: 

Capacitance ____________________ 10 ________ 2. 

Inductance_____________________ ResiduaL _ Residual. 

Resistance, ohms _______________ ResiduaL_ Residual. 

VoUage ________________________ 940-~----- 940. 

Ten microfarads capacitance are used for the lower 

concentration range (0.0003 to 0.026 percent), two 

microfarads for the higher concentration range (0.026 

to 4.2 percent). 

Vibration or shaking type of grinding and mixing 

equipment is used, a mechanical shaker aided by 

manual brushing for sieving, a pellet press giving 

40,000 pounds force, a furnace heating to 1 000°C, 

Plattner mortar, a 4-inch mortar and a pestle, and 

special pellet holders as shown on figure 288.1. 

The spectrograph is a grating spectrograph having 

a reciprocal linear first-order dispersion of about 5 

angstroms per millimeter and may be used either for 

photographic or photoelectric recording. An entrance 

slit of 50 microns and exit slits of 100 microns wide 

are used for this work. Receiving or exit slits are set 
SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 1417-292 C-381 

FIGURE 288.1.-Pellet holder ; pellet to the left. 

on the :following lines, second order spectrum : bery Ilium 3131.07A, beryllium 2348.6A, lithium 3232.61A 

and boron 3451.41A. 

The lithium line is used as the time monitoring line; 

that is, the apparatus is so arranged that all recording 

is cut off when the lithium photomultiplier has received a set amount of radiation. A simultaneous check 

with the boron line showed a different reaction to 

excitation changes than beryllium 3131.07 A and thus 

eliminated its use as a possible monitor in place of 

the lithium line. The beryllium 3131.07 A line was 

selected :for the analysis because it was more intense 

and less diffuse than the beryllium 2348.6A line with 

the excitation conditions used. The spectra of several 

samples containing 1 percent concentrations of thorium, tantalum, and molybdenum, and 0.5 to 5 percent 

concentrations of chromium were recorded photographically and studied :for possible interferenc~s with 

beryllium lines and also :for selecting the most favorable type of discharge. 

ANALYTICAL PROCEDURE 

Silicate rock and beryl concentrates, chemically 

analyzed :for beryllium, are used to prepare standards 

covering a concentration range from 0.00026 percent 

to 4.22 percent beryllium. An additional 1.06 percent 

beryllium standard are used :for the high concentrations. 

One hundred mg of the sample or standard and 

800 mg of lithium tetraborate are lightly mixed in a 

mortar and transferred to graphite crucibles. The 

crucibles are placed in a nickel tray designed to hold 

12 crucibles and are heated in a muffle furnace :for 8 

minutes at 1,000°C. The lithium tetraborate fusions 

:form clear beads which are easily removed after cooling because there is no wetting of the graphite by the 

molten lithium tetraborate. 

The cool bead is crushed in a Plattner mortar and 

then pulverized with an automatic grinding apparatus. 

A 12 mm tungsten carbide ball strikes tungsten carbide 

plates in the caps at either end of an alumina cylinder 

4.4 em long and 1.9 em inside diameter. The mechanical vibrator is run :for 3 minutes and provides about 

2000 impacts per minute. The powdered material is 

passed through a 325-mesh stainless steel screen by 

means of a mechanical shaker aided by manual brushing. The small amount of coarser material remaining 

is ground by hand in a boron carbide mortar until it 

passes 325 mesh. 

A 300 mg portion of the powdered sample bead and 

600 mg of briquetting graphite are weighed into a 2.6 

em glass vial of 1.5 em inside diameter, which holds 

a 5 mm nylon ball. The vial is capped with a plastic 

cover and placed in a small vibrator which mixes the 

material :for 3 minutes. The sample-graphite mixture 

is then placed in a 112-inch hydraulic press die and 

subjected to 40,000 pounds :force :for 20 seconds. The 

pellet is placed in a labeled powder box and stored in 

a desiccator until ready :for analysis. 

The pellet is pressed into a stainless steel pellet 

holder (fig. 288.1) and the surface of the pellet is then 

cleaned by rubbing over a piece of filter paper on a 

flat surface. The surface is rubbed clean between each 

sparking. The dial readings for at least three "runs" 

are averaged :for each pellet. The pellet constitutes the 

lower electrode of the discharge gap which is kept at 

a 3 mm spacing throughout the recording time. The 

upper electrode is a pointed %,-inch graphite rod. A 

horizontal cylindrical lens at the slit :focuses the source 

on the collimator and a vertical cylindrical lens focuses 

the source on the slits. No filtering is used. 

The capacitance used :for the source, and the multiplier phototube potential are adjusted to give approximately 40-second exposures and 3 analytical ranges 

from 0.0003 percent to 4 percent beryllium. 
C-382 GEOLOGICAL SURVEY RESEARCH 1 9 61 

400~------------------------------------------~ 

0 

z 

::::> 

0 

0:: 

<!l100 

::.: 

u 

<t: 

CD 

(f) 

::::> 

z 

! 

(!l 

z 

0 

~ 0:: 

10 

.1 

500 

0 

z 

::::> 

0 

0:: 

(!l 

~100 

<t: 

CD 

(f) 

::::> 

z 

! 

(!l 

z 

0 

<t: 

LLI 

0:: 

10 

.01 

200 

100 

0 

z 

::::> 

0 

0:: 

(!l 

::.: 

u 

<t: 

CD 

(!l 

z 

0 

<t: 

LLI 

0:: 

1 

.0001 

·High range, 0.2 to 5.0 percent beryllium. 

1 PERCENT Be 10 

Medium range, 0.02 to 0.5 percent beryllium. 

.422 

.26 

.094 

.0422 

.026 

.1 PERCENT Be 

Low range, <0 .0003 to 0.03 percent beryllium. 

.0026 

.000422 

.01 .04 

FIGURE 288.2.-Analytical curves for the determintati'on of beryllium in three concen'trati·on ranges, using a direct-reading 

spectrograph. 

In a continuous period of analysis a group of 3 or 

4 standards and a lithimn tetraborate blank are sparked 

at the beginning of the period and after each group 

of 8 sample pellets. This procedure corrects for any 

slight curve shift caused by electronic variations. The 

beryllium concentrations are read fron1 curves relating 

the average readings of the standard pellets to concentration (fig. 288.2). 

A preliminary check of the accuracy of the method 

was made with 4 samples which had been chemical1y 

analyzed by 7 laboratories. The results are shown in 

table 288.1. 

Additional comparisons were made with analyses 

using a general spectrographic method devised by 

Bastron and others (1960), and with fluorimetric 

analyses using a method developed by I. May and F. S. 

Grimaldi (oral communication, 1960). The results are 

given in table 288.2 . 

TABLE 288.1.-Comparison of results from direct-reading spectrograph with chemical analyses 

Sample 

·Beryl concentrate ___________________ _ 

Medium-grade beryl ore ______________ _ Low-grade beryl ore _________________ _ Tailing waste _______________________ _ 

Beryllium (percent), determined by method indicated 

Chemical Direct-reading analysis spectrograph 

4. 04 

1. 99 

. 50 

. 094 

4. 0 

1.9 

. 42 

. 086 

TABLE 288.2.-Comparison of results from direct-reading spectrograph with analyses using general spectrographic and fluorimetric 

methods 

[Spectrographic analyses by H. Bastron; fluorimetric analyses by I. May and F. 

Grimaldi] 

Beryllium (percent), determined by method indicated 

Sample General Fluorimetric Direct-reading 

spectrographic spectrographic 

60-ASN-53 _____ 0. 0002 0. 0002 0. 0003 

60-ASN-84 _____ . 0008 . 0016 (avg of 3) . 0010 

60-ASN-96 _____ . 0011 . 0015 (avg of 3) . 0011 

60-ASN-69C ____ . 18 . 15 . 15 

60-ASN-141. ___ . 22 . 21 . 18 

Blue Jay-L ____ ---------- . 83 . 79 

Boomer-1 ______ ---------- 4. 2 4. 2 

REFERENCES 

Bastron, Harry, Barnett, P. R., and Murata, K. J., 1960, 

Method for the quantitative spectrochemical analysis of 

rocks, minerals, ores, and other materials by a powder 

d-e arc technique: U.S. Geol. Survey Bull. 1084-G, p. 165-

182. 

Tingle, W. H., and Matocha, C. K., 1958, Spectrochemical 

analysis of non-metallic samples: Anal. Chemistry v. 

30, p. 494-498. 
SHOR1' PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 14,7-292 C-383 

289. USE OF BATHOPHENANTHROLINE FOR DETEJ;tMINING TRACES OF IRON IN ZIRCON 

By FRANK CuTTITTA and JESSE J. WARR, Washington, D .C. 

Some studies involving measurements of magnetic 

susceptibility require the determination of trace 

amounts of iron in zircon. This paper describes the 

use of 4, 7-diphenyl-1, 10-phenanthroline commonly 

called bathophenant:hroline (Smith and others, 1952) 

in the spectrophotometric determination of trace 

amounts of iron in zircon. Previous work by other investigators (Smith and others, 1952; Peterson, 1953; 

Seven and Peterson, 1958) has shown that the optimum 

pl-I for full color development is from 2 to 9. Our 

data show further that in the presence of their recommended buffer (acetic acid-sodium acetate, resulting 

in a pl-I of 4.5), a white gelatinous hydrous oxide of 

zirconium precipitates when the sample size exceeds 

5 to 8 milligrams of zircon. Amounts of zircon in exeess of 5 t·o 8 mg require a complexing agent to keep 

zirconium in solution. I-Iydroxy organic acids such as 

citric, tartaric, salicylic, and sulfo-salicylic acids are the 

best mn.terin.ls to prevent the precipitation of zirconium 

at elevated pll. From past experience, the choice of 

complexing agent was limited to tartrates and citrates. 

1\{eso-tartn.ric acid was selected as the complexing 

n.gent to pre\rent the precipitation of zirconium in the 

pi-:I range recommended for full chelate formation. 

"Then sodium acetate is used as the buffer salt in the 

estimation of iron with bathophenanthrolil1e, complete 

color is attained n.fter the solutions have stood at room 

temperature for 15 minutes. I-Iowever, when tartrates 

are used to complex zirconium the color of the iron 

chelate does 11ot reach a maximum value until at least 

an ·hour and a half after preparation of the solution. 

The inhibition of the color development can be overcome by allowing t.he solution to stand for at least half 

n.n hour at 60°C in a water bath or by adding N,N'-

dimethylformamide (Dl\1:F) in an amount not less 

thnn20 percent (v/v). The latter practice was adopted 

because DMF also obviates the turbidity (opalescence) 

often experienced in using bathophenanthroline for the 

speet:rophotometric determination of iron. 

In the course of this investigation, the following 

observn.tions were made: (a) reagents must be n.dded 

in the order given; (b) absorbance due to 10 JJ.g (microgrn,ms) of iron in 25 ml was stn.ble (0.815 ±0.005) for 

a period of 6 days; (c) iron in zircons is determined with 

error.·s less than 0.05 J.l.g of iron per 25 ml; (d) developtnent of the pink color of the ferrous-bathophenanthroline complex is complete within 15 minutes at rootn 

temperature in the presence of dimethylformamide 

(at least 20 percent v/v); (e) boron (from' flux used in 

the decomposition of zircon) has no effect on the color 

system; (f) extraction of the red iron complex into 

solvents such as n-amyl alcohol, iso-amyl alcohol, 

n-hexyl alcohol, or nitrobenzene permits the determination of less than 1 ppm of iron when using a 1-g sample. 

The high sensitivity of 4, 7-diphenyl-1, 10-phenanthroline (molar absorptivity=22;400) plus the use of 

carefully purified "iron-free" reagents makes it possible 

to measure smaller amounts of iron than can be 

measured with other iron reagents. 

REAGENTS 

BathozJhenanth?·oline, 0.0015M.-Dissolve 99.7 mg of 

the reagent (C24Hl6N2, mol wt 334) in 50 ml N,N'-

dimethylformamide (DMF) and dilute the solution to 

200 ml with D l\{F. 

IiydToxyla?nine hyd?·ochloTide, 10 ]Jer·cent 1.0/v solution.-Reagent grade NH20H · HCl contains appreciable amounts of iron. Prepare 100 ml of a 10 percent 

aqueous solution of NH20H · HCl and add 5 ml of the 

0.0015M bathophenanthroline solution. Th~ solution 

has a pH of 1.5 to 1.8. Place the solution in a 25-ml 

plastic-stoppered (Teflon) separatory funnel and extract twice by shaking with 15 ml portions of iso-amyl 

alcohol (alternately, n-amyl alcohol, n-hexyl alcohol, 

or nitrobenzene can be used). 

111 eso-taTta?·ic solution.-Dissolve 62.5 g of mesotartaric acid in 100 ml of water. Add 50 ml of ammonium hydroxide (prepared from cylinder ammonia) 

to the tartaric solution and transfer the solution to a 

250-ml plastic-stoppered (Teflon) separatory funnel. 

Add 10 ml of the hydroxylamine hydrochloride solution to reduce the iron present and 20 ml of the bathophenanthroline solution. Extract the red iron complex 

by adding 20 ml of iso-amyl alcohol and shaking the 

contents of the separatory funnel thoroughly. When 

the two phases have separated completely (2 to 3 minutes), draw off the ]o·wer tartrate layer into a second 

separatory funnel and repeat the extraction to insure 

complete removal of iron. After the second extraction, 

draw off the tartrate layer, add an additional 50 ml 

of the ammonium hydroxide, and make up to 250 ml 

with water. Store the tartrate solution in a polyethylene bottle. A 5 ml aliquot of this solution contains 

1.25 g of tartaric acid and enough Nl:I40H to produce a pH of 5 in the recommended procedure. 
C-384 GEOLOGICAL SURVEY RESEARCH 1 9 6 1 

PROCEDURE 

Preparation of sample solution.-Grind the sample to 

an impalpable powder in a boron carbide mortar and 

mix thoroughly. Small particle size is necessary to 

insure complete fusion in a reasonable time. Weigh 

out a 50-mg sample (should contain 15 to 50 fJ.g of iron) 

into a 10-ml platinum crucible and add half a gram of 

carbonate-borate flux prepared by mixing equal portions by weight of anhydrous sodium carbonate and 

anhydrous sodium borate (Ampt, 1935). Mix thoroughly. Cover the crucible, place it in a furnace, and 

heat to 150° or 200° C, to drive off any moist.ure. 

Gradually increase the temperature until the mass is 

a viscous liquid (approxi~ately 925 ° C.) Keep the 

crucible at this temperature for 20 to 30 minutes. 

Cool to room temperature and place the crucible and 

melt in a 50-ml beaker, add 5 ml water, cover, and 

digest. on a steam bath until the melt has completely 

disintegrated to a fine "silt". Then add 12.4 ml 1:1 

HCl, cover, and digest on a steam bath until the 

"silt" just dissolves. Transfer the solution quantitatively to a 25-ml volumetric flask, remove and wash 

the crucible. Adjust volume to 25 ml. The final HCl 

concentration is 20 percent v/v. Process a rea~ent 

blank with the samples. 

Spectrophotometric determ inat~·on.-Transfer a 5-ml 

aliquot (contains from 2 to 10 fJ.g of iron) to a 25-ml 

flask. Add 2 ml of hydroxylamine hydrochloride 

solution. Add 5 ml bathophenanthroline solution. 

This will make the final solution at least 25 percent 

v/v DMF. Add 5 ml of the tartrate solution gradually 

shaking the flask vigorously during the addition of the 

reagent. The pH is now between 4.8 and 5.0. Allow 

solutions to cool to room temperature. Adjust the 

volume to 25-ml with water, stopper the flask, and 

mix thoroughly. Read absorbance at 535 fJ. in a 5-cm 

cell against water as a reference solution. Process 

reagent blanks and iron standards used in preparing 

the standard curve along with the· samples. 

REFERENCES 

Ampt, G. A., 1935, Determination of zirconium: Australian 

Chern. Inst. Jour. and Proc., v. 2, p. 321-334. 

Peterson, R. E., 1953, Improved spectrophotometric procedure 

for determination of serum iron: Anal. Chemistry v. 25, p. 

1337. 

Seven, M. J., and Peterson, R. E., 1958, Spectrophotometric 

determination of iron in urine using bathophenanthroline: 

Anal. Chemistry v. 30, p. 2016. 

Smith, G. F., McCurdy, W. H., Jr., and Diehl, H., 1952, 

Bathophenanthroline. Use in the determination of iron 

in raw and treated water: Analyst, v. 77, p. 418. 

290. DITHIZONE MIXED-COLOR METHOD FOR DETERMINING SMALL AMOUNTS OF THALLIUM IN 

MANGANESE ORES 

By FRANK CUTTITTA, Washington, D. C. 

The determination of thallium is often required in 

a variety of materials undergoing geochemical studies. 

This paper describes an application of the thalliumdithizone mixed-color system (Clarke and Cuttitta, 

1958) for determining small amounts of thallium in 

manganese ores. The dithizone data summarized by 

Sandell ( 1959) show that manganese and iron are 

major interferences. Manganese (II) forms a primary 

dithizonate complex in alkaline media, 'vhich is unstable (air oxidation) and forms brown floes in chloroform. In addition, thallium dithizonate is also accompanied by dithizonates of lead, bismuth (III), tin 

(II), and indium. The thallium value so obtained is 

in error to an extent equivalent to the amount of tin, 

bismuth, lead, or indium present. The modified procedure eliminates any increase of thallium values due 

to lead, bismuth, tin, or indium. It also provides a 

means for the total separation of large amounts of 

manganese and iron which interfere in the extraction 

of thallium with dithizone. 

Several investigators (Bock and others, 1953; Irving 

and Rossotti, 1952; Reith and Gerritsma, 1946; and 

vVada and Ishii, 1934, 1938) have made intensive studies of the extraction of metal halides from aqueous 

halogen acid solution by ethyl ether. This procedure 

utilizes ether extraction of thallium (I or III) bromide 

as a preliminary separation of interfering metallic 

ions. Irving and Rossotti ( 1952) reported that the 
•• 

:+· 

.SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-385 

ether extraction of thallium (I or III) bromide provides a better separation of thallium than does extraction of the chloride. At 0.5 to 1N HBr ferric iron, 

gallium, or indium are extracted. Very small amounts 

of tellurium, zinc, mercury, molybdenum, and antimony are also extracted. These elements are removed 

from the ether layer by shaking the organic phase 

with 1N I-IBr. Gold (III) follows thallium quantitatively. Reith and Gerritsma (1946) found in their 

experiments that the extractability of thallium (I or 

III) bromides into ethyl ether is greater than 99.9 

percent at room temperature using equal volumes of 

phases and multiple extractions. My investigation confirms this and shows that microgram quantities can be 

separated satisfactorily in this way. 

The organic content of the thallium-bearing extracts 

is destroyed by wet-ashing with HN03 • The thallium 

is then determined spectrophotometrically with dithizone as described by Clarke and Cuttitta (1958). A 

standard curve was prepared from known amounts of 

thallium carried through the ether extraction of the 

bromides and dithizone steps. Results obtained on a 

few samples of manganese ores agree with those 

obtained by X-ray fluorescence (H. Rose, oral communication, 1960). 

Proe7Jaroation of solution. - A sample containing 

n.pproximately 100 to 500 p.g of thallium is weighed 

into a 100-ml plastic beaker. (Platinum is not used 

because of the solvent action of ferric iron in strong 

l:IBr.) Ten rnl1 :1 I-IBr and 2 ml HF are added. The 

beaker is covered with a plastic disc and left on the 

steam bath for 11/2 hours. The cover is removed and 

the solution is evaporated to dryness. The salts are 

converted to bromides by evaporation to dryness several times with I-IBr. Sixteen ml of 1 :1 HBr are 

added and the. covered solution is heated on the steam 

bath until all salts are dissolved. The solution. is transferred quantitatively to a 50-ml volumetric fl.ask and 

the volume adjusted to 50 ml with water. The final 

acid concentration is 1.5 N HBr. A reagent blank is 

processed along with the samples. 

Elin~ination of interoferoences.-A 5-ml aliquot of the 

stoek solution (containing 10 to 50 p.g of thallium) is 

transferred to a 60-ml plastic-stoppered (Teflon) separatot·y fnnnel. This is diluted with 5 ml water. The 

acidity is now 0.75 N HBr. Ten m] of chilled ethyl 

ether and 5 drops of alizarin indicator (used to dye the 

ether layer so that a sharp separation of the phases can 

be made) are added to the solution in the separatory 

funnel. The thallium is then extracted as thallium bromide into the ether from the 0.75 N HBr solution by vigorous shaking for 2 minutes. The lower aqueous layer 

is then transferred to a second separatory funnel. The 

ether extraction of thallium bromide is repeated three 

more times and all four ether extracts are combined in 

the first separatory funnel. Entrained interfering elements are back-stripped with 10 ml of 1N HBr by 

shaking the two phases for 2 minutes. The aqueous 

HBr layer is discarded. The ether extracts are transferred quantitatively to a 100-ml beaker, and the funnel 

washed 3 times with 3-ml portions of fresh ether. The 

ether washings are combined with the ether extracts 

in the beaker. The ether extracts are evaporated to 

dryness on a steam bath using a petri dish as a platform. The organic residue is wet-ashed with two 10-ml 

portions of 1:1 HN03 , evaporating the solution to dryness after each addition. The remaining residue is 

dissolved with 1 percent HCl and transferred quantitatively to a 125-ml plastic-stoppered separatory funnel. 

The resulting volume of solution and rinsings is about 

30 to 35 ml. 

Spectroophotometric deteromination.-The thallium is 

determined by the dithizone procedure as described by 

Clarke and Cuttitta (1958) using chloroform as the 

solvent. The samples, reagent blanks, and thallium 

standards used in the preparation of the standard 

spectrophotometric curve are processed (ether extraction and dithizone separation-determination steps) 

simultaneously. 

REFERENCES 

Bock, H., Kusche, H., and Beck, E., 1953, On the separation of 

inorganic mixtures by extraction : Zeitschr. Anal. Chemie, 

v. 138, p, 167. 

Clarke, R. S., Jr., and Cuttitta, Franl{, 1958, Determination 

of thallium by a dithizone mixed-color method: Anal. 

Chim. Acta, v. 19, p. 555-562. 

Irving, H. M., and Rossotti, F. J. C., 1952, The solvent extraction of Group III B metal halides: Analyst, v. 77, no. 

920, p. 801-812. 

Reith, J. F., and Gerritsma, K. W., 1946, A combined microgravimetric and titrimetric microdetermination of thallium 

and other toxicological material: Rec. trav. chim., v. 

65, p. 770. 

Sandell, E. B., 1959, Colorimetric determination of traces of 

metals: 3d ed, New York, lnterscience Publishers, Inc., 

p. 139-176. 

Wada, I., and Ishii, R., 1934, Extraction of thallium as bromide 

from its hydrobromic acid solution by ether: lnst. Phys. 

Chern. Research (Tokyo) Bull., v. 13, p. 264. 

--1938, Separation and detection of the elements of the 

silver and thallium group : lnst. Phy~. Chern. Research 

(Tokyo) Sci. Papers, v. 34, p. 787. 
C-386 GEOLOGICAL SURVEY RESEARCH 1 9 61 

291. DETERMINATION OF FERROUS IRON IN MAGNETITE AND ILM.ENITE IN THE PRESENCE OF 

AMPHIBOLES AND PYROXENES 

By JosEPH J. FAHEY, Washington, D. C. 

The analysis of amphibolites and pyroxenites for 

their content of magnetite, hematite, and ilmenite must 

be preceded by a heavy-liquid separation of these 

oxides. If a Clerici solution having a specific gravity 

of 4.2 is used, magnetite, hematite, and ilmenite can 

be completely separated from the silicates provided 

intergrowths do not cause some of the silicates to be 

carried down with the heavy oxides. However, because 

of intergrowths, grinding to pass a 200-mesh sieve generally does not effect a complete Separation of the 

oxides from the silicates. 

In one common method, FeO is determined by using 

a solution of hydrofluoric acid and sulfuric acid in 

an inert atmosphere to liberate the ferrous iron, which 

is then titrated by a standard permanganate solution. 

This procedure obviously cannot be used to determine 

FeO in magnetite or ilmenite that is associated with 

ferrous iron silicates, because it would yield a figure 

for total FeO that would include the ferrous iron from 

the silicates. This difficulty was avoided by breaking 

up the magnetite and ilmenite in a nonoxidizing environment by hot ( 1 + 1) HOI that does not attack many 

of the minerals of the amphibole and pyroxene groups. 

A 1f2-gm sample of heavy oxides obtained by a 

Clerici separation, including intergrown silicates, is 

placed in an Erlenmeyer flask of 50-ml capacity. After 

displacing the air with COz, 10 ml of ( 1 + 1) HOI is 

added and the flask is immediately tightly closed with 

a rubber stopper and placed in a steam bath. The 

stopper is held in place against increasing pressure 

within the flask by an inverted 250-ml beaker. The 

time during which the flask is allowed to remain in the 

steam bath is not critical. Usually over night (16 to 

24 hours) was found to be sufficient for the decomposition of the oxides. The steam bath is then turned off 

and after about l/2 hour the flask is chilled in cold 

water. 

The contents of the flask are quickly transferred to 

a large beaker ( 800 ml) containing 300 ml of 5 percent HzS04 plus 25 ml of Reinhardt's solution by 

keeping the 1nouth of the flask below the surface of the 

sulfuric acid solution, thereby allowing a minimum 

contact with the air. ·Ferrous chloride is quickly oxidized on contact with air. The flask is held inverted 

in this position while the solution is titrated with 

permanganate. The flask is used instead of a stirring 

rod to agitate the solution. When the end point of 

the titration is reached, the flask is quickly filled with 

some of the solution from the beaker. The solution in 

the flask is then returned to the beaker and the end 

point again attained. In using permanganate to titrate 

a solution containing hydrochloric acid and Reinhardt's solution, the color of the end point does not 

pe:r;-sist as long as it does when sulfuric acid alone is 

present. However, when the end point is reached, the 

color of the permanganate will not fade within thirty 

seconds. 

Complete decomposition of samples of magnetite 

and hematite (minus 200 mesh) is attained by one 

overnight treatment in (I+ 1 )HCl as described above. 

Most samples that are very high in ilmenite are similarly decomposed. However, a small percentage of 

ilmenite samples require a second overnight treatment 

with the (l + l)HCI. This is done by decanting the 

titrated solution and transferring the undecomposed 

opaque material that has settled to the bottom of the 

800-ml beaker to the 50-ml flask. A stream of water 

from the wash bottle readily moves the remaining oxide 

to the flask. The water is then carefully decanted, 

the air displaced by C02, and the procedure repeated 

as described above. 

In order to demonstrate that there is no n1easurable 

amount of oxidation of the ferrous iron prior to titration, 10 ml of a ferrous iron sulfate solution (10 n1l =0= 5.8 

ml permanganate solution =C= 0.0432 gm FeO) was 

pipetted into the 50-ml Erlenmeyer flask, the air was 

displaced by C02, 10 ml (l+I)HCl was added, and 

after tightly stoppering the flask it was allowed to 

remain in the steam bath over night. The next 

morning a titer of 5.8 ml of permanganate was required, 

showing that no oxidation had taken place during the 

18 hours on the steam bath. 

A sample of magnetite from Franklin Furnace, N. J., 

yielded 30.57 percent FeO by the conventional hydrofluoric acid and sulfuric acid procedure. By the method 

described in this .paper the figure 30.49 percent FeO 

was obtained. The theoretical figure for magnetite is 

31.0 percent FeO. 

•• 

.... 

.... 
,., SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-387 

The analysis of the magnetite and the nonmagnetite 

fractions obtained from a sample of amphibolite from 

the Adirondacks is given in table 291.1. 

The low totals (table 291.1) for the analysis of the 

magnetite and nonmagnetite fractions are due to the 

presence of nonopaque minerals, mostly amphiboles, 

that contain ferrous iron. A determination of FeO in 

the nonmagnetite fraction by the conventional hydrofluOI·ic acid-sulfuric acid procedure yielded 39.21 percent FeO. This figure is 4.14 percent higher than that 

obtained by the method described in this paper, and 

is undoubtedly due to the FeO in the amphiboles 

present in the sample. 

TABLE 291.1.-Chemical analysis and computed mineral cornpo- -sition of the heavy oxides obtained from a sample of amphibolite 

from the Adirondacks, N.Y. 

[In percent] 

Oxide Magnetite 

fraction Nonmagnetite fraction 

Fe20a--------------------------- 59.01 9. 12 FeO____________________________ 31. 81 34. 97 

Ti02--------------------------- 7. 00 42.31 1----------1---------- TotaL____________________ 97. 82 86. 40 

Magnetite__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 82. 22 

Hematite_______________________ 2. 30 

Ilmenite _______ ----_____________ 13. 30 

Ti02 (excess) _______________________________ _ 

Total ____________________ _ 97. 82 

9. 12 

73. 87 

3. 41 

86. 40 

292. DENSITY COMPARISON METHOD FOR THE DETERMINATION OF 0 18/016 RATIOS IN PREPARED WATERS 

By J. H. McCARTHY, JR., T. S. LoVERING, and H. W. LAKIN, Denver, Colo. 

Naturn,J variations in 0 18/016 ratios can be determined 

by measuring differences in the density of prepared 

waters of constant hydrogen isotope content; a fallingdrop comparison method is used for these density 

measurements. 

• • • this method involves timing the fall of a drop (of 

lmown size) of the fluid to be analyzed through a definite distance in a liquid or mixture of liquids immiscible with the 

fluid • '' • The heavier the drop, the faster it will fall. • • • 

'l'he rate of fall, all other things being constant, depends upon 

both the radius and the density of the drop. With a properly 

constructed pipette the drop size can be kept sufficiently uniform so that the rate of fall of the spherical drop is a measure 

of its specific gravity. (Kirshenbaum, 1951.) 

The method has been modified by the present authors 

so that the density of a standard and of an unknown 

water are compared simultaneously; and it now has 

sufiicient sensitivity and precision to be used to detect 

small variations in 0 18/016 ratios such as are associated 

with geologic processes. 

APPARATUS 

In brief, the apparatus consists of (a) a large constant temperature bath in which a cylinder containing 

an immiscible falling-drop medium is maintained at 

0°C, (b) a carefully constructed double pipette that 

dispenses uniform drops, and (c) manually controlled 

electric timing stopclocks. 

The constant temperature bath is composed of two 

double-walled, insulated tanks, one inside the other. 

Narrow windows in the front and back of both tanks 

allow a view of the entire length of two fall tubes 

within the central cylinder. 

Water is circulated in the inner tank by a rotating 

transparent plexiglass tube, 41;2 inches in diameter, 

with fins· fixed at the top and bottom. Circulation is 

constant except for the brief period of recharging the 

tanks with ice. 

The falling-drop medium, which is a mixture of 

ortho-fluorotoluene and xylene in proportions that 

give the desired falling time, is contained in a stationary glass cylinder in the center of the rotating plastic 

tube. Inside the glass cylinder are two precision-bore 

glass tubes of 18 mm inside diameter that guide the 

drops. The entire constant temperature bath is covered 

with a double-walled top, the walls of which are regularly filled with ice and water. Working ports are 

provided for changing and adjustment of the pipette. 

The specially made double pipette allows two uniform drops of known size to be dispensed simultaneously. The pipette may be raised and lowered by 
C-388 GEOLOGICAL SURVEY RESEARCH 1 9 61 

remote control. Ten synchronous motor electric stopclocks are used to measure the falling time of tlie 

drops and the accuracy of timing is at least to 0.1 

second. 

All of the apparatus described is placed on suitable 

supports in a small air-conditioned room maintained 

at 45°F and under these conditions the constant temperature bath requires about 30 pounds of ice cubes 

every 24 hours, only 1 pound of which IS required 

for the inner tank. 

OPERATION 

The pipettes are filled and positioned in the top of 

the constant temperature bath. After 1 hour 0.025 cc 

(25 lambda) drops are dispensed from each pipette at 

regular intervals and the time of fall through 20 em 

is recorded. The average falling time of four drops 

is then used to estimate the density of the water. 

About 0.1 ml of water is used 'for a determination· ' however, it is desirable to have 2 or 3 ml of each 

sample water. After purification of the water all contact with air is avoided to exclude soluble impurities, 

such as carbon dioxide, that appreciably alter the 

density of water. All water samples are stored under 

nitrogen in specially prepared polyethylene bottles. 

In practice the sample water is placed in one pipette 

and a standard water in the other. By using this 

teQhnique small fluctuations in temperature, which 

change the density of the falling medium and the 

water, are obviated inasmuch as both the unknown 

and standard water are affected similarly. Distilled 

water is used as the primary sta;ndard and all density 

measurements are made relative to this standard. Secondary standards are prepared by adding known 

amounts of deuterium oxide to the· primary standard· . ' 

a series of such secondary standards differing from the 

primary standard water in small increments of density 

is used for evaluating the method in the range of 

interest. 

As there are exceedingly small variations in ternperature within the apparatus that perceptibly change 

the density of the falling medium, both pipettes are 

filled with the primary standard and the difference in 

falling time is used as a correctio;n factor on subsequent 

measurements. The frequency with which this factor 

is determined depends on the : accuracy desired ; in 

obtaining the measurements listed in table 292.1, the 

correction factor was determined daily. Using this 

technique the densities of 3 or 4 samples are determined in a working day. 

In operation the drops are extruded and dislodged 

into the falling-drop medium by raising the pipette 

through the surface of the liquid. The drops travel 

TARLE 292.1.-Experimental data for standard series 

Density Equivalent val11es in delta units of 

Density differences 018{015 

Date of differences Falling calc,.lAted 

experi- of prepared time dif- from falling ment waters ferences 1 tir:.es Calc11- Variation 

(nanograms (seconds) (nanograTT's Pre- lated inexreri- per cnbic per cnbic pared from Error mental 

centimeter) centimeter) waters falling data 

times 

-------------------------

1961 Jan. 27 125 2. 01 122 o. 5 0. 5 -~ l Feb. 14 125 1. 78 103 . 5 .4 

Feb. 14 125 1. 81 104 .5 .4 -.1 <±.1 

Mar.13 125 2. 55 135 .5 . 5 0 .Tan. 27 250 4, 21 255 1.0 1.0 0 

Feb. 2 250 3. 92 237 1. .9 -.1 <±.1 

Feb. 15 250 4.27 246 1. 1. 0 . 

Jan. 30 500 8. 79 507 2. 2. g } Feb. 6 500 8.15 493 2. 2. <±-1 

Feb. 7 1000 16.57 1002 4. 4. Mar. 15 1000 18.25 972 4. 3. 9 -.? } <±.1 

Feb. 7 2000 29.93 1809 8. 7. 2 -.8 } Feb. 8 2000 30.59 1849 8. 7.4 -.6 <±.1 

Feb. 8 4000 52.45 3171 16. 12.7 -3.3 

Feb. 9 } 4000 52.13 3152 16. 12.6 -3.4 <±.2 

Feb. 10 4000 53.18 3215 16. 12.9 -3.1 

Feb. 10 8000 97.22 5878 32. 23.5 -8.5 

Feb. 13 8000 } 98.48 5954 32. 23.8 -8.2 <±.2 

Feb. 14 8000 101.45 5851 32. 23.4 -8.6 

1 Difference in falling time at total falling time of about 850 seconds. 

10 em before reaching the upper timing mark to assure that terminal velocity is attained, and the time 

required to fall through the next 20 em is recorded. 

The sensitivity and precision of the data shown in 

table 292.1 were attained by adjusting the density of 

the falling-drop medium so that a 25 lambda drop of 

standard water falls 20 em in about 850 seconds. The 

falling time of four drops was averaged to compensate 

for the effect of small differences in drop size. 

RESULTS 

The series of secondary standards, prepared with 

deuterium oxide, differ in density from the primary 

standard (81) by 125, 250, 500, 1,000, 2,000, 4,000, and 

8,000 ng per cc (nanograms per cubic centimeter) 

where one nanogram equals 10-9 grams. If the density 

of the prim_ary standard water is 1.000,000 g per cc 

the density of the first secondary standard (82) is thus 

1.000,000,125 g per cc, and so forth. Experimental 

data for the standard series listed above are shown in 

table 292.1. Equivalent values in delta units 1

, which 

are com.m.only used in reporting isotopic variations, 

have been calculated using the density data. Although 

the equivalent delta values listed in table 292.1 are not 

based on variations in 0 18/016 ratios, they do represent 

equiva]ent variations in terms of the change in the 

density of water that accompanies variations in the 

isotope ratio. 

The difference in falling time given in column 3, 

table 292.1, is based on the average falling tim.e of four 

25-lambda drops. Using Stokes law, modified to correct 

1 Delta values expressed in deviation per mil are given by 

[

R(samole) J 6

= R(standard) 1 1

•

000 

where R=ratio OIB/016, 
.;. 

.. 

I. 

SHORT PAPERS IN THE GEOLOGIC AND HYDROLOGIC SCIENCES, ARTICLES 147-292 C-389 

for wall effect (Partington, 1951) a difference in density 

of 125 ng per cc results in a calculated difference in 

falling time of 2.20 seconds. 

'Ihe reproducibility obtained in the range 0 to 8 ° /oo 

(equivalent delta 0 18 units) is<± .1 °/oo and in the range 

16 to 32 °/oo the variation is < ± 0.2 °/oo. Agreement 

of experimental and known values in the range 0 to 4 °/oo 

is ± 0.1 °/oo, but above 8 °/oo this agreement decreases 

in a uniform manner. A calibration curve using the 

experimental data is plotted on figure 292.1. Because 

of the precision of measurement the curve can be used 

8000 32 

ffi vi 

16 ... ~ 4000 z :::e :::l 

.t= 

u;u 

1:~ 2000 ~= ._:::e ~~ Zo:: CCC U.IUJ 

:::l -'C.. 

:!!:U 1000 ~~ ~ffi :::lzc.. 8'~ u.~cn zG:i o::;:e -c 

~~ 500 U.lz U- -~ co ~ z 

~ <C 

z 250 :!!: c 

125 0.5 200 

DIFFERENCE IN FALLING TIME, IN SECONDS 

FIGURE 292.1.-Plot of standard series data. Curve A, experimental data; curve B, data calculated from known density 

difference, using modified Stokes law . 

to assign an acceptable va]ue to unknown samples in 

all ranges. 

In his work in the Gilman mining district, Colorado, 

Engel (Engel and others, 1958) found that the maximum 

difference in o 0 18 observed between altered and unaltered carbonate sediments is 15.2 °/oo. Assuming this 

figure is representative, the falling-drop method can be 

used to distinguish· differences in 0 18/016 ratios with 

sufficient accuracy and precision to be a useful exploration tool. Relative paleotemperatures could be determined for carbonate sediments and perhaps for igneous 

and other rock types. This technique might also prove 

useful in scanning waters obtained at· elevated temperatures from clays, micas, and other hydrous minerals. 

In general, the method provides a simple and inexpensive means of obtaining relative data on 0 18/016 ratios. 

REFERENCES 

Engel, A. E. J., Clayton, R. N., and Epstein, Samuel, 1958, 

Variations in isotopic composition of oxygen and carbon in 

Leadville limestone (Mississippian, Colorado) and in its 

hydrothermal and metamorphic phases: Jour. Geology, v. 

66, no. 4,_p. 374-393. 

Kirshenbaum, Isidor, 1951, Physical properties and analysis of 

heavy water: New York, McGraw-Hill Book Co., Inc., 

438 p. 

Partington, J. R., 1951, An advanced treatise on physical 

chemistry, v. 2, The properties of liquids: New York, 

Longmans, Green and Co., 448 p. 
.I.. 

..... 

• I 
SUBJECT INDEX 

[Numbers refer to articles; finding list of article page numbers follows author index] 

A 

Article 

Abo formation, Zuni Mountains, N. 

l\Iex. --------------- 206 

Ahrlgo formation, Galluro Mountains, 

Ariz. --------------- 207 

Abundancltt formation, TeresitaChula area, Atacama 

Province, Chile ------ 229 

Activation unalysls, beryllium ----- 287 

Aerial photographs, transfer of geologic data by direct 

tracing ------------- 281 

Aftershock-energy release, versus 

tidal effects --------- 246 

Aggregate, lightweight, from slate__ 152 

Aguada limestone, Arecibo-Barceloneta area, Puerto Rico_ 221 

Alaska, Copper River basin, glacial 

geology ------------- 218 

northwestern, paleontology ____ 231 

Ogotoruk Bench, geomorphology 220 

quartz diorite line ----------- 183 

Seward Peninsula, economic 

geology ------------- 151 

geochemistry ------------ 151 

Alluvium, earthquake damage to 

structures on -------- 276 

permeability in relation to grain 

size ---------------- 157 

water-bearing properties--204, 221, 222 

Al[llne formation, I..ake Bonneville, 

Utah --------------- 186 

Alumina-rich soil, derived from 

weathered basalt ----- 219 

Amphiboles. Sec Magnetite, Ilmenite. 

Amphibolite, variations in properties 

of hornblende -------- 262 

Antarctica, Ross Sen region, geochemistry ----------- 225 

petrology --------------- 225 

South Victoria Lund, Taylor 

Glacier, glaciology ____ 224 

Antelope Valley limestone, new members, Nevada Test Site, 

Nev. ---------------~ 189 

' Appalachians. Sec pm·ticular State. 

Aragonite, artitlcal conf3olidatlon___ 257 

Arctic America, Permian, correlations --------------- 231 

Arlknree formation, Colorado-Nebrnska-W.roming ----- 209 

Arizona, Defiance uplift, stratigraphy ----------------- 206 

Gallnro Mountains, stratigraphy_ 2017 

Little Colorado River, geomorphology --------- 237 

Mogollon Rim, stratigraphy __ 205, 206 

Monument Valley, stratigraphy_ 206 

Oralbl Wash, hydrology ------ 156 

Safford basin, hydrology ------ 204 

stratigraphy ------------ 204 

Uvver Colorado Hiver basin, 

hydrology ----------- 195 

Verde Valley, strntlgmphy_____ 205 

Zapatn. Mountain-Holy Joe Peak 

area, geologic map ___ 207 

Article 

Arkansas, Arlmnsas River valley, 

hydrology _.:_________ 157 

stratigraphy ------------- 182 

northwestern, stratigraphy ____ 180 

western, mineralogy ---------- 181 

Arkose, hydrozircon-bearing ------- 256 

Artificial fill, earthquake damage to 

structures on -------- 276 

Artificial minerals, FKeSiaOs ------ 260 

Atoka formation, Arkansas River 

valley, Arkansas ____ 181, 182 

Oklahoma --------------- 181 

Aymam6n limestone, Arecibo-Barceloneta area, Puerto 

Rico ---------------- 221 

Aysees member. See Antelope ValBaca 

ley limestone. 

formation, 

River, 

Mexico 

B 

Little Colorado 

Arizona-New 

237 

Bahamas, aragonite muds, artificial 

consolidation -------- 257 

Balaklala rhyolite, French GulchDeadwood district, California ------------- 147 

Bandurrias formation, ~'eresita-Chulo 

area, Atacama Province, Chile ---------- 229 

Basalt, deep weathering of -------- 219 

deformed caprock . aquifer ----- 20::1 

explosion-produced craters in__ 278 

thickness determinations by 

electrical resistivity 

method ------------- 247 

water-bearing properties _____ 203, 219 

Bastnaesite, in granite ----------- 254 

Bathophenanthroline, semimicrodetermina tion of traces of 

iron in zircon ------- 289 

Beach sediments, sorting ---------- 220 

Bed roughness, forms ------------ 165 

Bentonite, boron content --------181, 253 

in Atoka formation ---------- 181 

Berkshire schist, Litchfield, Conn. __ 268 

Bertrandite, in limestone --------- 193 

Beryl, in limestone -------------- 193 

in stream sediments ---------- 151 

Beryllium, determination, contactprint method -------- 286 

direct-reading spectrographic 

method ------------- 288 

gamma-ray activation 

method ------------- 287 

Beryllium minerals, deposits, Alaska_ 151 

Nevada ----------------- 193 

Bldahochi formation, Little Colorado 

River, Arizona-New 

Mexico ------------- 237 

Bolsa formation, Galiuro Mountains, 

Ariz. --------------- 207 

Article 

Bonanza King formation, Nevada 

Test Site, Nev. ------ 187 

Bonneville, glacial Lake, Utah ----- 186 

Borate minerals, hydrous strontium 255 

Boron, in bentonite and shale ----- 253 

Boulton equation, for pumping-test 

analysis ------------ 155 

Brachiopods, MississiJ)pian_________ 234 

Permian, Alaska______________ 231 

Bragdon formation, French GulchDeadwood district, California 

Brazer limestone, Mackay quad147 

rangle, Idaho -------- 236 

British Columbia, quartz diorite line 183 

Bryozoans, l\:Iississippian, Nevada___ 234 

c 

Cadiz formation, Nevada Test Site, 

Nev. --------------- 187 

Cadmium, in phosphatic rock ----- 250 

California, Caliente Range, paleontology and stratigraphy ---------------- 235 

Central Valley, hydrology _____ 215 

Darwin area, geophysics ------ 249 

French Gulch-Deadwood district, 

economic geology _____ 147 

geologic map ------------ 147 

Klamath Mountains, paleontology and stratigraphy _ 216 

Kramer borate district, mineralogy ---------------- 255 

quartz diorite line ------------ 183 

Sacramento River, hydrology___ 16,2, 

214, 21•5 

San Francisco, City College 

fault, geologic map __ 217 

engineering geology _.:.____ 217 

San Joaquin Valley, hydrology_ 215 

Tecolote Tunnel, hydrology____ 277 

Cambrian, Antarctica, Ross Sea 

region -------------- 225 

Arizona, Galiuro Mountains ___ 207 

Nevada, Nevada Test Site ____ 187, 188 

Snake Range ------------ 193 

Carboniferous, Idaho, Mackay quadrangle -------------- 236 

See also l\IississipJ)ian, Pennsylvanian. 

Cationic-sensitive electrodes, in 

measurement of sodium 

activities in clay suspensions ------------ 284 

Chainman shale, Diamond Mountains, 

Nev. ---------------- 191 

Schell Creek Range, Nev.______ 26.7 

Challis volcanics, south-central Idaho 212 

Chambless formation, Nevada Test 

Site, Nev. ----------- 187 

Chaiiarcillo group, ~'eresita-Chulo 

~ area, Atacama Province, 

Chile --------------- 229 

C-391 
C-392 

Channels, bed material, particle-size 

distribution --------- depth-discharge relations ____ _ 

effect of riparian vegetation on 

shape -------------- See also Surface water, open 

channels. 

Chile, earthquakes of 1960 --------

engineering geology-----------

northern, geochemistry -------

Terestta-Chulo area, Atacama 

Province, stratigraphy_ 

Chinle formation, Colorado Plateau_ 

Chloride, in ground water --------

Chloritoid, analysis of ------------

Chromium, in black shale ---------

in phosphatic rock ----------- Cibao formation, Arecibo-Barceloneta area, 1Puerto Rico ___ _ 

Clay, glaciomarine ---------------

minerals, Atoka formation __ _ 

distribution in coastal-plain 

formations ----------

in weathered basalt ------

Inyan J{ara group --------

Pierre shale ------------- suspensions, measurement of 

sodium activities ___ _ 

Clinoptilolite, in Oak Spring formation ---------------- Coal, deformation and stress distribution around mine 

workings ------------

spheroidal ------------------ Cobalt, in phosphatic rock --------

Coconino sandstone, Mogollon Rim, 

Ariz. --------------- Colorado, Coal Creek area, geologic 

map ---------------- structural geology -------

Gunnison, mineralogy --------

Gypsum Valley, geologic map __ 

structural geology ------- northeastern, stratigraphy ___ _ 

Paradox basin, paleontology and 

stratigraphy -------- Raleigh Peak, mineralogy ____ _ 

petrology --------------- Roberts Tunnel area, geologic 

map ---------------- geophysics -------------- Rocky Mountains, geologic map 

geophysics --------------

plant ecology ------------

San Miguel Mountains, structural geology ----------

Silverton. caldera, economic 

geology -------------

Trinidad coal field -----------

Uinta Basin, economic geology _ 

Upper Colorado River basin, 

hydrology -----------

Wilson Peak stock, structural 

geology ------------- Colorado Plateau, stratigraphy ____ _ 

Comus formation, Edna Mountains, 

Nev. --------------- Connecticut, Litchfield, petrology __ _ 

southeastern, geoiogic map ___ _ 

structural geology ______ _ 

Contact-print method, determination 

of beryllium --------

Copley greenstone, French GulchDeadwood district, California ---------•----

Copper, in black shale ------------

Corals, Mississippian, Nevada _____ _ Craters, explosion ________________ _ 

impact ----------------------

Article 

265 

165 

156 

276 

2.76 

230 

229 

199 

251 

259 

267 

250 

221 

171 

181 

263 

219 

210 

253 

284 

264 

274 

153 

250 

206 

196 

196 

271 

197 

197 

209 

197 

254 

254 

244 

244 

245 

245 

239 

198 

149 

153 

154 

195 

198 

199 

267 

268 

169 

169 

286 

147 

267 

234 

2,78 

272 

INDEX 

Article 

Cretaceous, Antarctica, Ross Sea 

region -------------- 225 

Chile, Teresita-Chulo area_____ 229 

Cretaceous, Colorado, Paradox basin 197 

Montana, western ------------ 211 

New Jersey, Trenton area ___ 173, 263 

New Mexico Central mining district ---------------- 150 

Silver City_______________ 208 

Rhode Island, Block Island ___ 240 

South Dakota, Black Hills ____ 210 

Wyoming, Black Hills -------- 210 

Cutler formation, Monument Valley, 

Arizona-Utah 206 

D 

Dakota sandstone, 

Colo. 

Gypsum Valley, 

197 

Datil formation, 

River, 

Mexico 

Little Colorado 

Arizona-New 

237 

De Chelly sandstone, Defiance uplift, 

Arizona-Utah -------- 206 

Dedham granodiorite, southeastern 

Massachusetts ------- 170 

Deep Creek formation, Deep Creek 

Mountains, Idaho ____ 213 

Deformation, coal mines ---------- 274 

Density comparison method, determination of 0 18/016 __ 292 

Depth-discharge relations, alluvial 

channels ------------ 165 

Deseret limestone, Mercur Dome, 

Utah --------------- 267 

Devonian, California, Klamath 

Mountains ---------- 216 

French Gulch-Deadwood 

district ------------- 147 

Maine, Boundary Mountain anticlinorium ----------- 168 

Greenville quadrangle ____ 152 

Massachusetts, Assawompset 

Pond quadrangle _____ 170 

Diamond Peak formation, Diamond 

Mountains, Nev. ____ 190, 191 

Dichromate oxidation, in determination of organic carbon content of rocks _____ 285 

Dissolved solids, in ground water___ 251 

in worldwide runoff ---------- 266 

Dithizone mixed-color method, determination of thallium in 

manganese ores ------ 290 

Dripping Spring quartzite, Galiuro 

Mountains, Ariz. _____ 207 

Dry Beaver Creek rocks, Verde 

Valley, Ariz. -------- 205 

Duluth gabbro, St. Louis County, 

Minn. --------------- 241 

Dunderberg shale, Nevada Test Site, 

Nev. --------------- 187 

E 

Earthquakes, aftershock-energy release and tidal effects_ 246 

California, Arvin-Techachapi, 

1952 ---------------- 277 

Chile, 1960 ------------------ 276 

Montana, Hebgen Lake, 1959___ 246 

Echinoids, Mississippian, Nevada___ 2,34 

Economic geology. See particular 

mineral name and under 

State names. 

Electrical .. resistivity, in determination of thickness of 

basalt flows --------- 247 

properties of sulfide-mineralized gabbro --------- 241 

Article 

Electrochemical potentials, measurement in the field ___ _ 

Ely Springs dolomite, Nevada Test 

Site, Nev. ----------- Engineering geology. See under State 

names. 

Erosion cycles, ancient, of Little 

Colorado River ------

Eskers, Kittatinny Mountain, N. J._ 

Eureka quartzite, Nevada Test Site, 

Nev. ---------------

F 

~~an River formation, Black Hills, 

South Dakota-Wyo- ming ______________ 210, 

Faults and faulting, Bold Bluff 

thrust, Nevada ______ _ 

Brevard fault, North CarolinaSouth Carolina ------

Cameron Creek laccolith, New 

~iexico ------------- Chino Quarry fault, New Mexico-_ 

City College fault, California __ 

Cobern Mountain o·verthrust, 

Montana ------------ Cumberland overthrust, Kentucky-Tennessee ____ _ 

Marquette synclinorium, Michigan ---------------- Quinn River thrust, Nevada __ _ 

Spring Creek thrust, California_ 

Taylor Glacier, Antarctica ___ _ 

E'eldspar, sanidine, synthetic ______ _ 

Finite-difference method, computation of flows in tidal 

reaches ------------- Fissures, caused by earthquakes 

Floods. See Surface water. 

Fluorine, in hot spring deposits 

in rhyolitic glasses -----------

Fluorspar deposits, Mexico --------

Folds and folding, Boundary Mountain anticlinorium, 

Maine-New Hampshire_ 

Hunts Brook syncline, Connecticut ---------------- Marquette synclinorium, Michigan ---------------- Middlesboro syncline, KentuckyTennessee ----------- Taylor Glacier, Antarctica ___ _ 

Foraminifera, Carboniferous, Idaho __ 

Cretaceous, New Jersey _______ _ 

:b~ractures, in coal mine workings __ 

influence on shape of explosionproduced craters ____ _ 

Frost-wedged bedrock_ ____________ _ 

Fumaroles, composition of gases from 

G 

Gabbro, sulfide-mineralized, electrical 

properties ----------- Gamma-ray activation method, analysis of beryllium ------

Gases, chemical composition, from 

volcanic fumaroles and 

igneous rocks -------

Gazelle formation, Klamath Mountains, Calif. ---------

Geochemical investigations, beryllium, in rocks _______ _ 

dissolved solids in world-wide 

runoff -------------- gases in volcanic fumaroles and 

igneous rocks -------- granite rocks, Antarctica _____ _ 

280 

189 

237 

172 

189 

243 

191 

174 

208 

208 

217 

211 

177 

178 

192 

147 

224 

260 

162 

276 

149 

258 

226 

168 

169 

178 

177 

224 

236 

2.73 

274 

278 

170 

261 

241 

287 

261 

216 

286 

266 

261 

225 

.•. 
Article 

Geochemical investigations-Con. 

iron In mngnetlte and Ilmenite 291 

Iron in zircon, bathophenanthrollne method --------- 289 

ore and gangue-forming solutions --------------- 149 

QlBfQlO ratios in prepared 

waters ------------- 292 

salts in rhyollte tuff --------- 230 

slllcll In thermlll water ------- 269 

thallium In m11nganese ores --- 290 

water, electrochemlclll potentials ---------------- 280 

Sec also un(le1· St(~te nantes. 

Geomngnethnn, anomalies In California ----------------- 249 new Instruments ------------- 282 

Geomorphology. See particular type 

of Jeatttrc and under 

State names. 

Geophysics. Seo 1)articular method 

and under State names. 

Geysers. Sec Thermal springs. 

Glacial lakes, Bonnev1lle, Utah_____ 186 

Glaciers, stngnation -------------- 227 

structure of ----------------- 224 

Glaclolncustrlne deposl ts, macrofabrlcs ---------------- 218 

Glorieta snndstone, Defiance uplift, 

Arizona and Utah ---- 206 

Zuni Mountains, N. Mex. ------ 206 

Gold, locallzntiou of deposits ----- 147 

Goodwin limestone, Nevada Test 

Site, Nev. ----------188, 189 

Grain size, bench sediments ------- 220 

relation to permeability ------ 157 

streambed material ----------- 265 

Gmvlty surveys, anomalies in California -------------- 249 

crustal structure, South 

Dakota-Wyoming ----- 243 

western Washington ------ 248 

det:ermhuition of structure of 

plutons from--------- 242. 

profiles, across southern Rocky 

Mountains ---------- 245 

nlong Roberts Tunnel, Colo. 244 

Gra-ywuclcc, prehnlte-pumpellylte- · 

zeolite alteration ----- 201 

Great Blue limestone, Deep Creek 

Mountnlns, Idaho ---- 213 

G1·eenland, Centrum S~. geophysics__ 228 

cast, glncinl geology --------- 227 

Green River formntion, Uinta Basin, 

Utah and Colorado --- 154 

G1·ound wntcr, Arizona, Oraibi Wash_ 156 

Safford basin_____________ 204 

Arkansas, Arkansas River valley ----------------- 157 

artesian, relation of deep and 

shallow aquifers______ 185 

Cnllfornia, Central Valley_____ 215 

clnsslftcntion of provinces, hydrologic units, and 

chemicnl types ------- 195 

Colomdo, Rocky Mountains foothills -------- ------- 239 

Upper Colorado River basin_ 195 

dissolved solids -------------- 251 

field measurement of electrochemical properties __ 280 

from oll fields --------------- 184 

in alluvium ------------204, 221, 222 

in basnlt ------------------203, 219 

Interchange with surface water 215 

Interference between aquifers__ 185 

moisture studies ------------- 279 

Nevada, Humboldt River valley_ 164 

Nevada Test Site_________ 194 

601530 0- 61 - 2.6 

INDEX 

Article 

Ground water-continued 

New York, northern St. Lawrence 

County ------------- Oregon, Columbia River ______ _ Cow Valley _____________ _ 

permeablllty in relation to grain size ______ _: ________ _ 

Puerto Rico, Areciho-Barceloneta 

area ---------------- Tallaboa Valley-----------

pumping tests, analysis of ___ _ 

recharge, fan gravel ---------- saline, northern New York ___ _ 

specific yield, sediments ------

tritium age of --------------- Utah, Ashley Valley on field ___ _ Lynndyl area ____________ _ 

H 

Hartshorne sandstone, northwestern 

Arkansas ------------ IIawall, Kauai, geochemistry _____ _ 

hydrology --------------- Hayesville tlll, northeast-central 

Ohio --------------- Hermosa formation, Gypsum Valley, 

Colo. --------------- Herzenbergite, X-ray powder data __ 

Heulandite-like mineral, associated 

with clinoptllollte ___ _ 

Hickey formation, Verde Valley, 

Ariz. --------------- Hiram tlll, northeast-central Ohio _ 

Hornblende, variations in properties during metamorphism --------------- Hornfels, cordierite --------------

Hot springs. See Thermal springs. 

Hydrology. See Ground water, Surface water, and under 

State names. 

Hydrozircon, in arkose -----------

Hygrometer, for measurements in 

the unsaturated zone _ 

I 

Idaho, Deep Creek Mountains, paleontology and stratigraphy ---------------- 1\Iackay quadrangle, paleontology 

and stratigraphy ----- south-central, stratigraphy ___ _ 

Igneous rocks, composition of gases 

from --------------- Ilmenite, determination of ferrous 

iron in _: ___________ _ 

Inyan Kara group, Black Hills, South 

Dakota-Wyoming -----

Ion exchange, ground water -------

Iron, ferrous, · in magnetite and 

ilmenite ------------

Iron, in zircon -----·------------- Iron-sanidine, X-ray and optical 

properties -----------

J 

Joints, frost-wedged bedrock 

Jurassic, Colorado, Gypsum Valley _ 

Kaibab limestone, 

Ariz. 

K 

Mogollon Rim, 

Kayenta formation, 'Colorado Plateau 

Keechelus andesitic series, Cascade 

Range, VVash. -------

2:51 

202 

203 

157 

221 

222 

155 

204 

251 

164 

194 

184 

185 

180 

219 

219 

176 

197 

273 

264 

205 

176 

262 

268 

256 

279 

213 

236 

212 

261 

291 

210 

251. 

291 

289 

260 

170 

197 

206 

199 

232 

C-:-393 

Article 

Kentucky, southeastern, structural 

geology ------------- 177 

Killbuck glacial lobe, northeastcentral Ohio -------- 176 

Kona dolomite, Marquette iron 

range, Michigan ____ 178, 179 

L 

Lakota formation, Black Hllls, South 

Dakota-Wyoming ---- 210 

Landslides, caused by earthquakes__ 276 

Lares limestone, Arecibo-Barceloneta 

area, Puerto Rico ---- 221 

Latham shale, Nevada Test Site, 

Nev. --------------- 187 

J,ava, as an aquifer -------------203, 219 

Lichawe1'ia, northwestern Alaska __ 231 

Limestone, artificial -------------- 257 

Lodgepole limestone, Deep Creek 

~:lountuins, Idaho ---- 213 

McAlester formation, northwestern 

Arkansas ----------- 180 

1\Iagnetic-susceptibility bridge ------ 282 

Magnetism. See Geomagnetism. 

Magnetite, determination of ferrous 

iron in ------------- 291 

Mahogany oil-shale bed, Utah ----- 154 

Maine, Boundary Mountain anticlinorium, geologic map _ 168 

stratigraphy ------------ 168 

structural geology -------- 168 

Greenville quadrangle, economic 

geology ------------- 152 

l\:loosehead Lake, geophy.sics ___ 242 

Mammalia, 'l'ertiary, California, Cali-

. ente Range ---------- 235 

Mancos shale, Gypsum Valley, Colo. 197 

Manganese, in epithermal veins and 

hot spring deposits --- 149 

Manganese ores, determination of 

·thallium in --------- 290 

Manning Canyon Shale, Deep Creek 

Mountains, Idaho ____ 213 

Manning n, variation in an open 

channel ------------- 159 

Marble, use in impact tests -------- 272 

l\lariana Islands, Pagan, petrology _ 223 

Marine deposits, late glacial ------ 171 

Massachusetts, Assawampset Pond 

quadrangle, geomorphology -------------~--- 170 

Salem quadrangle, glacial 

geology ------------- 171 

Mexico, fluorspar deposits_________ 226 

l\:lichigan, Marquette iron range, 

geologic mnp -------- 178 

petrology --------------- 179 

structural geology ------- 178 

Millbrook till, northeast-ce,n tral Ohio 176 

Mi~eralogy. See pm·tiettlar minf!ral 

name and under State 

?!-ames. 

Minnelusa formation, Hot Brook 

Canyon, S. Dak. 267 

Minnesota, St. Louis County, geophysics ------------- 241 

Miocene, central Arizona ---------- 205 

See also Tertiary. 

Mississippian, Idaho, Deep Creek 

Mountains ---------- 213 

·Mackay quadrangle ------ 236 

Nevada, Diamond Mountains 190, 191 

Elko County ------------ 234 . 

Utah, Mercur Dome ---------- 267 
C-394 

Missouri-Mississippi River basin, 

flood magnitude-frequency relations ____ _ 

Moenave formation, Colorado Plateau ---------------- Moenkopi formation, Colorado Plateau ---------------- Mollusks, Tertiary, California _____ _ 

Molybdenum, in black shale -------

in phosphatic rock ----------- Montana, Carter County, geochemistry ----------------- Hebgcn Lake, geophysics ------

Lewis and Clark County, structual geology---------

Stillwater complex, petrology __ 

Moraines, Kittatlnny Mountain, N . .T _ 

Mount Laurel sand, Trenton area, 

New .Jersey ---------

N 

Nantoco formation, Teresita-Chulo 

area, Atacama ProvArticle 

160 

199 

199 

235 

267 

250 

253 

246 

211 

252 

172 

173 

ince, Chile ---------- 229 

Navarre till, northeast-central Ohio_ 176 

Navesink formation, Trenton area, 

New Jersey --------- 173 

Nebraska, western, stratigraphy ___ 209 

Negaunee iron formation, Marquette 

iron range, Michigan__ 178 

Neocomian rocks, Teresita-Chulo 

are~ Chile___________ 229 

Nevada, Diamond Mountains, geologic map ----------- 191 

stratigraphy ____________ 190, 191 

Edna Mountains, geochemistry__ 267 

Elko County, paleontology ____ 234 

Fish Creek Range, geochemistry 26i 

Humholdt River valley, hydrology ---------------- 164 

Kings River Range, geolo.gic 

map ---------------- 192 

structural geology ------- 192 

Mount Wheeler mine area, geologic map ----------- 193 

Nevada Test Site, engineering 

geology ------------- 278 

geochemistry ------------ 194 

geophysics -------------- 247 

hydrology --------------- 194 

mineralogy -------------- 264 

paleontology and stratigra- phy _______________ 187-189 

Schell Cre:ek Range, geochemistry ----------------- 267 

Snake Rang:e,, mineral depoSi-ts __ , 193 

New Hampshire, Bo-undary Mountain 

anticlinorium, geologic 

map ---------------- 168 

stratigraphy ------------- 168 

structural geology -------- 168 

New .Jersey, Kittatinny Mountain, 

geologic map -------- 172 

glacial geology ----------- 172 

Trenton area, mineralogy ----- 263 

paleontology and stratigraphy ---------------- 173 

New Mexico, Cameron Creek laccolith, 

structural geology ---- 208 

Central mining district, economic geology ------- 150 

Hurley West quadrangle, geologic· map ----------- 208 

Little Colorado River, geomorphology ------------- 237 

Rio Grande, sedimentation 

studies ------------- 265 

INDEX 

Article 

New Mexico-continued 

Silver City, structural geology __ 

Upper Colorado River basin, hydrology -------------

Zuni uplift, stratigraphy ------

New York, Adirondack Mountains, 

mineralogy ----------

petrology --------------- St. Lawrence County, hydrology 

geochemistry -------------

Nickel, in black shale -------------

phosphatic rock -------------- Ninemile formation, Nevada Test 

Site, Nev. -----------

North Carolina, Brevard belt, petrology ----------------- structural geology --------

Fletcher, structural geology __ _ 

Mason Mountain, petrology ___ _ 

Mount Airy, structural geology 

0 

ots;o1u ratios, density comparison 

method of determination ---------------- Oak Spring formation, Nevada Test 

Site, Nev. -----------

Ohio, Mad River basin, hydrology __ 

northeast-central, glacial geology 

Oil shale, potential reserves, Uinta 

Basin ---------------

Ogallala formation, ColoradoNebraska-Wyoming __ _ 

Oklahoma, eastern, mineralogy -----

Open-channel flow. See Surface 

water. 

Oquirrh formation, Deep Creek 

Mountains, Idaho 

Ordovician, Nevada, Edna Mountains 

Nevada Test Site ________ _ 

Ore con,trols, gold ----------------

uranium -------------------- Oregon, Aldrich Mountains, mineralogy and petrology __ 

Columbia River, hydrology ----

Cow Valley, hydrology --------

Lake County, petrology -------

quartz diorite line ------------

Organic carbon content of rocks, determination by dichromate oxidation -------

Ostracodes, Mississippian, Nevada_:.._ 

p 

Pabell6n formation, Teresita-Chulo 

area, Atacama· Province, Chile ----------

Paiute Ridge member. See Antelope 

Valley limestone. 

Paleobotany. See particular plant 

name and under State 

names. 

Paleontology. See particular fossil 

name and under State 

names. 

Paleotopography, as an ore control 

Pantellerite ---------------------

Peleycpods, Mississippian, Nevada __ _ 

Pennsylvania, Solebury Mountain, 

geophysics ----------

Pennsylvanian, Arkansas, Arkansas 

Valley -------------181, 

northwestern ------------

Colorado, Gypsum Valley _____ _ 

Idaho, Deep Creek Mountains __ 

Mackay quadrangle ______ _ 

208 

195 

206 

262 

262 

251 

251 

267 

250 

189 

174 

174 

174 

270 

174 

292 

264 

175 

176 

154 

209 

181 

213 

267 

189 

147 

148 

201 

202 

203 

200 

183 

285 

234 

229 

148 

200 

2.34 

242 

182 

180 

197 

213 

236 

Pennsylvanian-continued 

South Dakota, Hot Brook 

Canyon ------------- Permeability, relation to grain size __ 

Permian, Alaska, northern --------

Arizona, Defiance uplift -------

Mogollon Rim -----------

Monument Valley --------

Colorado, Gypsum Valley ------

Idaho, Deep Creek Mountains __ 

New Mexico, Zuni Mountains __ 

Nevada, Kings River Range ___ _ 

Utah, Defiance uplift ---------

Monument Valley --------

Wyoming, Afton area ---------

Dry Creek Canyon -------

Petrofabrics, glaciolacustrine 

deposits -------------

Phenactte, in limestone ---~------­

in stream sediments ----------

Phenoclasts, orientation in laminated 

glaciolacustrine deArticle 

267 

157 

231 

206 

206 

206 

197 

213 

206 

192 

206 

206 

250 

267 

218 

193 

151 

posits -------------- 218 

Phosphatic rock, uranium and 

vanadium content ____ 250 

Phosphoria formation, Western 

United States -------- 267 

Wyoming, Afton area -------- 250 

Piedmont Province, data on mean 

annual flood --------- 167 

Pierre shale, Montana-South 

Dakota-Wyoming ___ 253, 285 

Piezomet~rs, influence of hole diameter on depth determinations ----------- 158 

Pikes Peak granite, Raleigh Peak, 

Colo. --------------- 254 Pio~he shale, Snake Range, Nev. 193 

Plagioclase, X-ray determination 252 

Plant ecology. See Vegetation. 

Pleistocene. See Quaternary. 

Pliocene, central Arizona ---------- 205 

See also Tertiary. 

Plutons, structure, determination by 

gravity measurements _ 242 

Pogonip group, Nevada ----------- 189 

Ponce limestone, Tallaboa Valley, 

Puerto Rico --------- 222 

Precambrian, Antarctica, Ross Sea 

region -------------- 225 

Arizona, Galiuro Mountains ___ 207 

Colorado, Coal Creek area ----- 196 

Michigan, Marquette iron 

range -------------178, 179 

Minnesota, St. Louis County __ 241 

New Yol'k,- :Adirondack 

Mountains ---------- 262 

Prehnite-pumpellyite- zeolite alteration· of graywacke ---- 201 

Puerto Rico, Arecibo-Barceloneta 

area, hydrology ------ 221 

Tallaboa Valley, hy.drology ---- 222 

Puget group, King County, Wash. -- 233 

Pumping tests, analysis of -------- 155 

Pyroxenes. See Magnetite, Ilmenite. 

Q 

Quartz diorite line, northwestern 

North America ------- 183 

Quaternary, Alaska, Copper River 

ba~n --------------- 218 

Arizona, Little Colorado River 237 

Safford ba~n ------------ 204 

Massachusetts, Salem 

quadrangle ---------- 171 

Mariana Islands, Pagan ------- 223 
Quaternary-continued Article 

New Jersey, Kittatinny 

Mountain ----------- 172 

New Mexico, Little Colorado 

River --------------- 237 

Ohio, northeast-central -------- 176 

Puerto Rico, north-central ----- 221 

R 

Ranger Mountains member. See Antelope Valley limestone. 

Rare-earth minerals, in granite ___ _ 

Raton formation, Trinidad coal field, 

Colorado ------------

Remanent magnetometer ----------

Rhabdotlhane, similarity to thoriumbearing minerals -----

Rhode Island, Block Island, 

geophysics ----------

Rhodolite, petrology of ------------ Rhyolite tuff, Andean cordlllera ___ _ 

Rhyolitic glass, fluorine during 

hydration ----------- Rico formation, Gypsum Valley, Colo. 

s 

Saline deposits, origin ------------

Salt anticlines, Gypsum Valley, Colo_ 

Snltcedar, Influence on channel 

shape ----~---------­ Salts, derived from rhyolite tuff ----

San Andres limestone, Defiance uplift, Arizonn. and Utah_ 

Seismology, aftershock-energy release 

versus tidal effects __ _ 

Mesozoic rocks, Rhode Island __ 

Selenium, In black shale ----------

In phosphn.tic rock -----------

Shn.le, black, metal content --------

boron content ----------------

Slllca, in thermn.l water ----------

Slltclficatlon, Kona dolomite, 

Michigan ------------

Silurian, California, Klamath Mountains --------------- Maine, Greenvllle quadrangle __ 

west-central -------------

New Hn.mpshire, northern -----

Slate, lightweight aggregate materiaL 

Smoky member. Sec Windfall member. 

Soda rhyolite, acmite and other sodium-bearing minerals in_ 

Sodium, in ground water ----------

Sodium activities, measurement in 

clay suspensions -----

Soil moisture, as a determinant of 

plant communities ----

Solenhofen limestone, Bavaria _____ _ 

South Carolina, Brevard belt, 

petrology -----------

structural geology --------

Poor Mou~1tain, structural 

geology ------------- South Dakota, Black Hllls, 

geophysics ----------

mineralogy --------------

structural geology --------

geochemistry ---------------- Hot Brook Canyon, geochemistry 

Specific gravity, minerals, rocks, and 

sand, new method for 

determining --------- Specific yield, sediment samples ___ _ 

Spectroscopy, determination of 

beryllium ----------- Springs, effect of tunnel construction 

on flow -------------

254 

153 

282 

271 

240 

270 

230 

258 

197 

230 

197 

156 

230 

20() 

246 

240 

267 

250 

267 

253 

269 

179 

216 

152 

168 

168 

152 

200 

251 

284 

239 

257 

174 

174 

174 

243 

210 

243 

253 

267 

283 

164 

288 

277 

INDEX 

Article 

Stirling quartzite, Nevada '.{'est Site, 

Nev. ---------------- 187 

Stratigraphy. Sec pm·ticular formation name, system 

names, a.n(l under State 

names. 

Streams, bed material, particle-size 

distribution --------- 265 

depth-discharge relations in 

alluvial channels -----

directions in Triassic rocks ___ _ 

effect of tunnel construction on 

flow ---------------- ephemeral, influence of riparian 

vegetation on channel 

shape --------------- flood plains ------------------ geochemical investigations ____ _ 

sedimentation studies ---------

tributary, interchange of surface 

and ground water ___ _ 

Structural geology. See Deformation, 

Faults and faulting, 

Folds and folding, Fractures, Plutons, Subsidence, and under State 

names. 

Subsidence, Chilean earthquakes of 

1960 ---------------- Supai formation, Defiance uplift, Arizona and Utah -------

Mogollon Rim, Arizona and 

Utah ---------------

Surface water, California, Central 

Valley -------------- Sacramento River _____ _: __ _ 

Tecolete Tunnel area _____ _ 

dissolved solids, worldwide ___ _ 

effect of tunnel construction on 

springs and small 

streams ------------- floods, effect of urban growth on 

in relation to vegetation __ _ 

mean annual, bankfull depth 

and depth of flow __ _ 

variation of ratios with 

drainage-area size ___ _ 

Interchange with ground water 

low flow in permeable basins __ 

lowest multi-year moving average, independent multiyear means, comparison ----------------- Ohio, Mad River basin ________ _ 

open channels, depth determination ---------------- flow, tidal values ---------

tidal effect ------------~-

unsteady phenomena _____ _ 

variation of the Manning n_ 

runoff, effects of urban growth _ 

low flow in a p2rmeable 

basin --------------- streamflow, annual minimum __ _ 

computations ------------

effect of tunnel construction 

on ----------------- errors in measurements __ _ 

"tidal reaches, computation of 

flows · by finite-difference method ---------

tide-affected flow -------------

variation of flood magnitude 

with drainage area __ _ 

Washington, D.C., Potomac River 

basin ---------------

165 

199 

277 

156 

238 

266 

165 

215 

276 

206 

206 

215 

2,14 

277 

266 

277 

275 

238 

167 

160 

215 

175 

166 

175 

158 

162 

214 

163 

159 

275 

175 

175 

202 

277 

161 

162 

214 

160 

238 

C-395 

T Article 

Taconic orogeny, Maine and New 

Hampshire ---------- 168 

'L'eallite, X-ray powder data ------- 273 

Tennessee, northeastern, structural 

geology ------------- 177 

Tensiometer, for measurements in 

the unsaturated zone _ 279 

'L'ertiary, Antarctica, Ross Sea region ---------------- Arizona, Little Colorado River 

Mogollon Rim area _____ _ 

Safford. basin ------------

Verde Valley ------------ California, Caliente Range ___ _ 

Colorado, northeastern --------

San Miguel Mountains ___ _ 

San Juan· region ---------

Uinta Basin -------------

Idaho, south-central ----------

Nebraska, western ------------

Nevada, Nevada Test Site ----

New Jersey, Trenton area -----

New Mexico, Central mining district ---------------- Little Colorado River_ ___ _ 

Silver City -------------- Puerto Rico, north-central -----

Utah, Uinta Basin ----------- Washington, Cascade Range __ 232, 

Puget Sound lowlands ___ _ 

western ----------------- Wyoming, Shirley Basin area __ 

southeastern ------------- '.rhallium, in manganese ores ------

Thermal regime, thawing of a lake __ 

Thermal springs, field measurement 

of silica in water from_ 

in origin and evolution of ore __ 

Thermoluminescence, as an indicator 

of shock damage ---------- Thorium, minerals with rhabdophanelike structure --------

Thrusts and thrusting. See Faults 

and faulting. 

Tidal effects, versus aftershock-energy 

release -------------- Tidal flow. See Surface water. 

Tin lodes, u.s source of beryllium ___ _ 

Tin sulfides, X-ray powder data __ _ 

Titanium, in phosphatic rock ------

Topographic maps, transfer of data 

from aerial photographs -------------- Totoralillo formation, Teresita-Chulo 

area, Atacama Province, Chile ---------- Trace elements, in granitic rock ___ _ 

in phosphatic rock -----------

Transducer, for measurements in the 

unsaturated zone ____ _ 

Trap-door instrusion --------------

Triassic, Colorado Plateau ---------

Nevada, northwestern -------- Oregon, Aldrich Mountains ___ _ 

Pennsylvania, Solebury Mountnin ---------------- Rhode Island, Block Island ___ _ 

Tritium, in ground water ---------

Troy quart:~:ite, Galiuro Mountains, 

Ariz. ---------------

Tuff, rhyolite, source of salts ------

•.runellite, a new hydrous strontium 

borate -------------- Tungsten, in epithermal veins and 

hot spring deposits __ _ 

Tunnels, effect on flow of springs and 

small streams --------

gravity survey along ----------

225 

237 

205 

204 

205 

235 

209 

198 

149 

154 

212 

209 

264 

263 

150 

237 

208 

221 

154 

233 

233 

248 

148 

209 

290 

228 

269 

149 

272 

271 

246 

151 

273 

250 

281 

229 

225 

250 

279 

208 

199 

192 

201 

242 

240 

194 

207 

230 

255 

149 

277 

244 
C-396 

U Article 

Uranium, association with zircon___ 256 

in phosphatic rock____________ 250 

paleotopographic control of de~ 

position ------------- Urban growth, hydrologic effects __ _ 

Utah, Ashley Valley oil fields, 

hydrology ----------- Defiance uplift, stratigraphy __ _ 

Lynndyl area, hydrology ------

Lake Bonneville, historical 

geology ------------- 1\lercur Dome, geochemistry __ _ 

Monument Valley, stratigraphy 

Sunnyside No. 1 mine, engineer· 

ing geology ----------

geologic map ------------

Upper Colorado River basin, 

hydrology ----------- Uinta Basin, economic geology _ 

v 

148 

275 

184 

206 

185 

186 

267 

206 

274 

274 

195 

154 

Vanadium, in black shales -------- 267 

in phosphatic rock ----------- 250 

Vegetation, relation to soil type ___ 239 

relation to flood frequency ----- 238 

·riparian, effect on channel shape_ 156 

Vermejo formation, Trinidad coal 

field, Colorado 153 

Volcanic gases, chemical composition_ 261 

w 

Washington, Cascade Range, paleo· 

botany and stratigra· 

phy ---------------232, 233 

INDEX 

Washington-continued 

Columbia River, hydrology 

Puget Sound lowlands, paleobotany and stratigraphy __ 

quartz diorite line ------------

western, geophysics -----------

Washington, D. C., hydrology ------

Wave characteristics, Alaskan 

beaches ------------- Wenonah formation, Trenton area, 

New Jersey ----------

White Marl, Lake Bonneville, Utah 

White River formation, ColoradoNebraska-Wyoming __ _ 

Windfall formation. Nevada Test 

Article 

202 

233 

183 

248 

238 

220 

173 

186 

209 

Site, Nev -----------187-189 

Wind River formation, Gas Hills, 

Wyo. --------------- Shirley Basin, Wyo. ----------

Wood Canyon formation, Nevada 

Test Site, Nev. -------

Wyoming, Afton area, economic 

geology. -------------

geologic map ------------

Black Hills, mineralogy -------

geophysics --------------

structural geology --------

Dry Creek Canyon, geochemistry 

Fremont County, mineralogy __ _ 

Gas Hills, mineralogy ---------

Niobrara County, geochemistry _ 

Shirley Basin area, economic 

geology ------------- paleogeologic and paleotopographic map --------- southeastern, stratigraphy ____ _ 

Upper Colorado River basin, 

hydrology -----------

256 

148 

187 

250 

250 

210 

243 

243 

267 

271 

256 

253 

148 

148 

209 

195 

Wyoming-continued Article 

Yellowstone National Park, geochemistry ----------- 269 

X 

X-ray diffraction, clay minerals ____ 253 

heulanditelike mineral -------- 264 

plagioclase ------------------ 252 

sanidine ------------------- 260 

synthetic feldspar ------------ 260 

thorium-bearing minerals ------ 271 

tin sulfides ------------------ 273 

tunellite -------------------- 255 

y 

Yellow Clay, Lake Bonneville, Utah_ 186 

Yellowstone National Park, geochemistry --------------- 268 

Yeso formation, Zuni Mountains, 

N. Mex. ------------- 206 

Yucca Flat formation, Nevada Test 

Site, Nev. ----------- 187 

Yukon, quartz diorite line --------- 183 

Yule marble, impact experiments on_ 272 

z 

Zeolites, in tuffs ----------------- 264 

metamorphic facies ----------- 201 

Zinc, in black shale -------------- 267 

in phosphatic rock____________ 250 

Zircon, determination of iron in ___ 289 

Zirconium, in uranium-bearing arkose ---------------- 256 
,.. 

Article 

Adams, J. W. ------------------- 254 

Akers, J. P. --------------------- 237 

Albee, A. L. --------------------168, 196 

Alber~ J. I~ -------------------- 147 

Allen, W. B. -------------------- 240 

Anderson, I. E. ------------------ 161 

Anderson, L. A. ------------------ 282 

Annen, C. S. -------------------151, 288 

Appleman, D. E. ----------------- 260 

Arno\v, Ted --------------------- 221 

Back, William ------------------- 280 

Baltzer, R. A. ------------------- 162 

Barker, Fred ------------------268, 270 

Burnes, Harley ------------187, 188, 189 

Burne~ Ivan -------------------- 280 

Bedinger, M. S. ------------------ 157 

Bell, Henry, III ------------------ 174 

Bergendnhl, 1\'l. H. ---------------- 209 

Bethke, P. M. ------------------- 273 

Bluck, R. A. -------------------243, 247 

Bluckmon, P. D. ----------------- 263 

Blake, M. C., Jr. ----------------- 183 

Bonlllu, M. G. ------------------- 217 

Brunson, F. A. ------------------ 239 

Brew, D. A. -------------------190, 191 

Bromfield, C. S. ----------------- 198 

Brown, C. E. ------------------- 201 

Brynn~ Bruce ------------------- 174 

Burbank, W. S. ------------------ 149 

Byers, l!'. M., Jr. ---------------188, 189 

Campbell, R. H. ------------------ 281 

Carr, J. W. ---------------------- 213 

Cashion, W. B. ------------------ 154 

Clark, J. R. --------------------- 255 

Clebsch, Alfred, Jr. --------------- 194 

Cohen, Phlllp -------------------- 164 

Coleman, R. G. ------------------- 256 

Cooley, M. E. -------------------- 237 

Corwin, Gilbert ------------------ 223 

Cral~ F. C. --------------------- 214 

Culbertson, J. K. ----------------- 265 

Cuttlttu, Frunk ----------------289, 290 

Davidson, D. F. ------------------ 267 

Davidson, E. S. ------------------ 204 

Dawdy, D. R. ------------.. -------- 160 

Denson, N. M. ------------------ 209 

Dickey, D. D. ------------------- 278 

Dobrovolny, Ernest --------------- 276 

Dooley, J. R., Jr. ---------------- 271 

Duncun, Helen ------------------ 234 

Durum, W. H. ------------------- 266 

Dutro, J. T., Jr. ----------------- 231 

Elston, D. P. -------------------- 197 

Emmett, W. W. ------------------ 158 

Engel, A. E. J. ----------------- 262 

INDEX 

AUTHOR INDEX 

.Article 

Engel, C. G. --------------------- 262 

Englund, K. J. ------------------- 177 

Erd, R. C. ---------------~----25~ 256 

Ericksen, G. E. ------------------ 230 

Espenshade, G. H. ---------------- 152 

Fahey, J. J. -------------------283, 291 

Feltis, R. D. -------------------- 184 

Foster, M. D. ------------------- 259 

Fournier, R. 0. ------------------ 269 

Foxworthy, B. L. ---------------- 203 

Frezon, S. E. -------------------- 181 

Friedman, Irving ---------------- 258 

Frost, I. C. --------------------- 285 

Gair, J. E. --------------------178, 179 

Godfrey, R. C. ------------------- 163 

Goldsmith, Richard -------------- 169 

Good~ H. D. ------------------- 184 

Gordon, Mackenzie, Jr. ----------- 234 

Gower, H. D. ------------------- 233 

Grantz, Arthur ------------------ 183 

Griffitts, W. R. ------------------- 286 

Grossman, I. G. ------------------ 222 

Hadley, R. F. -------------------- 156 

Hahn, G. W. -------------------- 240 

Haley, B. R. -------------------- 180 

Hamllton, Warren ______________ 224, 225 

Hamlin, H. P. ------------------- 152 

Hardison, C. H. ----------------- 166 

Harris, Joseph ------------------- 258 

Harshman, E. N. ----------------- 148 

Hartshorn, J. H. ----------------- 227 

Hathaway, J. C. ---------------257, 271 

Haushlld, W. L. ----------------- 165 

Havens, R. G. ------------------- 262 

Hayes, P. T. --------------------- 224 

Heath, R. C. -------------------- 251 

Heidel, S. G. -------------------- 266 

Helz, A. W. --------------------151, 288 

Remley, J. J. -------------------- 269 

Hernon, R. M. ------------------- 150 

Hofmann, R. B. ------------------ 246 

Huffman, Claude, Jr. ------------- 253 

Jackson, E. D. ------------------ 252 

Johnson, G. R. ------------------ 272 

Johnson, H. S., Jr. -------------- 174 

Johnson, R. B. ----------------153, 278 

Jones, B. F. -------------------178, 179 

.Tones, W. R. -------------------150, 208 

Kane, 1\f. F. -------------------- 242 

Kilpatrick, F. A. ---------------- 167 

Koteff, Carl --------------------- 170 

Krieger, M. H. ------------------ 207 

Krinsley, D. B. ------------------ 228 

C-397 

.Article 

Lukin, H. W. ------------------- 267. 292 

Landis, E. R. ------------------- 197 

Lee, D. E. ---------------------- 193 Lemke, R. W. ____________ _:______ 276 

Lester, C. M. -------------------- 159 

Lipp, H. H. -------------------- 287 

Love, J. D. ---------------------- 250 

Lovering, T. S. ------------------ 292 

Luedke, R. G. ------------------- 149 

1\fabey, D. R. ------------------- 249 

McCarthy, J. H., Jr. ------------- 292 

McGrath, J. G. ------------------ 272 

McQueen, I. S. --------~--------- 239 

Mapel, W. J. -------------------- 210 

Merewether, E. A. --------------- 182 

Merriam, C. W. ----------------- 216 

Mlller, R. F. --------------------- 239 

Minard, .T. P. -------------172, 173, 263 

Moore, G. W. -------------------- 220 

Moore, .T. G. --------------------- 183 

Morey, G. W. -------------------- 269 

Morgan, Vincent ----------------- 255 

Mosburg, Shirley ----------------- 273 

Moston, R. P. ------------------- 2'79 

Mountjoy, Wayne ---------------- 287 

Mower, R. W. ------------------- 185 

Nordin, C. F., Jr. ---------------- 265 

Oldale, R. N. -------------------- 171 

Orem, H. M. -------------------- 202 

Osterwald, F. W. ---------------- 274 

Overstreet, W. C. ----------------- 174 

Owens, J. P. ------------------173, 263 

Palmer, A. R. -------------------- 187 

Patten, L. E. ------------------- 286 

Patterson, S. H. ----------------- 219 

Phoenix, D. A. ------------------ 195 

Plouff, Donald ------------------- 244 

Pommer, A. M. ------------------ 284 

Poole, F. G. -------------------189, 199 

Pratt, W. P. -------------------150, 208 

Rantz, S. E. -------------------215, 277 

Read, C. B. --------------------- 206 

Reed, J. C., Jr. ------------------ 174 

Repennlng, C. A. ---------------- 235 

Richardson, Donald -------------- 215 

Richardson, E. V. --------------- 165 

Roach, C. H. -------------------- 272 

Roberson, C. E. ------------------ 219 

Robertson, E. C. ----------------- 257 Roller, J. C. ________________ .:_ __ 243, 247 

Ross, C. P. ---------------------- 212 

Ross, D. R. ---------------------- 273 

Ross, R. J., Jr. ------------------ 189 

Rowe, J. J. --------------------- 269 
C-398 

Article 

Sainsbury, C. L. ----------------- 151 

Salvas, E. H. ------------------- 251 

Schmidt, R. G. ------------------- 211 

Schmoll, H. R. ------------------ 218 

Schneider, W. J. ----------------- 175 

Schultz, L. G. -------------181, 210, 253 

Segerstrom, Kenneth -------------

Shen, John ----------------------

Shepard, A. 0. ------------------

Sheridan, D. M. -----------------

Shoemaker, E. l\L ---------------

Sigafoos, R. S. ------------------

Simons, D. B. -------------------

Skipp, B. A. L. ------------------

Spence, F. H. -------------------- Stallman, R. W. _______________ 155, 

Stuart, D. J. -------------------245, 

229 

162 

264 

196 

197 

238 

165 

236 

272 

279 

248 

INDEX ..,__ 

Article 

Thaden, R. E. ------------------178, 179 

Tison, L. J. --------------------- 266 

Todd, Ruth ---------------------- 173 

Toulmin, Priestley, 3d ------------ 273 

Tourtelot, H. A. ----------------- 253 

Trimble, D. E. ------------------- 213 

Tutti~ C. R. -------------------- 240 

Twenter, F. R. ------------------ 205 

Van Alstine, R. E. ---------------- 226 

Van Horn, Richard --------------- 186 

Varnes, D. J. ------------------- 186 

Vedder, J. G.·-------------------- 235 

Vine, J. D. --------------------- 233 

Waananen, A. 0. ---------------- 275 

Wahl, R. R. --------------------- 245 

Article 

Walker, G. W. ------------------- 200 

·wanek, A. A. -------------------- 206 

Waring, G. A. ------------------- 261 

Warr, J. J. --------------------- 289 

Wells, J. D. -------------------- 196 

Westley, Harold ·----------------- 151 

White, D. E. --------------------- 261 

White, G. W. ------------------- 176 

Whitebread, D. H. ---------------- 193 

Willden, Ronald ------------------ 192 Wolfe, J. A. __________________ 232, 233 

Wones, D. R. -------------------- 260 

Young, E. J. 254 

Zablocki, C. J. ------------------- 241 

Zubovic, Peter ------------------- 211 

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