RELATIONS OF THE WASATCH AND GREEN RIVER FORMATIONS IN 

NORTHWESTERN COLORADO AND SOUTHERN WYOMING, WITH NOTES 

ON OIL SHALE IN THE GREEN RIVER FORMATION. 

By J. D. SEARS and W. H. BRADLEY. 

INTRODUCTION. 

PURPOSE AND SCOPE OF THE REPORT. 

Since the early geologic explorations of 

Powell, King, and Hayden the Eocene deposits 

of the Rocky Mountain and Plateau provinces 

have been the object of much attention by 

stratigraphers. More widespread interest in 

these deposits has been stimulated by the discovery of vast quantities of oil shale in the 

Green River formation of Wyoming, Colorado, 

and Utah. 

The writers have had an opportunity to 

Hayden named the Green River and Wasatch 

formations, and the latter name thus has 

priority over the "Vermilion Creek series" of 

King and the "Bitter Creek group" of Powell. 

In 1907 the western part of the Little Snake 

River coal field was examined by Ball.5 In 

1907 and 1908 Schultz 6 mapped in detail the 

coal-bearing formations of the Rock Springs 

uplift. As a result of this work and of later 

reconnaissance to . the south and east, he prepared a map 7 covering most of the area 

described in this paper. 

see the depositional edge of the Eocene forma- FIELD WORK. 

tions on the northeast flank of the Uinta 

Mountains and to study the significance of In 1921 and 1922 a large part of Moffat 

their character along this margin as compared County, Colo., and a few townships in southern 

with their character farther out in the basin. Sweetwater County, Wyo., were examined by 

The purpose of this report is to describe the parties in charge of the senior writer. He was 

lithology, areal distribution, and interfingering assisted in 1921 by K. K. Landes, in 1922 by 

of the Wasatch and Green River formations in James Gilluly, and in both seasons by the junior 

northwestern Colorado and southern Wyoming writer. Mapping was done largely by means of 

and to draw conclusions as to their source of plane tables and telescopic alidades, on a 

material, mode of origin, time relations, and system of triangulation extended westward and 

proper nomenclature. The method and place northwestward from the Craig quadrangle, 

of deposition ~re of special importance in Colorado. Isolated structural and areal feaconsidering the Green River formation, as they tures were mapped by means of stadia or pace 

largely determine the relative richness of the traverses according to the degree of refinement 

oil shale found in that formation. desired. The mapping was tied to section 

EARLIER INVESTIGATIONS. corners at numerous points. The geologic map (Pl. XXIV) accompanying 

The area discussed in this paper is part of the this report is compiled from the work of Ball, 

region explored half a century ago by Hayden/ 

Powell, 2 Hague and Emmons,S and King. 4 

I Hayden, F. V., U.S. Geol. Survey Terr. Third Ann. RepL, 1869. 

2 Powell, J. W ., Report on the geology of the eastern portion of the 

Uinta Mountains, U.S. Geol. and Geog. Survey Terr., 2d div., 1876. 

s Hague, Arnold, and Emmons, S. F., U. S. Geol. Expl. 40th Par 

Rept., vol. 2, 1877. 

4 King, Clarence, idem, vol. 1, 1878. 

a Ball, M. W., The western part of the Little Snake River coal field 

Wyo.: U.S. Geol. Survey Bull. 341, pp. 243-255, 1909. ' 

6 Schultz, A. R., The northern part of the Rock Springs coal field, 

Sweetwater County, Wyo.: U. S. Geol. Survey Bull. 341, pp. 256-282, 

1909; The southern part of the Rock Springs coal field, Sweetwater 

County, Wyo.: U. S. Geol. Survey Bull. 381, pp. 214-281, 1910. 

7 Schultz, A. R., Oil possibilities in and around Baxter Basin, in the 

Rock Springs uplift, Sweetwater County, Wyo.: U. S. Geol. Survey 

, Bull. 702, pl. 1, 1920. 

93 
94 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

Schultz, and Sears. The location of the area is 

shown in Figure 9. 

ACKNOWLEDGMENTS. 

The writers gratefully acknowledge the 

cordial assistance and hospitality given by the 

local ranchers, especially MessrR. Sparks. 

Crozier, and Grounds. 

TOPOGRAPHY. 

In the southwestern part of the area mapped 

Cold Spring Mountain and other ridges on the 

north flank of the Uinta Mountains rise to an 

altitude of about 8,500 feet above sea level. 

To the north, northeast, and east is the Green 

River Basin, separated by the Rock Springs 

uplift into the Bridger Basin on the west and 

the Washakie and Sand Wash basins on the 

east. Although the Green River Basin is of less 

STRATIGRAPHY. 

WASATCH FORMATION. 

The Wasatch deposits were named by Hayden 8 because of their excellent exposures on 

the eastern slopes of the Wasatch Mountains. 

Their lithologic character in that region is illustrated by his brief description of their appearance in Echo and Weber canyons, Utah, 

where the formation consists of 1,500 to 2,000 

feet of conglomerate. In a later report Hayden 9 described this section more fully, noting 

the large size and well-rounded shape of the 

boulders and the predominant red color of the 

sandstones that make up the lower 500 to 800 

feet of the formation. He noted also the rapid 

lateral changes near the base from fine sand to 

coarse conglomerate. 

It is perhaps unfortunate that the name was 

taken from the Wasatch Mountains, where 

the formation has a lithologic character very 

rr=======7,~=~===7.5======::;'ll different from that shown in most other areas. 

Hayden 10 described the Wasatch at Carter 

Station, Wyo., as consisting of ·pink, red, and 

purple indurated sandy clays, alternating with 

gray and reddish sandstones; this description is 

--~- ---·-14'1" more applicable to the formation throughout 

FIGURE 9.-Index: map showing location of area in northwestern 

Colorado and southern Wyoming. 

most of its area of distribution. Hayden 

believed that the beds were deposited in large 

fresh-water lakes. 

Within the area mapped by the writers in 

1921-22 the Wasatch consists chiefly of variegated clay shale and irregular, crudely bedded sandstone. The predominant colors of 

the clay . shale are red and gray, commonly 

banded with yellow, lavender, pink, brown, pale 

green, drab, and other shades. Most of the 

sandstone is gray, buff, or dark brown; a few 

beds are white, pink, or red. The ·materials of 

the sandy beds range in size from very fine 

altitude than the Uinta Mountains it contains grains to coarse grits, and locally the sandstone 

here and there high cliffs and isolated peaks; grades into conglomerate carrying boulders as 

the highest point is Diamond Peak, 9,925 much as 6 feet in diameter. 

feet above sea level. In the Vermilion Creek basin the middle 

The major stream of the area mapped is part of the Wasatch contains a few beds of 

Green River, which flows southward along its coal, fissile carbonaceous shale, shell marl 7 

western margin. Green River, with its main and many more beds of sandstone than elsetributaries, Bitter and Vermilion creeks, drains where in the field. 

the Rock Springs uplift and a large part of the ' In general the Wasatch formation weathers 

Washakie Basin. Across the southeast corner into tYJ?ical badlands that suppor~ lit~le or _no 

of the area runs Little Snake River, which, veget'atwn. Topography of this kind Is varied 

with its tributaries, Sand and Powder washes, 

drains the Sand Wash Basin and part of the 

Washakie Basin. 

s Hayden, F. V., U. S. Geol. and Geog. Survey Terr. Third Ann. 

Rept., p. 91, 1869. 

g Idem, Fourth Ann. Rept., pp. 147, 155-156, 1871. 

10 Idem, p. 147. 
U. GEOLOGICAL StlllVBY 

R. 10 7 W. R . I0 2 W . 

s 

GEOLOGIC MAP 

SH WING RELATION AND DISTRIBl TION OF 

W SAT H AND GREEN RI\ ER FORMATIONS 

IN NORTHWE 'TERN COLORADO AND SOUTHERN WYOMING 

Bu. compiled from fo.td aheeta 

and r rom townahip plata of the 

G.neral LAnd Office 

By J. D. Sears and W. H. Bradley 

Scale so6ooo 10 15 20 25 

1924 

G.otoay compolod from the work of 

A. R.. Schultz, M. W . Ball, and J. D. S..ra 

Surveyed in 1907-t9n 

PROFESSIONAL PAPER 132 PLATEXXIV 

R . IOI .W . R . IOOW. R.9 9 w . R. 98W· R. 97 W. R . 92 W, R . 91 W. 

R. 92 W. 

EXPLANATION 

SEDIMENTARY ROCKS 

Bi hop cong omerat.e (ll'a.IU.-no rued ,._ 

gwlrtr pcOOI• ruod bovl- <Wn 111 jiur fi"Jwl rutd •~~<~ M4trU. 1 .. ...nt..,.., 

op\JIW.. """'"""'" t bc..J 

aro-. ~-"""· Prl.rlr qf [Of"MGIIOIU 

UNCON F ORMI T Y 

Post-"Laramle" formation 

rGro.w o.IOd tnvw.o ..,..uw,..; gral' a..d drab Joau. oool W.: oo•g/Dm.rau a.t t.u.J 

J{ 

UNCONFORM ITY 

Gray, white, 

~ and brown ndstone ; coal beds; gray shale; eonglom r· ate; variegated day shale 

[X] Gray thin-bedded lim tonei white cross-bedded sa.ndstone; reo, gray. and drab shale 

UNCONFORMI TY 

// 

// // / 

Great thickness of red quartzite and sandstone; some shale and white 

sandstone and quartzite 

IGNEOUS ROCKS 

rn 

Basalt 

EB 

Anticlinal axis 

EJ Fault 10. do..m.t.row: U. "ptJorow) 

Boundaries taken from U. S. Geol. Survey Bull. 702, by A. R. Schultz, and from Bull. 341, by M. W. Ball 

Location of measured section referred to in the text 

} 
WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 95 

by low escarpments and benches where the The Green River formation is peculiarly 

sandstone is comparatively resistant. resistant to weathering and rises in high, steep 

GREEN RIVER FORMATION. cliffs of monotonous buff, gray, or bluish-white 

tints, contrasting sharply with the brightly 

Remarkable exposur~s along Green River colored badlands. of ·the Wasatch. Almost as. 

led Hayden 11 to apply the name of that stream striking is the contrast between the Green 

to the series of shale and sandstone overlying River and the overlying Bridger, which weathers 

his Wasatch "group." The type locality of into fantastic badlands of ash or bluish gray, 

the formation is at the town of Green River, Wyo., where, according -to W:lnchester,t2 an varied by dark-green and light-bluish sandstones and a few patches of red and orange- incomplete section has a thickness of 755 feet. 

Other sections near by/3 in Tps. 17 and 19 N., colored clay shale. 

R. 106 W., show a thickness of approximately STRUCTURE. 

1,350 feet. In all these sections a coarse, The southern margin of the field is the north 

massive brown sandstone, 125 to 245 feet flank of the Uinta Mountain-Axial Basin arch. 

thick (the " Tower sandstone" of Powell), is West of Little Snake River the Eocene beds, 

included in the top of the formation. The dipping away from the mountains, rest with 

remainder of the formation at the type locality marked angular unconformity upon the upconsists almost entirely of finely laminated turned edges of Mesozoic rocks, showing that 

shale, some of which is rich oil shale. A few uplift of the Uinta region both preceded and 

beds. of thin platy sandstone and sandy shale followed Eocene deposition. Farther southoccur at wide intervals in these sections. A east no angular unconformity is found below 

very striking feature of the Green River in · the Wasatch and Green River, a fact which 

this part of the field is its bluish-white color on indicates that · movement of th~ Axial Basin 

weathered surfaces. anticline began after the end of Eocene time. 

Farther southeast, in the outcrops sur- North of this great uplift is the broad 

rounding the Washakie and Sand Wash basins, Green River Basin, which in the area here 

the formation shows a somewhat different mapped is divided by the north-south Rock 

lithology. The "Tower sandstone" of Powell Springs uplift into two synclinal depressions. 

was not recognized by the writers in the southern The western depression, known as the Bridger. 

part of this area, but it may be represented by Basin, is partly within this area. The eastern 

one or more of the sandstones in the upper depression is separated by one or two eastpart of their Green River. The contact west arches into the Washakie Basin on the 

between this formation and the overlying north and the Sand Wash Basin· on the south. 

Bridger was difficult to determine; it was drawn The present southern edge of the Eocene 

in the field at the horizon considered to mark outcrops is determined partly by the original 

most plainly a change . in conditions of sedi- limits of deposition and partly by structure. 

mentation. This mapping includes at the top At the southwest it is marked in part by the 

of the Green River about 135 feet of beds that great Uinta fault, · which extends for many 

resemble somewhat the overlying as well as the miles westward from the northwest corner of 

underlying rocks. The Green River in this Colorado; some if not all of the movement 

part of the field is about 1,200 feet thick and along this fault was post-Wasatch. It is 

consists principally of finely laminated shales, possible that the fault between the Cretaceous 

many of which are very limy, and some beds of and the Wasatch rocks, extending from Dialow-grade oil shale. The formation weathers mond Peak southeastward to a point beyond 

to a characteristic buff color. In the upper East Fork of Vermilion Creek, is a continuation 

500 or 600 feet there is a greater amount of of the Uinta fault, but their relation is conclay shale and thin-bedded to massive sand- cealed by recent debris. 

stone. A few thin beds of oolitic limestone, From Vermilion Creek southeastward to 

generally silicified, and calcareous alga reefs Sand Creek· the margin of Eocene deposits is 

are scattered through the section. marked by a zone of en echelon faults and 

u Hayden, F. V., U. S. Geol. and Geog. Survey Terr. Third Ann. 

Rept., p. 90, 1869. 

12 Winchester, D. E., Oil shale of the Rocky Mountain region: U.S. 

Geol. Survey Bull. 729, p. 125, 1923. 

1a Idem, pp. 124-126. 

sharp anticlines. These and other faults 

farther out in the basin have no bearing on 

the character and relations of theW asatch and 

Green River and need not be described here. 
96 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

ORIGIN AND RELATIONS OF THE WASATCH 

AND GREEN RIVER FORMATIONS. 

THE UINTA MOUNTAINS AS A SOURCE OF 

MATERIAL. 

Powell 14 noted the occurrence of thick conglomerates in the basal part of his "Bitter 

Creek group" (Wasatch formation) .on the 

north side of the Uinta Mountains from Richards Peak, Wy6., to a point east of Bruce 

Mountain, Colo. The conglomerate consists 

of boulders and pebbles of sandstone and 

limestone; in the vicinity of Richards Peak 

the limestone boulders contain Jurassic fossils. 

From these facts Powell inferred that in 

Wasatch time erosion of the Uinta Mountains 

had in places reached the Carboni£ erous rocks; 

that the conglomerate referred to was formed 

from sandstone and limestone of Mesozoic age, 

and, to a lesser extent, of Carboniferous age; 

and "that the badland rocks of Mesozoic age 

were carried from the Uinta region and redistributed as badland beds of the Bitter Creek 

period. " 15 Powell 16 noted also' that near the 

Uinta uplift the Green River formation " is 

much thickened, and the shales are replaced 

by sandstones and conglomerates of fine 

pebbles " ; from this he inferred that the Green 

River was " derived from the Uinta region, 

and that the material was supplied from limestones and sandstones 'of Carboniferous age." 

Additional evidence pointing to the Uinta 

Mountains as -a source of material was collected 

by the writers in 1922. Conglomerates in 

both the Wasatch and the Green River are 

thickest and carry the largest boulders near 

the mountains and thin rapidly toward the 

basin. The most conspicuous example is at 

Sugarloaf Butte, in sees. 15 and 16, T. 11 N., 

R. 101 W., where there is in the lower part of 

the Wasatch an. alternating series, 150 to 200 

feet thick, of very coarse conglomerate, ·grit, 

and lenses of coarse cross-bedded friable buff 

to white sandstone. Most of the boulders 

are well rounded by stream action, but some 

are angular and subangular; the largest boulders are 6 feet in diameter. (See Pl. XXV, A.) 

This notable aggregation of coarse detritus, in 

which there is only the crudest kind of stratiH Powell, J. W ., Report on t he geology of the eastern portion of the 

"Uinta M ountains, pp. 162-164, U.S. Geol. and Geog. Survey Terr., 2d 

-div., 1876. 

~~ I dem, p . 165. 

16 I dem, p . 166. 

fication, grades laterally within less than a 

mile to the north and east in to carbonaceous 

shale, shell marl, and coarse but regularly 

bedded sandstone-the typical Wasatch assemblage of this vicinity. The interfingering of 

these several types is clearly exposed eastward 

in the bluffs along Talamantes Creek and to the 

north in deep tributary gulches. There can be 

no doubt that the material was derived from 

the Uinta uplift, as the conglomerate thins 

away from the mountains and consists principally of gray cherty limestone identical with 

the massive Carboniferous limestone now 

exposed high on the flank of Cold Spring 

Mountain, less than 2 miles to the southwest. 

Evidently the Carboniferous_ rocks of the uplift 

were being eroded during at least a part of 

Wasatch time. 

Westward from Sugarloaf Butte the Wasatch 

contains near its base several beds of conglomeratic sandstone consisting of abundant white 

sugary-textured quartzite pebbles and boulders 

as much as 8 inches in diameter in a white or 

gray sandy matrix. These white quartzites 

are very similar to the Weber and older 

Pennsylvanian quartzitic sandstones exposed 

in the Uinta Mountains. Eastward from 

Sugarloaf Butte as far as East Fork of V ermilion Creek conglomerates in the lower 

Wasatch are characterized by pebbles of black 

chert; the source of the chert is unknown, but 

the pebbles strongly resemble those of the 

Dakota in color, roundness, and high polish, 

and they may have been reworked from that 

formation. 

Eastward from Godiva Ridge several conglomeratic sandstones near the base of the 

Wasatch contain many well-rounded chert 

pebbles less than half an inch in diameter; 

these pebbles, predominantly white and to a 

lesser extent red and black, may have been 

derived either from the Uinta Mountains or 

from the Park Range, to the east. 

The developEent of conglomerate close to 

the mountains is illustrated also in the Green 

River formatio . Along Canyon Creek from 

sec. 18, T. 12 N., R. 101 W., westward to Pine 

Mountain the upper 300 feet of the Tipton 

tongue of the Green River formation is represented by massive medium to coarse grained 

sandstones separated by very thin partings of 

hard greenish shale. In these sandstones, 

especially in the upper ones, are zones of 
WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 97 . 

pebbles and boulders as large as 6 inches. in 

diameter, of white and brown quartzite, 

angular red chert, hard shale, and cherty limestone; a few boulders consist of red quartzite 

lithologically identical with the red quartzite 

that forms the core of the Uinta Mountains. 

Schultz 17 noted these conglomeratic sandstones on Canyon Creek and says: "Upstream 

on Ruby Creek toward the mountains the 

percentage of conglomerate and the size of the 

pebbles rapidly increase. Within a mile boulders as large as 2 feet are encountered.'' Northward from the Canyon Creek coal mine, in sec. 

17, T. 12 N., R. 101 W., the conglomeratic 

sandstone grades laterally into gray fissile 

shale that is characteristic of the Tipton 

tongue. 

Another type of evidence pointing to the 

Uinta Mountains as a source of material may 

be summarized as follows. An erosional window 

in the Browns Park formation, in T. 9 N., R. 

100 W., exposes the Bridger resting with 

marked angular unconformity upon Mancos 

and older Mesozoic rocks dipping northeastward on the flank of the Uinta Mountain 

arch. The Bridger is very conglomeratic, 

the boulders consisting largely of gray cherty 

limestone containing Carboniferous fossils. Inasmuch as a few n1iles farther north there is no 

angular unconformity between the Bridger 

and Green River, the fact that in T. 9 N., 

R.100 W., the Bridger restsdirectlyuponMesozoic rocks seems to s'4ow that the Wasatch 

and Green River were not deposited this far 

south, and that the Bridger was laid down as 

an overlap beyond the margins of the older 

Eocene beds. This conclusion, together with 

the conglomeratic nature of the Bridger, indicates that the east end of the Uinta Mountains was never buried under Eocene beds but 

was the site of erosion that furnished the 

Eocene sediments. On the other hand, it 

seems probable that the Wasatch and Green 

River formations (and possibly the Bridger) 

of the Green River and Uinta basins were 

continuous around the east end of the mountains; this inference is drawn from the narrow 

interval (14 n1iles) now separating the northern and southern Wasatch and Green River 

outcrops east of Cross Mountain and from 

the lack of angular unconformity between 

17 Schultz, A. R., Oil possibilities in and around Baxter Basin, in the 

Rock Springs uplift, Sweetwatoc County Wyo.: U. S. Geol. Survey 

Bull. 702, p. 31, 1920. 

. Wasatch and Cretaceous rocks in the Axial 

Basin anticline, showing that that arch was 

not uplifted at the earliest until after Green 

River time. · 

BROAD VARIATIONS AWAY FROM THE SOURCE. 

In addition to the local changes within the 

formations near the mountains, there are 

large-scale lateral variations in the sediments 

farther out in the basin of deposition. 

In the basin of Vermilion Creek the upper 

part of the Wasatch is principally variegated 

clay shale in which red is the predominant 

color. The lower part consists largely of gray 

and buff clay shale and sandstone; it includes 

also some brightly colored clay shale, a few 

bed~ of coal which in places are thick enough 

to be mined for local use, thin-bedded carbonaceous shale and interbedded shell marl 

(which superficially resemble the Green River 

formation), and at least one calcareous alga 

reef. In the vicinity of East Fork of Vermilion 

Creek, northeastward from sec. 4, T. 10 N., 

R. 100 W., a zone of clay shale and sandstone 

near the top of the lower Wasatch grades 

laterally into gray fissile shale of Green River 

appearance. Farther north this zone includes 

beds of low-grade oil shale; it thickens from 

about 200 feet in sec. 3, T. 10 N., R. 100 W., 

to nearly 400 feet in sees. 27 and 28, T. 12 

N., R. 99 W. The method of thickening is 

illustrated at the base of the fissile shale in 

sees. 34 and 35, T. 11 N., R. 100 W., where a 

long wedge of papery, low-grade oil shale replaces toward the north a band of gray and 

buff clay shale, and the whole Green River 

zone thickens 100 feet in about a mile. Similar 

examples were noted elsewhere along the outcrop. 

Thus the Wasatch is split northward into 

two parts by a wedge of very different material. 

The thickness of the lower part is unknown, 

as the base is not exposed. The upper part, 

called by Schultz 18 the Cathedral Bluffs red 

beds member of the Green River formation, is 

1,200 feet thick at Lookout Mountain and 600 

feet thick northwest of the Washakie Basin; 

westward and northwestward, according to 

Schultz, it merges laterally into typical Green 

River shale. The wedge of fissile shale and 

oil shale was named by Schultz 19 the Tipton 

shale member of the Green River formation. 

1s Idem, p. 28. 

19 Idem, p. 30. 
98 $HORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

On the east side of the Washakie-Sand Wash 

depression a similar change northward occurs 

in the Wasatch. Godiva Ridge is capped by 

the main body of the Green River formation, 

which in this area is the Laney shale member. 

Below this is exposed the entire Wasatch 

formation, 5;600 feet thick, consisting of 

brightly colored clay shale and subordinate . 

sandstone, with no beds of Green River type. 

North of Baggs, Wyo., the Tipton tongue of 

the Green River enters in the midst of the 

Wasatch beds, thickens northward, and, encircling the north end of the Washakie Basin, 

unites with the Tipton to the west. Thus · 

the outcrop of the Tipton tongue has the 

shape of the letter U with the open side toward 

the south . . The Tipton lake may have extended southward to a line between Baggs 

and East Fork of Vermilion Creek; and there 

is a possibility that much of the Cathedral 

Bluffs tongue of red beds, deposited as this 

lake retreated, was derived from the east and 

southeast. 

In contrast to the relations described above, 

Green River deposition on the east rim of 

the Bridger Basin was evidently not interrupted by a temporary regression of the lake, 

as the Wasatch and Green River show no 

interfingering, even close to the mountains. 

In this area the lake probably reached the 

foot of the mountains, but as the finely laminated shale and oil shale of the Green River 

indicate deposition in very quiet water, material must have been carried out from the 

mountains very slowly if at all. 

On the rim of the · Washakie-Sand Wash 

depression the main body of the Green River 

formation (Laney shale member) undergoes 

a very gradual northward change. Near the 

mountains it is prevailingly buff and much 

of its shale is limy and poor in oil-yielding 

organic matter. Although sandstones are numerous, only one conglomerate was observed. 

This conglomerate, about 5 feet thick, contains small · subangular pebbles of black and 

green chert and of coarse-grained red quartzite, 

some grains of glassy quartz, and a few compact clay balls. The pebbles average a quarter of an inch in diameter; a few pebbles of 

black chert are an inch in diameter. This 

conglomeratic lens, near the top of the Laney 

shale member in 'i.'. 9 N., R. 100 W., passes 

rapidly northward into a coarse-grained sandstone with a limy cement. Just west of Little 

Snake River, near the center of T. 8 N., R. 

97 W., two or three thin beds of coal and 

numerous beds of partly humified plant remains occur in the Laney shale several hundred feet above the base. The coal beds are 

bony and very lenticUlar, ranging from a 

few inches of carbonaceous material to beds 

3 feet thick Toward the north the Green 

River formation contains· fewer and thinner 

sandstones, and its buff color changes gradually 

to the more characteristic bluish-white tone, 

probably owing to an increasing richness of 

the oil shale. 

NOMENCLATURE. 

The early explorers believed that the Green 

Rive.r formation is not only different from the 

Wasatch in lithology but is also distinctly 

younger throughout. Such a belief is justified 

in the Bridger Basin, where the Wasatch was 

followed by continuous Green River deposition. Farther east, however, in the WashakieSand Wash depression, this belief led them to 

draw the boundary at the base of the beds later 

named Laney shale member by Schultz, thus 

including in the Wasatch the deposits here 

called the Tipton tongue of the Green River 

formation and the Cathedral Bluffs tongue of 

the Wasatch formation. The boundary was 

drawn at the same horizon by Schultz 20 in his 

reports on the coal fields of the Rock Springs 

uplift. In a later report, however, Schultz 21 

described the northwestward gradation of his 

Cathedral Bluffs red beds member into shale of 

Green River type and suggested that his Tipton 

shale member might die out toward the southeast, causing an interfingering of the two formations. He believed that the Green River west 

of the Rock Springs uplift is the time equivalent of all beds east of the uplift between the 

base of the Tipton tongue and the base of the 

Bridger, and hence he treated the Tipton 

tongue and the Cathedral Bluffs tongue as 

members of the Green River formation. 

20 Schultz, A. R., The northern part of the Rock Springs coal field, 

Sweetwater County, Wyo.: U. S. Geol. Survey Bull. 341, pp. 256-282, 

1909; The southern part of the Rock Springs coal field, Sweetwater 

County, Wyo.: tr. s. Geol. Survey Bull. 381, pp. 214-281, 1910. 

21 Schultz, A. R., Oil possibilities in and around Baxter Basin, in the 

Rock Springs uplift, Sweetwater County, Wyo.: U. S. Geol. Survey 

Bull. 702, pp. 25, 28-31, 1920. 
WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 99 

Although the time equivalenc.e suggested by arch and carried great amounts of sediment out 

Schultz is essentially correct, the writers believe over the lowlands. Alluvial fans of poorly 

that ·his classification does not adequately ex- sorted boulders were built up at the foot of the 

press the time and depositional relations of the mountains by torrential streams; flood-plain 

Wasatch and Green River. The interfingering silts and stream-channel deposits, which later 

of these formations, now proved to exist, may became colored clay shale and coarse, irregube better indicated by the use of the term lar sandstone, were laid down farther out in the 

''tongue," introduced by Stephenson. 22 The basin. Here and there swamp conditions pernames Cathedral Bluffs tongue of the Wasatch mit ted the ) accumulation of plant remains, 

formation and Tipton tongue of the Green which later became carbonaceous shale and 

River formation are therefore here used to re- coal. To the east and west these deposits of 

Vicinity of 

Green River, 

Wyo. 

Vicinity of 

Lookout Mountain, Colo. · 

-- --·--

Vicinity of 

Little Snake River, 

Colo. 

·Fluviatile and fresh-water 

lake deposits 

__ -----Laney shale member of 

_-- Green River formation 

1,100' 

Fresh-water 

lake deposits and oil shale lake deposits ___ ---

---- _ .... _________ ....::- .._ 

1,350± -=-==- ~ ~ --Cathedral Bluffs tongue .-.=;;::".:-- of Wasatch formation 

~-==--:::.-=------~ Tipton tongue-;;[(};~ Rlv-;- --

------------------------- Fluviatile 

deposits 

FIGURE 10.-Sections from northwest to southeast in the Green River Basin, Wyoming and Colorado, showing interfingering of the Wasatch 

and Green River formations. 

place the members of Schultz. The relations 

of these tongues are shown diagrammatically in 

Figure 10. 

early Wasatch time merged with material 

brought from the Park and Wasatch ranges. 

As erosion cut deeper into the mountain mass, 

older rocks were exposed and fragments of CarSUMMARY OF GEOLOGIC HISTORY. boniferous limestone were carried into the 

The,geologic events bearing on the deposition basin. Scattered shallow ponds swarmed with 

and relations of the Wasatch and Green River organisms such as Unio and Goniobasis, as is 

in this area may be summarized as follows: 

After Cretaceous time the Mesozoic and 

older rocks were lifted many thousands of feet 

in the Uinta Mountain arch, and ori the north 

side part of this movement resulted in great 

faulting. Streams began a vigorous attack on 

the Mesozoic rocks forming the surface of the 

22 Stephenson, L. W., Tongue, a new stratigraphic term, with illustrations from the Mississippi Cretaceous: Washington Acad. Sci. Jour., 

vol. 7, pp. 243-250, 1917. 

attested by the abundant shell marl interspersed in lenses of finely laminated carbonaceous shale. The increasing thickness of the 

Wasatch deposits caused an encroachment 

upon the lower flanks of the mountains, as illustrated on Vermilion Creek by the overlap of the 

Wasatch upon beds ranging in age from Mesaverde to Twin Creek. East of the Uinta 

Mountains the Wasatch was laid down upon 

practically horizontal Cretaceous rocks. 
100 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

Over these flood-plain deposits spread gradually a broad, shallow lake. Toward the west 

this lake reached the foot of the Uinta Mountains; here its transgression marked the end of 

Wasatch sedimentation, as the lake maintained its position until the end of Green River 

time. Farther east the margin of the lake 

was a line between East Fork of Vermilion 

Creek and Baggs, Wyo. Into the quiet waters 

of this lake was transported fine sediment, 

which became mixed with varying amounts of 

organic matter and formed the gray fissile 

shale and oil shale of Green River type. 

Some coarser debris was carried into the edges 

of the lake, as shown by the conglomerate in 

the Tipton tongue on Canyon Creek. Meanwhile sedimentation of Wasatch type was continuing over the flood plains not transgressed 

by the lake. 

After the deposition of several hundred feet 

of shale, forming the Tipton tongue, the margin 

of the lake gradually receded to a line roughly 

marked to-day by the axis of the Rock Springs 

uplift. Within the limits of the restricted 

lake the formation of Green River sediments 

continued, while over the fine silt left exposed 

by its retreat was deposited the brightly colored clay shale of the Cathedral Bluffs tongue. 

After the formation of 600 to 1,200 feet of 

sediments composing the Cathedral Bluffs 

tongue Wasatch deposition came to an end 

by a new advance of the Green River lake, 

which this time encircled the east end of the 

mountains and united with the lake of the 

Uinta Basin. The much smaller thickness of 

the entire Green River formation at Green 

River, Wyo., compared with the thickness of 

its age equivalents-the Tipton and Cathedral 

Bluffs tongues and Laney shale member (possibly including representatives of the "Tower 

sandstone" and plant beds of Powell)-at 

Lookout Mountain, may be partly ,accounted 

for by a gradual southeastward tilting that 

may have been an important factor in the 

second transgression of the Green River lake. 

Later folding and faulting have changed the 

attitude of the . Wasatch and Green River but 

have not affected their relations. 

Two questions may be outlined as problems 

for future study. What was the mode of disappearance of the Green River lake~ Are the 

earliest Green River beds of the Uinta Basin 

the age equivalents of 1the basal Tipton tongue 

or the basal part of the Laney shale member~ 

OIL SHALE IN THE GREEN RIVER FORMATION. 

PHYSICAL PROPERTIES. 

The oil shale in the Green River formation 

may be divided into tw.o distinct varieties, between which there are many gradations. One 

variety is hard and tough. On fresh surfaces 

it is chocolate-brown to black and generally 

shows no distinct lamination. When weathered 

it is predominantly of a bluish-white color, and 

its finely laminated structure is indicated by the 

alternation of thin dark-gray bands with bluishwhite layers. (See Pl. XXV, B.) The fracture is commonly subconchoidal; freshly broken 

faces have a vitreous or pitchy luster in the 

richest grades and are dull in the leaner grades. 

The other variety has very pronounced bedding 

of paper thinness and is commonly called 

papery shale. Its laminae, which are remarkably flexible, separate very readily. (See 

Pl. XXV, 0.) Fresh samples are light to 

dark brown or less commonly black; weathered 

surfaces are light blu~sh gray or white. In 

general, the tough, massive variety yields more 

oil than the papery shale. 

CHEMICAL PROPERTIES. 

Oil shale contains little or no petroleum as 

such, and only a small percentage of the organic . 

matter can be extracted with common petroleum solvents such as· carbon tetrachloride 

carbon bisulphide, and benzene. The per 

centage extracted varies with the cha;racter of 

the shale and the solvent, but according to a 

table prepared by Gavin 23 the average amount 

extracted by six solvents fr<;>m three samples of 

Green River shales was only 1.3 per cent of the 

weight of the samples. 

Upon destructive distillation the organic 

matter in the shale yields a crude oil. According to Steuart,24 Prof. Crum Brown gave the 

name ''kerogen" to this organic matter of 

indefinite and variable chemical composition. 

The economic value of the shale depends 

upon the character of the kerogen and the 

proportions of kerogen and clastic mineral 

matter. McKee and Goodwin 25 · show that 

23 Gavin, M. J ., Oil shale-an historical, technical, and economic study: 

U.S. Bur. Mines Bull. 210, p. 28, 1922. 

24 Steuart, D. R., Oil shales of the Lothians, pt. 3, The chemistry of the 

oil shales, 2d ed., p. 159, Scotland Geol. Survey Mem., 1912. 

25 McKee, R. H., and Goodwin, R. T., A chemical examination of the 

organic matter in oil shales: Colorado School of Mines Quart., vol. 18, 

No. 1, pp. 8, 20, 1923. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXV 

A. CONGLOMERATE IN THE LOWER PART OF THE WASATCH FORMATION AT 

SUGARLOAF BUTTE, SEC. 15, T. 11 N., R. 101 W., COLO. 

Compare size of boulders with height of man on right side of photograph 

B. OIL SHALE IN THE GREEN RIVER FORMATION,- SHOWING CHARACTERfSTIC 

THIN, REGULAR BEDDING 

Photograph by D. E. Winchester 

C. PAPERY OIL SHALE, SHOWING FLEXIBILITY 

Photograph by D. E. Winchester 

WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 101 

the chemical composition of the kerogen and 

hence of the oil distilled from it differs in 

different shales and even from place to place 

in the same formation. For example, shale 

oil from the Green River formation in Colorado 

has a mixed paraffin and asphalt base, whereas 

shale oil from a locality in Utah has an asphaltic 

base. The yield of oil is to some degree 

dependent upon the chemical composition of 

the shale, but is determined far more by the 

amount of kerogen present. 

EFFECT OF VARYING CONDITIONS OF FORMATION 

Researches of numerous careful students 26 

indicate that kerogen was formed by the accumulation in fresh water of spore exines, pollen grains, the more resinous parts and somewhat macerated cuticles of larger plants, and 

the remains of various types of algae, particularly the more gelatinous and filmy types. 

The low orders of plant life, both sessile and 

planktonic, the drift material, and the parts 

of higher plants would be distributed in varying amounts through a body of fresh water 

according to depth, cun·ents, wave action, 

source of supply of extraneous material, prevailing winds, and other factors. Where clastic material was being carried into the lake 

the organic content of the shale formed would 

be relatively smaller and the value of the shale 

as an oil producer would be lessened. Where 

the organic debris could accumulate without 

much influx of inorganic material the resultant 

shale would be very much richer in kerogen. 

From this reasoning it is easily understood 

why the oil shale of the Green River formation 

near the east end of the Uinta Mountains is of 

very low grade. Much clastic material was 

carried out from the mountains and deposited 

in the shoreward portion of the Green River 

lake; the proportion of included organic material was small. Farther out in the lake, and 

also near shore at places where little clastic 

material was being supplied, the proportion of 

organic debris was much larger; and the shale 

is far richer in the oil-yielding kerogen. The 

variation is strikingly shown by comparison of 

sections of the Tipton tongue in T. 10 N., 

R. 100 W., Colo., and T. 12 N., R. 102 W., 

Wyo., with a section on Shell Creek in T. 12 

N., R. 99 W., Colo.; it is indicated also by 

comparison of sections of the Laney shale member in T. 8 N., R. 97 W., and T. 10 N., R. 100 

W., with those in T. 13 N., R. 99 W., and T. 

17 N., R. 106 W. These sections, given on 

following pages, show a gradation northward; 

as the sandstones and the more limy and 

sandy shales disappear the percentage and 

richness of oil shale in~rease. 

MEASURED SECTIONS AND TESTS. 

The following sections, measured by the 

writers except as otherwise noted, indicate the 

character of the formation at different localities and present more detailed data concerning 

lateral changes. Results of distillation tests 

are given opposite the descriptions of the beds 

sampled. Beds described as low-grade oil shale 

yield less than 10 gallons to the ton. 

Sections of Tipton tongue of Green River formation in 

Moffat County, Colo., and Sweetwater County, Wyo. 

Locality 1, sec. 3, T. 10 N., R. 100 W. 

Ft. in 

Sandstone, buff, hard, medium grained ___ _ 2 6 

Sandstone, brown, thin bedded, interbedded with hard gray-green shale _____ _ 21 

Sandstone, gray, massive, medium grained. 2 8 

Shale, gray-green, platy ________________ _ 2 6 

Sandstone, brown, medium grained ______ _ 2 

Shale, greenish brown, platy to lumpy ___ _ 8 

Sandstone, brown, platy, medium grained_ 3 

Shale, gray-green, platy _________________ . 3 

Sandstone, reddish brown, medium grained, 

undulating bedding planes ____________ _ 1 6 

Shale, greenish brown, sandy, platy _____ _ 8 6 

Sandstone, brown, very fine grained _____ _ 2 

Shale, gray-green, platy _______________ _ _ 2 

Sandstone, brown, very fine grained _____ _ 4 26 Bertrand, C. E., Les charbons humiques et les charbons des purins: Shale, gray-green, platy ________________ _ Lille Univ. Trav. et Mem., vol. 6, Mem. 21, pp. 13-178, 1898; Con- 4 

ferences sur les charbons de terre: Soc. beige geol. Bull., vol. 11, p. 287, Sandstone, brown, very fine grained_-----

1897. Davis, C. A., On the fossil algae of the petroleum-yielding shales Clay shale, light gray------------------- ofthe Green River formation of Colorado and Utah: Nat. Acad. Sci. Shale, gray-green, soft, platy ____________ _ 

Proc., vol. 2, pp. 114-119, 1916; quoted in Winchester, D. E., Oil shale in Sandstone, yellow-brown, thin bedded, fine 

northwestern Colorado and adjacent areas: U. S. Geol. Survey Bull. 

641, p. 165, 1916; Oil shale of the Uinta Basin, northeastern Utah: u. s. grained __ ---------------------------- Geol. Survey Bull. 691, pp. 46-47, 1918. Jeffrey, E. c., The nature of Shale, gray-green, platy to lumpy _______ _ 

some supposed algal coals: Am. Acad. Arts and Sci. Proc., vol. 46, pp. Shale, brown, carbonaceous, papery; trace 

273-290, 1910. Thiessen, Reinhardt, and White, David, The origin of of oiL _____________________________ _ _ coal: U. S. Bur. Mines Bull. 38; pp. 199-203, 1913; Origin of certain oil S 

shales: Econ. Geology, vol. 16, pp. 289-300, 1921. White, David, Late hale, gray to light brown, flaky---------

theories regarding the origin of oil: Geol. Soc. America Bull., vol. 28, Shale, chocolate-brown, carbonaceous; trace p. 730,1917. I of oiL ______________________________ _ 

6 

3 

6 

8 

5 6 

5 6 

31 

3 6-
102 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

Shale, gray, flaky----- _________________ _ 

Sandstone, buff., cross-bedded, medium 

grained _____________________________ _ 

Shale, brownish gray, papery; contains 

many humified plant fragments _______ _ 

Sandstone, buff, cross-bedded; upper 3 feet 

platy with shaly partings _____________ _ 

Shale, dark brown, papery, brittle, carbonaceous; contains abundant humified 

plant fragments _____________________ _ 

Wasatch formation. 

Locality 2, sec. 15, T. 12 N., R. 102 W. 

Sandstone, brown, cross-bedded, very 

coarse grained, locally conglomeratic, 

carrying red and brown quartzite 

boulders as much as 5 inches in diameter __ 

Sandstone, hard, gray; irregular thin bedding _______________________________ _ 

Sandstone, light gray, cross-bedded, medium 

to coarse grained ____________________ _ 

Sandstone, gray, very hard, thin bedded, fine grained _________________________ _ 

Interval concealed, probably fine-grained 

lumpy sandstone ____________________ _ 

Sandstone, cross-bedded, from medium 

grained to conglomeratic _____________ _ 

Sandstone, hard, fine grained ___________ _ 

Sandstone, brown, massive, coarse grained __ 

Sandstone, hard, massive, fine grained ___ _ 

Sandstone, massive, coarse grained; carries a few pebbles ____________________ · ___ _ 

Shale, hard, sandy, interbedded with thinbedded sandstone ____________________ _ 

Sandstone, platy, interbedded with thin, 

hard, impure limestones ______________ _ 

Sandstone, hard, platy, very fine grained __ 

Sandstone, gray, soft, thin bedded to cross- bedded, medium grained _____________ _ 

Sandstone, greenish gray, hard, irregularly 

bedded; contains numerous soft white 

specks _____________________________ _ 

Sandstone, buff, massive, fine. grained ____ _ 

Sandstone, greenish gray, hard, irregularly 

bedded; contains numerous soft white specks __________________ ___________ _ 

Sandstone, gray, cross-bedded, in part con- glomeratic __________________________ _ 

Sandstone, thin bedded, fine grained, interbedded with hard brown low-grade oil shale _________________ ___________ _ 

Sandstone, basal 3 feet conglomeratic, 

carrying pebbles of white quartz, hard 

shale, red and gray chert, and limestone; 

remainder fine grained and irregularly thin bedded _________________________ _ 

Shale, very low-~rade oil shale, interbedded 

with numerous fine-grained platy sandstones _____________________________ _ 

Sandstone, brown, slightly cross-bedded; 

carries subangular- white and pink 

quartzite pebbles ____________________ _ 

Ft. 

3 

24 

19 

56 

227 

15+ 

2 

2 

7 

7 

3 

4 

2 

10 

2 

24 

6 

4 

5 

5 

11 

9 

8 

22 

6 

12 

in. 

Sandstone, blue-gray, soft, fine grained ___ _ 

Sandstone, light gray, very coarse grained, 

10 locally cross-bedded and conglomeratic __ 

Sandstone, massive to platy, medium to 

fine grained _________________________ _ 

Shale, sandy, platy ____________________ _ 

Sandstone, greenish gray, massive, sugary 

textured, medium grained ____________ _ 

Shale, sandy, interbedded with thin-bedded 

medium-grained sandstone ____________ _ 

Shale, hard, brown; low-grade oil shale; 

contains small limy concretions ________ -

Sandstone, soft, medium to coarse grained 

and slightly cross-bedded; several 6-inch 

partings of hard shale ________________ _ 

Shale, laminated to lumpy; contains sandy lenses ______________________________ _ 

Sandstone, reddish brown, massive, medium 

6 grained _________________ ____________ _ 

Shale, greenish gray, hard, lumpy _______ _ 

Shale, hard, brown; low-grade oil shale; 

weathers blue-gray_~ __ ---------------

6 Sandstone, soft, medium to coarse grained __ 

Sandstone, thin bedded; interbedded with 

shale _______________________________ _ 

Sandstone, brown, medium grained _____ _ _ 

Shale, dark brown, laminated; low-grade 

oil shale _______________________ -_---_ 

6 Sandstone, brown, coarse grained _______ ;.._ 

Shale, hard, brown, massive; low-grade oil 

shale ____________________ . ____________ . 

Sandstone, brown, medium grained ______ _ 

Shale, chocolate-brown, hard, massive; lowgrade oil shale ________ ..:. _____________ _ 

-Sandstone, red-brown, massive to thin 

bedded, medium to fine grained; carries 

leaf impressions; numerous thin partings 

of sandy shale _______________ ___ _____ _ 

Shale, sandy, gray; few thin platy sandstones ______________________________ _ 

Shale, brown, papery; few thin sandstones; 

trace of oiL _________________________ _ 

6 Concretionary zone; probably calcareous 

alga reef ____________________________ _ 

Sandstone, soft, coarse grained, cross-bedded; 

lower part sandy clay shale ___________ _ 

Sandstone, brqwn, thin bedded, fine grained 

Clay shale, hard, gray _________________ _ 

Sandstone, brown, soft and friable, coarse 

6 

grained _____________________________ _ 

Clay shale, blue-gray ____ ---- ___ -----_--

Shale, papery; low-grade oil shale _______ _ 

Clay shale, sandy, hard and lumpy ______ _ 

Shale, brown, papery; low-grade oil shale __ 

Clay shale, gray; few thin sandstones ___ _ _ 

Shale, chocolate-brown, papery; low-grade oil shale ______________________ ~ _____ _ 

Sandstone, "limy; full of Goniobasis shells __ 

Gray and maroon clay shale of Wasatch 

formation. 

Ft. in 

9 

10 

7 

6 

3 6 

4 6 

5 

24 

2 3 

2 6 

2 6 

3 

4 

5 

15 

69 

14 

11 

2 

30 

4 

9 

18 

15 

10 

18 

11 

5 

17 

509+ 

9 

3 

8 

10 

8 

2 
W ASAXCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 103 

Locality 3, sees. 27 and 28, T. 12 N., R. 99 w. 

Red and green clay shale and sandstone of 

the Cathedral Bluffs tongue of Wasatch 

formation. 

Shale, greenish gray; upper part clayey; 

lower part laminated low-grade oil shale_ 

Sandstone, brown, soft, thin bedded, fine 

grained; ripple-marked at top _________ _ 

Shale, greenish gray, hard, laminated ____ _ 

Sandstone, brown, thin bedded, fine grained, 

interbedded with sandy shale _________ _ 

Shale, sandy, hard _____________________ _ 

Sandstone, light gray, soft, thin bedded, 

interbedded with sandy shale _________ _ 

Shale, hard and sandy, interbedded with 

thin fine-grained micaceous sandstones __ 

Sandstone, brown, hard, medium grained, 

in part cross-bedded; abundant mica 

flakes _________ ________ _____________ _ 

Sandstone and interbedded bluish-gray 

shale; both micaceous ________________ _ 

Zone of hard brown sandy concretions ___ _ 

Sandstone, dark gray, much cross-bedded, 

fine grained; distinct parting planes of 

mica flakes _________________ ________ _ 

Shale, light gray; few thin micaceous sandy lenses ______________________________ _ 

Alga reef, calcareous ___________________ _ 

Shale, hard, dark gray, papery; low-grade oil shale __________ __________________ _ 

Sandstone, buff, medium grained; numerous 

partings of hard sandy shale ___________ _ 

Sandstone, buff, very thin bedded _______ _ 

Shale, dark gray, papery; trace of oiL ___ _ 

Shale, sandy, interbedded with irregular 

thin sandstones _____________________ _ 

Shale, hard, sandy, interbedded with hard 

light-gray shale that shows trace of oiL_ 

Shale, sandy, and thin sandstone ________ _ 

Shale, bluish gray, hard, flaky; shows trace 

of oil _____________________________ _ _ 

Shale, sandy, and thin sandstones ___ ____ _ Clay shale, sandy ______________________ _ 

Sandstone, brown, medium grained, irregu- larly bedded ______________________ __ _ 

Shale, gray-green, hard; trace of oil; few 

thin lenses of very fine sand __________ _ 

Sandstone, brown, soft, fine grained, mas- sive, micaceous ______________________ _ 

Shale, bluish gray, sandy _______________ _ 

Sandstone, buff, soft, medium to coarse grained, massive, micaceous ___________ _ 

Shale, gray, hard, sandy; few thin sandstone lenses; carries a few plant frag- ments ______________________________ _ 

Sandstone, drab, soft, medium grained, mi- caceous _____________________ _______ _ 

Shale, dark gray, sandy, fissile __________ _ 

Ft. in. Sandstone, coarse grained, thin bedded ___ _ 

14 

4 

2 

6 

6 

3 

6 

8 

1 

10 

2 

5 

1 

2 

2 

1 

1 

6 

2 

2 

7 

9 

6 

Shale, sandy, interbedded with thin sandstones; both carry abundant mica flakes __ 

Sandstone, white, very friable, coarse grained ____________________________ _ 

Shale, dark gray, fissile _________________ _ 

Shale, dark brown, papery; tough; low-grade oil shale ____________________________ _ 

Shale, sandy, and thin sandstones _______ _ 

Sandstone, white, friable, medium grained, 

micaceous _________ ~ ________________ _ 

7 Shale, dark chocolate-brown, soft ________ _ 

Shale, sandy, and thin soft sandstones ___ _ 

Sandstone, white, very soft and sugary, medium grained, micaceous ______________ _ 

2 Sandstone, dark reddish brown, hard, coarse grained, cross-bedded ________________ _ 

Sandstone, buff, massive, fine grained ____ _ 

8 Sandstone, dark brown, much cross-bedded, 

medium grained _____________________ _ 

Clay shale, light brown _________________ _ 

8 Sandstone, buff, soft, coarse grained _____ _ 

Shale, sandy _____ 7" ___________________ _ 

Sandstone·, brown, irregularly bedded, fine 

grained ______________________ ______ _ 

Shale, gray, soft, flaky ___________ ______ _ 

Shale, very dark brown, hard, tough (sample IV-53; 7.5 gallons) _______________ _ 

Shale, gray to brownish, flaky ___________ _ 

6 Shale, dark chocolate-brown, papery; lowgrade oil shale _______________________ _ 

6 Clay shale, greenish gray, sandy _________ _ 

4 Shale, dArk brown to nearly black, papery; 

5 low-grade oil shale ____________ ______ _ 

Limestone, hard, shaly ___________ ______ _ 

3 Shale, dark chocolate-brown, papery, somewhat carbonaceous; low-grade oil shale __ Clay shale ____________________________ _ 

6 Concealed, apparently sandy shale ______ _ 

Sandstone, fine grained, thin bedded _____ _ 

6 Clay shale, light gray __________________ _ 

10 Limestone, hard, shaly ________________ _ 

8 Shale, chocolate-brown, papery, tough; lowgrade oil shale ______________________ _ 

7 Shale, greenish gray, sandy, flaky _______ _ 

Shale, dark brown, papery, flexible laminae; 

6 low-grade oil shale ___________________ _ 

Shale, sandy, flaky ____________________ _ 

Shale, dark brown, papery; low-grade oil 

6 shale __________________________ ____ _ 

Clay shale, sandy, and thin sandstones ___ _ 

Shale, nearly black, papery; low-grade oil 

shale _______________________________ _ 

Silicified bed of small Goniobasis shells ____ _ 

Sandstone, gray, medium grained, thin bedFt. in. 

2 

8 

5 

6 

9 6 

2 

6 6 

1 4 

6 6 

8 

2 6 

6 

2 

3 

2 

10 

5 

14 

8 

M 

15 

18 

6 

40 

5 

6 

6 

6 

10 

6 

4 8 

4 

6 

4 

14 

4 

32 

4 

2 

1 6 ded; carries a few larger Goniobasis shells_ 

10 Wasatch fm;mation, main body. ----

388 4 
104 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

Sections of Laney shale member of Green River formation 

in Moffat County, Colo., and Sweetwater County, lVyo. Clay shale, light gray; contains waterLocality 4, sees. 22 and 27, T. 10 N., R. 100 W. 

Sandstone, limestone, and clay shale of 

Bridger formation. 

Sandstone, greenish brown, medium to 

coarse grained, micaceous, cross-bedded __ Clay shale, sandy ______________________ _ 

Sandstone, greenish brown, medium grained, 

cross-bedded ________________________ _ 

Sandstone, greenish brown, medium grained, platy ______________________________ _ 

Clay shale, sandy ______________________ _ 

Shell marl, largely Goniobasis shells ______ _ 

Clay shale, greenish gray _______________ _ 

Sandstone, dark brown, medium grained, 

crudely bedded ______________________ _ 

Clay shale, gray _______________________ _ 

Sandstone, brown, medium grained ______ _ 

Clay shale, greenish gray, hard __________ _ 

Sandstone, brown, platy ________________ _ 

Clay shale, gray _______________________ _ 

Sandstone, hard, limy, medium grained; 

carries Goniobasis shells ______________ _ 

Clay shale, sandy ______________________ _ 

Sandstone, dark brown, platy ___________ _ 

Alga reef, calcareous; some calcareous 

shale _______________________________ _ 

Clay shale, gray _______________________ _ 

Sandstone, gray, fine grained ____________ _ 

Clay shale, greenish gray _______________ _ 

Sandstone, brown, shaly ________________ _ 

Limestone, shaly, buff __________________ _ 

Shale, brown, flaky ____________________ _ 

Shale, hard, limy ______________________ _ 

Shale, buff, blocky _____________________ _ 

Sandstone, light gray, sugary textured, 

medium grained, friable, massive ______ _ 

Clay shale, sandy, pale green ___________ _ 

Sandstone, greenish gray, fine grained ____ _ 

Clay shale, greenish gray _______________ _ 

Sandstone, gray, medium grained ________ _ 

Clay shale, greenish gray _______________ _ 

Shale, calcareous, platy ________________ _ 

Clay shale, gray _______________ .:. _____ ~ __ 

Shale, calcareous, platy"'"---------------- Clay shale, gray _______________________ _ 

Shale, calcareous, hard, platy ____ _______ _ 

Clay shale, gray; contains lenses of loose 

fine to coarse sand ___________________ _ 

Limestone, buff, shaly, hard, blocky _____ _ 

Shale, yellowish brown, lumpy __________ _ 

Limestone, brown, hard, impure, in part crystalline __________________________ _ 

Shale, gray to brown, platy and flaky ____ _ 

Sandstone, light gray, friable, medium to coarse grained _______________________ _ 

Clay shale, greenish gray, lumpy and 

flaky _______________________________ _ 

Limestone, shaly, buff, hard, blocky _____ _ 

Clay shale; contains water-rounded clay balls _______________________________ _ 

Shale, buff, hard, platy _________________ _ 

Ft. 

1 

7 

2 

3 

7 

1 

5 

9 

11 

5 

1 

2 

21 

4 

8 

20 

1 

2 

15 

22 

7 

2 

8 

1 

6 

10 

1 

4 

1 

4 

21 

1 

12 

7 

1 

1 

rounded clay balls ____________________ · 

Marl, shaly; irregular bedding; carries pelecypod shells ________________________ _ 

in. 

Alga reef, calcareous, in part silicified; 

carries some oolites ________________ · __ _ 

6 Clay shale, greenish gray, lumpy ________ _ 

2 

Sandstone, very friable, very fine grained __ 

Shale, carbonaceous; partly humified plant 

remains abundant_ __________________ _ 

Shale, gray, flaky and lumpy ____________ _ 

6 Shale, calcareous, hard, platy ___________ _ 

6 Shale, gray-green, flaky ________________ _ 

2 Shale, very carbonaceous _______________ _ 

Clay shale, gray _______________________ _ 

Sandstone, massive, medium grained _____ _ 

8 Sandstone, extremely friable, very fine 

grained _____________________________ _ 

6 Sandstone, medium grained _____________ _ 

6 Sandstone, soft, very fine grained _______ ~_ 

10 Concealed, probably clay shale __________ _ 

Shale, gray, flaky ______________________ _ 

Limestone, shaly, hard, buff ____________ _ 

3 Concealed, probably soft sandstone and 

clay shale __________________________ _ 

8 Shale, buff, hard, platy; trace of oiL _____ _ 

Shale, brown, hard, limy _______________ _ 

6 Clay shale _____________ -- -- ________ _ 

Clay shale, sandy ______________________ _ 

Sandstone, brown, very friable, medium 

6 grained _____________________________ _ 

Clay shale, greenish gray _______________ _ 

Sandstone, gray, fine grained, banded ____ _ 

Shale, brown, carbonaceous; thin shell 

8 marls ______________________________ _ 

Clay shale, sandy; lenses of soft sandstone ______________________________ _ 

Clay shale, gray-green ___ ---------------

Shale, brown to black, carbonaceous _____ _ 

Concealed, probably clay shale __________ _ 

Shiny black, soft, earthy matter; yields some oiL ___________________________ _ 

Concealed, probably clay shale __________ _ 

Clay shale, gray-green, sandy ___________ _ 

Clay shale, gray _______________________ _ 

Shale, papery; poorly exposed ___________ _ 

Shale, dark chocolate-brown, hard, tough 

(sample 0114-A; 10 gallons) __________ _ 

Shell marl, containing flat gastropods, fish 

vertebrae, and bone fragments ________ _ 

10 Shale, limy, brown; carries plant fragments; 

low-grade oil .shale ___________________ _ 

Shale, limy, hard ______________________ _ 

5 Shale, chocolate-brown, hard, tough; lowgrade oil shale ______________________ _ 

Clay shale, gray _______________________ _ 

11 Shale, reddish brown, carbonaceous, very 

fissile; numerous plant fragments ______ _ 

Sandstone, friable, very fine-grained car4 bonaceous partings __________________ _ 

Clay shale, gray _______________________ _ 

10 Shale, brown, platy ____________________ _ 

7 Shell marl; Goniobasis and Unio shells ___ _ 

Ft. in. 

1 8 

8 

1 3 

8 4 

21 

1 8 

6 2 

3 

2 6 

1 

6 

1 6 

15 

1 

2 6 

13 

7 6 

52 

7 

7 

11 

1 

8 

8 

1 4 

2 

3 5 

28 

2 6 

10 

17 

33 

2 

4 

6 

4 

2 7 

3 

19 6 

1 4 

11 4 

1 

8 

1 3 

1 

3 6 

2 1 
WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 105 

Shale, platy; carries ostracodes _________ _ 

Shell marl; Goniobasis shells ____________ _ 

Shale, dark gray; some plant fragments; 

interbedded thin shell marls ____________ _ 

Limestone, shaly, hard _______________ __ _ 

ShaJe, dark-brown, hard; carries ostracodes; low-grade oil shale ____________ _ 

Shell marl, limy; largely ostracodes ______ _ 

Shale, dark brown, hard, platy __________ _ 

Shell marl, sandy; mostly small pelecypods_ 

Shale, gray-brown; plant fragments ______ _ 

Clay shale, dark greenish gray, waxy ____ _ 

Shale, gray-brown, soft, fissile; carries 

ostracodes and fragments of fish teeth __ 

Shale, dark brown, papery ______________ _ 

Limestone, blue-gray, hard, lenticular ____ _ 

Shale, hard, pale green, blocky (sample 

086-A; 4 gallons) ___________________ _ 

Limestone, gray, hard _________________ _ 

Shale, brown, hard, locally papery; lowgrade oil shale __ ____________________ _ 

Limestone, buff, shaly, hard _____ _______ _ 

Shale, brown, hard, platy; some beds are 

low-grade oil shale ___________________ _ 

Sandstone, limy; carries Goniobasis shells_ 

Shale, brown, soft, platy ______ ________ _ _ 

Shale, dark brown, carbonaceous ________ _ 

Sandstone, limy, hard ___________ ______ _ _ 

Shale, dark brown, hard, platy; low-grade oil shale _____________________ _______ _ 

Sandstone, platy ______________________ _ 

Shale, greenish brown, soft_ ___ _________ _ 

Limestone, sandy; carries ostracodes _____ _ 

Shale, brown, soft_ ____________________ _ 

Shale, yellowish brown; abundant plant fragments _______________ __________ _ _ 

Shale, limy, soft, laminated _____________ _ 

Shale, light brown, laminated; low-grade oil shale _____________________ _______ _ 

Shale, gray , flaky ______________________ _ 

Shale, limy, yellow-brown, papery, soft_ __ _ 

Shale, light gray, hard, platy ___________ _ 

Limestone, sandy, crystalline ___________ _ 

Shale, light brown, soft_ _______________ _ 

Shale, limy, yellowish gray, soft; traces of 

oil _________________________ _______ _ 

Limestone, shaly, hard ________________ _ _ 

Shale, gray, flaky ______________________ _ 

Sandstone, yellow, coarse grained _______ _ 

Shale, limy, yellow-brown, platy _______ _ _ 

Limestone, sandy, lenticular ____________ _ 

Clay shale, gray _______________ _______ _ 

Shale, limy, light brown, papery, soft_ ___ _ 

Limestone, buff, shaly, hard ___ _________ _ 

Shale, limy, light yellowish brown, papery __ 

Clay shale, reddish gray _______________ _ 

Alga reef, calcareous; abundant ostracodes_ 

Limestone, oolitic, hard _______ · __ _______ _ 

Shale, limy, yellow brown ______________ _ 

Limestone, gray, hard _________________ _ 

Shale, limy, gray _____________ _________ _ 

Clay shale ____________________________ _ 

Ft. in. 1 

11 Limestone, buff, shaly, hard ____________ _ 

29 

14 

10 

5 

1 

13 

3 

21 

83 

43 

7 

10 

87 

16 

2 

13 

5 

1 

5 

23 

1 

5 

36 

2 

2 

13 

3 

5 

9 

19 

30 

1 

1 

1 Clay shale, light brown ___________ ------

Shale, limy, papery, light brown, soft ____ _ 

Alga reef ( ?) ________ - - - - - - - - - - - - - - - - - - -

6 Sa.ndstone, medium grained _______ ------.. 

Shale, light brown, laminated; trace of oiL 

4 Sandstone, medium grained ______ .:. ______ _ 

6 Limestone, gray, hard _______________ ---

Clay shale, gray ___________ ------------

10 Shale, limy, papery ______________ __ - _---

7 Sandstone, buff, limy, medium to coarse 10 grained ____________________________ _ 

Clay shale, gray ___________ ------------

Shale, limy ; faint bedding _____________ _ 

4 Shale, dark gray, papery; trace of oiL ___ _ 

5 Sandstone, buff, medium to coarse grained; 

carries few small pebbles; locally crossbedded------------------~------------

4 Sandstone, shaly, blocky _______ ________ _ 

Sandstone, buff, soft, friable, coarse grained 

Sandstone, limy, buff, fine grained _______ _ 

5 Shale, greenish, limy ___________________ _ 

Shale, limy, light yellow-brown, laminated_ 

Shale, limy, hard, not laminated _____ ___ _ 

3 Shale, limy, light yellow, papery ________ _ 

Limestone, shaly, lenticular _______ _____ _ 

Shale, sandy and limy; plant fragments __ _ 

3 Clay shale, gray ______________________ _ 

Shale, light brown, papery ______ _______ _ _ 

3 Clay shale, dark gray __________________ _ 

10 Sandstone, buff, fine grained ____________ _ 

Clay shale, gray; grades up into gray 

1 papery shale ________________________ _ 

6 Clay shale of Cathedral Bluffs tongue of 

8

1 Wasatch formation. 

Locality 5, sec. 20, T. 8 N., R. 97 W. 

Top of bluff. 

Sandstone; carries Goniobasis and U nio 

shells. 

6 Sh:a.le and thin sandstones _______ _______ _ 

3 Sandstone, coarse grained ______________ _ 

Shale and thin sandstones ______________ _ 

Shale, limy, buff; trace of oiL ___________ _ 

Shale, carbonaceous and clayey _____ ____ _ 

4 Sandstone, fine grained, thin bedded _____ _ 

1 Shale, carbonaceous and clayey _________ _ 

Shale, limy, hard ______ ________________ _ 

8 Shale, gray, carbonaceous and clayey ____ _ 

Shale, greenish; plant fragments ____ _____ _ 

Limestone, shaly, gray _________________ _ 

1 Cla.y shale, gray _______________________ _ 

9 Shale, limy, hard ______________________ _ 

Shale, light brown, platy; low-grade oil 

shale ______________________________ _ 

Clay shale, sandy; contains thin beds of 

3 coal _____ __________________________ _ 

.5 Sandstone, brown, coarse grained ________ _ 

3 Shale, black, carbonaceous __ _______ ___ __ _ 

2 Shale, limy, soft_ ___ ____________ _______ _ 

3 Shale, brown; some plant fragments _____ _ 

Ft. 

1 

9 

12 

7 

7 

2 

3 

1 

5 

9 

5 

3 

1 

22 

4 

1 

18 

1 

1 

2 

1, 199 

Ft. 

11 

2 

28 

5 

6 

3 

21 

2 

41 

1 

2 

3 

23 

16 

5 

1 

Ill. 

2 

10 

6 

2 

9 

10 

4 

8 

6 

5 

2 

8 

1 

5 

3 

3 

1 

4 

2 

2 

6 

9 

11 

in. 

10 

6 

8 

3 

6 

4 

6 

7 

6 

3 

4 

8 
106 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

Clay shale, gray and pink _______ ,_ ______ _ 

Sandstone, gray, hard, platy, thin bedded __ 

Shale, limy, buff, platy _________________ _ 

Shale, limy, buff, hard; trace of oiL _____ _ 

Shale, gray; lower 48 feet limy; upper part 

low-grade oil shale ___________________ _ 

Shale, brown to black, carbonaceous _____ _ Shale, sandy, gray _____________________ _ 

Sandstone, fine to medium grained_ ·- ____ _ 

Shale, sandy, hard _____________________ _ 

Shale, limy, hard, buff _________________ _ 

Sandstone, gray, fine grained ___________ _ 

Shale, sandy, fissile _________________ .,. __ _ 

Shale, carbonaceous ___________________ _ 

Shale, limy _______________ ~ __ _________ _ 

Shale, gray, hard; low-grade oil shale __ __ _ 

Shale, gray, soft; trace of oiL ___________ _ 

Shale, brown, hard; low-grade oil shale ___ _ 

Shale, limy, hard, barren _______________ _ 

Shale, brown, laminated; low-grade oil 

shale _______________________________ _ 

Shale, very limy, brown; low-grade oil shale 

Shale, limy, hard, barren _______________ _ 

Shale, limy, hard (not sam- (sample 1- Shale, brown, laminated, hard_} · 1 ~ 

Sh~~:~;;~;~~~~~i~~t~d~ h~;d~ :~~~!~~· 5 

Shale, limy, hard, barren _______________ _ 

Shale, gray to brown, hard, laminated; lowgrade oil shale ______________________ _ 

Limestone, shaly, buff, hard ____________ _ 

Shale, gray to brown, hard, laminated; lowgrade oil shale ______________________ _ 

Limestone, shaly, buff, hard ____________ _ 

Shale, brown; weathers papery; low-grade oil shale ____________________________ _ 

Shale, black, carbonaceous ____ -'- ________ _ 

Shell marl, silicified ____________________ _ 

· Sandstone, gray, hard, fine grained ______ _ 

Shale, pia ty, silicified __________________ _ 

Shale, brown, fis'sile; low-grade oil shale __ _ Shale, silicified ________________________ _ 

Shale, gray, fissile _____________________ _ 

Shale, limy, hard ______________________ _ 

Shale, dark brown, hard, tough; low-grade 

oil shale __ ~ _________________________ _ 

Shale, silicified ________________________ _ 

Shale, gray to brown; low-grade oil shale __ _ 

Shale, limy, hard ______________________ _ 

Shale, dark brown, hard, platy; low-grade oil shale ____________________________ _ 

Limestone, silicified ____________________ _ 

Shale, brown to buff; trace of oiL _______ _ 

Clay shale, greenish ___________________ _ 

Shale, gray, soft_ _______________ "" ______ _ 

Shale, dark gray, hard; low~grade oil shale_ 

Shale, gray, hard, blocky; trace of oil; interbedded with few thin hard shaly limestones ______________________________ _ 

.Shale, gray, papery; limy shale interbedded_ 

·Clay shale, greenish, waxy---------------

Shale, limy, yellow, hard _______________ _ 

.Shale, light brown, laminated ___________ _ 

Ft. 

12 

4 

41 

6 

61 

4 

9 

2 

3 

4 

1 

3 

20 

52 

79 

8 

1 

3 

15 

2 

9 

1 

1 

1 

25 

1 

13 

14 

2 

8 

8 

4 

5 

1 

8 

in. 

4 Limestone, shaly, hard, buff ____________ _ 

7 Shale, gray to buff, hard, platy to papery; 

some beds of low-grade oil shale _______ _ 

Shale, dark gray; fragments of shells; will 

probably yield some oiL _____________ _ 

6 Shale, black, soft ______________________ _ 

6 Clay shale(?), soft, yellow, waxy ____ _: ___ _ 

5 Shale, gray, soft---------------~-------

6 Limestone, shaly, gray, hard ____________ _ 

Shale, gray, sandy and limy, flaky _______ _ 

7 Sandstone and sandy shale, thin bedded __ _ 6 Shale, limy ___________________________ _ 

8 Sandstone, thick bedded to massive ____ ;.. __ 

1 Shale, limy, platy __ _: __________________ _ 

6 Sandstone, irregularly thin bedded to mas- sive ___________________ ____________ _ 

6 Shale, gray, papery ____________________ _ 

10 Sandstone (base of Green River) ___ _____ _ 

3 

8 

6 

8 

Locality 6, sec. 3, T. 13 N., R. 99 W. 

[According to Schultz.27] 

Top of bluff. 

Sandstone, coarse grained, not massive ___ _ 

6 Sandstone, containing fossil shells _______ _ 

2 Sandstone, coarse grained, thin bedded ___ _ 

10 Covered, probably sandy shale __________ _ Sandstone, coarse ______________________ _ 

10 Covered, mostly shale __________________ _ 

5 Shale, papery, drab, lean _______________ _ 

Shale, thin, barren, and sandstone _______ _ 

8 Shale, drab, thin, lean __________________ _ 

3 Shale, thin, drab, barren _______________ _ 

Shale,thin,lean ______ ~------ -----------

2 Sandstone, concretionary _______________ _ 

2 Shale, thin, lean _______________________ _ 

2 Oolite and chert. 

2 Shale, thin bedded, lean ________________ _ 

8 Shale, thin bedded; weathers 

3 

blue; rich ________________ _ 

7 Shale, gray, sandy (not in1 d d . 1 ) (sample1; 

2 c u e m samp e ----------

6 Sandstone, yellow (not in- 30 gal- lons.) eluded in sample) _________ _ 

4 Shale, thin bedded; weathers 

2 blue; rich ________________ _ 

11 Shale, yellow, sandy ___________________ _ 

5 Shale, papery, lean ____________________ _ 

Shale, drab, fissile _____________ 7 _______ _ 

10 Sandstone, concretionary _______________ _ 

5 Shale, drab, 'papery (over 15 gallons) ____ _ Oolite ____ ____________________________ _ 

2 Shale, drab, papery (over 15 gallons) _____ _ 

Sandstone, oolitic ______________________ _ 

3 Shale, drab, fissile _____________________ _ 

Sandstone, micaceous ___________________ . 

Sandstone, yellowish ___ . __ .:. _____________ _ 

4 Shale, drab; thin sandstone lenses _______ _ 

Sandstone, shaly, yellowish_ :- ___________ _ 

Ft. in· 

4 

83 6 

2 

8 1 

2 

4 

1 

1 8 

33 6 

27 

38 4 

14 2 

6 8 

4 4 

11 

814 3 

Ft. in. 

50 

10 

35 

8 

30 

5 

72 

3 

20 

30 

1 

14 

4 

14 6 

2 

1 7 

1 

3 

28 

40 

10 

1 

13 

10 

6 

4 

12 6 

1 

3 

26 

1 

2 

9 

27 Schultz, A. R., Oil possibilities in and around Baxter Basin, in the 

Rock Springs uplift, Sweetwater County, Wyo.: U. S. Geol. Survey 

Bull. 702, p. 54, 1920. 
WASATCH AND GREEN RIVER FORMATIONS IN COLORADO AND WYOMING. 

Shale, drab, papery, barren _____________ _ 

Sandstone, shaly; yellowish _____________ _ 

Shale, greenish drab ___________________ _ 

Cathedral Bluffs tongue of Wasatch formation. 

Locality 7, sees. 17 and 19, T. 17 N •• R.106 W. 

[According to Winchester.2SJ 

Sandstone, massive, brown, coarse ("Tower 

sandstone" of Powell) ________________ _ 

Sandstone, thin bedded ________________ _ 

Sha~e, papery, gray ____________________ _ 

Sandstone, shaly, gray _________________ _ 

Shale, sandy, lean _____________________ _ 

Shale, hard; contains fish remains (sample 

120; 14 gallons) _____________________ _ 

Shale, lean ____________________________ _ 

Shale, thin, with lenses of very rich waxy 

shale _______ ~--~--------------------- Shale, hard ___________________________ _ 

Shale, hard (sample 119; 12 gallons) _____ _ Shale, hard, lean ______________________ _ 

Shale, gray, sandy _____________________ _ 

Shale, hard, rich (more than 15 gallons) __ _ 

Shale, gray, sandy, thin sandstones, and a 

few 1 to 3 inch beds of rich shale ______ _ 

Shale, hard, thin, medium rich __________ _ 

Shale, barren _________________________ _ 

Shale, medium, with large gypsum crystals_ Shale, thin, barren _____________________ _ 

Shale, medium, with gypsum crystals _____ _ Shale, gray, sandy _____________________ _ 

Shale, medium, with gypsum crystals ____ _ 

Shale, hard, rich (over 15 gallons) _______ _ 

Sandstone, thin, gray __________________ _ 

Shale, hard, rich (over 15 gallons) _______ _ Shale, gray, sandy _____________________ _ 

Shale, hard, rich (over 15 gallons) _______ _ 

Shale, thin, gray, sandy ________________ _ 

Ft. 

5 

1 

37 

489 

in.[ . Shale, hard, nch (over 15 gal~ons) _______ _ 6 Shale, sandy __________________________ _ 

Sandstone, graY-----------------~------ Shale, sandy, greenish __________________ _ 

Sandstone, gray, thin bedded ___________ _ 

4 Shale, sandy, green ____________________ _ 

Shale, sandy, thin bedded, gray _________ _ 

Sandstone and shale, green, in · beds 2 feet 

Ft. in. thick; sandstone concretionary ____ ____ _ 

125 

35 

25 

32 

65 

5 

20 

55 

15 

5 

12 

20 

1 

90 

1 

15 

1 

80 

26 

1 

8 

17 

9 

Shale, sandy, gray, slope _______________ _ 

Sandstone, massive, cross-bedded, forming 

ledge and capping hill ________________ _ 

Shale, forming slope __ ------------------

Sandstone, rather massive, forming ledge __ _ 

Shale, soft, thin, platy, barren __________ _ 

Shale, medium hard, rather thin, very lean_ 

Shale, medium hard (sample 116; 4 gallons)_ 

Shale, sandy, lean to barren ____________ _ 

Shale, medium hard, very lean __________ _ Shale, lean ____________________________ _ 

Sandstone, brown, persistent_ __ ~ ________ _ Shale, lean ____________________________ _ 

Shale, hard to mediu.m hard (sample 115; 9 

gallons) __________________ ------------

4 Shale, lean to barren ____________ _- ______ _ 

Shaly sandstone, barren ________________ _ 

Shale, sandy, forming slope, lean ________ _ 

6 Shale, hard (sample 114, lower 4! feet; 11 

gallons) ____________________________ _ 

6 Shale, hard (sample 113; 10 gallons) _____ _ 

Shale, hard ________________ } { 

8 Sandstone _________________ (sample 112; 

Shale, fairly soft, thin bedded_ 9 gallons)__ · 

6 Shale, hard __________ ------

10 Shale, hard, rich (sample 111; 19 gallons) __ _ 

Shale, hard, rich (sample 110; 19 gallons) __ _ 10 Shale, soft _________________ } { 

2 Shale, hard, rich ____________ (sample 109; 

2 Shale, soft _____________ -- - - 11 gallons)_ 

Shale, hard, rich ______ _____ _ 

2s Winchester, D. E., Oil shale of the Rocky Mountain region : U.S. 

Geol. Survey Bull. 729, pp. 124, 125, 1923. 

107 

Ft. in. 

10 

118 

4 

6 

1 

27 

21 

58 

97 

5 

43 

10 

30 

4 11 

4 10 

70 

10 

4 6 

8 

3 6 

4 6 

75± 

15 

47 

5 6 

5 3 

1 4 

3 

2 9 

1 

5 4 

6 3 

7 

2 5 

6 

2 3 

1, 360 ±