Results of Geologic Exploration 

By Core Drilling, 1953 

Land-Pebble Phosphate District 

Florida

GEOLOGICAL SURVEY BULLETIN 1046-K

This report concerns work done on behalf 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission

Results of Geologic Exploration 

By Core Drilling, 1953 

Land-Pebble Phosphate District 

Florida

By JAMES B. CATHCART and LAWRENCE J. McGREEVY

CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

GEOLOGICAL SURVEY BULLETIN 1046-K

This report concerns work done on behalf, 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission

UNITED STATES GOVERNMENT PRINTING OFFICE ,WASHINGTON : 1959
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

The D. S. Geological Survey Library has cataloged this publication as follows:

Cathcart, James Bachelder, 1917-

Results of geologic exploration by core drilling, 1953, 

land-pebble phosphate district, Florida, by James B. Cathcart and Lawrence J. McGreevy. Washington, U. S. Govt. 

Print. Off., 1959.

iv, 221-298 p. map, col. diagr., profiles, tables. 23 cm. (U. S. 

Geological Survey. Bulletin 1046-K. Contributions to the geology of 

uranium)

"Work done on behalf of the U. S. Atomic Energy Commission."

Part of illustrative matter in pocket.

Bibliography: p. 267-268.

1. Borings Florida. 2. Mines and minerals resources Florida, 

i. McGreevy, Lawrence J., joint author, u. Title: Land-pebble phosphate district, Florida. (Series: U. S. Geological Survey. Bulletin 1046-K. Series: U. S. Geological Survey. Contributions to the geology of uranium)

557.59

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

Washington 25, D. C.
CONTENTS

	Page

Abstract______________________________________.__ 221

Introduction. ___________________________________________________ 222

General geology _______________________________________________ 224

Stratigraphy_____________________________________ 225

Eocene series._______________________________________________ 225

Ocala limestone.._________________________________________ 225

Oligocene series.______________________________________________ 226

Suwannee limestone______________________________________ 226

Miocene series._______________________________________________ 228

Tampa limestone________________________________________ 228

Hawthorn formation_______________________________________ 229

Unnamed sand and limestone-______________________________ 231

Pliocene(?) series._______________________________ 233

Alachua(?) formation...___________________________ 233

Pliocene series__________________________________________ 234

Bone Valley formation_____________________________________ 234

Pleistocene and Recent series____________________..______________ 235

Terrace sand and other surficial deposits.______________________ 235

Mineralogy.____________________________________________________ 235

Chemistry_______________________________________ 236

Weathering_______________________________________ 238

Economic geology.________________________________________________ 240

Calcium phosphate zone________________________________________ 240

Aluminum phosphate zone______________________________________ 241

General relations.___________________________________________ 242

Suggestions for exploration.________________________________________ 243

Discussion of cross sections_________________________________________ 244

Cross section !________________________________________________ 244

Cross section 2________________________________________________ 246

Cross section 3__-___-_____-____-__--________________________ 247

Cross section 4________________________________________________ 248

Cross section 5_____________________________-_-________________ 249

Cross section 6________-_______________________________________ 250

Cross section 7___________-_-_____________________-____________ 251

Cross section 8________________________________________________ 252

Cross section 9______-_______________________________________ 253

Cross section 10-_________-_-__--_______________-___________-__ 254

Cross section 11________________________.______________________ 256

Cross section 12_______________________________________________ 257

Cross section 13___________--__--_______.___-_-_._______-____ 259

Cross section 14___________________________________________ 260

Cross section 15-_________--__-__----__-____-_-____________ 261

Cross section 16___-______-____________________________________ 263

Cross section l7-____-__-____-__________________________-______ 264

Cross section 18_______________________________________________ 265

m
IV CONTENTS

Page

Tonnage calculations_____________________________________________ 266

Aluminum phosphate zone______________________________________ 266

Calcium phosphate zone (matrix)_______________________________ 266

References cited__-________________________________________________ 267

Basic data_______________.____________________ 269

Analytical and screen data for cross sections 1-18________________ 271

Tonnage computations for cross sections l-18_____-__________-____ 287

Index._________________.___________________________ 297

ILLUSTRATIONS

[All plates in map case]

PLATE 16. Cross section 1.

17. Cross section 2.

18. Cross section 3.

19. Cross section 4.

20. Cross section 5.

21. Cross section 6.

22. Cross section 7.

23. Cross section 8.

24. Cross section 9.

25. Cross section 10.

26. Cross section 11.

27. Cross section 12.

28. Cross section 13.

29. Cross section 14.

30. Cross section 15.

31. Cross section 16.

32. Cross section 17.

33. Cross section 18.

34. Isometric fence diagram, land-pebble phosphate district,

Florida. Page

FIGURK 26. Index map of the land-pebble phosphate district, Florida.___ 223
CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

RESULTS OF GEOLOGIC EXPLORATION BY CORE

DRILLING, 1953, LAND-PEBBLE PHOSPHATE

DISTRICT, FLORIDA

By JAMES B. CATHCART and LAWRENCE J. McGREEVY

ABSTRACT

A program of core drilling to delimit the uranium- and phosphate-bearing 

strata (the aluminum and calcium phosphate zones) of the land-pebble phosphate 

district, and to study the stratigraphic relations of the Bone Valley formation, 

was carried out in the fall of 1953.

A series of cross sections, an isometric fence diagram, and a series of tables 

summarize the lithologic, stratigraphic, analytical, and economic data derived 

from the drilling.

The Bone Valley formation of Pliocene age was deposited by a transgressing 

sea. In most of the district, the Bone Valley overlies limestone or dolomite 

of the Hawthorn formation (middle Miocene) ; but in the northern part of the 

district in northern Polk County, where the Hawthorn thins to an erosional 

featheredge, the Bone Valley overlies the Tampa formation (early Miocene), 

and farther to the north, in Pasco County, clayey sand of the upper part of the 

Bone Valley overlies the Suwannee limestone (Oligocene). To the east and 

south, however, the Bone Valley overlies unnamed sand and limestone that 

contains fossils of late middle Miocene age. This material in turn overlies the 

limestone or dolomite of the Hawthorn formation.

In the northernmost line of holes drilled, material correlated with the upper 

part of the Bone Valley on the basis of lithologic character overlies a sandy clay 

that contains angular white phosphate particles, material very similar to the 

hard-rock phosphate. It is thought that this material, here called Alachua (?) 

formation, may represent the Alachua formation. It appears, therefore, that 

the Bone Valley is in part equivalent to the Alachua formation, but that a part 

of the Bone Valley formation may be somewhat younger than the Alachua. 

Three holes in the northeast part of the area penetrated the Ocala limestone 

(Eocene). Indications are that this limestone may occupy an upthrown fault 

block.

After the deposition of the Bone Valley, weathering altered the formation, 

changing fluorapatite to wavellite and crandallite (pseudo-wavellite), and forming the aluminum phosphate zone.

In the northwestern part of the land-pebble district, the aluminum phosphate 

zone extends beyond the limits of the calcium phosphate zone. To the east 

and south, the calcium phosphate zone extends beyond the limits of the aluminum

221
222 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

phosphate zone. In the northern part of the area where the phosphate deposition 

was thinnest the entire Bone Valley formation may have been leached, whereas 

to the south, where the formation was thicker, only the top part of the formation 

was leached, and both zones are present. Still farther to the south, in Hardee 

and Manatee Counties, the Bone Valley formation may not have been exposed 

to subaerial weathering, and the aluminum phosphate zone was not formed. 

The present limit of the aluminum phosphate zone is the result of a combination 

of erosion after the zone was formed, and the possibility that to the east and 

south, phosphatic sediments were not exposed to weathering in the Pliocene. 

The aluminum phosphate zone and the calcium phosphate zone both cut across 

stratigraphic units. This is clearly shown in some of the cross sections where, 

for example, aluminum phosphate minerals have formed in the Bone Valley, 

the Hawthorn, and the Tampa formations. The calcium phosphate zone may 

be entirely within the Bone Valley formation, entirely within the Hawthorn 

formation, or most commonly, it includes the bottom part of the Bone Valley, 

and the weathered top of the Hawthorn formation. The phosphate deposits of 

the land-pebble district are thus complex partly residual, partly marine reworked, and partly phosphatized clay.

INTRODUCTION

The land-pebble phosphate district is located in west-central peninsular Florida between 27°00' and 28°15' north latitude and 81°45' 

and 82°15' west longitude. The district is divided on the basis of 

phosphate content and tonnage into a northern, high-grade part, 

which is in Polk and Hillsborough Counties, and a southern, lower 

grade part, which is in Hardee and Manatee Counties (fig. 26).

A program of core drilling to delimit the uranium- and phosphatebearing strata of the Bone Valley formation, and to study the stratigraphic relations of the Bone Valley formation was conducted by the 

U. S. Geological Survey on behalf of the Division of Raw Materials 

of the U. S. Atomic Energy Commission. The drilling was done by 

a private firm under contract let by the Atomic Energy Commission. 

A spokelike pattern of lines of drill-hole sites was laid out; the first 

site in each line was selected within the limits of the land-pebble 

phosphate district. Drilling permits from the landowners were obtained under the direction of Emerson C. Willey of the Geological 

Survey. A sampler followed the drilling in the field, checked core 

recovery, and collected chip samples from the core at 1-foot intervals. 

A total of 115 holes aggregating 7,112 feet was drilled from May 26 

to October 21, 1953, with a truck-mounted rotary drill. Heavy drilling mud was used to prevent caving and contamination during coring. 

Average core recovery was 74 percent; losses were noted and are 

shown on the cross sections. Holes with low recovery were redrilled 

to recover enough sample for analytical purposes. All holes were 

cased with 1%-inch inside diameter (ID) cast-iron pipe, and gammaray logs were made. Casing was necessary to prevent caving prior 

to gamma-ray logging.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 223

EXPLANATION

FIGUBE 26. Index map of the land-pebble phosphate district, Florida, showing limits of 

calcium phosphate and aluminum phosphate zones.

Samples corresponding to the high-peak areas on the gamma-ray 

logs were split from most cores for analysis. These samples represent, 

at least in part, the aluminum phosphate zone. Where visual inspection showed abundant phosphate grains, a sample was also taken that 

represented the calcium phosphate zone or "matrix." The sample 

was weighed, then washed over a 14-mesh screen, and the oversize 

retained, dried, and weighed. The undersize was screened on 35- and 

150-mesh screens. The material retained on the 35-mesh screen was
224 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

dried and weighed. If phosphate minerals were present in the 

 35+150-mesh material, it was treated in a laboratory flotation cell to 

separate the quartz sand and phosphate minerals. The material passing the 150-mesh screen (the slime fraction) was dried, weighed, and 

retained. Weight percents of sample fractions were computed from 

the dry weights. Equivalent uranium and, where necessary, chemical 

uranium were determined for all sample splits. The samples highest 

in uranium content were analyzed for P2O5 , CaO, F, and A12O3 .

The drill holes were logged by the following geologists: D. G 

Alverson, W. J. Carr, J. B. Cathcart, K. B. Ketner, L. J. McGreevy, 

and R. G. Petersen of the U. S. Geological Survey. Samples of the 

fossiliferous material were examined by F. Stearns MacNeil of the 

U. S. Geological Survey, and all fossil determinations and age assignments from fossils were made by him.

Studies of the limestone cores from cross sections 1-4: were made 

by W. J. Carr and D. C. Alverson (1953), and the writers have used 

their age assignments for nonfossiliferous limestone in those sections. 

A. M. Coleman and Charlotte Axsell assisted the writers in the 

preparation of the tables and illustrations. All analytical work was 

done in the laboratories of the U. S. Geological Survey. Radioactivity analyses were made by J. Goode and B. McCall under direction of F. Flanagan. Chemical analyses were done by J. Smith, 

W. Tucker, J. Budinsky, L». Jenkins, E. Campbell, I. Barlow, 

R. Smith, S. Bethea, R. Moore, A. Sweeney, T. Murphy, J. Waring, 

and G. Daniels, under direction of I. May.

All the factual data obtained during the drilling are given in tables 

at the end of the report. Mechanical and chemical analyses are given 

for all samples, and tonnage and grade computations are given for 

the aluminum phosphate and calcium phosphate zones.

A series of cross sections, one for each line of drill holes, summarize 

the lithologic, stratigraphic, and economic data. Lithologic correlations, shown in dashed lines, were made from geologists' logs of the 

core, plus the writers' examination of the core chips with the binocular 

microscope. The writers' stratigraphic correlations are shown in solid 

lines, and are based on lithology, except for the few fossiliferous beds. 

The fossil lists and age identifications are given in the text.

The aluminum phosphate and the calcium phosphate zones are delimited by stippled patterns. The delineation of these zones was made 

with the use of the chemical analyses of the samples, and for the 

aluminum phosphate zone, from the high peaks on the gamma-ray 

logs.

GENERAL GEOLOGY

The land-pebble phosphate district is a part of the Gulf Coastal 

Plain, and is underlain by thin, nearly flat-lying formations that dip
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 225

very gently to the south and southeast. King (1951) has pointed 

out that the geology of peninsular Florida differs from that of the 

remainder of the coastal plain in that Florida was a positive, relatively stable area during a large part of middle and late Mesozoic 

and Cenozoic time, and because of its distance from the main part of 

the North American continent, it received relatively small amounts 

of land-derived sediment.

Phosphate deposits in the land-pebble district are part of the Bone 

Valley formation of probable Pliocene age and (or) phosphatebearing sandy clay of the Hawthorn formation. The Bone Valley 

formation was deposited on the eroded surface of the underlying 

phosphatic Hawthorn formation of middle Miocene age, and in the 

northern part of the district, where the Hawthorn formation thins to 

an erosional featheredge, on the Tampa formation of early Miocene 

age. On the fringes of the district (to the north, west, and east), 

drilling penetrated rocks of the Suwannee limestone of Oligocene age 

and the Ocala limestone of Eocene age, and on the northern edges of 

the district, clayey sand, tentatively assigned to the Bone Valley 

formation on the basis of lithologic character, rests on the Suwannee 

limestone.

The Bone Valley formation was deposited by a transgressing sea 

that reworked and partly sorted the residual mantle formed on the 

Hawthorn at the close of the Miocene. After its deposition, the 

upper part of the Bone Valley was deeply weathered. Much of the 

phosphate in this upper zone has been removed, and some of the 

phosphate combined with alumina from clay minerals to form aluminum phosphate minerals. The phosphate deposits of the Bone Valley 

are thus complex partly residual, partly marine reworked, and partly 

phosphatized clay.

The district is covered by a blanket of loose quartz sand of probable 

Pleistocene age. Wind-blown sand, swamp deposits, and bars and 

flood plains of streams are probably Recent.

STRATIGRAPHY

Details of the stratigraphy and local stratigraphic relations, are 

shown on plates 16-33. Stratigraphic relations and the geographic 

distribution of the formations based on core drilling are shown on 

plate 34.

EOCENE SERIES 

OCALA LIMESTONE

The Ocala limestone was named by Dall and Harris (1892, p. 103), 

for the city of Ocala in Marion County. Cooke (1915, p. 117) believed the Ocala was of late Eocene age. Vernon (1951, pp. 111-113)

466352 59 2
226 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

divided the Ocala into his Ocala limestone (restricted) at the top 

and the Moodys Branch formation as used by him at the base. He 

divided the Moodys Branch formation into a lower, his Inglis, member, and an upper, his Williston, member. Because only a few, short 

cores of the Ocala were obtained in the present study, it was not possible to subdivide the Ocala.

The Ocala is a white, cream to yellow very pure limestone, which in 

places contains over 99 percent calcium carbonate. It ranges in thickness from about 50 to almost 400 feet.

Ocala fossils were collected at the following locations:

Cross section 15, hole 5 (SW%SW% sec. 3, T. 27 S., R. 26 E.):

Amusium ocalanum 

Cross section 16, hole la (SWMSWM sec. 21, T. 26 S., R. 25 E.) :

Chlamys sp. cf. C. spillmani

Lepidocyclina ocalana

Tubulostum sp. 

Cross section 16, hole 2 (NW^4NW% sec. 21, T. 26 S., R. 25 E.) :

Lepidocyclina sp. cf. L. pseudomarglnata

The elevation of the Ocala limestone in these holes is about the same 

as the elevation of the Hawthorn formation in adjacent holes. (See 

pis. 30 and 31.) Calcareous clay, assigned to the Hawthorn, overlies 

the Ocala limestone at these drill holes. This indicates that a part of 

the Hawthorn formation, the Tampa limestone and the Suwannee 

limestone, may have been cut out. Thus, the Ocala limestone here 

may occupy an upthrown fault block (see pi. 34). If this is a fault 

block, the age of the faulting is probably pre-Bone Valley, because 

sediments assigned to the Bone Valley are apparently not affected by 

the faulting.

OLIGOCENE SERIES 

SUWANNEE UGMESTONE

The name Suwannee limestone was proposed by Cooke and Mansfield (1936, p. 71) for limestone exposed along the banks of the 

Suwannee Kiver. Cooke (1945, p. 88) says the Suwannee is the 

equivalent of the Chickasawhay limestone of late Oligocene age. 

MacNeil (1947) indicates that the Suwannee limestone is the equivalent of the Byram and the Chickasawhay formations combined, and 

thus includes rocks of middle and late Oligocene age.

The Suwannee limestone is a yellow or cream limestone. It is commonly soft and granular. Small solution holes, filled with green clay, 

probably residual from the limestone, are abundant. In places, the 

lime has been leached from the surface of the limestone, leaving a mass 

of flint. Chemical analyses (Mossom, 1925) show that the Suwannee 

contains between 91 and 98 percent calcium carbonate.

The Suwannee limestone lies unconformably on the Ocala, and is 

unconformably overlain by the Tampa limestone, of early Miocene
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 227

age or by younger rocks. The thickness of the Suwannee limestone 

in the land-pebble district is about 130 feet (MacNeil, oral communication, 1956). 

Suwannee fossils were collected at the following localities:

Cross section 1, hole 4 (SW%NE% sec. 19, T. 27 S., R. 22 E.):

Kuphus incrassatus

Phacoides (Miltha) sp. aff. P. chipolanus

Turritella? n. sp.

sp. aff. T. bowenae 

Cross section 2, hole 4 (NE^SW^sec. 6, T. 28 S., E. 21 E.):

Chlamys sp. cf. G. brooksvillensis

Kuphus incrassatus

Peneroplis sp.

Sorites sp. 

Cross section 17, hole 5 (SW%SW% sec. 8, T. 26 S., R. 23 E.) :

Amauropsisf sp.

Anatina sp.

Chione sp.

Chlamys sp. cf. G. ItrooJcsvillensis

Corbula sp.

Divaricella sp.

Glycymeris suwannensis

Myrtaea gp. cf. M. taylorensis

Orthaulax hernandensis

Pitar sp.

sp. cf. P. heilprini

Turritella halensis

Venus sp. 

Cross section 17, hole 6 (NW%NW% sec. 1, T. 26 S., R. 22 E.) :

Barnea sp.

Cofikinolina floridana

Tritiariafn. sp.

Venus sp. 

Cross section 17, hole 9 (NW%SE*4 sec. 13, T. 25 S., R. 21 E.) :

Asterigina subacula floridensis

Peneroplis sp. 

Cross section 17, hole 10 (SW}iNE% sec. 11, T. 25 S., R. 21 E.) :

Asterigina subacula floridensis

Peneroplis sp.

Sorites sp. 

Cross section 17, hole 11 (NW%SE% sec. 22, T. 24 S., R. 21 E.) :

Sorites sp.

In addition to the fossiliferous limestone, material at the bottom 

of hole 5 of cross section 1, hole 3 of cross section 2, and holes 3, 7, 

and 8 of cross section 17, was tentatively assigned to the Suwannee. 

All of the drill holes that penetrated Suwannee limestone are at the 

north end of the mapped area (pi. 26). In this part of the area, 

the Tampa and Hawthorn formations, which normally overlie the 

Suwannee, are thinning. None of the holes in the south, east, or west
228 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

penetrated the Suwannee limestone, which indicates a general thickening of the younger formations southward.

MIOCENE SERIES 

TAMPA UGMESTONE

The name Tampa formation was first used by Johnson (1888, p. 

235); Cooke and Mossom (1929, p. 78-93) changed the name to 

Tampa limestone. Both Cooke (1945) and MacNeil (1947) put the 

Tampa limestone in the early Miocene.

The limestone of the Tampa is much more variable in composition than either the Suwannee or the Ocala. It is a white to cream 

sandy and clayey limestone, and contains abundant chert fragments 

and very few phosphate nodules. The limestone is interbedded with 

beds of clay and sandy clay, and is often covered with a residual mantle 

of green calcareous clay that contains chert and limestone fragments 

and a few phosphate nodules.

The Tampa limestone lies unconformably on the Suwannee limestone, but the relations between the Tampa and the overlying formations are uncertain. Cooke (194:5, p. 115) indicates that in the northern part of Florida, near the Georgia State line, the contact between 

Tampa limestone and Hawthorn formation is gradational and conformable. Recent work by Carr and Alverson (1953, p. 182) in the 

land-pebble district indicates that the contact between the Tampa and 

the Hawthorn is marked by an erosional interval. According to Mansfield (1937, p. 14) the Tampa limestone is about 65 feet thick near 

Tampa.

Tampa fossils were collected at the following localities:

Cross section 1, hole 3 (NH%SB% sec. 31, T. 27 S., R. 22 E.) :

Helisoma sp.

Cross section 2, hole 3 (SE%SE% sec. 8, T. 28 S., R. 21 E.) (molds and casts in 

siliceous bed at top of calcareous clay) :

Helisoma sp.

Cross section 3, hole 2 (SE%SE% sec. 35, T. 28 S., R. 20 E.) (fossils in limestone 

fragments in green clay) :

Camerina sp.

Sorites sp.

Trigonacardia sp. 

Cross section 4, hole 1 (SW%SW% sec. 4, T. 30 S., R. 20 E.) :

Anomaloccwdia penita

Area irregularis

Oardium sp. cf. C. anclotensis

Murex sp. cf. M. trophonoformis 

Cross section 4, hole 3 (NW%SE% sec. 13, T. 30 S., R. 19 E.) :

Sorites sp.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 229

Cross section 14, hole 7 (NW%SE% sec. 15, T. 28 b., R. 26 E.) :

Amauropsis sp.

Arcopsis sp.

Chlamys crocus

Phacoide? sp.

Turritella tampae

Hillsboroensis 

Cross section 14, hole 8 (NW%SE% sec. 14, T. 28 S., R. 26 E.) :

Camerina sp.

Peneroplis sp.

Sorites sp.

FenMS sp. 

Cross section 17, hole 4 (NE%SW% sec. 27, T. 26 S., R. 23 E.) :

Anadara latidentata

Architectonicaf n. sp.

Callocardia sp.

Cardium delphicum

Chlamys sp.

Corbula sp.

Knefastia sp. cf. J!L BroofcsutKewsts

Olivella sp. cf. 0.

Terebra sp. 

Turritella atacta 

Venus sp.

Cross section 17, hole 9 (NW%SE% sec. 13, T. 25 S., R. 21 E.) : 

Glycymeris sp.

In addition to the fossiliferous localities, limestone or clastic rock 

called Tampa on the basis of lithologic character was cored at holes 1, 

2, and 4 of cross section 1, hole 4 of cross section 2, holes 1 and 3-5 of 

cross section 3, hole 4 of cross section 14, and holes 3, 5-8, and 10 of 

cross section 17. All of the drill holes that intersected limestone or 

clastic rock of the Tampa are in the northern half of the area mapped, 

but, in the northernmost holes of cross sections 1 and 17, the Tampa 

was missing, and the formation thins northward. Because the formation extends farther to the north than does the overlying Hawthorn, 

the thinning may be in part, at least, erosional.

HAWTHORN FORMATION

The Hawthorn formation was named for the town of Hawthorn, 

Alachua County, by Ball and Harris (1892, p. 107). The Hawthorn 

was placed in the middle Miocene by Cooke (1945) and MacNeil 

(1947) . In the land-pebble district the Hawthorn formation consists 

of interbedded layers of limestone or dolomite, sand, sandy clay, and 

greenish-blue or gray clay, all of which contain abundant phosphate 

nodules. Where exposed in the mining pits of the land-pebble district, the Hawthorn formation is a soft buff to yellow sandy, clayey 

phosphate-bearing dolomite. In studying cuttings from a deep well
230 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Berman (1953) found an abrupt change at 80 feet from dolomite to 

limestone. It is believed that the upper dolomitic zone may be a replacement of the limestone.

A thin, discontinuous deposit of soft, water-saturated plastic sandy 

calcareous clay (called bedclay by the phosphate companies) overlies 

the dolomite of the Hawthorn formation in most of the pits in the 

district. This clay is gradational with the material below and probably was derived from the hard dolomite beneath by leaching.

No limestone of the Hawthorn formation was found in the drill 

holes in the northern fringe of the district (See pis. 16,17, 32, and 33.) 

The formation is very thin in this area and pinches out northward. 

In the southern part of the area, the drill holes penetrated sandy clay, 

clay, and sand of the Hawthorn formation, but many bottomed in 

limestone or dolomite of the Hawthorn (See pis. 22, 23, and 25.) 

The Hawthorn formation is unconformably overlain by the Bone 

Valley formation of Pliocene age, or by sand of the Pleistocene. The 

Hawthorn ranges in thickness from a featheredge north of the district 

to a maximum of several hundred feet south of the district.

Hawthorn fossils were collected at the following localities:

Cross section 4, hole 2 (SW%SW% sec. 18, T. 30 S., R. 20 E.) :

Ostrea sp. 

Cross section 10, hole 8 (SW%SW^4 sec. 15, T. 34 S., R. 25E.) :

Anadara sp.

Chione sp.

Cross section 11, hole 1 (NW%NW% sec. 1, T. 34 S., R. 25 E.) (late Hawthorn age) :

Anadara sp.

Cancellaria sp.

Cardium sp.

Dosinia sp.

Glycymeris sp.

Phacoides sp.

Plicatula sp.

Semicassus?

Venericardia sp.

Venus sp. 

Cross section 11, hole 5 (NE%SE% sec. 35, T. 33 S., R. 26 E.) :

Olycymeris sp.

Phacoides sp. 

Cross section 11, hole 6 (NE%SE% sec. 31, T. 33 S., R. 27 E.) :

CMone sp.

Chlamys sp.

Venericardia sp.

Venus sp. 

Cross section 12, hole 1 (sec. 36, T. 31 S., R. 25 E.) (Hawthorn?) :

Anadara sp.

Cross section 12, hole 6 (NW^NE^ sec. 31, T. 31 S., R. 27 E.) (fossils are in a 

limestone gravel) :

Chlamys sp.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 231

Cross section 12, hole 8 (NB^SW1^ sec. 33, T. 31 S., B. 27 E.) (Hawthorn?):

Chlamys sp.

Pect en sp.

Turritella sp. 

Cross section 13, hole 1 (SW%SW% sec. 7, T. 30 S., R. 26 E.) (Hawthorn?) :

Chlamys sp.

Phacoides sp.

Venericardia sp. 

Cross section 13, hole 2 (NW%SE% sec. 17, T. 30 S., R. 26 E.) :

Anadara sp.

Chione chipolana 

Cross section 13, hole 5 (NW%SE% sec. 13, T. 30 S., R. 26E.) :

Cardium (Trachycardium) sp.

Chlamys sp. (Probably say anus)

Tellina sp.

Limestone and clastic rock, correlated with the Hawthorn formation on the basis of lithologic character, were cut by all drill holes except holes 4: and 5 of cross section 1, and holes 4-11 of cross section 17. 

(See pis. 16 and 32.) The approximate northern limit of the Hawthorn formation is shown on plate 34. The northward thinning and 

pinch out of the Hawthorn is shown on plates 16 and 32. In addition, 

plate 18 indicates a westward thinning of the Hawthorn. The northern thinning of the Hawthorn is believed to be erosional; outliers of 

the formation are shown on the geologic map of Florida (Cooke, 

1945), to the north of the area mapped. The thickening of the formation southward is shown from logs of deep wells.

UNNAMED SAND AND UGMESTONE

Fossils, identified as being near the middle Miocene-late Miocene 

boundary in age, were found in three drill holes. These three collections are identified as late middle Miocene, middle(?) Miocene, 

and late(?) Miocene in age respectively. The beds from which the 

fossils came and others correlated with them on the basis of lithologic 

similarity are grouped into a single unnamed sand and limestone unit 

of middle Miocene to late( ?) Miocene age.

On the eastern fringe of the district in eastern Polk County the 

easternmost drill holes in cross sections 12 and 15 (pis. 27 and 30) 

penetrated a bed of olive-green fine to very fine grained micaceous 

clayey sand that contains abundant shell fragments and a minor 

amount of black phosphate grains. Lithologically similar material 

was identified in cross sections 11,13, and 14 (see pis. 26, 28, and 29), 

and is tentatively correlated with this fossiliferous bed. The f ossiliferous material in hole 8 (pi. 27), identified as late middle Miocene 

in age, overlies fossiliferous limestone of the Hawthorn formation. 

In hole 6 (pi. 30), the fossiliferous material, identified as middle(?) 

Miocene, overlies limestone that is assigned to the Hawthorn on the 

basis of lithologic character.
232 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Southward at the north end of De Soto County (hole 14, pi. 25) 

fossils identified as late(?) Miocene were found in a white to cream 

sandy and clayey limestone that contains a few black phosphate 

nodules. This fossiliferous bed overlies a nonfossiliferous limestone 

that is put in the Hawthorn because of its lithologic character. According to Bergendahl (1956) most of the upper Miocene is sand but 

contains variable amounts of clay. This sand, from Bergendahl's 

description of it, is similar to the sand in the eastern part of the area 

of this report, and was penetrated in holes 12, 13, 15, and 16 at the 

south end of cross section 10. That part of Bergendahl's sand of the 

upper Miocene penetrated in cross section 10 is placed in the unnamed 

sand and limestone unit in this report.

The clayey sand beds of cross sections 11-15 lie to the east of the crest 

of a subsurface ridge that is parallel to and east of the Peace River. 

The land-pebble phosphate district as an economic unit does not 

extend to the east of this ridge (see fig. 26), although noneconomic 

phosphate beds overlie the unnamed sand and limestone unit east of 

the ridge.

The total thickness of the unnamed unit is uncertain. In hole 8 

(pi. 27) a tan sand, containing abundant coarse phosphate, overlies 

the olive-green clayey sand that contains late middle Miocene fossils. 

This tan material is tentatively put into the Bone Valley and if this 

correlation is correct, the unnamed sand and limestone unit is only 

10 feet thick in this drill hole, from a depth of 59.8 feet (the base 

of the phosphorite bed) to 70.1 feet (the top of the fossiliferous Hawthorn). In hole 6 (pi. 30) the fossiliferous beds of the unnamed 

unit are overlain by a tan sand that contains coarse phosphate nodules, 

which is also tentatively put into the Bone Valley, and are underlain 

by nonfossiliferous limestone, called Hawthorn on the basis of its 

lithologic character. The unnamed beds extend from a depth of 

74.4 to 86.0 feet, a thickness of only 11.6 feet. This may represent the 

approximate shoreline of the late middle Miocene sea, as the unit 

thickens to the east and south as shown on the cross sections, plates 

25-30. In hole 16 (pi. 25) the olive-green sand tentatively correlated 

with the unnamed unit extends from a depth of 28.0 to 84.0 feet, a 

thickness of 56 feet.

Fossils identified are as follows:

Cross section 10, hole 14 (Ny2 SE% sec. 21, T. 36 S., R. 25 E.) : 

Cardita sp. 

Cardium sp. 

Chlamys sp.

Ostrea sp. aff. O. puelchana 

Spisula? 

Venusf
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 233

The oyster (0. sp aff. 0. puelchana) is unlike anything in the 

Hawthorn, and this assemblage is identified as upper (?) Miocene.

Cross section 12, hole 8 (NE%NW% sec. 33, T. 31 S., 27 E.) : 

Anadara sp. 

Anomia sp. 

Chlamys sp. 

Dosinia sp. 

Mulinia orthria 

Pliacoides sp.

Mulinia orthria has been known only in the Shoal Kiver formation of middle Miocene age. (This is a late middle Miocene assemblage).

Cross section 15, hole 6 (NE^4NW% sec. 7. T. 27 S., R. 27E.) : 

Anadara sp. cf. A. idonea harveyensis 

Cancellaria sp. cf. C. tabulata

Chlamys (Plagioctenium) eboreus subsp. watsonensis 

Crepidula sp. 

Olivella say ana, 

Pecten (Pecten) sp. 

Spisula (Hemimactra) delumbis 

Turritella sp. cf. T. alumensis 

Venus sp.

PLIOCENE (?) SERIES 

ALACHTJA (?) FORMATION

The name Alachua was applied by Ball and Harris (1892, p. 127) 

to the bone-bearing beds found in sinks in Alachua County. Cooke 

(1945, p. 199) puts the Alachua in the middle Pliocene. Vernon 

(1951, p. 183) suggests that the Alachua formation ranges in age 

from lower Miocene to Pleistocene, and includes the terrestrial equivalent of the entire marine Miocene of Florida. Fossils found in 

the Alachua include bones of Miocene, Pliocene and Pleistocene 

animals. Simpson (1929, p. 259; 1930, p. 176) regarded the Pliocene 

animals as the indigenous fauna.

The formation is a blue, gray, or green sandy clay, which weathers 

to a yellow or red. The sand fraction is medium to coarse grained; 

the formation also contains white angular fragments of phosphate.

Sediments assigned to the Alachua (?) formation were cored only 

in holes 8-11 of cross section 17 (pi. 32). The sediments are nonfossiliferous coarse sandy clays containing angular white phosphate 

fragments. They overlie rocks assigned to the Tampa in holes 8- 

10, and Suwanee limestone in hole 11. Coarse quartz grains are 

not found in the Ocala, Suwannee, or Tampa limestones, but are 

characteristic of the Hawthorn. It is likely, therefore, that the sediments assigned to the Alachua(?) were derived largely from the 

Hawthorn, if they are not a residuum of the Hawthorn. The angu466352 59 3
234 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

lar phosphate fragments are probably phosphatized Ocala or Suwannee limestone. The fragments are present throughout the Alachua (?) 

and may indicate some reworking. The Alachua (?) is overlain at 

hole 10 of cross section 17 by a sandy clay, containing phosphate 

nodules, that is similar lithologically to the lower part of the Bone 

Valley and so assigned. In holes 8, 9, and 11 of cross section 17, 

the Alachua (?) is overlain by clayey sand lithologically similar 

to the upper Bone Valley and assigned accordingly. It seems likely, 

therefore, that these sediments assigned to the Alachua(?) are at 

least in part equivalent to the Bone Valley, but may also be somewhat older.

PLIOCENE SERIES 

BONE VAUUBY FORMATION

The Bone Valley gravel was named by Matson and Clapp (1909, 

p. 138-141), from a railroad stop west of Bartow, Fla. They divided the Bone Valley gravel into a lower unit rich in phosphate 

nodules and an upper, noneconomic unit that contains only traces 

of phosphate. Cooke (1945, p. 203) suggested a change in name to 

Bone Valley formation, as gravel makes up only a small part of 

the material.

The Bone Valley formation is generally regarded as Pliocene 

in age on the basis of land vertebrates (Simpson, 1929), although it 

may be latest Miocene. Brodkorb (1955, p. 38-39) says: "The avifauna, therefore, must be of late Miocene to middle Pliocene age, 

and the agreement is closest to other avifaunas recorded from the 

early or middle parts of the Pliocene." Bergendahl (1956) shows 

an interfingering of "undifferentiated phosphate", in part equivalent 

to the Bone Valley formation, and a sand containing marine invertebrates that may be very late Miocene in age. At present, this 

discrepancy in age assignment has not been resolved; the landvertebrate chronology may be a portion of an epoch ahead of the 

marine-sediments chronology.

The Bone Valley formation consists of a lower unit that is composed of phosphate nodules, sand, and clay, and an upper unit that 

is composed predominantly of clayey sand but includes minor 

amounts of phosphate nodules.

The lower unit, which ranges in thickness from a featheredge to 

more than 30 feet at hole 1 (pi. 23), is composed of interbedded, lenslike beds of sand, clay, and clayey sand. All of the beds contain phosphate particles, and individual beds may vary from almost barren 

clay or sand to those which are almost entirely phosphate nodules. 

The upper part of the Bone Valley formation ranges from a slightly 

clayey sand to a sandy clay, and generally contains a few phosphate
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 235

nodules. The contact between the lower and upper parts of the Bone 

Valley formation is gradational over a vertical distance of a few 

inches. The upper part ranges in thickness from a featheredge to 

about 68 feet at hole 6 (pi. 27). Toward the fringes of the district 

(cross section 1, pi. 16) the phosphate beds of the lower Bone Valley 

are not present, and the Pliocene is represented by clayey sands. These 

beds are lithologically similar to the upper part of the formation and 

are correlated accordingly.

The lower, phosphorite unit of the Bone Valley formation is present 

almost throughout the area. The limits of the calcium phosphate zone, 

shown on figure 26, also represent, at least roughly, the limits of the 

lower unit of the Bone Valley formation. The lower unit is not 

present, except as small patches north of Polk and Hillsborough 

Counties. The limits of the formation to the south are not known; the 

southernmost drill holes contained material assigned to the Bone 

Valley on the basis of lithologic similarity.

The upper, clayey sand unit of the Bone Valley formation is present 

throughout the area mapped. The distinctive lithology, a mediumto-fine-grained quartz sand, lightly bound with white clay, was noted in 

every drill hole.

PLEISTOCENE AND RECENT SERIES

TERRACE SAND AND OTHER STJRFICIAL. DEPOSITS

The loose sand overlying the Bone Valley is probably Pleistocene 

in age. No fossils were found in any of the drill cores, but a few horse 

teeth of Pleistocene age have been found in the loose surficial sand in 

the land-pebble district. The sand is nearly pure quartz, with only 

traces of clay, heavy minerals, and as much as 0.5 percent P2O5. 

Generally, the sand is white, but locally is stained gray by organic material or light brown or tan by iron. Wind-blown sand, swamp deposits, and bars and flood-plain deposits of streams are considered 

Recent in age.

MINERALOGY

The mineralogy of the land-pebble phosphate district has been 

described by Altschuler and others (written communication, 1955). 

For the purposes of this report, the mineralogy will be described only 

briefly.

Berman (1953) points out that the deeper, unaltered limestone of the 

Hawthorn in a deep drill hole contains calcite, quartz, a minor amount 

of apatite, and the clay minerals, either kaolinite or montmorillonite. 

Closer to the surface the Hawthorn formation consists of dolomite, 

attapulgite, quartz, and apatite; the "matrix" of the Bone Valley formation is quartz, montmorillonite, and apatite; and the overburden
236 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

is quartz and a minor amount of montmorillonite. This section is 

typical of those areas where aluminum phosphate minerals were not 

formed.

X-ray spectrometer analyses of a series of vertical channel samples, 

each sample representing a very limited vertical interval, were made by 

L. V. Blade of the Geological Survey in 1952. All of the sections 

were taken at mines in the district, from the surface to the base of the 

pit. The following are generalizations from several sections that are 

believed typical of areas that were leached and where aluminum 

phosphate minerals were formed.

The loose surface sand contains only quartz, except near the contact 

with the clayey sand of the upper part of the Bone Valley, where minor 

kaolinite was detected. The clayey sand of the upper Bone Valley, 

whether obviously leached or not, contains kaolinite, wavellite, crandallite, and possibly a minor amount of montmorillonite. Quartz is 

ubiquitous. The same minerals are present at the top of the lower 

part of the Bone Valley, but at the upper contact, or slightly above it, 

montmorillonite is the most abundant clay mineral, apatite is abundant, 

and commonly crandallite is more abundant than wavellite. In the 

lower Bone Valley ("matrix") apatite and montmorillonite are the 

most abundant minerals; kaolinite and aluminum phosphate minerals 

are minor constituents. The residual Hawthorn (bedclay) contains 

calcite and dolomite in addition to apatite and montmorillonite.

CHEMISTRY

Analytical and screen data from the drilling are given below. Only 

samples that were clearly in one of the stratigraphic intervals shown 

were used. Many of the samples taken included more than a single 

stratigraphic interval. For example, in many of the drill holes, a 

single sample of the calcium phosphate zone was taken; the sample 

may include phosphate of both Hawthorn and Bone Valley.

The weight distribution shows that samples of the limestone of 

the Hawthorn contain the highest percentages of pebble, and the 

analyses show that the pebble fraction is low in phosphate, and from 

the ratio of calcium to phosphate, contain excess calcium. Probably 

the pebble sample contains abundant particles of slightly phosphatized 

limestone, as well as the coarser particles of calcium phosphate. The 

limestone also contains the highest percentage of slime, and the lowest 

percentage of quartz sand (the tailing fraction) of any of the samples. 

Clastic rock of the Hawthorn, however, has much less pebble, slightly 

less slime, much more sand, and about the same amount of concentrate 

as the limestone.

The phosphate of the unnamed sand and limestone unit differs from 

the Hawthorn principally in the amount of the slime fraction, which is
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 237

only half of that in the Hawthorn. The pebble fraction is higher, the 

concentrate about the same, and the sand fraction is increased slightly.

Comparison of screen-size distribution and chemical analyses, and averages of 

samples from different stratigraphic intervals

[The sample washing and flotation was done by a private firm under contract let by the Geological Survey. 

All chemical analyses were done in the laboratories of the U. S. Geological Survey]

Mesh size

+14 (pebble). 

-14+35 (feed)-........... _

-35+150 (feed)i.-....-.-.....

(Tailings) ...

-150 (slime)

Weight percent retained on screen

Limestone 

of the 

Hawthorn

19.3

10.7

10.1 

25.5 

34.4

Calcium phosphate zone

Clastic 

rocks of the 

Hawthorn

5.1 

13.0

10.5 

45.1 

26.2

Unnamed 

unit

8.3 

18.0

10.6 

49.6 

13.5

Bone Valley (lower)

Dark

phosphate

11.2 

14.7

6.2 

54.5 

13.4

Light 

phosphate

8.3 

14.3

6.8 

44.0 

26.4

Aluminum 

phosphate 

zone, Bone 

Valley

1.6 

17.0 

66.6

14.9

Percent P:Oe

Pebble 17.9

22.9

22.1

30.1

25.6

30.0

27.0

31.5

31.8

34.1

11.2

12.4

Percent Uranium

Pebble . 

Slime 

0.007

.006

O nno

.008

0.014

.011

0.013

.010

0.016

.012

0.008

.020

CaO: PsOs

Pebble 

Slime 

3.15

2.67

1.62

1.47

1.69

1.37

1.47

1.39

1.32

1.38

0.61

.49

F:P2Os

Pebble - 0.119

.115

0.114

.110

0.114

.112

0.114

.114

0.108

.110

0.079

.052

i The 35+150 mesh feed fraction was separated, by flotation, into a concentrate and sand tailings fraction. 

No concentrate was present in the samples from the aluminum phosphate zone in the Bone Valley formation.

Phosphorite of the Bone Valley is here divided into those deposits 

characterized by black phosphate nodules and those characterized by 

lighter colored nodules (white, tan, and gray). The darker material 

contains a high pebble percentage and a lower concentrate fraction 

than the unnamed sand and limestone unit or the lighter material of 

the Bone Valley. Also, the slime fraction of the darker material is 

low, half as much as in the lighter material. The aluminum phosphate 

zone is characterized by a very minor pebble fraction, high sand percentage, no concentrate fraction, and a medium slime fraction.
238 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Several generalizations about the phosphate content of the nodules 

in the different stratigraphic units can be made: First, the pebble fraction always has less phosphate than the concentrate fraction; second, 

the phosphate content of the aluminum phosphate zone is only about 

half that of the calcium phosphate zone; and third, the phosphate content of the nodules is highest in the Bone Valley, and gets progressively 

lower in the unnamed unit and the clastic rock of the Hawthorn, and 

is lowest in the limestone of the Hawthorn.

The uranium content also varies in a more or less regular manner 

and follows the variations in phosphate content. In general, the 

uranium content of the phosphate nodules is greater in the coarser 

fraction, is higher in the calcium phosphate zone of the Bone Valley 

and unnamed unit than in the clastic rock of the Hawthorn, and the 

limestone of the Hawthorn contains the least amount of uranium. It 

is also notable that the highest average uranium content is found in 

the slime fraction of the aluminum phosphate zone.

The ratio of calcium to phosphate is lowest in the aluminum phosphate zone, increases regularly through the Bone Valley, the unnamed sand and limestone, and clastic rock of the Hawthorn, and is 

greatest in the limestone of the Hawthorn. This change in ratio corresponds to a change in mineralogy from aluminum phosphate to calcium phosphate to calcium phosphate plus calcite. It is also interesting to note that the ratio is generally higher in the pebble fraction than 

in the concentrate fraction. The ratio of calcium to phosphate in 

fluorapatite (Palaehe, Berman, and Frondel, 1951) is slightly more 

than 1.3, and only those samples highest in phosphate, (the pebble 

fraction of the light phosphate of the Bone Valley, the concentrate 

fractions of the Bone Valley and the unnamed unit) approach this 

theoretical ratio. All of the other samples contain an excess of calcium.

The ratio of fluorine to phosphate is less than 0.1 only in the samples 

of the aluminum phosphate zone, is about the same for all of the 

samples of the calcium phosphate zone, and is slightly higher in the 

samples from the limestone of the Hawthorn. Fluorapatite has a theoretical ratio slightly in excess of 0.10. The pebble fraction of the light 

phosphate of the Bone Valley formation approaches this theoretical 

ratio most closely; it is also these samples that are closest to the theoretical ratio of calcium to phosphate for fluorapatite.

WEATHERING

Intense weathering has altered the rocks in the land-pebble district, 

apparently several times. Lack of fossils, and the similarity of the 

rock types make it difficult to separate the different weathering cycles. 

The unconformable relations between the Bone Valley and the Haw-
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 239

thorn formations cannot be demonstrated from the drilling, but these 

relations have been noted in mining pits where basal phosphorite conglomerates of the Bone Valley rest directly on the irregular, eroded 

surface of limestone or dolomite of the Hawthorn formation. It 

seems likely that a period of weathering followed the deposition of 

the Hawthorn. This weathering dissolved the calcium carbonate, leaving behind a residuum enriched in phosphate particles. The transgressing sea of the Bone Valley reworked this residuum and deposited 

the Bone Valley formation on the irregular karst topography of the 

Hawthorn. It has been noted that the limestone of the Hawthorn 

has been dolomitized close to the surface. That this dolomitization 

took place after the deposition of the Bone Valley formation is indicated by the fact that the phosphate particles of the Bone Valley, many 

of which are phosphatized limestone, contain no magnesium; complete 

analyses show that phosphate particles average less than 0.3 percent 

MgO, whereas the limestone of the Hawthorn may contain 20 percent 

MgO or more. Weathered sections of the Hawthorn (the thicker 

sections of calcareous bedclay) are close to and apparently related to 

the present land surface. Deeper beds in the Hawthorn are fresh, 

unweathered rocks. Therefore, it is believed that the residuum formed 

on the surface of the Hawthorn prior to the deposition of the Bone 

Valley formation, may have been entirely reworked into the Bone 

Valley.

The intense weathering that formed the aluminium phosphate, or 

leached zone, took place after the deposition of the Bone Valley. 

This zone of alteration underlies and is older than the surficial soil 

profile, a ground-water podzol, typified by the acid Leon soil, (Fowler 

and others, 1927, p. 11). Plate 21 illustrates the typical soil profile 

loose light-gray surficial sand, overlying a dark-brown to black ironcemented and organic sand. Below this layer the sands are loose 

and stained brown by iron.

The alteration is generally confined to the upper part of the Bone 

Valley formation and to the top of the lower part, although there is 

some aluminum phosphate as low in the stratigraphic section as the 

Hawthorn formation, (pi. 16); and even the Tampa (pi. 32). 

The alteration changed calcium phosphate minerals to aluminum 

phosphate minerals, and the dominant clay mineral from montmorillonite to kaolinite. It is possible that in addition this period of 

weathering also altered the limestone of the Hawthorn to a dolomite 

and, by continued leaching, changed the limestone to calcareous clay. 

The formation of the surficial soil profile is the last episode of the 

weathering, and presumably occurred during one or more of the 

Pleistocene withdrawals of the sea.
240 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

ECONOMIC GEOLOGY

Two zones of economic significance are shown on the cross sections 

(pis. 16-33) by stippled patterns. These zones are the calcium phosphate zone or "matrix", and the aluminum phosphate or "leached" 

zone. Neither term is used in a stratigraphic sense; both zones cut 

across the stratigraphic units. (See pi. 25, holes 11-13.)

CALCIUM PHOSPHATE ZONE

The calcium phosphate zone is that part of the stratigraphic section characterized by nodules or particles of carbonate fluorapatite 

(Altschuler and Cisney, 1952). This zone is nearly synonymous with 

the "ma,trix", which is that part of the section which can be 

mined profitably under existing economic conditions. The calcium 

phosphate zone may be entirely within the lower unit of the Bone 

Valley formation, or it may be entirely the residual Hawthorn (the 

calcareous bedclay), or a combination of the two.

Many of the drill holes bottomed in formations older than the 

Hawthorn. In many of the holes, sections of core from the Hawthorn contained phosphate nodules. These sections of phosphatebearing Hawthorn are not included in the calcum phosphate zone 

when they are separated from the lower, phosphatic unit of the Bone 

Valley formation by barren clay or sandy clay. The phosphate-bearing calcareous clay of the Hawthorn formation is considered a part 

of the calcium phosphate zone only when it immediately underlies 

the Bone Valley formation, and is close enough to the surface to be 

mined. The calcium phosphate zone as used in this report is not 

synonymous with "matrix" because some of the factors necessary for 

deciding whether a given drill hole contains economic phosphate 

could not be computed. Factors that must be considered in separating economic from noneconomic phosphate are (1) thickness of waste 

material (overburden) above the zone (computed in cubic yards of 

material removed to recover one ton of product); (2) amount of 

recoverable phosphate (computed in tons per acre); (3) amount of 

waste material in the phosphatic zone (computed in cubic yards of 

matrix per ton of product); (4) P2O5 content of the phosphate particles (computed as percent of bone phosphate of lime BPL); (5) 

thickness of the zone in feet; and (6) total combined iron and alumina, in percent. If any of these factors are above the maximum 

allowable limit, or below a given minimum limit, the deposit is probably not minable. Because each active company in the district has 

slightly different standards for each factor, the figures given below 

are approximate.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 241

Economic factors Maximum Minimum

"Cubic yards overburden per ton of recoverable product_ 15-20

 Cubic yards matrix per ton of recoverable product___ 5-7 ________

Thickness (in feet) of matrix bed_____________ __ ___ 3. 0

'Tons per acre foot of recoverable product_________ 400

Percent BPL 1 (Percent P2O5 X2.185) ___________ _____ 66.0

Percent combined iron and alumina__________ 5. 0 

1 BPL, bone phosphate of lime.

These factors are not absolute. For example, a deposit containing 

only 66 percent BPL must have a smaller factor of cubic yards per 

ton and a greater factor of tons of product per acre than a deposit 

containing 75 percent BPL. In addition, a single drill hole might

 contain some factors that were not economic, but if located in an area 

containing better than average material, it would be mined if the 

average of the larger area was economic. To block out a deposit 16 

holes per 40 acres are drilled, or 1 hole in each 2.5-acre block. The 

area of a standard drill hole is about one-millionth of the area of the 

2.5-acre block. Thus, the accuracy of tonnage and grade estimates 

for this drilling is extremely low, and tonnage and grade figures are 

not projected, but are given only in tons per acre, or cubic yards per 

acre.

ALUMINUM PHOSPHATE ZONE

The aluminum phosphate zone is that part of the section that has 

been strongly altered by acid ground waters. The zone is characterized by the presence of aluminum phosphate minerals, kaolinite, 

and generally, by the highest uranium content as indicated by the 

high peaks on the gamma-ray logs. The alteration is generally confined to the upper part of the Bone Valley formation and the top of 

the lower part, although aluminum phosphate minerals were developed as low as the Hawthorn (pi. 16) or the Tampa (pi. 32). The 

.zone can be identified by some or all of the following features: 

Vesicularlike texture, secondary cements, white color, low specific 

gravity, and indurated or friable character.

Factors concerned in the economics of the aluminum phosphate 

.zone are more uncertain than those for the calcium phosphate zone 

because so little is known as to the possible processes that may be 

used to recover the various materials in the zone. For example, any 

one or combination of three products phosphate, alumina, and uranium might be obtained from this zone. For purposes of this 

report, it is assumed that phosphate and uranium will be recovered, 

and that alumina will not be a product. The lines of possible economic correlation on the cross sections are drawn on this assumption. 

If alumina should be recovered as a third product, some of the upper 

clayey sand that has been excluded from the aluminum phosphate

466352 59 4
242 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

zone on the cross sections may become economic. However, because 

the clayey sand is low in uranium, it was not analyzed for phosphate 

or alumina. Therefore, it is not possible to say whether it contains 

enough alumina or phosphate to be economic.

If the above assumptions are correct, the factors that affect the 

economics of the aluminum phosphate zone are (1) thickness of the 

waste material above the zone, (2) thickness of the zone, (3) phosphate and uranium content of the zone in percent, (4) CaO and 

A12O3 content of the zone in percent, and (5) whether economic calcium phosphate zone underlies the aluminum phosphate zone. At 

present, all mining of the zone must be integrated with the mining 

plans of the active companies for the phosphate matrix. As indicated 

on figure 26, fringe areas to the west and northwest of the central 

part of the land-pebble district are underlain by aluminum phosphate 

zone, which is not underlain by matrix.

An absolute figure for excessive overburden thickness cannot be 

given. However, because the digging depth of the largest draglines is 

about 70 feet, more than about 50 feet of waste material overlying the 

zone would be excessive.

The cutoff value of contained P2O5 has been arbitrarily placed at 

5 percent, principally because large areas contain aluminum phosphate zone with more than 5 percent P2O5, and other large areas are 

underlain by clayey sand that contain less than 5 percent P2O5.

A lower limit of 0.005 percent uranium has been chosen because 

most of the samples above this value had high contents of uranium 

in the slime fraction (in which the aluminum phosphate minerals are 

concentrated). The uranium content of the slime fraction tends to 

be greater than 0.010 percent in samples where the head assays range 

from 0.005 to 0.010 percent uranium. Conversely, in samples where 

the head assay is less than 0.005 percent uranium, the slime fractions 

tend to be less than 0.005 percent.

Little is known about the effect of high or low CaO content, but 

processing costs possibly could rise with high calcium.

If the final product is to be a fertilizer, a high alumina content 

could be somewhat less desirable than a lower content, but it is not 

possible to evaluate the effect of varying alumina content.

GENERAL RELATIONS

The index map (fig. 26) shows the location of the drill holes, the 

limits of the calcium phosphate zone, and the limits of the aluminum 

phosphate zone. The limits of the phosphate zones are based only on 

the 115 drill holes shown. Figure 26 shows that to the northwest the 

aluminum phosphate zone extends beyond the limits of the calcium 

phosphate zone (see cross sections 1, 4, 17, and 18), and that the
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 243

aluminum phosphate zone apparently extends farther south, in Hardee 

and Manatee Counties, than was previously known. This extension 

is based on cross sections 9 and 10, and because of limited data it is 

possible that only patches of aluminum phosphate zone are present 

in this area. East and south the calcium phosphate zone extends beyond the limits of the aluminum phosphate zone. The difference in 

position of the two zones may be explained by the facts that 

(1) in the northwest, phosphate deposition was thinnest, the entire 

calcium phosphate zone apparently was leached, so that only remnants 

of it remain, and (2) where the Bone Valley formation was thicker 

to the south, only the top part of the formation was leached, and 

hence both zones are still present. Still farther south, in Hardee and 

Manatee Counties, the formation may not have been exposed to subaerial weathering, and no aluminum phosphate zone was formed. 

(See discussion of cross sections 7, 8, and particularly, 9.) The 

limit of the aluminum phosphate zone on the east coincides approximately with the present topographic ridge to the east of the Peace 

River. The land east of the ridge, which is lower in elevation than 

the land to the west, also probably was not exposed to subaerial 

weathering. The present limit is the result of a combination of two 

factors: (1) erosion after the zone was formed, and (2) the possibility that somewhere to the east the phosphatic sediments were not 

exposed to weathering.

SUGGESTIONS FOB EXPLORATION

The area east of B. 26 E. even though there may be some leached 

material present, is deeply buried by barren sand of the overburden, 

and is not a good area for exploration. The most promising areas for 

exploration, based on the results of this drilling program, are first, 

the area to the northwest in Hillsborough and Pasco Counties, where 

the aluminum phosphate zone is not underlain by economic matrix, 

and second, the area to the south, in Hardee and Manatee Counties, 

where extensive deposits may be present. This latter area has not been 

extensively explored by the private companies because of the low 

grade of the phosphate nodules in the matrix. It is most probable that 

the area is not entirely underlain by aluminum phosphate zone, but in 

some localities, particularly adjacent to the Peace Eiver, aluminum 

phosphate zone material may be present. Results of scattered drilling 

west of the Peace River, in Hardee and Manatee Counties, indicate 

that patches of the aluminum phosphate zone are present. This area 

should be explored further if it becomes necessary to outline reserves 

of the aluminum phosphate zone more fully. The remainder of the 

district, in Polk and Hillsborough Counties, probably has been well-
244 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

enough explored by private companies at least for preliminary estimates of tonnage and grade.

DISCUSSION OF CROSS SECTIONS

A summary of the lithologic characteristics used in stratigraphic 

correlation is given below. The table shows, for example, that the 

clastic rocks of the Hawthorn formation are loose sand, clayey sand, 

calcareous clay, and green or blue sandy or silty clay, all containing 

phosphate particles low in P2O5 content. The clastic rock of the 

Hawthorn contain more phosphate particles and fewer chert fragments than the clastic rock of the Tampa. The criteria as shown on the 

table are not invariable, but are in general characteristic of the formations. For example, chert fragments do not always occur m the clastic 

rock of the Tampa limestone, and occasional chert fragments, or silicified fossil fragments are found in the Hawthorn formation. However, 

chert fragments in a calcareous clay overlying fossiliferous Suwannee 

limestone (pi. 16) was considered enough evidence to classify this 

material as Tampa.

Cross sections 1-18 are shown on plates 16-33. All analytical data 

and results of screen-size analysis and tonnages and uranium contents 

are given at the end of the report.

CROSS SECTION 1 

STRATIGRAPHY

Swwannee. Fossils from the bottom of hole 4 were identified as 

Oligocene in age. Hole 5 was bottomed in a very hard bed, probably 

siliceous limestone, that is correlated with the Suwannee limestone 

of hole 4.

Tampa. Fossils from the bottom of hole 3 were identified as 

early Miocene in age. In addition, the sandy calcareous clay from 

sample 13 (see p. 211) contained no phosphate particles, and is included in the Tampa. The limestone in holes 1 and 2 is lithologically 

identical with that in hole 3 and is thus correlated. In holes 1, 2, 

and 4, the calcareous clay above the limestone contains chert fragments, limestone fragments, and very sparse phosphate nodules; 

this material is tentatively called Tampa.

Hawthorn. Green silty clay, calcareous clay, and sand, all of 

which contain phosphate nodules, overlie the sandy clay of the 

Tampa limestone in holes 1-3. These materials are tentatively correlated with the Hawthorn formation. The contact between the Hawthorn and the Bone Valley is marked in holes 1-3 by a green silty 

clay underlain by a bed of quartz sand containing amber phosphate 

nodules. The Hawthorn formation pinches out to the north; apparently it is not represented in holes 4 and 5.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 245

-«s&

1 *

 8 £

1 X

is 5

t «3i I

S~

e

I

ii*'

lil

a I

*

33 d» ,2

_M)O

X

X

X

X X

H ^ H H

X

X!

XXX

X

«

XX

HP i-3 O 3 O

g=sg 5&i 02 R 9 .j G> OS °3 ^

an ||

3 ooO
246 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Bone Valley. Slightly clayey sand overlies the green clay of the 

Hawthorn formation in holes 1 and 3, the calcareous clay of the 

Tampa limestone in hole 4, and the hard material on which hole 5 

was bottomed. Phosphate sand is between the clayey sand and the 

green clay of the Hawthorn formation in hole 2. The clayey sand 

and the phosphate sand are believed to be Pliocene in age and equivalent to the Bone Valley formation.

Terrace sand. White loose quartz sand overlies the iron-stained 

clayey sand in each drill hole. These surficial sands are lithologically 

alike and are believed to be of Pleistocene age.

ECONOMIC GEOLOGY

The calcium phosphate zone was cut only by hole 2, where it is 

thin, low grade, low in tonnage (see p. 287), and not economic. Small 

amounts of phosphate nodules, low in P2O5 content were found in 

samples of the Hawthorn formation from holes 1 and 3; because of 

excessive depth, low tonnage, and low grade, these samples are not 

included in the calcium phosphate zone.

The aluminum phosphate zone was penetrated by holes 1-4. The 

thick section of clayey sand in hole 5 probably contains some aluminum phosphate minerals, but the content is too low for the sand to 

be an economic source of phosphate and uranium.

CROSS SECTION 2 

STRATIGRAPHY

Suwannee. Fossils from the limestone of hole 4 were identified as 

Oligocene in age. The hard material at the bottom of hole 3 is tentatively correlated with the Suwannee because fossils of early Miocene age were found above the hard material. The Suwannee was 

probably not intersected in drill holes 1 and 2.

Tampa. Casts and molds of fossils identified as early Miocene 

in age were found in a thin bed of siliceous material cut by hole 3. 

Although it is possible these fossils are reworked, the lithology of 

the material in which they were found is similar to the lithology of 

the core from hole 4 that overlies the Suwannee.

Hawthorn. The green silty clay, sandy clay, and clayey sand, all 

of which contain phosphate grains, are called Hawthorn on the basis 

of lithologic character. In holes 1, 3, and 4 these materials overlie 

material assigned to the Tampa for the same reason. The Hawthorn 

is thickest at hole 1 and is a little thinner to the northwest.

Bone Valley. The Bone Valley formation is thickest at hole 1, 

and thins northwestward to hole 4, except that at hole 2, in the sink 

hole, the formation is even thicker than in hole 1, and the base was 

not reached. The calcium phosphate zone is present at holes 2 and
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 247

3, is absent at hole 4, and may be present at hole 1, in the section of 

core that was not recovered.

White, gray, or brown (iron stained) clayey sand form the upper 

part of the Bone Valley formation at holes 1-3. At hole 4 all the 

Bone Valley present is clayey sand, lithologically similar to the 

clayey sand of holes 1-3.

Terrace sand. The base of the Pleistocene at hole 1 is put at the 

base of the highly organic sand. The great thickening of the section 

at hole 2 is due to the filling of a sink hole. The base of the Pleistocene at holes 3 and 4 is the contact of the loose, surficial sand with 

the clayey sand of the upper part of the Bone Valley.

ECONOMIC GEOLOGY

Although the calcium phosphate zone is present at holes 1-4, no 

economic material is present. Samples 21 and 22 (see p. 272) from 

hole 1 contain calcium phosphate nodules, but they are low in grade, 

low in tonnage, and are covered by too great a thickness of barren 

material (overburden) to be economic, therefore, this material is not 

considered a part of the calcium phosphate zone.

The aluminum phosphate zone, a part of the clayey sand of the 

upper part of the Pliocene Bone Valley formation, varies in its position in the section. It forms the bottom part of the clayey sand at 

holes 1 and 2, the upper part the clayey sand at hole 3, and at hole 4 

the entire zone of clayey sand is possibly aluminum phosphate zone. 

The highest gamma-ray peak, 2700 cpm (counts per minute), in the 

aluminum phosphate zone is in hole 1. In hole 2 the high peak is 

greater than 1800 cpm, in hole 3 it is less than 1800 cpm, and in hole 4, 

the high peak barely reaches 900 cpm. Thus, in the concentration 

of uranium there seems to be a decrease northwestward and toward 

the fringe of the district.

CROSS SECTION 3

STRATIGRAPHY

Tampa. Early Miocene fossils were found in limestone fragments 

in sandy clay in the bottom of hole 2. Lithologically similar material from holes 1 and 3-5 is considered a part of the Tampa. No 

fossils were found in the limestone cores from holes 1 and 3-5, but 

this limestone is lithologically like the limestone of the Tampa and 

is tentatively correlated with the Tampa.

Hawthorn. Green sandy clay and clay, in part containing nodules 

of calcium phosphate, are tentatively correlated with the Hawthorn. 

The contact of the Hawthorn with the underlying Tampa at hole 2 

is the base of the phosphate-bearing clay, with a somewhat different
248 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

fossiliferous sandy clay lying below. The Hawthorn formation thins 

westward.

Bone Valley. The Bone Valley formation at hole 1 consists of an 

upper unit of clayey sand that contains a few soft white phosphatenodules, and a lower phosphorite unit that contains abundant coarsephosphate. At holes 2 and 3-5, the lower unit is not present, and 

the Bone Valley is represented by white or tan clayey sand, which 

probably contains some aluminum phosphate minerals. The clayey 

sand is lithologically similar in all holes.

The top of the Bone Valley at hole 3 is marked by a gray clay bedThis clay is not like any other clay bed in the cross section.

Terrace sand. Loose gray, tan, or white quartz sand overlies the 

clayey sand of the upper part of the Bone Valley in all drill holes* 

This sand is tentatively classed as Pleistocene.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated only by hole 1, where 

it is thin, but very high in P2O5 content. (See p. 272.) The analyzed 

material from hole 4 (sample 35) is high enough in P2O5 content to. 

be a part of the calcium phosphate zone, but tonnages are very low,, 

therefore it is not included in the calcium phosphate zone. Thephosphate-bearing material from hole 3 was not analyzed; visual 

inspection of the core indicated that only noneconomic amounts of 

phosphate were present.

The aluminum phosphate zone, at holes 1 and 2, at the top of the 

section of clayey sand, was delineated by analysis and by the high 

radioactivity shown on the gamma-ray logs. The clayey sand of 

holes 3-5, analyzed only from hole 4, is too low in uranium content 

and probably in phosphate content to be economic, although aluminum phosphate minerals are probably present. The material, therefore, is not included in the aluminum phosphate zone.

CROSS SECTION 4 

STRATIGRAPHY

Tampa. Fossils from the limestone cores at the bottom of holes 

1 and 3 were identified as early Miocene in age. A zone of ironstained and cemented, laminated sandy clay at hole 1 occurs above 

the limestone. The lithology of this material does not resemble anything in the Hawthorn, so this sandy clay is very tentatively correlated with the Tampa.

Hawthorn. The limestone at the bottom of hole 2 contained fossils identified as probably middle Miocene. The green sandy clay 

above the Tampa at hole 1, plus the phosphate-bearing sandy clay 

of sample 41, are tentatively correlated with the Hawthorn. The
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 249

phosphate-bearing calcareous clay from hole 3 together with the calcareous clay above it are put into the Hawthorn.

Bone Valley. Lower Bone Valley was penetrated by holes 1-3. 

At hole 1, the contact of the Bone Valley with the Hawthorn is at 

the top of the sandy clay of sample 41, which contains nodules of lower 

P2O5 content than the clayey sand of sample 40 (see p. 273). The 

lower unit of the Bone Valley rests on limestone of the Hawthorn 

at hole 2. The contact between the units is sharp; the phosphorite 

above the contact is bedded and noncalcareous. At hole 3, the lower 

unit of the Bone Valley rests on green calcareous sandy clay of the 

Hawthorn. The upper clayey sand of the Bone Valley is present 

at holes 1 and 2, but is absent at hole 3, where highly carbonaceous 

sand rests directly on the lower unit of the Bone Valley.

Terrace sand. The loose slightly iron-stained and highly organic 

sand at the surface is tentatively correlated with the Pleistocene.

ECONOMIC GEOLOGY

Possibly economic calcium phosphate zone was penetrated by all 

drill holes in this line (see p. 288). The calcium phosphate zone at 

holes 1 and 3 is made up of the lower unit of the Bone Valley formation and the phosphate-bearing beds of the Hawthorn formation. 

However, the entire calcium phosphate zone at hole 2 is represented 

by the lower unit of the Bone Valley formation.

Possibly economic aluminum phosphate zone material was penetrated only in hole 1, where it is delimited by the gamma-ray log. 

Hole 2 penetrated clayey sand of the upper Bone Valley, which probably contains some aluminum phosphate minerals. This material is 

not considered a part of the aluminum phosphate zone because the 

gamma-ray log was not above background in the interval represented 

by the clayey sand. Clayey sand of the upper part of the Bone Valley 

formation was not penetrated by hole 3.

CROSS SECTION 5 

STRATIGRAPHY

Hawthorn,. Phosphate-bearing sandy, clayey limestone at the bottom of holes 3 and 4 is correlated with the Hawthorn. Although no 

limestone was recovered in holes 1 and 2, the holes were bottomed on 

hard material that is assumed to be limestone of the Hawthorn. 

Calcareous, sandy, phosphatic clay overlying the limestone at hole 3, 

and similar clay in holes 1 and 2 are tentatively correlated with the 

Hawthorn.

Bone Valley. The lower unit of the Bone Valley formation was 

penetrated in holes 1-3. The contact with the underlying Hawthorn

466862 59 6
250 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

is put at the top of the calcareous clay. Clayey sand of the upper 

part of the Bone Valley formation is present at all drill holes. The 

contact of the upper unit with the lower unit is placed at the appearance of calcium phosphate nodules.

Terrace sand. Loose quartz sand, tentatively assigned to the 

Pleistocene, was cut by each drill hole. The contact with the upper 

Bone Valley formation is placed at the base of the iron-stained loose 

sand.

ECONOMIC GEOLOGY

The calcium phosphate zone is present at holes 1-3 (see p. 288). At 

holes 2 and 3 the zone includes phosphate deposits of both the lower 

part of the Bone Valley and the Hawthorn formation. The basal 

calcareous clay at hole 1 was excluded from the calcium phosphate 

zone because of probable very low tonnages. The analyzed material 

from hole 4, although it is not too different in phosphate content from 

the material in other drill holes, is excluded from the calcium phosphate zone because it is in a limestone that would be very difficult to 

mine and process.

The aluminum phosphate zone is present at holes 2 and 4. The 

zone was delimited by the use of the gamma-ray logs. The material 

of sample 42, hole 1, contains aluminum phosphate minerals but was 

excluded from the aluminum phosphate zone because the computed 

head analysis would be too low in phosphate and uranium content.

CROSS SECTION 6

STRATIGRAPHY

Hawthorn. Limestone was penetrated only by hole 3. The limestone contains abundant phosphate particles, sand, and clay and is 

therefore considered to be a part of the Hawthorn formation. The 

remaining holes in this line bottomed on a hard material from which 

no core was recovered. This material is tentatively considered to be 

limestone of the Hawthorn formation. The calcareous, sandy, 

phosphate-bearing clay at the bottom of each hole is considered to be 

Hawthorn. Except at hole 5, the phosphate particles in the calcareous 

clay contain very low amounts of P2O5 .

Bone Valley. The lower phosphorite unit of the Bone Valley is 

present at holes 1-3, but is absent from holes 4 and 5. The contact of 

the Bone Valley with the Hawthorn in these holes is placed at the top 

of the calcareous clay. In addition, the phosphate particles of the 

Bone Valley contain much higher amounts of P2O5 than the phosphate particles in the calcareous clay of the Hawthorn (see p. 274). 

The upper, clayey sand of the Bone Valley formation is present at all 

drill holes. This unit contains trace amounts of apparently un-
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 251

leached phosphate particles at holes 3 and 4. The material is leached 

at holes 1 and 2 where aluminum phosphate minerals are present.

Terrace sand. The loose surficial sand shows evidence of a typical 

Leon soil profile. At holes 2-5, the loose white surficial sand is 

underlain by iron-stained and organic sands, which in turn is underlain by brown and tan loose sand. The contact of the Pleistocene 

with the Bone Valley formation is placed at the top of the clayey 

sand where the iron staining becomes insignificant. At hole 5 the 

contact is placed in the middle of the section of core that was not recovered, at the point where there is a slight rise in the gamma-ray log. 

This rise probably coincides with an increase in clay content.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by holes 1-3, where 

it is entirely within the lower unit of the Bone Valley formation. 

Analyzed material below the calcium phosphate zone, in the Hawthorn 

formation, contains too little P2O5 to be economic; this material is 

therefore not considered a part of the calcium phosphate zone. (See 

p. 288.) Phosphate-bearing calcareous clay of the Hawthorn formation in holes 4 and 5 is excluded from the calcium phosphate zone 

because of excessive thicknesses of overburden and too little tonnage 

of phosphate.

The aluminum phosphate zone is present at holes 1, 2, and possibly 

at hole 3. The top contact in each of these holes is placed at the rise 

in the gamma-ray log; the basal contact, at the appearance of calcium 

phosphate particles. At hole 3, the material called aluminum phosphate zone because of the rise in the gamma-ray log contains phosphate nodules, and may be calcium phosphate zone.

CROSS SECTION 7

STRATIGRAPHY

Hawthorn. Limestone core was recovered only from hole 4; all 

other holes bottomed in hard material, presumed to be limestone of the 

Hawthorn. Sandy, clayey, phosphate-bearing, calcareous clay at 

the bottom of all holes is tentatively correlated with the Hawthorn.

Bone Valley. The lower, phosphorite unit of the Bone Valley 

formation was penetrated by all drill holes. The contact of the Bone 

Valley with the Hawthorn is the top of the calcareous clay. P2O5 

contents of the phosphate nodules are higher above this contact than 

below it. The upper, clayey sand of the Bone Valley formation was 

also penetrated by all drill holes in this line.

Terrace sand. Loose white surficial sand is underlain by ironstained and cemented and highly organic sand, which in turn is 

underlain by brown loose sand, probably forming a soil profile; these
252 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

are tentatively assigned to the Pleistocene. The contact of the 

Pleistocene with the underlying Bone Valley is at the top of the 

clayey sand. This contact generally coincides with a rise in the 

radioactivity, as shown by the gamma-ray logs.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by all drill holes; however, stratigraphically this zone is made up of Bone Valley, Hawthorn, 

or both, in this section. The zone is composed of both Hawthorn 

and Bone Valley at holes 1-4. The entire calcium phosphate 

zone at hole 5 is represented by the lower unit of the Bone Valley 

formation.

The aluminum phosphate zone is present only at holes 1-3 where 

it is delimited by the high peaks on the gamma-ray logs. The high 

peak at hole 4 is apparently entirely within the calcium phosphate 

zone, and radioactivity as shown by the gamma-ray log at hole 5 

is only about twice background, too low for the clayey sand to be 

considered possibly economic.

CROSS SECTION 8

STRATIGRAPHY

Hawthorn. Although no limestone cores were recovered from any 

of the drill holes, each hole bottomed on hard material, presumed to 

be limestone, probably of the Hawthorn formation. The green, calcareous sandy clay and clayey sand at the bottom of holes 1, 2, and 4, 

are tentatively correlated with the Hawthorn, because of their high 

phosphate content, color, and general appearance. At hole 3, phosphorite of the Bone Valley formation rests directly on the hard 

material.

Bone Valley. The lower, phosphorite unit of the Bone Valley is 

present at all drill holes. The material consists of quartz sand and 

coarse black phosphate particles, with only a small amount of clay. 

The screen analyses (see p. 275) show that the clay content of the Bone 

Valley is less than the clay content of material correlated with the 

Hawthorn. The upper, clayey sand of the Bone Valley formation 

was penetrated by holes 1 and 3, and is absent at holes 2 and 4. The 

upper contact of the lower unit of the Bone Valley is put at the rise 

in the gamma-ray log.

Terrace sand. Loose quartz sand at the surface, iron-stained or 

cemented sand, and highly organic sandy clay are all tentatively correlated with the Pleistocene. Organic sand is close to the surface 

at holes 1 and 4, but at holes 2 and 3, a very highly organic sandy 

clay is at the base of the Pleistocene.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 253 

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by all drill holes. The 

coarse fraction (pebble) is invariably too low in P2O8 content to be 

economic, but the concentrate fraction is, in most of the samples, high 

enough in phosphate content to be considered economic. Material 

from both the Bone Valley and Hawthorn has been included hi the 

calcium phosphate zone, except at hole 3, where a thin gravel probably representing the base of the Bone Valley rests on hard material 

that was not recovered. Generally, the phosphate particles in the 

Hawthorn are somewhat lower in P2O5 content than are the particles 

in the Bone Valley.

The aluminum phosphate zone is not present in this cross section. 

Clayey sand of the upper part of the Bone Valley is present only at 

holes 1 and 3, and gamma-ray logs indicate this clayey sand contains 

no abnormal radioactivity. At holes 2 and 4, sand of the Pleistocene 

rests on the lower, phosphorite zone of the Bone Valley.

CROSS SECTION 9

STRATIGRAPHY

Hawthorn. Limestone, assigned to the Hawthorn on the basis of 

lithologic character, was recovered only from hole 12; the remaining 

holes in this cross section bottomed on hard material, presumed to 

be limestone of the Hawthorn formation. Green, calcareous, clayey 

sand, containing phosphate nodules, was cored in each drill hole, and 

ranges in thickness from less than 2.0 feet in holes 1, 2, and 6, to a 

maximum of about 30 feet in hole 9. The calcareous sand is tentatively correlated with the Hawthorn. Phosphate nodules in the 

calcareous sand contain lower amounts of P2O5 than the phosphate 

nodules in the noncalcareous sand above them. 

Bone Valley and Hawthorn is shown on pages 276-277; the Hawthorn 

formation was penetrated by each drill hole. The unit is a quartz 

sand, with a high percentage of dominantly black phosphate nodules. 

The upper, clayey sand unit of the Bone Valley formation was also 

present at each drill hole, except for hole 6, where loose white sand 

overlies the lower unit. At the south end of the cross section, in holes 

10-12, the upper unit contains traces of fresh appearing, black phosphate nodules; these nodules are not present in the upper zone in 

holes 1-9. This may indicate that the clayey sand in the south end 

of this cross section was not leached.

Terrace sand. Loose white quartz sand, iron stained in holes 2, 3, 

and 8-12, is tentatively correlated with the Pleistocene.
254 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM 

ECONOMIC GEOL.OGY

The calcium phosphate zone was penetrated by each drill hole in 

cross section 9. The zone ranges in thickness from about S feet at 

hole 11, to 41 feet at hole 9, and includes phosphate of both the Bone 

Valley and Hawthorn formations. Phosphate of the Bone Valley 

was penetrated by every hole, but the calcareous clayey sand of the 

Hawthorn was not included in the calcium phosphate zone in holes 

2, 7, 8, and 10, because of the low content of P2O5 in the phosphate 

nodules. The variation in phosphate content of the nodules in the 

Bone Valley and Hawthorn is shown on pages 276-277; the Hawthorn 

contains a higher percentage of concentrate fraction than does the 

Bone Valley. The ratio of pebble to concentrate fraction in the Bone 

Valley formation is always more than one; while in the Hawthorn the 

ratio is lower, and in most cases is less than one. In general, the 

phosphate content of the nodules is highest at the north end of the 

section, decreases to the south, to hole 11, where there is a rise in 

phosphate content. The reasons for this variation are not immediately 

apparent.

The aluminum phosphate zone is present at holes 1-9, except for 

hole 6, where no clayey sand is present, and loose sand of the Pleistocene is in contact with the lower unit of the Bone Valley formation. 

This may represent an old stream channel, where the clayey sand of 

the upper Bone Valley was removed by erosion. At holes 10-12, the 

upper, clayey sand unit of the Bone Valley contains small to trace 

amounts of apparently unleached phosphate nodules; no aluminum 

phosphate minerals are present in the clayey sands. In the area of 

these holes, the Bone Valley formation apparently was not subjected 

to weathering. No samples of the aluminum phosphate zone were 

analyzed, the zone is delimited entirely by the gamma-ray logs; the 

upper contact is placed at the sharp rise in radioactivity (pi. 24). 

The lower contact of the zone is put at the point where phosphate 

nodules become abundant and high in P2O5 content, as shown by 

analysis. (See p. 276.) The zone is thickest at hole 1, gradually 

decreases in thickness to hole 6, and then increases again in hole 7. 

The zone is more or less constant in thickness in holes 7-9, and is 

absent in holes 10-12.

CROSS SECTION 10 

STRATIGRAPHY

Hawthorn. The limestone, which was cored at most drill holes but 

contained identifiable fossils only at hole 8, is classed as Hawthorn because of its high phosphate content and abundant sand and clay impurities. The light-green calcareous clayey sand or sandy clay con-
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 255

taining a high percentage of fine-grained typically amber or black 

phosphate nodules is tentatively correlated with the Hawthorn. The 

calcareous sandy clay is present at holes 1-12, but is absent at holes 

13-16, where the only material assigned to the Hawthorn is the basal 

limestoneUnnamed sand and limestone. Fossils from limestone in hole 14 

were classed as late Miocene(?). (See fossil list, p. 232.) A darkolive-green to gray calcareous, clayey, micaceous sand in holes 12,13, 

15, and 16, is lithologically similar to fossiliferous sand of the unnamed unit in cross section 12, hole 6 and cross section 15, hole 6. Thus 

this sand is tentatively correlated with the unnamed unit. This sand 

is not lithologically like any other material in cross section 10. The 

material also contains shell fragments, which were not identifiable.

Bone Valley. The lower, phosphate-bearing unit was penetrated 

by drill holes 1-14. It is a noncalcareous clayey sand and typically 

contains white or gray phosphate particles that tend to be coarser in 

size than the amber phosphate material of the Hawthorn. The upper, 

clayey sand unit of the Bone Valley was penetrated by all drill holes. 

It thickens somewhat on the topographic highs (see holes 3 and 6, pi. 

25) and is somewhat thicker in the southern part of the section. The 

material is white and slightly clayey and the quartz sand fraction 

tends to be somewhat coarser than the material below or above it. The 

color of the clay in the unit tends to become darker toward the south.

Terrace sand. Loose quartz sand tentatively correlated with the 

Pleistocene was penetrated by each drill hole. Organic material below 

the loose sand was also, and rather arbitrarily, placed in the Pleistocene, as was done in other lines of drill holes.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by drill holes 1-14. (See 

p. 278.) The zone is made up of both Bone Valley and Hawthorn in 

roughly equal amounts at holes 1-10. However, at hole 11, the calcareous clay of the Hawthorn makes up the entire calcium phosphate 

zone; at hole 12, only the top part of the calcareous clay contains 

enough phosphate of high enough grade to be possibly economic; at 

holes 13 and 14, the entire calcium phosphate zone is within the Bone 

Valley formation; and at holes 15 and 16, where the lower unit of the 

Bone Valley formation and calcareous clay of the Hawthorn formation were not penetrated, the phosphate-bearing material is assigned 

to the unnamed unit and it is much too low in tonnage and percent 

P2O5 to be economic. This cross section (pi. 25) is a good example 

of the crossing of stratigraphic lines by the calcium phosphate zone, 

particularly between holes 12 and 13.
256 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

The aluminum phosphate zone was present at all holes in this cross 

section except for holes 13 and 15, where the clayey sand, as shown by 

the gamma-ray logs, was not abnormally radioactive. Samples of the 

aluminum phosphate zone were taken from a few of the cores, but in 

general, the zone is delimited, at the top, by the rise in the gamma-ray 

log, and at the base, by the contact with the calcium phosphate zone.

CROSS SECTION 11 

STRATIGRAPHY

Hawthorn. Fossils from limestone cores at the bottom of holes 

1, 5, and 6 were identified as middle Miocene in age. Limestone cored 

in the other holes is lithologically similar to the fossiliferous material 

and is correlated with the Hawthorn. Green calcareous sandy clay 

containing phosphate nodules overlies the limestone at holes 1,2,7, and 

8, and is tentatively correlated with the Hawthorn. The contact of the 

Hawthorn with the Bone Valley formation is put at the top of the 

calcareous clay at holes 1 and 2, and at the top of the limestone at holes 

3,4, and 5.

Unnamed sand and limestone. Dark-olive calcareous sandy clay, 

containing black phosphate nodules and mica flakes, is lithologically 

similar to the fossiliferous beds of the unnamed unit in cross sections 12 and 15, and is tentatively correlated with that unit. This material is present at holes 6-8.

Bone Valley. The lower, phosphorite unit of the Bone Valley 

formation is present at holes 2-5. The lower unit overlies calcareous 

clay of the Hawthorn at holes 1-3, and limestone of the Hawthorn at 

holes 4 and 5. The lower unit is absent at holes 1 and 6-8.

The upper unit of the Bone Valley formation was penetrated by 

all drill holes. It is thinnest at hole 1, thickens markedly at hole 2, 

and remains thick in the other holes of this line. The lower part of 

the upper unit contains traces of phosphate nodules at holes 3 and 

5-8. The contact of the lower unit with the upper unit of the Bone 

Valley formation is put at the point below which the phosphate content rises sharply.

Terrace sand. Loose surficial iron-stained quartz sand, containing 

organic material, is tentatively correlated with the Pleistocene. This 

sand is present at all drill holes.

ECONOMIC GEOLOGY

The calcium phosphate zone is absent from holes 1 and 8; in the 

remaining holes it represents different stratigraphic intervals. For 

example, at holes 2, 4, and 5, the calcium phosphate zone is the lower 

unit of the Bone Valley formation; at hole 3 it is both Bone Valley
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 257

and Hawthorn; and at holes 6 and 7 it is the lower part of the unnamed sand and limestone unit.

The zone is economic in holes 2 and 3, but because of low grade, 

is questionably economic in holes 4 and 5. The zone is covered by 

thick overburden at holes 6 and 7, and is also very low grade, particularly in the pebble fraction (see p. 281). For these reasons, the zone 

is probably not economic at holes 6 and 7.

The aluminum phosphate zone is present at holes 2-4, but is thin, 

and is high in the section of clayey sand of the upper unit of the Bone 

Valley formation. It is therefore, probably not economic in these 

holes. The zone was delimited by the use of the gamma-ray logs in 

all of these holes. The analyzed samples are too low in uranium content to be economic. The phosphate content of the slime (D) fraction of samples 49, 52, and 54 is high, which indicates the presence of 

aluminum phosphate minerals. It is possible that the thick sections 

of clayey sand in these drill holes could be economic for alumina, 

phosphate, and uranium, if the three-product process is used.

CROSS SECTION 12

STRATIGRAPHY

Hawthorn. Fossils, identified as middle Miocene in age, were identified from limestone cores at holes 1 and 8, and from a conglomerate 

at hole 6. Limestone cored at holes 2 and 3 is assigned to the Hawthorn on the basis of lithologic character, and holes 4 and 6 bottomed 

on hard material presumed to be limestone of the Hawthorn. Green 

calcareous sandy clay, containing abundant phosphate, was intersected 

by holes 1^, and is tentatively correlated with the Hawthorn. The 

contact of the Hawthorn with the lower unit of the Bone Valley at 

holes l-A is placed at the top of the calcareous clay. The contact of 

the Hawthorn with the unnamed sand and limestone unit is located on 

fossil evidence at the top of the limestone at hole 8; at hole 6, it is 

put at the contact of the fossiliferous conglomerate of the Hawthorn 

with the olive-green calcareous clayey sand.

Unnamed sand and limestone. Fossils, identified as late middle 

Miocene in age, were found at hole 8 in an olive-green slightly calcareous clayey sand that contained flakes of mica and low-grade black 

phosphate nodules. This clayey sand is assigned to the unnamed sand 

and limestone unit. Lithologically similar material overlies the conglomerate at hole 6; this material is tentatively correlated with the 

unnamed unit. At hole 8, the upper contact of the fossiliferous material is put at the contact of this material with a phosphate and 

quartz sand that is in sharp contact with the calcareous clayey sand 

beneath. Holes 1-4 did not intersect any material lithologically like

466352 59 6
258 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

the fossiliferous unnamed material in hole 8. It is believed that this 

material was not deposited on or to the west of the ridge on which hole 

4 was drilled.

Bone Valley. The lower, phosphorite unit of the Bone Valley 

formation was penetrated at holes 1-4 and 8 where it is a sand or 

clayey sand containing abundant white phosphate nodules. The 

nodules are somewhat coarser than those in the underlying Hawthorn. 

The lower unit apparently was not deposited at the location of hole 

6. The upper, clayey sand unit of the Bone Valley formation was 

penetrated by all holes. The unit thickens markedly to the east to 

the location of hole 6, then thins somewhat at hole 8. The upper contact of the clayey sand unit of the Bone Valley formation is placed at 

the base of the iron-stained loose sand of the Pleistocene at holes 2, 3, 

and 6, and at the base of the loose sand at holes 1,4, and 8.

Terrace sand. Holes 1, 2, 6, and 8 penetrated only loose or slightly 

iron-stained quartz sand of probable Pleistocene age. At holes 3 

and 4, however, the section is somewhat different. At these holes the 

section of core represented by samples 70 and 73 contained lumps and 

fragments of aluminum phosphate cemented sand and fragments of 

calcium phosphate. (See sample 73 A, p. 282.) At both holes, this 

material is underlain by thick sections of loose quartz sand. The 

material in these samples appears to be reworked; it is therefore correlated with the Pleistocene rather than the Bone Valley. At hole 4, 

from a depth of 14.5 to 28.6 feet, a red and white mottled clayey sand 

was cored. This material is lithologically unlike anything else in the 

cross section and is higher than the collar elevations of the other 

drill holes. The material is lithologically similar to material called 

Citronelle by Cooke (1945, p. 230). It is correlated with the Pleistocene in this cross section because of its elevation and position and 

because it is underlain by loose sand, and the possible reworked aluminum phosphate zone material of sample 73.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by holes 1-4, and 

consists of phosphorites of both the Bone Valley and the Hawthorn. 

The phosphate nodules in cores from these holes are high in P2O5 

content and contain more concentrate than pebble. The calcium 

phosphate zone is probably economic at holes 1-3; but because of its 

depth is probably not economic at hole 4. Calcium phosphate nodules 

are present at holes 6 and 8, but are too deep, and too low in tonnage 

and grade to be possibly economic; they are not considered a part of 

the calcium phosphate zone.

The aluminum phosphate zone was penetrated at holes 1-3 where 

it includes the entire upper, clayey sand unit of the Bone Valley
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 259

formation. Cores from holes 1 and 2 were sampled, but no sample 

was taken of the aluminum phosphate zone at hole 3; the zone is 

delimited by the sharp radioactivity peak shown by the gamma-ray 

log. (See pi. 27.) Although thick clayey sands of the upper Bone 

Valley were penetrated at holes 4, 6 and 8, the material was not above 

background radioactivity as indicated by the gamma-ray logs. This 

material is not considered a part of the aluminum phosphate zone. 

At holes 3 and 4, an upper zone of possibly reworked aluminum 

phosphate material was penetrated, and this material was analyzed. 

The material represented by sample 70 contains very high phosphate 

and uranium in the slime fraction. It is possibly economic. The 

material of sample 73, while lithologically similar, is not as high 

grade; it is of questionable economic importance.

CROSS SECTION 13 

STRATIGRAPHY

Hawthorn. The impure limestone cores from the bottom of holes 

1, 2, and 5 contained fossils identified as middle Miocene in age. The 

remainder of the drill holes bottomed in lithologically similar limestone, tentatively correlated with the Hawthorn. Calcareous clay at 

holes 1 and 2 is tentatively assigned to the Hawthorn.

Unnamed sand and limestone. Dark-olive-gray calcareous, micaceous clayey sand and sandy clay, containing black phosphate particles, overlie limestone of the Hawthorn at holes 3-8. These dark 

sands are lithologically like material in hole 6, cross section 12, which 

contained fossils of late middle Miocene age. They are therefore 

tentatively assigned to the unnamed sand and limestone unit.

Bone Valley. The lower, phosphorite zone of the Bone Valley was 

penetrated only at holes 1 and 2; it is apparently absent from the 

locations of holes 3-8. The bottom contact of the Bone Valley at 

holes 1 and 2 is placed at the top of the calcareous clay of the 

Hawthorn. The upper, clayey sand unit of the Bone Valley is divided 

into a lower, fine-grained clayey sand and an upper, coarser clayey 

sand. The clay fraction is very minor and is white. The contact of 

the upper unit of the Bone Valley with the unnamed unit is placed 

at the top of the dark-olive micaceous phosphate-bearing sand at 

holes 3-8.

Terrace sand. Loose surficial quartz sand is tentatively correlated 

with the Pleistocene. In addition, a red and white mottled clayey 

sand at holes 1 and 5, lithologically similar to the clayey sand of 

hole 4, cross section 12, is considered a part of the Pleistocene. (See 

discussion of cross section 12, page 257.)
260 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by all drill holes in 

this line, except for hole 8. The zone includes both Hawthorn and 

Bone Valley at holes 1 and 2. At holes 3-7, the calcium phosphate 

zone is a part of the unnamed unit. The zone is probably not economic at holes 3-7 because of excessive thickness of overburden, but 

it is high in P2O5 and in tonnage. At hole 8, the zone contains too 

little phosphate of too low grade to be economic, thus it is not considered a part of the calcium phosphate zone at this location.

The aluminum phosphate zone, at holes 1 and 2 is a part of the 

Bone Valley formation; at holes 3 and 4, it is a part of the unnamed 

unit. The zone is not present at holes 5-8. The zone was delimited 

by the high radioactivity of the gamma-ray logs at holes 1 and 2; at 

holes 3 and 4 a sample representing the high peak section of the 

gamma-ray log was split out from the core and analyzed.

CROSS SECTION 14

STRATIGRAPHY

Tampa. Cores at the bottom of holes 7 and 8 contained fossils of 

early Miocene age. Nonfossiliferous limestone cores at the bottom 

of holes 3 and 4 were similar in lithology to the f ossilif erous material; 

this limestone is tentatively correlated with the Tampa.

Hawthorn. Limestone cored at holes 1 and 2 is impure (sandy, 

clayey, and containing phosphate nodules); it is lithologically similar to the Hawthorn and is hence put in that unit. Green, calcareous 

sandy clay, containing abundant phosphate nodules at holes 1, 2, 4, 

7, and 8, is tentatively correlated with the Hawthorn.

Unnamed sand and limestone. Olive-green calcareous phosphatebearing micaceous clayey sand and sandy clay at the location of holes 

3-8 are lithologically similar to the material of hole 6, cross section 

15, and are tentatively correlated with the unnamed sand and limestone unit. The material is lower in elevation than the limestone of 

hole 2, and forms an eastward thickening wedge of lithologically distinct material.

The upper contact of this material is placed at the base of the 

slightly clayey sand of the upper part of the Bone Valley, at a distinct lithologic break.

Bone Valley. The lower, phosphorite zone of the Bone Valley is 

present only at hole 1. The contact of this unit with the underlying 

Hawthorn is placed at the top of the green calcareous clay.

The upper, clayey sand unit of the Bone Valley formation is present at all locations in this line. The unit consists of an upper, coarse-
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 261

grained sand, with a minor amount of white clay, and a lower, fine 

to very fine grained sand, with a minor amount of white clay.

Terrace sand. Loose iron-stained or cemented white quartz sand 

at the surface at each drill hole location is tentatively correlated with 

the Pleistocene. The basal contact of the terrace sand is placed at 

the bottom of the iron-stained sand and at the point where the sand 

becomes slightly clayey. At hole 8, the bottom half of the terrace 

sand is the red and white mottled slightly clayey sand lithologically 

similar to material in cross section 12 (pi. 27). It is arbitrarily 

placed at the base of the Pleistocene.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by holes 1 and 2. At 

liole 1, the zone consists of phosphorite from both the Hawthorn and 

the Bone Valley; at hole 2, the zone is entirely within the Hawthorn. 

Phosphate above the limestone at hole 3 is correlated with the unnamed unit. It is not put into the calcium phosphate zone because 

of low P2O5 content (see p. 284), low tonnage, and excessive depth of 

overburden. Phosphate at holes 4, 7, and 8, is not put into the calcium phosphate zone because of excessive overburden thickness. The 

phosphorite was so deep and contained so few phosphate nodules at 

these holes that it was not sampled.

The aluminum phosphate zone is present only at hole 1. Analysis 

of sample 94 showed the slime (D) fraction to be high in phosphate 

and uranium and low in calcium (see p. 284). The material represented by sample 97 at hole 2 is possibly aluminum phosphate zone, 

but the analysis is probably too low in phosphate and uranium for 

the material to be economic. Gamma-ray logs indicated no abnormal 

radioactivity at holes 3 and 4. At holes 7 and 8, the high peak of the 

gamma-ray log is probably aluminum phosphate material, but the 

excessive depth of overburden makes it unlikely that this material is 

economic. Sample 3, hole 8, was taken of this high count material. 

The sample analyses indicate the material is calcium phosphate, with 

too low phosphate content to be economic.

CROSS SECTION 15 

STRATIGRAPHY

Ocala. Fossils from limestone cored at the bottom of hole 5 were 

identified as Eocene. Although no other fossiliferous limestone was 

cored in this line, the limestone at the bottom of the other drill holes 

is put in the Hawthorn on the basis of its lithologic character. If 

this is correct, both the Tampa and Suwannee limestones are not 

present, and it is possible that the location of hole 5 represents an
262 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

upthrown fault block. Because there is no indication of faulting 

above the Ocala, the faulting, if present, is at least pre-Bone Valley 

in age.

Hawthorn. Sandy, clayey phosphate-bearing limestone at holes 1, 

2, 4, and 6 is tentatively correlated with the Hawthorn. Calcareous 

phosphate-bearing sandy clay above the limestone in holes 1-5 is 

also tentatively correlated with the Hawthorn. The contact of the 

Hawthorn with the overlying Bone Valley is placed at the top of the 

calcareous clay.

Unnamed sand and limestone. Fossils from the bottom of a section 

of core of olive-gray micaceous, calcareous clayey sand, containing 

black phosphate nodules, were identified as middle(?) Miocene in 

age. This material assigned to the unnamed sand and limestone unit 

is lithologically distinctive and is present only at hole 8. It is overlain by a loose sand that contains brown and black phosphate nodules 

and is correlated with the Bone Valley. At the bottom of drill hole 

8, the unnamed unit rests on limestone correlated with the Hawthorn.

Bone Valley. The lower, phosphorite unit of the Bone Valley 

formation was penetrated by all drill holes. The unit is a clayey sand 

that contains brown, tan, gray, and white phosphate nodules. The 

unit rests on calcareous clay of the Hawthorn in all drill holes except 

hole 8, where it rests on the unnamed olive micaceous clayey sand.

The upper, clayey sand unit of the Bone Valley consists of a medium 

to coarse-grained slightly clayey sand. The clay fraction is white.

Terrace sand. Loose white to slightly iron-stained sand at the 

surface at each drill hole location is correlated with the Pleistocene. 

In addition, a mottled red and white slightly clayey sand was penetrated at holes 3-5. This material is lithologically distinct and 

similar to the material in cross section 12. At hole 3, it is high in the 

section, at holes 4 and 5, it forms the basal part of the Pleistocene. 

The base of the Pleistocene at hole 2 is put at the base of the sand 

with some phosphate particles. The phosphate in this section of core 

consists of fine-grained, angular fragments. It appears to be broken 

particles of phosphate nodules and is thought to be reworked.

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated by all drill holes except 

for hole 6. The zone is entirely within the Bone Valley at holes 1-4, 

but consists of both Hawthorn and Bone Valley at hole 5. At hole 6, 

the phosphate is deep, low in P2O5 content, and low in tonnage; this 

material is not included in the calcium phosphate zone. The phosphate at holes 3 and 4 is covered by a thick section of barren material 

(overburden) and is probably not economic for that reason.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 263

The aluminum phosphate zone is present at holes 1 4. At these 

holes the top contact of the aluminum phosphate zone is taken at the 

mid-point of the sharp rise in radioactivity as shown by the gammaray logs (pi. 30). The zone is uniformly thin, and is covered by thick 

barren quartz sand ; it is probably not economic in this section.

CROSS SECTION 16

STRATIGRAPHY

Ocala. Fossils from limestone at the bottom of holes 1 and la were 

identified as Eocene in age. As mentioned in the discussion of cross 

section 15, the Ocala limestone here may be in an upthrown fault block.

Hawthorn. Limestone cored at the bottom of holes 1 and 3 are 

assigned to the Hawthorn on the basis of lithologic character. In 

addition, calcareous sandy phosphate-bearing clay above the limeetone at all holes except 4, is tentatively correlated with the Hawthorn. 

At hole 4 a thick section of green silty and sandy clay, phosphate 

bearing at the bottom and about the middle of the section, is tentatively correlated with the Hawthorn. This material may be equivalent 

to the Alachua( ?) and may represent a channel or sink-hole filling of 

reworked Hawthorn. The material is somewhat similar to the Hawthorn, but is also similar to material in cross section 17 that is called 

Alachua(?).

Bone Valley. The lower, phosphate unit of the Bone Valley formation is apparently not present in this section. The upper unit is 

divided into a lower stratum of slightly clayey fine-grained sand and 

an upper stratum of clayey coarse-grained sand. The clay fraction 

of the upper Bone Valley is white.

Terrace sand. Loose quartz sand, stained with iron and containing 

organic material at holes la and 2, is correlated with the Pleistocene. 

At hole 1, the middle part of the terrace sand consists of red and white 

mottled slightly clayey sand, and at hole 4, the bottom half of the 

terrace sand is composed of this material. The red and white mottled 

material is lithologically distinctive; it is arbitrarily placed in the 

Pleistocene. ( See discussion of cross section 12. )

ECONOMIC GEOLOGY

The calcium phosphate zone was penetrated at holes la, 2, and 5, 

and is entirely within the Hawthorn formation. It is absent at the 

location of the remainder of the holes in this line.

The aluminum phosphate zone is present at holes 1, la, 2, 3, and 5. 

The zone is very thin, and questionably economic. Except at hole 5r 

where it is within the Hawthorn, the zone is the basal part of the 

Bone Valley.
264 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

CROSS SECTION 17

STRATIGRAPHY

Suwannee. Fossils from limestone at the bottom of holes 5, 6, and

were identified as Oligocene in age and the limestone is assigned 

to the Suwannee. Lithologically similar limestone cored at holes 3, 

7, and 8 is tentatively correlated with the Suwannee.

Tampa. Green sandy calcareous clay, containing chert fragments 

and nodules, contain fossils identified as early Miocene at holes 4 and 

9. Lithologically similar clay at holes 3, 5-8, and 10 are tentatively 

correlated with the Tampa. Impure limestone cored at hole 2 is tentatively correlated with the Tampa. At hole 3, the Tampa is overlain 

by calcareous phosphatic sandy clay of the Hawthorn. At holes 4-7 

the Tampa is overlain by slightly clayey sand of the upper part of the 

Bone Valley, and at holes 8-10 the Tampa is overlain by sandy clay 

of the Alachua(?).

Hawthorn. Calcareous sandy phosphate-bearing clay at holes 1-3 

is tentatively correlated with the Hawthorn. At holes 1 and 2, the 

calcareous clay is overlain by green clay or sandy clay, also assigned 

to the Hawthorn. The Hawthorn is overlain at holes 1 and 2 by white 

clayey sand of the upper part of the Bone Valley, and at hole 3, by 

phosphorite of the lower Bone Valley. The Hawthorn is absent at 

holes 4-11, although the material assigned to the Alachua( ?) at holes 

8-11 may be a residuum of the Hawthorn.

Alachua(f). Coarse- to medium-grained sandy clay, green to blue 

to shades of red and yellow and containing fragments of angular 

white phosphate, were penetrated at holes 8-11. This material is 

lithologically distinct. The material overlies clastic rock assigned to 

the Tampa at holes 8-10, and limestone of Oligocene age at hole 11. 

It is overlain by clayey sand of the upper Bone Valley at holes 8, 9, 

and 11, and by phosphorite of the lower part of the Bone Valley at 

hole 10. From its position in the section, and distinctive lithology, this 

material is tentatively correlated with the Alachua( ?) formation, although it is possible that the material is equivalent to the lower part of 

the Bone Valley.

Bone Valley. The lower, phosphorite unit of the Bone Valley was 

intersected only at holes 3 and possibly 10. The unit is absent in the 

remaining drill holes. At hole 3, the lower unit overlies calcareous 

clay of the Hawthorn ; at hole 10 the material overlies sandy clay of 

the Alachua (?) formation. In both cases the contact is distinct.

The upper, clayey sand unit of the Bone Valley formation was intersected at all drill holes. The unit is distinctive lithologically, consisting of medium- to fine-grained sand and minor amounts of white clay.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 265

The unit apparently contains aluminum phosphate minerals, as indicated by the rise in the gamma-ray logs, at most drill-hole locations.

Terrace sand. A thin blanket of loose quartz sand, stained with iron 

at some locations, was penetrated at each drill-hole location. The loose 

sand thickens at hole 10, at the ridge, and the thickening may be due 

to the increased elevation at this locality.

ECONOMIC GEOL.OGY

The calcium phosphate zone was penetrated at holes 1-3 andlO; it is 

absent at the remaining locations. At holes 1 and 2, the zone is entirely 

within the Hawthorn formation, while at holes 3 and 10, it is entirely 

within the Bone Valley formation. Analyses of the samples from 

holes 2,3, and 10 indicate the zone is probably economic.

The aluminum phosphate zone was penetrated at all drill holes. The 

zone is delimited by the high peak of radioactivity as indicated by the 

gamma-ray logs. The zone was not sampled in this cross section. 

Cross section 17 is an excellent example of the nature of the aluminum 

phosphate zone, and the way the zone crosses stratigraphic lines. At 

holes 4, 5,7,10, and 11, the entire upper unit of the Bone Valley formation is aluminum phosphate zone. At holes 3, 8, and 9, only the basal 

part of the upper Bone Valley is aluminum phosphate zone. At holes 

1 and 2 the basal part of the upper Bone Valley plus the top part of the 

Hawthorn make up the aluminum phosphate zone, and at hole 6, the 

aluminum phosphate zone is within the Tampa formation. Although 

the zone varies in radiation intensity, it is marked in every drill hole 

by a peak of radiation intensity. (See pi. 32.)

CROSS SECTION 18

STRATIGRAPHY

Hawthorn. Limestone cored at the bottom of hole 1 is impure, 

sandy, clayey, and phosphate bearing; it is correlated with the Hawthorn. Calcareous clay overlying the limestone at hole 1 is also lithologically similar to the Hawthorn and is similarly assigned. Green 

slightly sandy clay at the bottom of hole 4 is tentatively correlated 

with the Hawthorn. The contact of the Hawthorn with the Bone 

Valley at hole 1 is placed at the top of the calcareous, phosphatic clay. 

At hole 2, the Hawthorn-Bone Valley contact is placed at the base 

of the white slightly clayey sand of the upper part of the Bone Valley.

Bone Valley. The lower, phosphorite of the Bone Valley was penetrated at hole 1. The upper, slightly clayey sand of the Bone Valley 

was penetrated at holes 1 and 4. At hole 4, the upper, clayey sand of 

the Bone Valley rests directly on green sandy clay of the Hawthorn.

Terrace sand. Loose slightly iron-stained quartz sand that contains
266 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

organic material is correlated with the Pleistocene. The sand is present at both locations in this cross section.

ECONOMIC GBOTjOGY

The calcium phosphate zone was intersected only at hole 1, where 

it consists of the lower, phosphorite unit of the Bone Valley plus 

the top of the calcareous clay of the Hawthorn. No phosphorite is 

present at hole 4.

The aluminum phosphate zone was intersected by both drill holes 

of cross section 18. At hole 1, the zone is the lower part of the clayey 

sand of the upper part of the Bone Valley, while at hole 4 the aluminum phosphate zone is entirely within the Hawthorn. The zone was 

not sampled and was delimited entirely by use of the gamma-ray 

logs.

TONNAGE CALCULATIONS

ALUMINUM PHOSPHATE ZONE

Tonnages were calculated by a modification of the method used 

in the district for calculating the matrix tonnages. The method is 

based on the thickness of the deposit and the weight per cubic foot 

of rock in place.

A bed one foot thick contains 1,613 cubic yards per acre.

43,560 (square feet per acre) XI (thickness in feet) =43,560 cubic 

feet per acre-foot. (1)

43,560 (cubic feet per acre-foot)

 Tjri r^ « i r-- j7 =1613.33 cubic yards per acre-foot, 27 (cubic feet per cubic yard) J r

and, rounding, (2) 

1,600 X thickness (in feet) = cubic yards per acre. (3)

Cubic yards per acre is shown on all of the tables because the weight 

per cubic foot of aluminum phosphate zone material varies between 

wide limits. This figure may be changed to tons per acre by using a 

factor of 90 pounds per cubic foot, the approximate average weight 

of a cubic foot of aluminum phosphate zone material. This is equivalent to 2,430 pounds per cubic yard; 1.088 long tons per cubic yard, 

or 1.215 short tons per cubic yard.

CALCIUM PHOSPHATE ZONE (MATRIX)

The tonnage calculations used in this report are based on the thickness of the phosphate bed, its percentage of contained pebble or concentrate, and the specific gravity of the deposit. The phosphate companies use the weight of a cubic foot of matrix instead of the specific
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 267

gravity. For much of the area, this weight is about 125 pounds. 

Thus, the tonnage calculations are as follows:

Square feet per acre (43,560) X 125 _J______£._____v ' '_____

long ton (2240 pounds) 

or 2430=constant. 2430 X thickness (feet) X percentage of pebble 

(or concentrate) =tons of pebble (or concentrate) per acre. (5)

No correction was made for the variation in weight per cubic foot. 

However, this variation is small; computation shows that a change 

of 1 pound in weight of a cubic foot of matrix changes the total 

tonnage Y5 ton per foot of matrix for 1 percent of pebble, or concentrate.

Long tons are used in this report to conform with general practice 

in the phosphate field. Long tons can be converted to short tons 

(2000 pounds) by multiplying the given tonnage figure by 1.12.

2240

2000=1.12 (6)

Grade is shown in percent BPL (bone phosphate of lime) the conversion factor is :

P2O5 percent X 2.185=BPL percent. (7)

Tonnage data for both the aluminum phosphate and calcium phosphate zones are given on pages 287-295.

KEFEBENCES CITED

Altschuler, Z. S., and Cisney, E. A., 1952, X-ray evidence of the nature of 

carbonate apatite [abs.]: GeoL Soc. America Bull., v. 63, no. 12, pt. 2.

Bergendahl, M. H., 1956, Stratigraphy of parts of DeSoto and Hardee Counties, 

Florida: U. S. Geol. Survey Bull. 1030-R

Berman, Robert, 1953, A mineralogic study of churn drill cuttings from a 

well through the Bone Valley formation, Hilk'.borough County, Florida 

Cabs.] : Nuclear Science Abstracts, v. 7, no. ISA.

Brodkorb, Pierce, 1955, The avifauna of the Bone Valley formation: Florida 

Geol. Survey Kept. Inv. 14.

Carr, W. J., and Alverson, D. C., 1953, Stratigraphy of Suwannee, Tampa, and 

Hawthorn formations in Hillsborough and parts of adjacent counties, 

Fla., in Geologic investigations of Radioactive deposits Semiannual progress report, June I to Nov. 30, 1953: U. S. Geol. Survey TEI-390, U. S. 

Atomic Energy Comm., Tech. Inf. Service, Oak Ridge.

Cooke, C. W., 1915, The age of the Ocala limestone: U. S. Geol. Survey Prof. 

Paper 95.

 1945, Geology of Florida: Florida Geol. Survey Bull. 29.

Cooke, C. W., and Mansfield, W. C., 1936, Suwannee limestone of Florida 

[abs.] : Geol. Soc. America. Proc. 1935.

Cooke, C. W., and Mossom, D. S., 1929, Geology of Florida: Florida GeoL 

Survey 20th Ann. Kept.
268 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Ball, W. H., and Harris, G. D., 1892, Correlation papers Neocene: TJ, S. GeoL

Survey Bull. 84. 

Fowler, E. D., and others, 1927, Soil Survey of Polk County, Florida: TJ. S.

Dept. Agriculture Soil Survey Kept. 39.

Johnson, L. C., 1888, The structure of Florida: Am. Jour. Sci., ser. 3, v. 36. 

King, P. B., 1951, The tectonics of middle North America Middle North America east of the Cordilleran System: Princeton, N. J., Princeton Univ. Press.

203 p.

MacNeil, F. S., 1947, Correlation chart for the outcropping Tertiary formations of the eastern Gulf Coastal Plain: U. S. Geol. Survey Oil and Gas

Inv. Prelim. Chart 29. 

Mansfield, W. C., 1937, Mollusks of the Tampa and Suwannee limestones of

Florida: Florida Geol. Survey Bull. 15. 

Matson, G. C., and Clapp, F. G., 1909, A preliminary report on the geology

of Florida with special reference to the stratigraphy: Florida Geol. Survey

2d Ann. Rept. 

Mossom, D. S., 1925, A preliminary report on the limestones and marls of

Florida: Florida Geol. Survey 16th Ann. Rept. 

Palache, Charles, Berman, Harry, and Frondel, Clifford, 1951, Dana's system

of mineralogy, V. 2: 7th ed., revised, New York, John Wiley and Sons, Inc. 

Simpson, G. G., 1929, The extinct land mammals of Florida: Florida GeoL

Survey 20th Ann. Rept. 

 1930, Tertiary land mammals of Florida: Am. Mus. Nat. History Ball.,

v. 59, art. 11. 

Vernon, R. O., 1951, Geology of Citrus and Levy Counties, Florida: Florida

Geol. Survey Bull. 33.
BASIC DATA

269

CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 271

ANALYTICAL AND SCREEN DATA FOB CROSS SECTIONS 1-18

[Screen size: A, +14 mesh; B, 14 +35 mesh; C, 35 +160 mesh; D, 150 mesh; E, 35 +150 concentrate;

F, -35 +150 tailings]

Hole and

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PaO, CaO F Al8 0i U eU

Cross section 1

[All samples are from lot 2545. Chemical analyses by E. Campbell, L. Jenktas, I. H. Barlow, R. Smith, 

J. Smith, W. P. Tucker, J. Budinsky. Radiometric (eU) analyses by B. A. McCall, J. H. Goode, Jr.]

1-1 . ......

1-2 

1-3 .......

1-4.. 

1-5 _____

1-8 _____ .

1-7.. 

2-8..........

2-9 ......

8-10.........

8-11.........

8-ia.........

3-18.. 

4-14.........

4-18.........

3-18 .....

M7 ...

9.1-10.8

10. 8-18. 8

18. 8-19. 4

24.5-26.2

26. 2-32. 9

34. 1-37. 2

39. 6-41. 7

5.0-9.1

9. 1-12. 1

7. 1-20. 5

20.5-22.0

29. 5-57. 6

52. 4-78. 5

8.0-15.0

15.0-19.4

5.0-20.9

20. 9-57. 4

A 

B ___ ...

C 

D ..

A.. _

B 

C __ .....

D .....

B

C-... .... .

D... 

A. __ ....

B . ...

D _ ......

D ..... .

A.... 

B _ ......

C... ... ...

D. ...

A..... ....

B... ... ...

C. ........

D. ...

A.. __ ...

B.. ..

C. ........

D .........

A 

B. _ .....

C.. 

D ....

A. __ ...

B.........

C . 

D _ ......

A...... ...

B. ........

C... .

D 

A _ .. ....

B... ... ...

C 

D. ...

A_ 

B .

C. ........

D 

B_. __ ...

C.........

D.... .....

A .........

B...... ...

C. .

D _ . _ 

B.. ...... .

C 

D __ ....

B. ... ..

C.. .......

D ...

12.7

14.0

58.5

14.8

.4

9.4

70.0

20.1

13.2

53.0

33.8

1.4

1.4

97.2

99.1

1.0

1.6

67.4

30.0

2.4

3.9

50.8

43.0

.8

8.1

72.9

18.2

1.8

12.4

54.8

31.0

.4

2.6

70.3

26.7

29.6

5.8

47.1

17.5

3.2

14.8

55.3

26.7

1.4

4.4

74.1

20.1

4.8

60.7

34.5

9.1

61.8

29.1

2.1

69.7

28.1

4.3

77.8

17.9

18.5

18.5

7.2

27.0

7.8

15.1

18.7

7.3

16.4

12.2

18.5

9.2

.55

9.0

3.74

4.12

9.70

38.10

12.30

23.60

29.6

10.6

0.84

.11

.10

.03

.60

2.93

1.34

1.61

.85

2.96

.83

1.70

2.40

.83

0.96

1.44

1.40

.61

.35

.21

26.5

30.4

14.6

12.8

28.5

25.0

14.9

29.4

0.021

<.001

.032

.013

.014

.001

.001

.002

.002

.012

.004

.003

.020

.021

.012

.002

.006

.006

.001

.002

0.005

.005

.002

.018

.005

<.001

<-001

.028

.005

.002

.011

.016

.006

.002

.001

.005

.004

.001

.002

.005

.002

.001

.002

.001

<.001

<.001

.002

.013

.003

.002

.005

.005

<.001

<.001

.003

.018

.005

.002

.018

.009

.002

<.001

.012

.001

<.001

< 001

.002

<.001

<.001

.004

<.001

<.001

.006

<.001

<.001

<.001

<.001

<-001

.001
272 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PsO» CaO P AlzOs U eU

Cross section 2

[All samples are from lot 2545. Chemical analyses by E. Campbell, L. Jenkins, I. H. Barlow, R. Smith 

J. Smith, W. P. Tucker, J. Budinsky. Radiometric (eU) analyses by B. A. McCall, J. H. Ooode, Jr.]

1-18 

1.10

1-20 

1-21 

1-22 

3-23 

3-24.. 

3-25. ........

3-26 

3-27 ___ 

4-28. .

4-29. .

4-30 

13. 5-23. 1

23. 2-32. 9

42.7-57.9

57.9-60.5

67. 7-75. 9

10. 9-12. 9

14.0-15.6

15. 7-20. 1

20. 1-33. 9

36.0-43.0

6. 6-16. 7

16. 7-21. 9

22. 6-26. 4

A.... .....

B. ....... .

C. ........

D.........

A...... 

B. ....... .

C... 

D.. .......

A. .. ......

B_ 

C. 

D_ 

A .

B 

C.. 

D. ........

A.........

B.. ..

C. 

D...... ...

B. - 

C 

D 

A. 

CD ..

A... .

B. -

C. 

D .

A. 

B.. 

C. 

D. 

A.........

BC. 

D. 

B.. .

C 

D. 

A.. .

B.. 

C.. ...

D. ...

A..... 

B. ...... ..

C. 

D ...

0.4

11.5

70.2

17.9

A. 9

16.5

52.7

26.6

1.2

1.2

42.9

54.8

.1

.1

9 0

89.9

6.2

6.8

60.1

26.9

33.8 

53.8

12.4

.1

5.8

75.6

18.6

.4

3.7

49.5

46.4

.5

4.4

64.5

30.6

11.0

3.4

48.0

37.5

19.3

69.2

11.5

.1

9.7

58.4

31.8

2.2

13.7

50.2

33.7

6.9

18.5

14.4

18.4

27.6

........

12.1

7.3

16.0

9.6

14.3

1.30

1.00

2.30

25.7

36.2

........

5.6

2.8

8.1

4.4

10.3

0.25

0.86

0.77

1.96

2.82

..........

.56

.33

.83

.63

.84

31.0

32.0

..........

32.0

24.4

0.011

.018

.031

.003

.010

.006

.019

.003

.006

.024

.001

flOO

.022

.022

.006

.001

.002

.009

.004

.005

0.005

<.001

<.001

.00&

.017

.003

.002

.036.

.003.

.003

.004

.003

.011

. .007

.005

.005

.020

.009"

.001

.002

<.001 

<.001

.006

.026

.004

.001

.020

.021

.003

.001

.019

.008

.003

<.001

.007

<.001

.002

<.001

.001

<.001

<.001

.003

<.001

<.001

.003

.004

.001

<.001

.005

Cross section 3 - '

[All samples are from lot 2545. Chemical analyses by S. Bethea, E. Campbell, L. Jenkms, I. H. Barlow, 

R. Smith, J. Smith, W. P. Tucker, J. Budinsky. Radiometric (eU) analyses by B. A. MeCall, J. H. 

Qoode, Jr.]

1-31 

1-32 .

1-33 

14. 9-16. 1

28.4-43.5

43. 6-59. 9

A...... ...

B 

C 

D 

E. ........

F.. . ......

A 

B 

C. ........

D.........

A.........

B. 

C... 

D 

19.2

17.1

43 0

7.9

12.9

3.2

16.3

44.5

36.0

.9

2.4

40.2

56.5

36.1

31.2

36.5

30.9

49.6

42.3

27.8

49.0

42.6

4.07

3.36

2.07

3.85

3.43

12.4

0.010

.010

.005

.012

.001

.001

0.012

.010

.006

.013

.004

.006

.001

.001

.002

.002

.002

.001

.002
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 273

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

P.O. CaO F A12 08 U eU

Cross section 3 Continued

2-36.........

2-37 .........

4-34.........

4-38... ......

5. 0-13. 1

13. 1-18. 1

6.9-14.0

21.8-22.9

A.........

B. . .......

C. .. ......

D 

A...... ...

B __ . ...

D. ........

E._... _ .

P..... .

A.........

B.. .......

C... ......

D.........

A.. .

B. ........

C.. .......

D... ......

fi Q

29.8

49.3

13.9

7.4

24.2

40.6

2.0

25.7

1.8

12.9

64.0

21.3

.1

6.0

43.0

60.0

7.2

16.1

10.7

32.5

1.5

.4

.7

41.9

6.26

i na

.69

3.39

27.5

23.3

0.006

.008

.005

.006

.002

0.008

<.001

<.001

.006

.006

.002

.007

.006

.001

.004

<001

<.001

.006

.005

.002

<.001

.002

Cross section 4

IAU samples are from lot 2545. Chemical analyses by S. Bethea, E. Campbell, L. Jenkins, I. H. Barlow, 

R. Smith, J. Smith, W. P. Tucker, J. Budinsky. Radiometric (ell) analyses by B. A. McCall, J. H. 

Qoode, Jr.]

1-40... ......

1-41.........

2-38..... _ .

3-39 

19. 2-35. 9

35. 9-39. 9

17.6-24.5

28. 6-45. 4

A.. ...... .

B.........

C ..

D. __ ....

A.........

B.. 

C ....

D 

A.........

B. 

C

D. ........

A_.__ _____

B.. ....

C 

D ..... _

2.9

8.1

60.3

28.6

2.1

3.6

59.3

35.0

1.6

4.7

47.0

46.8

3.7

8.0

51.1

37.2

35.1

30.7

29.1

30.2

46.2

41.9

44.9

45.2

3.79

3.29

3.50

3.21

0.007

.003

.002

.001

0.013

.004

.002

.005

.006

.003

.002

.002

.012

.004

.003

.002

<.001

.002

.001

<.001

Cross section 5

I All samples are from lot 2545. Chemical analyses by S. Bethea, E. Campbell, L. JenMns, I. H. Barlow 

R. Smith, J. Smith, W. P. Tucker, J. Budinsky. Radiometric (eU) analyses by B. A. McCall, J. H. 

Qoode, Jr.]

1-42 

1-43 

2-44 

2-45 

3-46 ......

4-47 

49. 2-56. 1

56. 1-71. 9

28.1-34.6

34.6-48.9

22. 5-32. 8

21.4-26.2

A 

B. ....... .

C.... 

D....-_ 

A __ .....

B..._. .

C

D 

A. ....... .

B..... .

C. ______ _,

D .

»

B. .... 

D 

E. ,..___..

F.. .......

A. ........

B. 

D

E. ..___-.

F.. .____ 

A... 

B.. ... .

C..._. 

D... _-_-._

E. ....____

P. .

0.4

44.1

50.3

5.2

7.7

17.9

60.4

14.0

2.7

14.3

55.1

27.9

2

1

7.5

52.3

6.8

31.3

2.7

15.2

38.4

15.0

28.7

12.5

9.1

55.5

5.3

17.6

5.7

10.3

5.1

18.6

30.4

16.4

30.6

23.7

24.4

8.2

30.8

3.5

6.2

8.9

39.5

43.4

24.7

45.0

39.9

37.7

24.6

45.2

0.2

.4

.8

2.6

3.5

1.9

3.6

2.8

2.9

1.2

3.6

21.2

16.2

3.7

0.012

.004

.005

.001

.003

.017

.011

0.006

.001

<.001

.006

<.001

.004

.002

.002

.014

.008

.004

.004

.008

.006

<.001

.008

.009

.006

.006

.002

.008

.003

.015

.015

.004

.016

.006
274 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

Pa05 CaO P AljOs U eU

Cross section 6

[All samples are from lot 2545. Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, 

L. Jenkins, E. Campbell, I. H. Barlow, R. Smith. Radiometric (eU) analyses by J. H. Qoode, Jr., 

B. A. McCall]

1-48.........

1-49-. _ ....

1-50.........

1-61 ......

2-52.. ___ .

2-53- __ ..

3-54.. ......

3-55..__..._.

5-56

27. 2-37. 6

37.6-44.6

44. 6-54. 4

54. 4-69. 1

27. 1-32. 0

32.0-48.6

67. 2-68. 8

68. 8-71. 9

46. 3-48. 6

A.........

B. ....... .

C. . ....___

D... ......

A.........

B. ........

G. ...... ..

D. . .

A.. ... -

B ...__-

C..-_____.

D ......

A. ........

B. ........

D _

E. ........

F _ ......

A.........

B.. .......

C. ....... .

D... ......

A.........

B. ........

C. .___.._.

D.........

A. __ ....

B... ......

D.. _ . ...

E.... _ ..

F... __ .

A.........

B... __ ..

D.........

E. ........

F.._ _

A.. __ ..

B... ......

D. __ . ...

E. ........

F ___ . ...

0.1

1.2

72.3

27.5

6.0

12.5

56.2

25.4

1.5

13.3

16.8

68.6

.5

4.8

90.0

1 o

3.6

4.4

8.5

1.7

6.4

55.4

36.6

11.3

14.5

30.7

4. 4

39.1

94 n

13.8

35.9

3.0

23.3

5.0

10.0

35.0

19.5

30.5

3J.8

25.5

33.3

18.3

40.0

a 7

18.4

33.8

46.1

38.7

38.3

40.7

47.5

36.2

45.2

33.4

SO 7

37.6

43.8

3.8

3.0

2.4

3.1

4.1

2.3

3.6

1.1

1 0

1.7

3.2

0.003

.002

.008

.001

<.001

.016

.002

.001

.016

.003

<.001

.006

.001

0.005

.004

.002

.005

.008

.005

.002

.001

.009

.003

.002

.002

.DOS

.004

.001

.00ft

.001

.018:

.007

.002

.00$

.008

.002

.001

.002

.016

.008

.004

.011

<.001

.004

<.001

<.001

.004

<.001

.007

.007

.001

.009

.003

Cross section 7

[All samples are from lot 2545. Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, 

L. Jenkins, E. Campbell, I. H. Barlow. R. Smith. Radiometric (eU) analyses by J. H. Qoode, Jr., 

B. A. McCall]

1-57... . ....

1-58. ......

1-59. .......

2-60. ......

2-61- _ .....

30. 6-36. 1

36. 1-45. 5

20. 3-28. 1

28. 1-34. 4

A.........

B. ........

C. ........

D.........

A.. .......

B. ........

D .........

E... __ .

F. ___ ...

A.........

B. ....... .

D. ........

E...... ...

F. ........

A.. __ ...

B. ........

D. ___ ..

E. ........

F.. .......

A. ........

B. ........

D... _ ...

E.. __ ...

F.. .......

4.1

10.3

77.4

8.2

5.4

7.0

11.6

13.0

63.0

1.3

11.3

31.4

12.3

43.7

6.5

13.7

15.5

7.0

57.4

1.4

6 9

43.1

1 0

46.7

DO A.

11.1

32.8

32.5

30.8

13.2

<?4 1

31.6

38.4

38.5

8.8

47.0

46.1

44.7

12.6

37.9

afi 4

43.0

3.3

1.1

3.8

3.5

3.8

1.5

3.3

3.8

3.5

16.3

0.034

.044

.005

.002

<.001

.006

.001

0.036

.012

.003

.045

.015

.006

.002

.008

<.001

.010

.005

.001

.007

<.001

.014

.006

.006

.011

.001

.012

.005

.002

.010

.002
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 275

Hole and 

sample

Sample 

Interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PnOt CaO F A12 0, U eU

Cross section 7 Continued

2-62 _._._...

2-63. ____

3-64-..-.- 

4-C5.... ...

4-66 _____

5-67.. ......

94 4_dS Q

45.9-63.1

39.8-51.5

39.9-56.0

56.0-65.9

41.4-73.0

A... 

B_ .....

D...... ...

E .........

F... ......

A. .... .

B... ...

D.........

E...-. .

F ____ .

A ... ...

B-.. 

D..--_..--

E .........

F ____ ..

A.........

B. _ .....

D ____ ..

E. ....... .

F... ......

A ......

B.. .......

D. ____ .

E. ........

F.........

A.. .......

B - ....

D ..... .

E. ........

F ____ ..

3.8

6.7

94 Q

7.8

56.9

1.4

5.2

42.1

6.7

44.6

1.7

6.6

34.6

6.9

50.2

4.5

14 ft

23.8

9.8

47.9

.5

6.4

47.0

8.8

37.3

1 Q

6.7

14.6

5.4

71.4

01 1

31.6

18.6

31.2

27.5

29.6

26.5

31.9

24.5

30.7

27.9

31.9

45.2

45.5

39.2

39.4

41.7

44.1

38.7

47.2

38.3

47.1

43.1

46.6

3.6

3.6

2.7

2.8

3.2

3.3

3.0

3.6

2.7

3.4

3.2

3.6

0.001

.001

.001

.006

.003

<.001

.002

0.012

.004

.002

.007

<.001

.009

.001

.001

.006

<.001

.011

.006

.002

.008

.001

.012

.006

.003

.008

<.001

.007

.005

<.001

.007

.001

.010

.004

.002

.007

<.001

Cross section 8

[All samples are from lot 2545. Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, 

L. Jenkins, E. Campbell, I. H. Barlow, R. Smith. Radiometric (eU) analyses by J. H. Qoode, Jr., 

B.A. Mcdall]

1-68.... ...

1-69-. _......

2-70 _.._._..

2-71 __

2-72 . 

2-73- __ ...

3-74... _ ...

51.0-83.0

83.0-94.0

39.2-52.4

57.5-77.8

77.8-83.5

83.5-87.5

60.0-62.4

A

B. ........

D.........

E. ........

F .........

A.. .

B.. - 

D. .....

E. _ . _ .

F .........

A --.-..

B... ...

D.........

E .........

F ____ ..

A..... .

B ......

D-. ...

E.. ___ .

F.........

B-. ....

D.........

E. ........

F ____ ..

A.. ....

B.........

D.. __ ..

E .........

F ____ ..

B.........

D.........

E.........

F.. .......

10.4

32.7

11.9

11.7

33.3

1.3

7.1

45.0

6.1

40.5

9.0

18.0

20.0

4.0

49.0

3.0

3.0

29.0

6.0

59.0

1.8

CO Q

2.5

37.0

8.5

18.0

6.5

6.2

60.8

51.0

2.0

2.0

3.7

41.3

16.8

O1 Q

18.4

27.1

18.6

31.5

13.5

28.5

28.7

13.3

28.9

13 ft

26.8

37.5

4.R 9

38.1

40.1

30.6

44.0

22.3

42.3

42.5

30.7

45.4

OO Q

42.1

1.9

3.7

2.2

2.8

2.3

3.5

1.5

3.4

3.1

1.5

3.2

1.6

3.2

0.005

.004

<.001

<.001

.003

.002

.001

.004

0.007

.006

.003

.010

<.001

.009

.004

.001

.008

<.001

.010

.002

.003

.010

<.001

.004

.002

.002

.006

.001

.002

.002

.007

.001

.005

.002

.002

.005

<.001

.008

.006

.005

.011

.002
276 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

Ps06 CaO F AlsOs U eU

Cross section 8 Continued

4-75 

4-76 .

45.5-50.3

56.1-63.4

A. ........

B. ........

D... ......

E. ........

F.. ...... .

A.........

B. ........

D.........

E. ........

F.. .......

14.8

10.2

14.4

5.2

55.4

8.6

6.6

15.2

7.9

61.6

25.6

7.4

30.0

22.9

30.6

36.2

11.0

43.4

40.2

45.1

2.9

.9

3.4

2.7

3.4

191

0-013

007

.001

.009

0.014

.005

nno

.010

.001

.012

.005

.002

.010

.001

Cross section 9

[Samples 78-100 are from lot 2545; samples 1 and 2 are from lot 2546. Chemical analyses by O. J. Daniels, 

R. Moore, J. Smith, W. P. Tucker, J. Budinsky, L. Jenkins, E. Campbell, I. H. Barlow, R. Smith. 

Radiometric (eU) analyses by J. H. Qoode, Jr., B. A. McCall]

1-78... ......

1-79. ........

2-80... 

2-81.... ..

3-82.........

3-83.........

3-84-. .

5-85... ......

5 86... ......

5-87 ......

677.. __ ...

26. 6-35. 4

35.4-43.3

38. 7-48. 6

48. 6-50. 2

23.6-38.9

42. 6-53. 0

53.0-59.3

17. 7-28. 7

28. 7-51. 4

51. 4-57. 4

31.4-39.3

A... ......

B.........

D.. ....

E... ......

F....... ..

A. .....

B. ........

D.........

E- ..

F.. .......

A.. 

B.........

D 

E...... ...

F.. .......

A.........

B.. .......

D... ......

E_ ...

F.. .......

A. ...

B... ......

D.........

E. ........

F.. .......

A.........

B.... _ ..

D ..

E... ......

F... ..

A.. _ .

B.........

D.........

E-.. ..

F.. .......

A ......

B.... .....

D _ ... ...

E-...- _ .

F.. .......

A.........

B. ........

D... .... ..

E. ........

F.. .......

A ......

B.. .......

D... ......

E. ........

F.. .......

A.. ..

B _ ......

D ....

E. ........

F.. .......

7.6

18.5

2.3

2.8

68.9

4.8

14.1

38.6

10.9

31.6

26.2

12.5

11.6

6.0

43.7

13.8

13.8

21.8

15.7

34.9

19.6

13.0

9.8

9.8

46.8

12.1

23.9

24.5

8.8

30.7

5.8

12.5

28.0

8.6

45.1

15.9

H o

32.1

2.8

37.3

3.5

19.4

23.8

10.7

42.6

8.1

22.9

16.4

10.5

42.1

11.5

14.2

10.6

5.1

58.5

31 9

31.6

99 4.

14.8

30.5

32.7

17.1

18.6

33.1

24.6

18.6

9O R

31.6

12 7

26.7

29.6

31.5

28.0

30.8

28.7

QO K

97 ft

32.7

24.1

V\ i

22.4

6.0

28.2

44 7

44.3

41.4

24.6

46.8

46.9

25.3

28.9

47.4

43 1

34.0

44.2

45.7

17.7

36.4

43.7

44.8

42.4

44.6

40 6

4fi *

Af> 7

47.1

41 n

54.5

40.7

23.5

41.2

3.6

3.6

2.5

1.6

3.4

3.6

1.9

2.2

3.7

2.8

2.4

3.2

3.7

1.3

3.8

3.1

3.5

3.1

3.4

2.7

3.7

3.1

3.7

2.8

3.5

2.7

.8

3.4

7.6

12.5

6.3

0.019

.007

.019

.003

.013

.006

.001

.010

.006

.001

.003

.006

.003

0.019

.008

.008

.013

<.001

.014

.020

.002

.011

.001

.015

.007

.007

.013

<.001

.011

.009

.002

.010

.001

.014

.008

.007

.010

<.001

.010

.006

.002

nno

<.001

ft! 9

.006

.001

.007

.001

.014

.007

.005

mo

<.001

.010

.005

.002

.008

.001

ftna

.005

.003

.009

.001

.011

.004

.004

.010

<.001
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 277

Hole and 

sample

Sample 

Interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

Ps06 CaO F A12O3 U eU

Cross section 9 Continued

7-88 

8-89 ..

8-90 . ..

8-91.........

942... ......

9-93 

9-94

9-95 

10-96 ........

10-97 ........

10-98.. .....

11-99 

11-100 

12-1 . .....

12-2 

22. 0-39. 0

35. 6-49. 0

49.0-66.2

66. 2-72. 3

34.8-51.2

51. 2-62. 0

62.0-75.3

75.3-81.3

37.3-55.2

55.2-75.2

75.2-77.2

45.8-50.6

50.6-53.7

52.0-60.9

62.4-72.4

A. .

B .___._

D ....

E 

F... 

A.. .......

B.... .....

D __ . _ .

E .....

F.. .......

A.. ....

B. ....... .

D.........

E. .....

F __ .....

A.........

B .

D.. ....

E.. .......

F... _ ...

A 

B. ........

C 

D ____ ..

A. ...

B..... ....

C.. 

D.........

A.... 

B. ........

D _ ......

E.. 

F.. ...... .

A. .

B 

D 

E...... ...

F.. .......

A 

B _ .. _ .

D.........

E...._ _ .

F.... _ ..

A.. ....

B. ........

D.... _ ..

E-. 

F.. 

A.. 

B. ...... ..

D . .. 

E.........

F...... ...

A _ ......

B.. 

D- ___ .

B.........

F.. .......

A.. 

B 

D 

E. ........

F _ ......

B....... ..

D.........

E 

F.. .......

B.. ...

D. ____ .

E. ........

F-.. 

6.2

21.9

11.7

3.1

57.1

7.0

25.4

3.4

9.8

53.4

3.4

9.1

8.0

13.9

65.6

2.9

3.8

30.2

9.1

54.0

2.2

20.2

65.9

11.7

3.6

14.7

63.8

17.9

.3

9.1

9.7

3.2

77.7

42.0

13.4

6.4

7.2

31.0

.1

1.0

36.8

2.5

59.6

5.5

15.1

8.7

3.5

67.2

8.2

17.5

9.3

14.3

50.6

13.2

14.1

2.3

8.4

62.0

.1

3.9

26.3

8.2

61.5

3.8

19.9

8.7

3.3

64.3

7.9

14.0

18.5

8.8

50.8

27.6

32.3

97 O

33.7

27.1

31.0

15.7

26.5

94 a

24 7

29.6

18.7

28.8

19.1

28.7

28.6

27.2

22.8

27.9

9O ^

34.5

23.7

33.9

no 7

9Q $

28.1

31.1

38.6

45.1

39.8

4.7 9

39.9

45.9

34.8

39.5

1O 9

40.1

43.7

40.0

44.7

33.3

38.9

39.0

42.3

37.9

41.2

49 »

AR 7

39.4

44.9

^n o

40 9

43.2

45 0

2.8

3.6

3.2

3.9

3.2

3.6

2.0

9 Q

2.8

2.8

3.4

2 4

3.2

2.5

3.1

3.1

3.1

2.5

2.9

3.3

3.5

2.5

3.2

3.5

3.7

3.3

3.7

0.007

.003

.009

.002

<.001

.006

.003

.001

.006

.001

.003

.008

.001

.004

<.001

.015

.004

<.001

.005

.016

.015

0.013

.004

.007

.013

<.001

.013

.005

.004

.010

<.001

.009

.005

.003

.008

<.001

.006

.004

<.001

.006

<.001

.013

.001

<001

.004

.012

.005

.001

.001

.008

<.001

.002

.010

<.001

.010

.005

.003

.010

 C001

.006

.001

.002

.007

<.001

.013

.003

.004

.010

.001

.007

.005

<.001

.007

<.001

.014

.007

.005

.008

.002

.008

.002

<.001

.005

.001

.018

.002

.004

.006

<.001

.015

.006

.003

.008

.001
278 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PjOs CaO F A12 03 U eU

Cross section 10

[All samples are from lot 2546. Chemical analyses by R. Moore, L. Jenkins, I. H. Barlow, E. Smith, 

J. Smith, W. P. Tucker, J. Budinsky, E. Campbell, A. Sweeney, T. Murphy, J. Waring. Eadiometric

1-101- ____

1-102 ...

2-105........

3-3 ..

4-4... ....

5-5... .......

5-6...... ..

6-7. .

6-8 .

6-9 .....

7-10 .........

7-11 

7-12.........

8-13. .

8-14.. ..

5.3-12.6

12.6-18.9

9.6-17.1

27.5-37.0

17.4-26.6

22.4-26.0

31.2-34.8

35.0-39.8

41.7-56.1

R(t 1_fiA Q

7.0-22.0

22. 0-28. 1

33.1-43.2

1C fl 99 Q

99 Q °.ft 9.

A ____ .

B. ...... ..

D_ . ....

E _____ .

F.. ..

A. __ ....

B.... __ .

D ... .

E.. .......

F... _ ...

A _ ..

B. 

D. 

E. _ ..

F.... 

A.. ..

B.. 

D_- _ ...

E. ........

F- ...

A.. 

B.. ....

D ~.

E...- _ ..

F .........

A... .

B 

0 ... ..

D ...

A..... 

B.... .....

D.. ..

E._. _ ...

F _ . .....

A.. .

B... _ ...

C....... ..

D 

A... ... ...

B..... ....

D __ .

B...... ...

F...... ...

A..... ....

B. _ . ....

D_. 

E _____ ,

F.. .......

j^

B. ........

C. .....

D.. ....

A ___ ....

B... .

C.. ....

D ..... .

A..... ....

B.. 

D ....

E.. 

F _ ......

A.. ... .

B..... ....

C. 

D ......

A. _ .....

B,. ...

D. 

E _ . .....

F _ ......

0.6

13.2

38.0

13.0

35.4

2.8

26.5

20.3

24.4

25.0

9 O

10.8

21.8

24.0

34.4

R 9

14.2

28.0

1O K

38.3

13.0

15.0

24.7

11.0

36.2

2 Q

Q 9

65.1

OO Q

12.8

14.8

*>A 9

16.0

22.3

.1

7.4

CO Q

9.3

1 9

11.9 ifi 1

9

e

40.6

1.0

16.4

43.3

»

c

29.7

.2

14.5

67.7

17.7

5.8

4.4

63.5

26.2

7.6

6.0

34 4

12.6

39.4

*> O

n

o

64.6

20.8

>\ Q

11.7

21.1

on o

41.0

28.0

34.6

on 7

39 A.

31.6

17.3

33.7

<M\ 9

SI 3

30.9

15.9

Q1 1

Qf| Q

19 A

90. n

9Q 7

10.6

25.6

90 O

V) 1

24 7

30.1

10.6

13.5

30.3

18.0

12.9

22.5

3D S

1Q A

16.9

31.5

15.7

QA O

39.2

47.9

44.3

47.7

45.2

25.4

49.7

44 7

&.*] 9

45.9

26.4

47.1

41.6

19 i

43.8

AA 7

9.5

.7

44 1

45 9

40 1

45.8

10.3

10.7

41.5

26.2

16.6

38.8

46.5

.8

42.2

18.4

46.8

3.2

3.8

3.1

3.6

3.8

2.0

4.0

3.5

3.4

3.6

2.0

3.7

3.3

1 9

3.4

3.6

1.1

1.1

3.6

3.7

2.9

3.5

1.0

1.2

2.2

2.1

1.6

2.7

3.5

1.4

1.8

3.4

1.8

3.7

7.8

6.0

17.3

32.0

20.7

15.3

27.7

12.8

0.009

.004

.016

.010

.008

.014

.016

.008

.014

.007

.050

.002

.001

.022

.040

.021

.017

.005

.015

.003

.011

0.012

.005

.010

.012

.002

.009

.005

.004

.007

.001

.017

.009

.011

.010

.001

.016

.006

.004

.010

<.001

.022

.009

.013

.014

<.001

.009

.004

.002

.005

.010

.007

.003

.004

.002

.003

.001

<.001

.029

.013

.002

.004

.010

<.001

.010

.004

.001

.007

.002

.012

.003

.002

.018

.030

.020

.004

.015

.008

.006

.002

.007

.001

.004

.001

.001

.013

.010

.004

.011

.008

<.001
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 279

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PaOs CaO F AljOj U eTJ

Cross section 10 Continued

8-15.. __ ...

9-16. 

9-17 

10-18 

10-19 

10-20 

10-21 

10-22 __ ....

11-23

11-24 __ ....

11-25. -

11-26. 

12-27 

12-28 

12-29 

12-30 

36.a-37.2

14.8-20.6

20.6-23.6

8. 0-17. 1

17.1-25.1

25.1-36.9

Oft n_4« K

52.4-57.4

20. 3-22. 0

22. 0-26. 3

28.2-38.1

38.1-39.1

19. 8-22. 1

22. 1-31. 5

31.5-34.2

34.2-38.5

A 

B 

D ..... .

E .

F _ .-..

A. .

B. ........

D.. .......

E. __ ...

F

A. 

B.. .......

D........ .

E.. .......

F _ ......

A _ ......

B.........

C ... .

D.. .......

B _ ......

C_ 

D.........

A 

B.. .......

D....... ..

E _ ......

F _ ......

A.........

B. __ ...

D.........

E.. .......

F ___ ....

j^

B

D.. .......

E _ ......

F.. .......

A.. 

B.........

C.... 

D.. .......

A... 

B.........

C.... .....

D.. .......

A 

B.........

D.........

E _ ......

F _ ......

A __ .....

B _ ......

D _ ......

E.........

F _ ......

A... 

B.........

C... ......

D.. .......

A. 

B.... _ ..

D.. ...... .

E... .... ..

F _ ......

A ....

B _ ......

D.........

E _ ......

F.. .......

A.........

B.. .......

D.........

E.........

F.. .......

27.3

12.1

24.2

17.4

19.0

5.6

11.5

38.3

10.9

33.7

1.6

7.8

23.6

22.3

44.7

.4

14.1

65.4

20.1

.2

>\ Q

63.9

30.0

5 4

16.9

21.8

in ft

45.1

1.3

4.7

30.1

10.1

52.8

8.7

10.9

32.0

14.8

33.6

.1

7.8

85.6

6.5

2.8

19.7

57.8

id 7

5.8

14.0

16.6

12.1

51.5

12.5

17.5

27.5

12.2

30.3

.8

19.5

71.6

8.1

8.5

17.3

7.9

11.0

55.3

4.6

17 Q

26.5

9.6

41.4

8.3

29.5

12.4

13.6

36.2

8.7

27.6

30.6

18.5

si *

28.6

32.0

7.6

12.6

31 7

8.5

30.8

Q1 Q

25.8

28.4

15.5

28 3

23 7

29.0

7.3

29.0

30.6

18.5

28.5

13.1

3.0

27.5

26.7

29.2

30.8

27.2

25.8

30.1

43 7

44 3

29.6

47.6

42.1

48.2

6.3

5.1

49 1

8.9

43.1

45 1

39.8

43.2

32.7

45.1

Oft Q

39.1

8.6

42.7

43.5

36.4

43.1

17.3

1 Q

41.0

39.3

43.3

44.3

49 7

39.1

1.2

3.2

3.6

2 4

3.7

3.1

3.7

.7

.7

3.1

1.1

3.0

i *>

3.0

3.4

2.0

3.5

2.8

3.7

1.1

3.5

3.3

2.4

3.3

1.7

.3

3.1

3.4

3.2

3.5

3.1

3.0

29.3

17.5

19.3

25.2

0.001

.001

.026

.004

.001

.001

.016

.008

.001

.017

<.001

.008

.015

.001

.661

0.004

.005

.003

.007

.001

.009

.006

.002

.008

.001

.011

.005

.002

.007

<.001

.008

<.001

.001

.027

.009

.003

.002

.005

.009

.007

.002

.008

<.001

.008

.004

.001

.008

<.001

.006

.005

.002

.007

<.001

.010

<.001

<.001

<.001

.016

.005

.002

.009

.010

.004

.002

.008

<.001

.008

.006

<.001

.006

.001

.019

<.001

<.001

.006

.016

.004

.005

.009

<.001

.010

.002

.002

.008

<.001

.011

.004

.002

.006

<.001
280 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PsOt CaO F AlsOs U eU

Cross section 10 Continued

12-31 

13-32. 

13-33 - 

13-34 .. .

13-35 ....

14-36 _

14-37 ...

14-38 .. ..

14-39 _

15-40- ..

15-41 .. ..

16-42 . ...

16-43 

16-44...,. ..

38.5-43.1

27. 7-38. 0

38.0-39.6

39. 6-54. 3

54.3-55.5

23. 3-25. 0

25.0-29.1

29. 1-34. 0

35.0-37.0

40. 2-49. 7

51. 3-54. 1

10. 2-13. 1

20.7-32.3

78. 4-84. 1

A 

B.. .

D 

E. -

F...... ...

B.... 

D...... 

E. _ ...

F.._._ _

A .

B_.-_...._

D.. ....

E. ........

F _

A. ........

B. . _ __

D.........

E-. ..

F.._ ...

A. _ .... .

B. _____._.

D_. _ ....

E 

F. __ ....

A. .

B. ........

C. .. ......

D ......

A.........

B..... ....

D.........

E. ........

F.-. ......

A. .

B. ........

D... ... ...

E- .... .

F.. . ......

A ......

B. ........

D.. .......

E.. _ ....

F.. .......

A.........

B.. .....

D. ........

E. ........

F.. .......

A.........

B. ........

D.........

E_. .......

F.. .......

A.........

B. ........

C. ........

D._ .......

A.........

B. ........

C. ...... .,

D.. .......

A.........

B. ........

D.. _______

E. ...

F....... ..

19 *

36.4

23.3

6.1

21.7

7.7

50.7

2.5

7.1

32.0

9 9

3.6

18.0

8.4

60.1

9 9

16.0

5.7

16.4

52.7

17.9

10.7

39.3

8.0

24 1

1.0

18.0

63.0

18.0

9 O

8 5

32.2

3.4

53.0

A*) O

5.7

42 3

2.6

7.1

4fi n

15.8

11.8

13.8

12.6

2.5

17.0

3.5

9 1

74.9

97 <\

7.7

28 6

7.5

9ft 7

16.5

76.7

6.6

.2

5.6

79.7

14.5

2.8

3.1

19.1

5.8

69.2

26.0

30.4

29.0

9 1

32.1

97 O

28.0

29.5

29.2

19.7

26.5

8 Q

4.5

30.0

15.5

30.0

3.6

9.2

3.8

3.8

9A. ">

27.7

1O 4

94 Q

O 4

7.6

21.0

1.5

10.3

26.2

28.6

si <*

OQ 9

11.6

30.7

28.6

27.1

29.9

28.0

26.0

27.6

7.2

2.9

29.5

16.7

31.1

35.0

49.2

30.9

33.3

35.2

41.0

OQ 9

43.1

10.3

4.2

33.9

3.7

41.4

43.4

3.0

3.6

3.3

.7

3.6

3.2

2.8

3.3

3.1

2.1

2.7

.7

.3

3.0

1.1

3.4

.4

1.1

.4

.4

2.6

3.2

2.3

2.9

.9

.3

2.5

.2

1.2

3.2

0.016

.013

.003

.001

.018

.007

.048

.010

0.011

.005

.001

.007

.001

.017

.005

.013

.011

.001

.012

.006

.003

.008

.001

.012

.004

.003

.007

<.001

.010

.004

.001

007

<.001

.012

.002

<.001

.013

.017

.006

.006

.013

.001

.002

.002

.002

.004

<.001

002

.002

.001

.001

<.001

.012

.004

.003

.009

<.001

.011

.007

.001

.009

<-001

.010

.003

.002

.027

.009

<.001

<-001

.003

.007

.003

.002

.011

.001
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 281

Holn and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

P?O5 CaO F AlsO3 U eTJ

Cross section 11

All samples are from lot 2546. Chemical analyses by Q. J. Daniels, R. Moore, A. Sweeney, T. Murphy, 

J. Waring, J. Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1-45 

2-46..........

2-47 .......

2-48. 

3-49..........

3-50 .......

3-51 .. 

4-52..... ...

4-53 .......

J5-54... . ....

3-55 .......

«-56 . ....

6-57... ...

7-58.... 

7-59.. 

8-60 .. 

13.3-16.9

18. 6-32. 0

32.0-39.3

39. 3-41. 9

8. 9-21. 4

39. 8-51. 5

51.5-53.9

13. 0-23. 2

50. 4-56. 5

5.2-17.4

36. 0-48. 9

12. 9-19. 8

66. 6-70. 2

34.9-49.9

49. 9-56. 1

20. 9-27. 0

A.. ....

B..... ....

D. ........

E._ ....

F.. .......

A..-.....-

B. ..___ 

C

D._.... 

A 

B

C.- ..

D-.._ _ ..

A.........

B...... ...

D.. .......

E--_ ...

F.. ...... .

A.........

B.... ..

C. ........

D... 

A.. ....

B.. __ ...

D- _

E .... 

F.. .......

A.. ....

B. .......

D..... 

E ......

F.. .......

A.........

B.........

C

D.. _ ....

A.. ....

B_. _______

D.. .......

E. .. ......

F.. .......

A. . .......

B. .....

C.. ....

D... ......

A . ..

B.. .......

D. ....

E.-... 

F ...... .

A... ......

B.... 

C... ......

D-_ ..

A.-. 

B--. 

D 

E... ...

F...... 

A... 

B.-. 

D 

E...... 

F... 

A.. ....

B -

D 

E

F... 

A.... ..

B. ...... ..

C 

D.... .....

51.4

14.0

11.2

3.3

20.1

.9

19.0

70.5

9.5

.3

10.5

79.0

10.1

16.6

23.2

3.9

4.5

51.8

.2

1.6

73.0

25.2

12.5

18.0

9.5

5.4

54.6

14.0

14.0

4.0

3.4

64.6

.1

8.0

50.8

41.1

14.9

24.0

26.4

2.9

31.8

1.7

8.8

67.4

22.1

1.9

27.2

6.7

3.2

61.0

.1

4.4

72.5

23.0

1.2

56.5

13.5

4.9

23.9

2.3

42.9

4.4

3.0

47.4

16.0

13.7

13.7

3.4

53.2

22.4

21.0

50 4

6.2

5.2

4.4

8.9

4.5

13.8

9.2

30.4

6.9

32.6

13.0

11.5

29.5

11.9

30.7

3.7

24.8

26.3

13.7

10.1

17.1

31.0

7.3

26.3

31.3

16.9

31.3

25.5

31.3

27.6

15.8

32.1

33.5

3.3

4.6

11.8

4.5

44.3

8.9

47.5

11.9

9.6

44.4

16.1

46.6

5.6

41.7

41.6

15.4

5.4

42.9

48.1

.9

39.1

43.0

36.1

46.4

41.6

47.4

37.3

.5

0.7

.6

.4

.3

.7

.4

3.4

.4

3.7

1.1

.6

3.5

1.1

3.7

.5

3.2

3.3

1.5

.4

3.0

3.7

.3

3.3

3.5

2.0

3.4

3.0

3 3

1.9

.1

0-005

.016

.001

.001

.019

.004

.012

.002

.002

.005

0.008

.006

.002

.004

.003

.003

<.001

<.001

.018

.008

<.001

<.001

.010

.014

.006

.006

.013

<.001

.006

<.001

<-001

.006

.020

.007

.006

.009

.001

.001

.004

.001

.007

<.001

.006

<.001

<.001

.008

.014

.006

.002

.010

.002

.002

<.001

<.001

.005

.013

.002

.003

.008

<.001

.005

<.001

<.001

.002

.010

.002

.002

.012

<.001

.014

.001

.004

.012

<.001

.012

(KM

.003

.002

.004

<.001

<.001

.005
282 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PzOs CaO F A12 03 U eU

Cross section 11 Continued

8-61 

8-R9

8-63 __ ....

65.6-70.2

70.2-77.0

77.0-78.1

A...... ...

B_ _

C... .

D_ ...

A___ ...

B. ........

D. ...

E.._ ...

F. ........

A 

B... .

D. .

E. ....... .

F.. ... .

.2

23.0

71.2

5.6

2.9

17.2

23.3

3.4

63.2

7.1

11.2

59.2

13.5

9.0

5.0

27.9

27.8

9.3

8.6

5.1

40 7

42.6

35.1

36.3

6.3

3.0

3.0

1.1

1.1

0.006

.001

<.001

0.002

.002'

,00ft

.006

.002'

.002'

.011

<.001

.006.

.004

.001

.003:

<.001

Cross section 12

[All samples are from lot 2546. Chemical analyses by G. J. Daniels-R. Moore, A. Sweeney, T. Murphy* 

J. Waring, J. Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCallJ

1-fU

1-65.. ....

1-66. 

2-67 

2-68- ..

2-69...... ...

3-70 ......

3-71. 

3-72... .

4-73.. 

4-74.........

6.0-11.0

11.0-19.0

22. 1-28. 0

8. 5-17. 2

17. 2-26. 5

26. 5-31. 0

8. 1-12. 6

35.4-40.6

40. 7-43. 1

42.0-47.1

91.3^97.0

A.._ ..

B 

D. ... ..

E. ...... ..

F-._.. 

A.._ 

B... 

D. ..

E--_. -

F. 

A... 

B-... 

D .

E... 

F... 

A... 

B.. .

C... 

D.. .

A... ..

B... ..

D.-. ...

E... ...

F. ........

A.. ...... .

B... 

D.. .

E. -.-..-..

F..... .

A...-...-

B-..-...._

CD

A.-.. .

B...... 

D. 

E. ...... ..

F.... ..

A.. 

B.........

D_ 

E... .

F.-.... 

A... ...

B. ...... ..

0... .

D. .....

A...... 

B. ........

D. 

E. ........

F. _ .....

9.3

9.3

36.2

.9

44.1

3.2

14.0

25.0

8.1

49.8

7.3

8.3

28.3

24.8

31.3

1.2

30.4

49.4

19.0

2.6

15.8

32.7

19.4

29.5

2.7

6.4

57.1

13.1

20.7

6.5

29.2

55.5

8.7

5.1

16.5

32.9

10.0

35.5

.1

2.9

60.7

14.5

21.8

.1

9.5

75.6

14.8

7.1

15.7

18.7

11.7

46.8

14 4

22.4

17.5

33.6

23.6

35.2

34.8

37.5

10.9

33.4

32.6

26.2

29.6

22.7

32.6

17.3

33.1

25.8

30.1

18.8

33.8

If! Q

35.6

9 0

6.3

13.3

45 6

21.4

50.7

50.6

52.0

6.5

48.1

48.6

43.8

48.0

4.2

46.5

23.1

48.3

43 4

47.9

27.7

45.2

23.8

50.7

0.3

.8

.9

3.2

1.4

3.8

4.0

4.3

.5

4.0

3.6

3.2

3.1

.5

3.1

1.3

3.4

3.1

3.6

2.1

3.6

1.5

3.9

0.010

.023

.015

.014

.016

ftOO

.016

.017

.014

004

.004

.030

.034

.016

.031

.024

.002

.013

.008

.010

0.011

nnt

.026 .oir

.002

.012

.007

.014

.012

ftftd.

.016-

.011

.011

.01&

.005.

.005.

<.001

.001

.019<

.015

.008.

.005

.010)

.001

.008.

.005

.001 007"

.002-

.006-

001

.001

.031

.036-

.017

.032:

.025

.002

.013.

008.

.002'

.011

MM

.012-

<.001

<.OOL

<.001

.014

.009-

.Olfr

.012

.004
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 283

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

Ps05 CaO F A12 03 17 eU

Cross section 12 Continued

4-75 ...

6-76 

8-78.. . -

97. 0-99. 1

101. 4-103. 5

50.9-59.9

A. ..

B. .....

D. __ ....

E. __ ....

F. ...

A. ....

B ____ .

D- __ . ...

E. . .

F. __ ....

A...... ...

B. ...

0 

D.. . ...

1.2

12.0

36.0

21.2

29.6

52.1

9.4

19.8

3.6

15.1

8.6

14.4

57.1

19.8

32.0

19.3

34.1

23.7

8 9

28.9

26.7

46.3

28.9

51.0

42.2

30.0

45.6

ifl fl

3.6

2.3

3.7

3.1

1.1

3.2

3.4

0.020

.006

019

MO

.014

.001

0.022

(119

.005

.021

.006

.009

.006

.020

.009

.007

.016

nn?

<.001

.003

Cross section 13

[All samples are from lot 2546. Chemical analyses by R. Moore, A. Sweeney, T. Murphy, J. Waring, 

J. Budinsky. Radiometric (eTJ) analyses by J. H. Goode, Jr., B. A. McCall]

1-79 . _ .

9.sn

2-81 - 

3-82... ___ .

3-83.. ...

3-84. ____

4-88..........

4-87 

4-77- ____ .

4-86 . ..

5-88 _..

62.9-74.6

37.4-46.0

46. 0-50. 8

75.8-81.2

81. 6-85. 8

72.3-75.8

66. 3-70. 0

70.0-75.0

75.0-81.5

91. 1-94. 3

80.9-85.9

A. 

B _ .. ....

D. ... ..

E. _ .....

F _ ......

A. . 

B. ........

D. -

E.... .....

F... ..

A.... 

B.........

D . . 

E.. _ ....

F..... ....

A.........

B..._. _ .

D_ 

E. ...... ..

F. ...

A... __ ..

B ____ .

D_ ...

E __ . ....

F... ...

A ...

B. ___ ..

C. ...

D..._._._.

A. .....

B __ .....

C...... ...

D. ....

A.. ___ .

B __ . ....

C...... ...

D... _ ...

A.... .....

B. ...

D .....

E.. ....

F_...._ 

A ....

B.. .......

D ....

E.. .......

F ___ ....

A...... ...

B. .....

D ......

E.. ....

F.-.-.. 

5.2

14.7

17.4

24.5

38.2

12.1

12.5

44.6

13.5

17.3

3.8

9.4

51.1

13.6

22.1

18.6

8.7

18.6

24.6

29.5

13.2

11.8

49.3

13.7

12.0

.7

4.8

83.4

11.1

.1

1.0

74.4

24.5

.5

11.8

59.3

28.4

11.9

12.2

5.0

27.1

43.8

36.2

14.5

11.6

3.7

34.0

9.2

10.7

17.5

.9

61.7

33.5

34.4

30.9

32.9

24.0

29.9

31.2

22.4

33.5

31.2

27.2

32.2

3.9

5.0

29.6

17.9

29.8

31.7

22.0

19.6

11 9

27.1

21.3

30.9

48.8

48.3

46.5

47.5

42.3

46.7

46.3

32.2

48.0

46 7

40.3

47.2

1.4

4.2

A3 7

26.0

.42.3

dfi 7

VI O

34.6

48 9

41.2

31.3

4fi ft

3.9

3.8

3.6

3.8

2.9

3.5

3.6

2.2

3.9

3.6

2.9

3.4

.3

.4

3.8

2 0

3.6

3.5

2.8

1.9

4.0

3.2

2.3

3.4

0 004

<.001

.010

.009

.001

.017

.014

.019

.013

.004

.015

.014

.001

.014

.021

.008

.012

.006

.004

.014

.001

0.010

.006

.004

.004

<.001

.015

.012

.007

.011

.001

.010

.007

.002

.007

.002

.020

.016

.021

.012

.004

.015

.010

.004

.017

.007

.006

.006

.002

.015

.002

.001

.002

.003

.016

.008

.004

.024

nn7

.005

.010

.006

.001

.011

<.001

.010

.013

.007

.012

.012

.005

.017

.003
284 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

PzOs CaO F AlsOj U eU

Cross section 13 Continued

6-90.... .-

6-91 - 

7-89. ~ .

8-92... 

R.oa

67.4-71.6

72.4-81.5

76. 9-78. 9

69.1-75.6

76.0-83.2

A. 

B.........

D ... ..

E. ........

F.. .......

A ......

B. ........

D.-.._...

E. ........

F. ........

A.........

B.. .......

D. ........

E. ........

F.. .......

A.........

B.. .......

C. 

D ......

A.. 

B.. .......

C. ........

D..-.____.

13.9

17.7

30.4

11.3

26.7

13.1

16.2

O7 K

13.5

29.7

10 O

iq 9

13.2

50.0

.1

.5

80.0

19.4

5.6

4 4

68.2

21.8

29.5

23.4

15.2

32.1

29.8

7.4

29.4

30.4

12.8

33.6

24.8

20.8

45.5

35.4

23.1

47.4

44.9

24.1

44.4

43.3

23.3

47.8

33.8

30.4

3.5

2.8

1.3

3.7

3.4

.8

3.3

3.5

1.6

3.9

2.6

2.5

0.024

.018

.016

.015

.013

.009

.017

.009

.003

.015

.002

0.026

.018

.015

.018

.007

.015

.009

.007

.008

.001

.019

.008

.011

.012

.004

.006

.004

.002

.002

.017

.012

.003

.004

Cross section 14

[Samples 94-100 are from lot 2546; samples 3 and 4 are from lot 2547. Chemical analyses by Q. J. Daniels, 

R. Moore, A. Sweeney, T. Murphy, J. Waring, J. Budinsky. Radiometric (eU) analyses by J. H. Qoode, 

Jr., and B. A. McCall]

1 <X1

1 Q5

1-96. 

2-97 

2-98- 

3-99.- 

3-100 

4-4 

8-3 

35. 1-40. 8

40.8-44.0

A A A-JlQ K

40. 5-43. 6

43. 6-49. 3

65. 6-73. 4

73. 4-75. 6

58. 0-75. 0

98. 0-101. 0

A 

B ...

C 

D 

A 

B_ 

D 

B. ........

F.. 

A 

B ...

D. ..

E.. ...

F.. ...

A. 

B_ 

C 

D 

A. ...

B

D _____

E .__

F... __

A....... ..

B

D...... ...

E. 

F.. ...

A..... 

B. ..... 

D .____

E... 

F..... ....

A. 

B _____

C _____

D ..

A ..

B 

C-... 

D.........

n i

8.9

85.5

>; 9

6.4

9

0

10.9

20.3

52.6

7.6

5.6

34.7

15.6

69.2

14.8

14 6

11.1

13.2

on q

5.8

6.4

17.5

2.3

68.0

13.4

U Q

Qrt Q

7.8

37.2

22.3

23.6

2.3

14.1

16.8

28.3

24.0

34.3

20.8

26.8

34.3

14.4

i i

33.9

26.0

17.1

33.5

26.8

27.2

26.5

16 9

21.5

2.5

8.2

41.7

35.3

48.5

29.4

38.7

49.5

18.3

5.1

48.3

39.3

25.1

50.0

42.6

32.8

43.8

28.7

51.1

1.7

0.8

3.3

1.9

3.7

2.3

3.1

3.9

i.4

.3

3.5

2.9

1.5

3.8

3.3

3.3

3.3

2.1

2.7

.2

0.021

.015

.002

.018

.018

.011

.020

.003

.016

.047

0.001

<.001

<.001

.022

.016

.011

.002

.012

.003

.009

.012

.003

.013

.002

.010

.001

<.001

.018

.018

.014

.010

.009

003

.022

.008

.004

.012

.002

.016

.010

.008

.008

.002

<.001

.001

.002

.005

.003

.002

.046
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 285

Hole and

sample

Sample

interval

(feet)

Screen

size

Weight 

(percent

retained

on

screen)

Analytical data (percent)

PsOt CaO F AkO3 U eU

Cross section 15

[All samples are from lot 2547. Chemical analyses by G. J. Daniels, A. Sweeney, W. P. Tucker, J. 

Budinsky. Radiometric (eU) analyses by J. H. Qoode, Jr., B. A. McCall]

1-1 

2-2. .-.-._

3-5. 

4-6 

6-7. -

16.9-25.9

64. 8-68. 8

55. 5-66. 5

A 

B... .

C- - 

D ...

A 

B__ _ .

D-- ..

E_ 

F...... ...

B 

D 

E. 

F.. 

A .

B.... ..

D ...

E

F.__ _

A.... ..

B-. ... .

D ....

E .

F._ .

0.1

5.0

84.3

10.6

13.4

16.4

11.9

4.5

53.8

20.7

8.6

41.3

3.3

26.1

9.4

12.0

27.3

10.0

41.3

8.1

7.6

26.5

10.7

47.1

4.0

27.7

31.6

35.8

22.3

16.3

34.5

32.5

11.8

33.9

31.1

22.5

on c

1.0

41.6

46.6

48.4

31.9

22.8

ifi 7

46.2

17.3

48.0

43.5

33.1

AA f\

0.3

3.6

3.9

3.9

2.5

1.3

3.8

3.7

1.0

3.8

3.4

2.7

3.5

0.015

.015

.001

.028

.018

.026

.014

.016

.015

.002

.015

.014

0.004

<.001

.001

.006

.016

.009

.006

.015

.002

.026

.018

.012

.027

.005

.015

.012

.017

.018

.002

.017

.011

.009

<.001

Cross section 16

[All samples are from lot 2547. Chemical analyses by Q. J. Daniels, W. P. Tucker, J. Budinsky. 

Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

la-19. ...

2-16 _ ......

8-16 

6-20 ...

58.5-71.5

60. 6-56. 4

35. 5-37. 4

39. 2-42. 4

AB. ........

D 

E. 

F--- 

A.. .

B. 

C-- 

D 

A -

B. ........

C 

D 

A-... ..

B 

D . 

E... ...

F.. 

7.4

6.1

22.6

5.4

58.5

3.8

6.1

50.7

39.3

5.3

9 3

70.5

14.7

5.2

10.4

18.3

5.3

60.8

24.4

32.2

18.3

7.0

14.0

26.8

32.0

35.9

47.2

26.5

39.7

21.1

41.4

31.4

AJ O

2.8

3.8

2.1

.6

3.1

1.5

3.2

2.5

3.6

0.011

.016

.015

.012

.002

.013

.017

.017

0.013

.012

.008

.016

.001

.017

.014

.003

.015

.010

.014

.001

.007

.018

.014

.008

.023

.001
286 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole and 

sample

Sample 

interval 

(feet)

Screen 

size

Weight 

(percent 

retained 

on 

screen)

Analytical data (percent)

P3 06 CaO F AlaOs U eU

Cross section 17

[All samples are from lot 2547. Chemical analyses by G. J. Daniels, A. Sweeney, W. P. Tucker/J. 

Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

2-12- ......

2-13........

2-14.........

3-8-.... ..

9-11 . ..

10-9- ___ -.-

10-10.. _ ...

34. 0-36. 0

36. 0-39. 0

43. 0-52. 0

23. 0-29. 0

53. 0-62. 0

79. 0-82. 5

82. 5-87. 0

A.........

B _

C__ - .

D ... _.

A-........

B.... ... .-

C-. ....

D...... ...

A. .. ......

B_. ....

D.... ..

E--- -

F---- 

A-. .......

B- .....

D_ _

E._ --_.

F

A... ......

B.. ....

C.. .......

D. __.__..

A.......

B. ........

"0. ........

E.........

F-.-_._ ...

A.........

B. ........

D ... ...

E_ 

F. ........

0.0

.0

.0

100.0

14.3

60.2

95 4.

3.6

11.4

25.3

13.5

46 2

7.1

12 3

35 8

5.4

39 4

.3

1.7

41.5

56.5

3.9

5.3

59.0

2 0

29.8

7.8

8.9

56.7

6.1

20.5

7 5

29 0

31.3

35.1

18.7

6.5

33.3

34.0

10.7

45.3

47.3

33.0

24.2

10.3

36.5

40.4

0.6

3.1

3.4

3.4

1.9

.7

3.7

3.8

0.006

.026

.014

.017

.011

.017

.007

0.011

.008

.002

.002

.004

.027

.016

.006

.020

.001

.020

.014

.012

.020

.002

.008

.005

.001

.007

.006

.004

.005

.006

.002

.009

.009

.006

.010

.003

Cross section 18

[Both samples are from lot 2547. Chemical analyses by G. J. Daniels, A. Sweeney. W. P. Tucker, J. 

Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1-17.........

1-18. ____ .

23.0-31.0

31.0-36.1

A.........

B. ____ .

D.........

E ____ .

F _ ......

A. _____

B ____ .

D._._ .

E _____

F.. .......

11.6

10.4

35.1

10.6

32.3

7.1

11.3

49.6

7.7

24.3

36.8

23.5

36.5

35.7

25.1

35.2

48.8

32.4

60.0

48.4

34.8

49.5

3.7

1.8

3.9

3.7

2.4

3.7

0.016

.015

.015

.016

0.015

.007

.010

.018

.003

.018

.013

.006

.018

.001
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 287

TONNAGE COMPUTATIONS FOB CROSS SECTIONS 1-18

(Percent TI: Head assay calculated from analyses of Individual fractions. Cpm: Counts per minute computed from gamma-ray log. Tons per acre: P, pebble fraction (+14 mesh); C, concentrate fraction ( 35 

+160 mesh)]

Hole

Depth 

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

TJ

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 1

[Chemical analyses by E. Campbell, L. Jenkins, I. H. Barlow, R. Smith, J. Smith, J. Budinsky. Radiometric (eU) analyses by B. A. McCall, J. H. Goode, Jr.]

1 . -

2. _

3 

4-... .

5 

9. 1-19. 3 

7. 0-9. 1 

9. 1-12. 1 

20. 5-22. 0 

5. 0-19. 4

16,320 

3,360

2,400 

23, 040

0.007

.011 

.003

800

130 (P). ... 40.5

Blank hole.

Cross section 2

[Chemical analyses by E. Campbell, L. Jenkins, I. H. Barlow, R. Smith, J. Smith, W. P. Tucker, J. Budinsky. Radiometric (eTI) analyses by B. A. McCall, J. H. Goode, Jr.]

I.. .

1 

2. -_ 

2 

3. .....

3 

4. .....

23. 1-34. 1 

34. 1-42. 1

131. 0-137. 4 

137. 4-150. 4

12. 8-20. 0 

31. 0-33. 9

17. 9-21. 9

17,600

10,240

11,520

6,400

0.010

.010

.003

1,100

Possible calcium phosphate 

zone. Top contact taken 

from gamma-ray log. Bottom contact at base of lost 

core.

Possible calcium phosphate 

zone. Not sampled, but 

coarse phosphate pebble 

present. Tonnage is low.

Base of sample 26. Samples 

show phosphate nodules. 

Not analyzed for PsOj. 

Possible calcium phosphate zone. Tonnage is 

low.

Cross section 3

[Chemical analyses by S. Bethea, E. Campbell, L. Jenkins, I. H. Barlow, R. Smith-J. Smith, W. P. Tucker, 

J. Budinsky. Radiometric (eU) analyses by B. A. McOall, J. H. Goode, Jr. Holes 3, 4, and 5 had no 

aluminum phosphate or calcium phosphate.]

1.... .....

1... ......

2 _ .... ..

7. 0-12. 0 

14. 9-16. 1

10. 3-18. 1

8,000

12.480 0.005

1,500

562 (P) . 

231 (C)....

78.7 

79.6
288 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole

Depth 

Interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 4

[Chemical analyses by S. Bethea, E. Campbell. L. Jenkins, I. H. Barlow, R. Smith, J. Smith, W. P. 

Tucker, J. Budiosky. Radiometric (eU) analyses by B. A. McCall, J. H. Goode, Jr.]

1. ..

1_ 

1 .........

2 ...

3 

3. .....

10. 5-19. 2

19. 2-35. 9

35. 9-39. 9

17. 6-24. 5

21. 2-28. 6

28. 6-45. 4

13,920

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

1 

' 000

........

1,168 (P)_.

187 (P) -

270 (P)- 

1,530 (P)_.

76.5

67.1

63.5

66.0

zone. Not sampled.

Cross section 5

[Chemical analyses by S. Bethea, E. Campbell, L. Jenkins, I. H. Barlow, R. Smith, J. Smith, W. P. 

Tucker, J. Budinsky. Radiometric (eU) analyses by B. A. McCall, J. H. Goode, Jr.]

1 _ . .... '»

 >

 5

«... . .....

 L.. 

56. 1-71. 9

28. 1-29. 9

29. 9-34. 6

34. 6-48. 9

22. 5-32. 8

-21. 4-23. 2

2,880

2,880

1,000

1,500

2,990 (P). _

714 (P).. ..

2,280 (C).. 

655 (P)- 

3,600 (C)..

40.6

66.4 

35.8

66.9

zone. Sample analyzed cnt 

both aluminum phosphate 

and calcium phosphate 

zones.

Some phosphate present in

limestone. Not calcium 

phosphate zone.

Cross section 6

| Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, L. Jenkins, E. Campbell, I. H. 

Barlow, R. Smith. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1 __ - ... :L. _ ---

a... ... 

2 ..... _

3 

3 

4 

5 

22. 6-37. 6

37. 6-44. 6

21. 0-27. 1

27. 1-32. 0

62. 9-67. 2

67. 2-68. 8

77. 2-81. 2

46. 3-48. 6

24,000

9,760

6,880

0.003

900

800

1,020(P)._

530 (P) .

440 ("PI

170 (C)_...

340(P)-._

940 (C)_...

69.5

72.6

87.3

34.5

73.8

zone. Not analyzed, overburden too thick, tonnage 

too low to be economic.

Possible calcium phosphate 

zone. Overburden too 

thick, strata too thin to 

be economic.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 289

Hole

Depth 

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 7

[Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, L. Jenkins, E. Campbell, I. H. 

Barlow, R. Smith. Radiometric (eTI) analyses by J. H. Goode, Jr., B. A. McCall]

! .. .. 

1 ____ .

1. ... -

2... __ .

2........

2. .....

3. .....

4 ... ...

«.-.-.. 

28.1-33.9

33. 9-48. 5

48.6-55.8

15.5-23.0

23. 0-45. 9

45.9-63.1

39. 8-51. 5

39. 9-65. 9

58. 8-78. 8

9,280

12,000

0.008

1,500

1,770 (P)..

3,200 (C).- 

300 (P). 

2,980 (O-.

1,840 (P)..

3,020 (C)_. 

610 (P) -

2,850 (C)_. 

500 (P)..-

2,020 (C)._ 

1,870 (P)..

5,960 (C).-

71.0

71.0

68.0

70.0 

40.5

68.1 

60.0

64.6 

57.0

68.0

phate zone; Bone Valley 

formation.

mation.

phate zone; Bone Valley 

formation. Weighted 

average bottom part of 

sample 60, and all of samples 61 and 62. 

Bottom part of calcium phosphate zone; Hawthorn formation.

zone; sample 64.

zone. Weighted average of 

samples 65 and 66.

pie included both upper 

and lower units of Bone 

Valley formation.

Cross section 8

[Chemical analyses by R. Moore, J. Smith, W. P. Tucker, J. Budinsky, L. Jenkins, E. Campbell, I. H. 

Barlow, R. Smith. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall. No aluminum 

phosphate zone present in this line of drill holes]

1. .....

1 _ ......

2. .....

2 

3 

4 _ ......

4. __ ....

4. .....

51. 0-83. 0

83.0^94.0

39.2-52.4

52. 4-87. 5 

57. 5-62. 4

45. 5-50. 3

50.3-56.1

56. 1-63. 4

-- - ........ ........

8,076 (P)..

9,087 (C)..

347 fP^

1,630 (C).. 

2,840 (P)..

1,260 (C)..

2,636 (P).. 

6,379 (C)..

6,075 (P)..

450 (C) . 

1,800 (P)_.

630 (C)..-

1,570 (P)--

1,440 (C)..

36.7

69.6 

40.3

59.2 

40.6

68.9

29.4 

62.4

30.2

58.6 

56.0

65.6

50.8

65.6

phate zone; Bone Valley 

formation.

phosphate zone; Hawthorn 

formation.

phate zone; Bone Valley 

formation. 

Bottom sample of calcium 

phosphate zone; Hawthorn 

formation. Weighted 

average of samples 71, 72, 

and 73.

zone; Bone Valley formation.

phate zone; Bone Valley 

formation.

phosphate zone; Hawthorn 

formation.
290 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole

Depth

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 9

[Chemical analyses by G. J. Daniels, R. Moore, J. Smith, W. P. Tucker, J. Budinsky, L. Jenkins, E. 

Campbell, I. H. Barlow, R. Smith. Eadiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1.... _ .

1...... _

1 . ......

2.-,-.....

2... ...

2... ......

3_.. ...

3.-. ..,

3... ... 

8.........

fi ...

6 ....

6 ....

0. ....

7.........

7_ ...

8 ...

8 

9 .

9.. ....

9 ...

10 

11 ........

11 ........

12.. 

8. 3-26. 6 

26. 6-35. 4

35. 4-43. 3

32. 2-39. 7 

39. 7-48. 6

48. 6-50. 3

15. 4-23. 6 

23. 6-38. 9

42. 6-59. 3

16. 0-17. 7 

17. 7-2S. 7

28. 7-57. 4 

27.0-31.4

31. 4-39. 3

14. 0-19. 7 

19. 7-39. 0

29. 7-35. 6 

35. 6-66. 2

27. 0-34. 8 

34.8-51.2

51. 2-75. 3

55. 2-75. 2

45.8-50.6 

50.6-53.7 

52. 0-72. 4

29,280

12,000

13, 120 

2,720

9,120

9,440

12,500

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

 

 - 

........

........

........

1,000

1,500

1 300

i «;nfi

1,000

1,500

1,000

........

1,650 (P)-_ 

630 (C) .

928 (P)_ 

2,120 (C)._

5,720 (P)_. 

1,310 (C) 

500 (P) - 

580 (C)..-

7,350 (P).. 

3,700 (C)..

4,950 (P)~ 

4,250 (C)._

4,2~50 (r-),. 

750 (C)....

3,120 (P) 

7,530 (C)._

2,240 (P).. 

1,190 (C)_.

2,560 (PK1,490 (C)..

3,690 (P).. 

8,900 (O)_.

880 (P) .

3,180 (P).. 

980 (C). 

2,680 (P).. 

1,700 (C)..

1,600 (P).. 

1,020 (C)_.

70 (P) .. 

590 (C) .

3,040 (P).. 

3,160 (C)..

68.1 

69.0

48.9 

66.0

71.4 

72.4

53.7 

64.6

69.0 

60.4

64.0

67.0

62.6 

71.0

58.0 

69.0

49.0 

61.6

60.4 

70.8

60.0 

69.0

57.9

54.0 

64.6

62.5 

59.4

64.5

75.4

51.7 

74.0

61.0 

67.0

Tipper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation.

Tipper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation.

Tipper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation.

Tipper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation. 

Not sampled. 

One sample of calcium phosphate zone; Bone Valley 

and Hawthorn formations.

Tipper part of calcium phosphate zone; Bone Valley 

formation.

Upper part of calcium phosphate zone; Bone Valley 

formation.

Tipper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation. 

Tipper part of calcium phosphate zone; Bone Valley 

formation.

Upper part of calcium phosphate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn 

formation. 

One sample of calcium phosphate zone; Bone Valley 

and Hawthorn formations.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 291

Hole

Depth

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Eemarks

Cross section 10

[Chemical analyses by R. Moore, L. Jenkins, I. H. Barlow, R. Smith, J. Smith, W. P. Tucker, J. Budinsky, 

E. Campbell, A. Sweeney, T. Murphy, J. Waring. Radiometric (eU) analyses by J. H. Goode, Jr., 

B. A. McCall]

1 ___ 1 ___

1...... ...

2. ........

2.........

2 .........

3. __ . ...

3 ...... 

4.........

4. ........

5. ........

5. ........

5. _____

5 .........

6. ........

6 ......

6 .........

6

7.........

7.........

7.........

7 _ ......

8.........

8 _ ......

8. ____

9... ......

9. ....

9. _ .....

10 

10 

2.0-5.3

6.3-12.6

12.6-18.9

1.5-8.2

8. 2-9. 6

9. 6-17. 1 

9. 0-27. 5

27.5-37.0 

9. 0-17. 4

7. 4-26. 6

3. 0-22. 4

22. 4-26. 0

26.0-31.2

31.2-318

35.0-39.8

39.8-41.7

41. 7-56. 1

56.1- 0.9

7.0-22.0

22.0-28.1

28. 1-33. 1

33. 1-13. 2

18.0-22.9

22.9-36.3

36. 3-37. 2

14. 0-14. 8

14.8-20.6

20. 6-23. 6

8.0-17.1

17. 1-25. 1

5.280

10,720

29,600

13, 440

31,040

7,680

24,000

7,840

1,280

14,560

........

 

0.006

.004

.005

2,800

1 ' 000

1,800

1,100

1,000

1,500

500

--------

100 (P) .

2,200 (C)_. 

400 (P)

3,560 (C)..

1,780 (P).. 

4,670 (C)-

1,430 (P)_. 

3,100 (C)..

2,840 (P)..

2,400 (C) 

OKO fp\

1,090 (P)..

1,360 (C)..

640 (P).._.

3,060 (C) 

108 (P)-...

970 (C) .

OEfl fD\

1,845 (P)..

3,060 (C)..

1,940 (P)..

6,640 fO)__ 

660 (P) .

420 (C)....

826 (P) .

1,580 (C)._ 

120 (P) -

1,670 (C)._

390 (P) -

61.1

75.6 

65.0

71.0

69.0 

73.6

66.0 

68.4

67.5

68.0

66.2

63.5

65.0

65.4

70.0 

54.0

65.7

66.2

49.1

67.2

68.8

74.7 

19.0

60.4

66.9

68.8 

68.5

70.0

69.0

phate zone; Bone Valley 

formation.

phosphate zone; Hawthorn 

formation.

phate zone; Bone Valley 

formation. Sample not 

assayed. 

Bottom sample of calcium 

phosphate zone; Hawthorn 

formation.

One sample Includes both 

Hawthorn and Bone Valley formations.

Hawthorn and Bone Valley formations.

phate zone; Bone Valley 

formation.

Bottom sample of calcium

phosphate zone; Hawthorn, 

formation.

Not recovered, probably

clayey sand (Aluminum, 

phosphate).

Hawthorn and Bone Valley formations.

phosphate zone; Hawthorn 

formation.

phate zone; Bone Valley 

formation.

phosphate zone; Hawthorn 

formation.

Hawthorn and Bone Valley formations.

Not calcium phosphate 

zone.

Top sample of calcium phosphate zone; Bone Valley 

formation.
292 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole

Depth 

Interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 10 Continued

10. .......

10. .......

10 

10 

11 11 

11 ........

11 ........

11- .......

12. .......

12 ........

12 ........

12 __ . ... 

13.. ...

13........

13 

14 ........

14........

14. .......

15 .....

16. ___ .

25.1-36.9

36. 9-46. 5

46. 5-52. 4

52. 4-57. 4

20. 3-22. 0

22. 0-26. 3

26. 3-28. 2

28 2-38 1

38. 1-39. 1

19. 8-22. 1

22. 1-31. 5

31. 5-34. 2

34. 2-43. 2 

27. 7-38. 0

38. 0-54. 3

54. 3-55. 5

19. 9-25. 0

25. 0-29. 1

29. 1-37. 0

40. 2-49. 7

10. 2-13. 1

2,720

3,680

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

8,160

4,640

0.001

.002

........

.005

........

800

1,570 (P)._

3,140 (C)_. 

351) (P) 

2,320 (O1,050 (P)..

1,800 (C)_.

300 (P) -

1,410 (P)..

2,940 (O290 (P)- ...

280 (C) 

1,960 (P)..

2,540 (C)_. 

330 (P)- ...

700 (C). 

2,170 (P)._ 

1,990 (C)-

1,870 (P)..

1,730 (C)._ 

3,700 (P)..

6,260 (C)._

43f) (P)

200 (C) .

290 (P) 

330 (C) 

puted. 

580 (P) .

480 (C). 

67.2

68.4 

M.4

62.0

33.9

61.8

63.5

63.3

66.9 

40.5

62.4

60.0

58.3 

63.7

67.2

58.0 

60.0

63.5

70.2 

63.6

63.4 

43.1

58.0

65.6

65.6 

8.0-20.0

52.9

60.5

phosphate zone; Hawthorn 

formation. 

Do.

Not sampled.

Bottom sample of calcium

phosphate zone; Hawthorn 

formation.

phate zone; Bone Valley 

formation. 

Do.

phosphate zone; Hawthorn 

formation. 

Do.

and unnamed unit. Not 

economic.

phosphate zone; Hawthorn 

formation. 

Bottom sample of calcium 

phosphate zone; Hawthorn 

formation. Weighted average of samples 30 and 31.

pnate zone; Bone Valley 

formation.

average of samples 33 and 

34. Not economic.

Not calcium phosphate 

zone.

phate zone; Bone Valley 

formation.

thorn. Not economic.

Cross section 11

'[Chemical analyses by Q. J. Daniels, R. Moore, A. Sweeney, T. Murphy, J. Waring, J. Budinsky. Radlometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1 _ ..

2. 

 2.. _ . ...

3...... ...

22. 5-28. 0

39. 3-41. 8

21. 3-24. 4

8,800

4,960

1,000

1,010 (P)._

270 (C)- 

66.5

71.2

phosphate zone and calcium phosphate zone is 

clayey sand; not economic.

phate zone; Bone Valley 

formation.

phosphate zone and calcium phosphate zone is 

clayey sand; not economic. 

Aluminum phosphate zone 

based on lithology; no 

analysis or gamma-ray 

data available.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 293

Hole

Death 

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

TJ

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 11 Continued

3 ... 

4.........

4. ____

5.........

o.........

7. .-._. 

8.........

39. 7-51. 4 

13.0-15.1

47. 5-51. 8

36.0-48.8

66.5-71.9

34.8-54.0

3,360

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

........

........

1 000

........

3,490 (P).. 

1,510 (C)_.

600 (P)- 

1,000 (C)..

 >An (T>\

630 (C) .

2,200 (P)_. 

1,390 (C)..

64.6 

67.3

57.4

68.4 

37.0

68.5

57.0 

68.0

One sample of calcium phosphate zone; Bone Valley 

and Hawthorn formations.

phosphate zone and calcium phosphate zone is 

clayey sand; not economic.

phate zone; Bone Valley 

formation. Not computed; 

sample analysis includes 

4.4 feet limestone beneath 

calcium phosphate zone.

phate zone; Bone Valley 

formation.

unnamed unit. Sample 

58 and part of 59 used to 

compute tonnage and grade. 

Calcium phosphate zone in 

unnamed unit. Sample 58 

and part of 59 used to compute tonnage and grade.

Cross section 12

[Chemical analyses by Q. J. Daniels, R. Moore, A. Sweeney, T. Murphy, J. Waring, J. Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1. ........

1 ......... 

1 .........

1. .... .

2 .........

2 .........

3. .....

3. ........

3 ... ...

3 . ..

4. ___ ..

4 ...

4. ........

4......... 

6.........

7 .........

6.0-11.0

11.0-19.0 

19.0-22.1

22.1-28.0

8. 5-17. 2

17. 2-26. 5

8. 1-12. 6

12. 6-30. 5

30. 5-35. 4

35.4-40.6

42.0-47.1

47. 1-91. 3

91.3-97.0

97. 0-99. 1

8,000

13,920

7,200

7 Rdn

8,160

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

0.012

fvu

.005

........

2 ' 500

800

........

620 (P) - 

1,570 (C)._

1 060 (P)

3,620 (C)..

566 (P) -

4,240 (C)..

finn fP\

1,200 (C)..

QRfl (T>\

1,564 (C)-

60 (P)..... 

1,030 (C)..

73.5 

77.0

76.0

82.0

73.0

71.2

71.2

72.2

73.9

77.6

70.0 

74.5

Upper part of calcium phosphate zone; Bone Valley 

formation.

phate zone; Hawthorn 

formation.

phate zone; both Bone 

Valley and Hawthorn 

formations.

aluminum phosphate material.

phate zone; both Bone 

Valley and Hawthorn 

formations.

phate zone; Bone Valley 

formation. 

Lower part of calcium phosphate zone; Hawthorn formation.

deep). 

Blank hole (low grade, low

tonnage).
294 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Hole

Death 

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

TJ

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 13

IChemical analyses by R. Moore, A. Sweeney, T. Murphy, J. Waring, J. Budinsky. Radiometrio (eU) 

analyses by J. H. Goode, Jr., B. A. McCalll

1 ......

1 ......

2 .........

2 .........

2.........

3 ._-_.-

3. ____ .

4... ......

4 .........

5 .... ..

 6.........

7.........

& .........

57. 0-62. 9

62. 9-74. 6

29. 2-32. 5

32. 5-37. 4

37.4-46.0

72.3-75.8

75. 8-81. 2

70. 0-75. 0

75.0-81.5

80. 9-85. 9 

67.4-79.5

76. 9-80. 7

9,440

5,280

5,600

8,000

0 004

.006

1 ' 000

1,700

1,500 (P)_.

6,850 (C)..

2,500 (P)_.

2,780 (C)..

2,480 (P)..

3,290 (C)..

1,880 (P)..

4,280 (C).. 

890 (P) . 

90 (C). . 

4,000 (P)..

3,500 (C)- 

i *)xf\ fp^

1,000 (C)-.

73.2

75.2

67.5

71.9

68.2

73.2

64.7

65.1 

59.2 

67.5 

64.6

67.8 

66.5

73.5

Total calcium phosphate

zone; Bone Valley and 

Hawthorn formations.

phate zone.

phate zone; Hawthorn formation.

unnamed unit.

named unit.

unnamed unit.

named unit. 

Calcium phosphate zone; unnamed unit. 

Calcium phosphate zone; unnamed unit. Weighted average of samples 90 and 91.

named unit. Includes 2.0 

feet of core not recovered.

Cross section 14

{Chemical analyses by G. J. Daniels, R. Moore, A. Sweeney, T. Murphy, J. Waring, J. Budinsky. Radiometric (eU) analyses by J. H. Goode, Jr., B. A. McCall. Holes 3, 4, 7, and 8 intersected no aluminum 

phosphate or calcium phosphate]

1 ......

1... ..... . 

2_. .......

38. 0-40. 8 

40. 8-49. 5

43. 6-49. 3

4,480

........

1 400

........

1,550 (P).. 

4,990 (C)_.

2,130 (P).. 

1,920 (C)..

51.7 

75.0

74.1 

73.2

One sample of calcium phosphate zone; Bone Valley 

and Hawthorn formations. 

Lower part of calcium phosphate zone; Hawthorn formation.

Cross section 15

.[Chemical analyses by O. J. Daniels, A. Sweeney, W. P. Tucker, J. Budinsky. Radiometeric (eU) analyses by J. H. Goode, Jr., B. A. McCall]

1 - _ .- 1. .....

2... __ ..

2.........

3_ .... .

3- __ .. 

4 ___ ...

4 ......

5.. .......

6 ...

21. 0-24. 5

24. 5-29. 0

35. 0-40. 0

41. 9-45. 9

54. 0-56. 5

56. 5-59. 9 

60. 0-64. 8

64. 8-68. 8

55. 5-66. 5

5,600

8,000

4,000

7,680

1,100

600

1 800

2,000+

1 300 (P)

440 (C). 

1,760 (P).. 

280 (C). 

920 (P) -

970 (C')-- - 

2,160 (P)_-

2,860 (C)..

60.3

69.0

78.4 

75.4

71.0

74.1 

68.0

67.6

zone.
CORE DRILLING, LAND-PEBBLE PHOSPHATE DISTRICT, FLORIDA 295

Hole

Death 

interval 

(feet below 

the surface)

Aluminum phosphate zone

Cubic 

yards per 

acre

Percent 

U

Cpm

Calcium phosphate 

zone

Tons per 

acre

Percent 

bone 

phosphate 

of lime

Remarks

Cross section 16

[Chemical analyses by G. J. Daniels, A. Sweeney, W. P. Tucker, J. Budinsky. Eadiometric (eU) analyses 

by J. H. Goode, Jr., B. A. McCalll

1 1 ...... 1-.. .-.

2. _____

3. ____ .

4 ____ .

5 

6 ...

78.0-82.0

56. 0-S8. 5

58. 5-71. 5 

47. 3-52. 4

32. 8-35. 5

36. 6-39. 2

39.2-42.4

6,400

4,000

8,160

4,320

4,320

 

1,100

900

1,400

900

1,300

2,340 (P).. 

1,700 (C)_-

379 (P) 

380 (C). 

53.4 

70.5

58.5

70.3

Lower part of calcium phosphate zone; Hawthorn formation.

phate zone; Hawthorn formation.

Cross section 17

[Chemical analyses by G. J. Daniels, A. Sweeney, W. P. Tucker, J. Budinsky. Eadiometric (eU) analyses 

by J. H. Goode, Jr., B. A. McCall]

1. .....

1 

2..... ....

2 __ .....

2

3 .........

3. .....

4 .. .. 

5 ...

6. ___ ..

7 ......

8. ___ -

9. . ....

10. 

10 

11.. ......

17. 3-25. 0

25. 0-39. 3

29. 5-39. 0

39. 0-43. 0

43. 0-52. 0

20. 0-23. 0

23. 0-29. 0

7. 4-15. 8

1.6-6.0

9. 0-12. 0

4. 0-10. 5

53.5-64.5

15. 5-25. 5

72. 5-78. 0

78. 0-87. 0

4.0-11.3

12,320

15,200

4,800

18,440

7,200

4,800

10,400

17,600

16,000

8,800

11,680

0.007

1,000

3,500

1,100

1,100

900

800

1,200

1,100

1,100

800

790 (P) 

2,960(C)..

1,000 (P) 

780 (C)....

1,180 (P)..

840 (C) .

63.5

68.3

76.6

72±

74±

zone.

Grades estimated. Sample

analyzed included only a 

part of the calcium phosphate zone.

Cross section 18

[Chemical analyses by G. J. Daniels, A. Sweeney, W. P. Tucker, J. Budinsky. Eadiometric (eU) analyses 

by J. H. Goode, Jr., B. A. McCall]

1... _ .. 1 _ .-

1 _ .....

4 - ....

20. 0-23. 0

23. 0-31. 0

31.0-36.1

38. 5-55. 0

4,800

26,400

1,300

1,000

2,260 (P)..

2,050 (C).. 

860 (P) 

930 (C). 

80.4

79.6 

78.0

76.9

Upper part calcium phosphate zone; Bone Valley 

formation.

Lower part calcium phosphate zone; Hawthorn formation.

INDEX

Page

Alachua formation, general features___ 233-234

stratigraphic correlation, cross section 17. - 264

Aluminum phosphate minerals, where formed. 236

Aluminum phosphate zone, characteristics.. 241

distribution,.._____.__.___... 243

economic details, cross section 1- ____ 246

cross section 2..__.________ 247

cross section 3..._._._-_.__ 248

cross section 4.. ___________ 249

cross section 5..__________. 250

cross section 6. ____________ 251

cross section 7...__________.. 252

cross section 8__..._._______ 253

cross section 9__ __________ 254

cross section 10__________... 256

cross section 11......_.______. 257

cross section 12..___________ 258-259 

cross section 13._________.... 260

crosssection 14.. ...____..... 261

cross section 15_____________ 263 

crosssection 16..______..._.. 263 

crosssection 17 _.. 265

cross section 18 _.. _________ 266 

economic factors_____________241-242 

relation to calcium phosphate zone. __ 242-243 

tonnage data, calculations....._____ 266

computations.-____._____ 287-295

Analyses, chemical____________ 237,271-295

radiometric....... .- .-.. .... 271-295

Barlow, I. H., analyst______.____ 271,

272,273, 274,275, 276, 278, 287, 288, 289, 290, 291

Bedclay, definition_____________ 230

Bethea, S., analyst........_..._ 272,273,287,288

Bone Valley formation, chemistry _____ 237,238 

Rental features. ,___ ._. 234 235 

matrix ___________________ 235 

mineralogy.__-. --.---.--..-...-. 235,236 

stratigraphic correlation, cross section I... 245 

cross section 2....____.-..--..-- 246-247

cross sections.-.._________ 248

cross section 4... __ _ ________ 249 

cross section 5., __________.. 249-250 

crosssection 6.._____.____ 250-251 

cross section 7..______-.-..--.... 251

cross section 8.. ..... 252

cross section 9-...._._._.--..... 253

cross section 10... ____- _____ 255 

cross section 11...._._... .. 256

cross section 12...... 258

crosssection 13...-. 259 

cross section 14...-_.....-..---... 260-261

crosssection 15...._._-..--.. .. 262

cross section 16.. _.__.___.... 263

Bone Valley formation Continued

stratigraphic correlation continued Page 

cross section 17. __....__._.... 264-265

cross section 18_._._._.. ... 265 

lithologic criteria ..... 245

weathering......_...--_._ ... 239

Brodkorb, Pierce, quoted _________.. 234

Budinsky, J., analyst_.. . . . 271,

272, 273, 274, 275, 276, 278, 281, 282, 283, 284,

285,286, 287, 288, 289,290, 291, 292, 293, 294, 295.

Calcium, ratio to phosphate.. ..... . 238

Calcium phosphate zone, characteristics 240 

distribution.... .. .. .. 242-243

economic details, crosssection 246 

cross section 2....__ _.. . 247

cross section 3.... .....-.-- 248

cross section 4.... 249

crosssection 5.-..-_.. . . 250 

cross section 6.-,-_- 251

crosssection 7..----.-.-.. 252

cross section 8.----.-..--- 253

cross section 9_...-..-_..-.. ...-. 254 

cross section 10.------. 255

cross section 11.-------------------- 256-257

crosssection 12.._.._-.__._.. 258 

crosssection 13-. . 260 

cross section 14..-------- 261

crosssection 15.. - 262 

cross section 16.._________.. 263 

cross section 17-.. -- 265 

cioss section 18..------ 266

economic factors___.- . 240-241

relation to aluminum phosphate zone 242-243

tonnage data, calculations.. 266-267

computations-. _ 287-295

Campbell, E., analyst.__... . . 271,272,

273,274, 275,276,278, 287,288,289,290, 291

Chemical analyses-.------------------ 237,271-295

Daniels, G. J., analyst . .- 276,

281,282,284,285,286,290,292,293,294,295

Drilling procedures..... 222

Flanagan, F., analyst- 224

Fluorine, ratio to phosphate 238

Fossils, Hawthorn formation . 230-231

Ocala limestone..- 226

Suwannee limestone 227

Tampa limestone -. --. 228-229

Geologic history___.-..._. - 225

Goode, J. H., Jr., analyst-____ _ 271, 272, 

273, 274, 275, 276, 278, 281, 282, 283, 284, 285, 

286, 287, 288, 289, 290, 291, 292, 293, 294, 295

297
298 INDEX

Page

Hawthorn formation, chemistry____ 236,237,238 

dolomitization _____________ 239 

fossils- . . .__._______ 230-231 

general features. _ __.____ 229-231 

mineralogy-________________ 235,236 

stratigraphic corielation, cross section 1_ 244 

crosssection 2......._________ 246

cross section 3.. __________ 247-248 

cross section 4.. __________ 248-249 

cross section 5..__._________ 249 

cross section 6..___________ 250 

cross section 7_____________ 251 

cross section 8______________ 252 

cross section 9._ __________ 253 

crosssection 10.__________ 254-255 

cioss section 11____________ 256 

cross section 12..___________ 257 

crosssection 13.____________ 2S9 

crosssection 14____________ 260 

crosssection 15......_________ 262

cross section 16__._________ 263 

cioss section 17. _ _________ 264 

cross section 18_____________ 265 

lithologic criteria____________ 245 

weathering. .____________ 239

Jenkins, L., analyst_____________ 271, 

272, 273, 274, 275, 276, 278,287, 288, 289,290, 291

Laboratory procedures- __.________ 222,224 

Limestone unit, unnamed. See Unnamed

sand and limestone. 

Location of area_______________ 222,223

McOall, B. A., analyst_____________ 271,

272, 273, 274, 275, 276, 278, 281, 282, 283, 284,

285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295

MacNeil, F. Stearns, fossil determinations . 224

Matrix, definition. _.____________ 240

Hawthorn formation.-..________ 235, 236

relation to calcium phosphate zone. ___ 240

May, L, analyst.________________ 224

Mineralogy, Bone Valley formation- -___ 235,236

Hawthorn formation...________ 235,236

Moore, K., analyst..274, 275, 276, 278, 281, 282, 283,

284, 288, 289, 290, 291, 293, 294

Murphy, T., analyst. ______________ 278, 

281, 282, 283, 284, 291, 292, 293, 294

Nodules, phosphate content_________ 238 

uranium content- _____________ 238

Ocala limestone, fossils..-.._________ 226

general features.._____________ 226,227

stratigraphic correlation, cross section 15- - 261-262

cioss section 16..____________ 263

lithologic criteria__._________ 245

Radiometric analyses. ..._______ 271-295

Samples, preparation____________ 223-224 

Sand unit, unnamed. See Unnamed sand and

limestone. 

Screen data..... ....._ 237,271-286

Page

Smith, J., analyst. ______________ 271,

272,273, 274,275, 276,278,287, 288,289, 290.291

Smith, R., analyst __.___...__ 271,

272, 273, 274, 275, 276, 278,287, 288,289, 290, 291

Stratigraphic coirelation, litholoeic criteria... 245

Stratigraphic correlation. See formation names.

Surflcial deposits________________ 235

Suwannee limestone, fossils.__..-.._._ 227

general features._ . .. ... 226-227

stratigraphic correlation, cross section 1 244

crosssection 2....__..__.__... 246

cross section 17.. . . - 264

lithologic criteria ... . 245

Sweeney, A., analyst_._________ 278.281,

282, 283,284,285,286, 291, 292, 293,294, 295

Tampa limestone, fossils-- _ ..... 223-229

geneial features__ ... . 228-229

stratigraphic correlation, cross section 1 244

cross section 2....._...... _ 246

cross section 3.. . 247 

cross section 4....._ ... _ 248

crosssection 14. ... 260 

cross section 17... __ 264 

lithologic criteria__.___.__... 245

Tenace sand, general features.._ __ 235 

stratigraphic correlation, cross section 1 246 

crosssection 2.. _ . 247 

cross section 3...___.__.__... 248 

cross section 4...__....__ - 249 

cross section 5...___.__.__ 250 

cross section 6.. 251 

cross section 7...___ 251-252 

cross section 8...______ 252 

cross section 9....__ ... . 253 

crosssection 10. . 255 

crosssection 11.. . 256 

crosssection 12..._____ . 258 

crosssection 13._______ 259 

crosssection 14.._... . . 261 

crosssection 15 262 

cross section 16________. _ 263 

crosssection 17....__ 265 

crosssection 18____________ 265-266 

lithologic criteria .. .. 245

Tucker, W. P., analyst __.___ _ 271, 

272,273, 274, 275, 276, 278, 285,286, 287,288, 

289, 290, 281,294, 295.

Unnamed sand and limestone, chemistry 236,237 

fossils. ._ 232-233

general features .... 231-232

stratigraphic correlation, cross section 10 255 

cross section 11...__ _ ...-- 256 

cross section 12. ___________ 257-258 

cross section 13_.__ _ ... 259 

crosssection 14.. 260 

crosssection 15..... ------ 262

Uranium content, phosphate nodules 238,241

Waring, J., analyst__.. .. . 278, 

281,282,283,284, 291, 292,293, 294 

Weathering, land-pebble district....... 238-239

o