Reconnaissance Investigation 

of Uranium Occurrences 

in the Saratoga Area 

Carbon County, Wyoming

GEOLOGICAL SURVEY BULLETIN 1046-M

^

This report concerns work done on 

behalf of the U. S. Atomic Energy 

Commission and is published with 

the permission of the Commission

Reconnaissance Investigation 

of Uranium Occurrences 

in the Saratoga Area 

Carbon County, Wyoming

By JAMES G. STEPHENS and M. J. BERGIN

CONTRIBUTION TO THE GEOLOGY OF URANIUM

GEOLOGICAL SURVEY BULLETIN 1046-M

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 Geological Survey has cataloged this publication for the Library of Congress as follows:

Stephens, James Gilbert, 1926-

Reconnaissance investigation of uranium occurrences in 

the Saratoga area, Carbon County, Wyoming, by James G. 

Stephens and M. J. Bergin. Washington, U. S. Govt. Print. 

Off., 1958.

iv, 321-338 p. maps (2 fold, in pocket) diagrs., tables. 25 cm. 

(U. S. Geological Survey. Bulletin 1046-M. Contribution to the 

geology of uranium)

Bibliography: p. 338.

1. Uranium ores Wyoming Carbon Co. I. Bergin, Marion 

Joseph, 1927- joint author, u. Title (Series U. S. Geological Survey. Bulletin 1046-M. Series: U. S. Geological Survey. 

Contributions to the geology of uranium)

553.493

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

Washington 25, D. C. - Price 55 cents (paper cover)
CONTENTS

	Page 

Abstract. ______________________________________________.____ 321

Introduction._____________________________________________________ 321

Geographic setting________________________________________________ 322

Geologic setting____________________________________________________ 323

Stratigraphy._____________________________________________________ 324

General.._______ .._____________________________._ 324

Age and nomenclature of the Tertiary rocks_______________----__- 326

Browns Park(?) formation.__________________________.____ 327

North Park(?) formation....___________________________ 327

Pediment deposits-_.._____-__________________-_____-___--_-_--- 328

Uranium occurrences__..__-___-__-__________-__-___--_-_--_-----_- 328

Uranium content of water._________________________________________ 332

Localization of uranium_..____________________________-______--____- 332

References cited____________________________________________________ 338

ILLUSTRATIONS

[Plates 39 and 41 are in pocket]

Page

PLATE 39. Reconnaissance geologic map of the northwest quarter of the 

Saratoga 30-minute quadrangle, Wyoming-Colorado.

40. A, Pit in the Browns Park(?) formation 3 miles west of 

Saratoga; B, Bulldozed cut on pediment surface 6 miles 

south of Saratoga______________________________Faces 329

41. Geologic sketch map showing distribution and uranium content of water in the Saratoga area. 

FIGURE 29. Index map of Wyoming showing the location of the Saratoga

area, Carbon County._________________________________ 322

30. Sketch map of part of Wyoming and Colorado showing the

geologic setting of the Saratoga area.___________________ 323

31. Stratigraphic section in the Browns Park(?) formation showing uranium and equivalent uranium contents of rocks at 

locality 7_..______________._.___________ __._____ _ 329

32. Stratigraphic section in the North Park(?) formation showing 

uranium a,nd equivalent uranium contents of rocks at 

locality 18..__-________________-_____-______---------- 330

33. Stratigraphic section showing uranium and equivalent 

uranium contents in pediment gravel and part of the North 

Park(?) formation at locality 30__------------_--------_ 331

m
IV

CONTENTS

TABLES

Page 

TABLE 1. Formations exposed in the Saratoga area._________________ 325

2. Summation of analyses of water samples from the Saratoga

area.________________________________ 332

3. Analyses of rock samples from the Saratoga area, Carbon

County, Wyo___________________________ 333

4. Analyses of water samples from the Saratoga area, Carbon

County, Wyo_-_____________--___----- 336
CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

RECONNAISSANCE INVESTIGATION OF URANIUM OCCURRENCES IN THE SARATOGA AREA, CARBON COUNTY, 

WYOMING

By JAMEIS G. STEPHENS and M. J. BERGIN

ABSTRACT

Uranium occurs in the Browns Park(?) formation of Miocene (?) age, the 

North Park(?) formation of Pliocene (?) age, and Quaternary pediment gravels 

in the Saratoga area, Carbon County, Wyo. No commercial deposits have been 

found to date. Carnotite, Kj^UOaMVCUVl-SHjO, the only uranium mineral 

identified in the area, was; found at two localities. It occurs in pediment deposits 

as a coating on individual cobbles and boulders and as disseminated specks in 

fine-grained material. Directly below the pediment gravel, carnotite is found as 

a caliche-like coating on limestone and sandstone. At 30 other localities the 

uranium is disseminated as a mineralogically unidentifiable form in chert, limestone, sandstone, siltstone, carbonaceous shale, or volcanic ash. The highest 

concentration of uranium (0.027 percent) was found in chert layers and irregular 

masses in silicified limestone. A concentration of 0.026 percent of uranium was 

found in a silicified volcanic ash bed 0.4 feet thick. A selected sample of pediment 

gravel containing carnotite analyzed 0.011 percent of uranium.

The carnotite occurrences are believed to have been formed by solution and 

redeposition of uranium by ground water.

Analyses of rock and water samples collected in the area and generalized 

descriptions of exposed strata are tabulated.

INTRODUCTION

The Saratoga area is in Carbon County, south-central Wyoming 

(fig. 29). The presence of the radioactivity anomalies shown on 

plate 39 was discovered by the U. S. Geological Survey in November 

1953 (Henderson, 1954) as a result of an airborne survey of part of 

the area. The main objective of the investigation was to study and 

sample in detail each of the anomalous radioactive areas in order to 

evaluate the possible presence of commercial grade uranium deposits 

and to obtain information concerning the origin of the anomalous 

radioactivity.

Fieldwork was carried on from July 5 to August 11, 1954. Rocks 

exposed in anomalous radioactive areas and in many prospect pits were 

examined, and then* radioactivity was tested with a scintillation 

counter. Rock samples from the localities shown on plate 39 were

321
322 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

collected for radiometric, chemical, and mineralogic analyses (table 3). 

Samples of water, the locations of which are shown on plates 39 and 41, 

were collected for uranium analyses as a possible aid in outlining areas 

for more intensive prospecting (table 4). Detailed work was supplemented by reconnaissance geologic mapping in the northwest quarter 

of the Saratoga 30-minute quadrangle, Wyoming-Colorado, and by 

reconnaissance into adjoining areas to examine other radioactivity 

anomalies found by aerial surveys.

Mr. John de la Montague, Dr. P. O. McGrew, and Mr. Paul Boden 

gave helpful suggestions and ideas regarding the geology of the area. 

The samples were analyzed in the Geological Survey laboratory.

GEOGRAPHIC SETTING

The Saratoga area includes about 210 square miles in the northwestward-trending Saratoga Valley which is bounded on the east by 

the Medicine Bow Mountains and on the southwest by the Sierra 

Madre (fig. 29). The northwest quarter of the Saratoga 30-minute 

topographic quadrangle map, Wyoming-Colorado, shows the area. 

Elevations range from 6,750 feet along the North Platte River to 

9,050 feet on the northeast flank of the Sierra Madre giving a maximum relief of about 2,300 feet. The mean elevation is about 7,100 

feet; the average relief is about 500 feet. The North Platte River 

and its permanent tributaries Jack Creek, North Spring Creek, 

South Spring Creek, and Cow Creek drain the area.

_A_J _ -i-r -4

I" (*S ', f \ If WASHAKIE £ /-"^W BOW \A yt«At X A R A MI E 

»....? Z? *P**'\Jj BASIN \ ^IER^AA».MTI?S /X / I j oci.«y«n«. j

rL'_'_Ll_^ J_^l..___L-L.-^^^i.-i J^Jl^-- J'"

FIGURE 29. Index map of Wyoming showing the location of the Saratoga area, Carbon County.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 323

Saratoga is the only town in the area; Encampment is about 20 

miles to the south; and Rawlins, the county seat of Carbon County, 

is 43 miles to the northwest. State Highway 230 crosses the southeast corner of the area, and State Highway 130 crosses the northeast 

quarter. Many improved and unimproved roads make most localities 

within the area accessible by automobile.

Cattle and sheep ranching are the main industries. Alfalfa and 

hay are grown in irrigated fields along permanent streams, and 

timber is cut in the mountainous regions to the east and west. Two 

test wells for oil and gas have been drilled in the area, but both were 

dry.

A sparse growth of brush and short grasses is the only vegetation 

at lower elevations, except along the major stream courses where 

cottonwood and other deciduous trees grow. The mountains are 

forest covered. Bedrock is comparatively well exposed throughout 

the area.

GEOLOGIC SETTING

The Saratoga area is in the Saratoga basin, a structural and topographic basin between the Precambrian masses of the Medicine Bow 

Mountains to the east and the Sierra Madre to the southwest (fig. 30).

EXPLANATION

fy7]

Tertiary intrusive rocks

Terflory sedimentary rocks

Mesozoic and EHPaleozoic rocks

Low-angle reverse fault 

Triangles on upthroxm side

Hlgn-angle reverse fault 

Hochures On downthrow! side; 

arrow indicates direction of dip

Normal foult or undifferentiofed

high-angle fault 

ffoeftures on downthrown sidt

105°

Modified from Tectonic Map of the United 

States, Longwell, C. R. and others, 1844 

2O Miles

FIOXJEE 30. Sketch map of part of Wyoming and Colorado showing the geologic setting of the Saratoga

area, Carbon County, Wyo.
324 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

The Miller Hill plateau, an erosional remnant of tuffaceous sandstone 

and limestone of Tertiary age, forms a high area extending northward from the Sierra Madre west of the Saratoga area. The Fort 

Steele, St. Mary's, and Pass Creek anticlines and their associated 

faults separate the Saratoga basin to the south from the Harma 

basin to the north. The Saratoga basin is separated from the North 

Park basin to the south by the Independence Mountain fault. Precambrian rocks have been thrust southward over rocks as young as 

Paleocene along this eastward-trending fault which dips northward 

at a low angle (Blackstone, 1953; Montagne, 1957; Walters, 1957).

Rocks of Precambrian, Paleozoic, Mesozoic, and Tertiary ages are 

exposed in the Saratoga basin. The Tertiary succession, which unconformably overlies Precambrian and gently folded Paleozoic and 

Mesozoic rocks, is composed of the Browns Park(?) formation of 

Miocene(?) age and the North Park(?) formation of PUocene(?) age.

Normal faults cut the Tertiary rocks at several places. In sec. 19, 

T. 16 N., R. 84 W., a displacement of about 10 feet on a pediment 

surface and the damming of small streams indicate that minor movements have taken place in relatively recent time.

STRATIGRAPHY

GENERAL

Because fieldwork was directed primarily toward the investigation 

of uranium occurrences in the area, rocks other than those related 

to the uranium occurrences are not discussed. The general characteristics and thicknesses of rocks exposed in the Saratoga area, given 

in table 1, are summarized from descriptions by Ashley (1948), 

McGrew (1951,1953), Weitz and Love (1952), Love (1953), and Vine 

and Prichard (written communication, 1956). Unusually high radioactivity in rocks older than Tertiary was not detected by the airborne 

survey or by a hand scintillation counter.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 

TABLE 1. Formations exposed in the Saratoga area

325

System

Tertiary

Cretaceous

Jurassic

Precambrian

Series

?

?

Pliocene(?)

Miocene(?)

Upper

Lower

Upper

Lower

Formation

Pediment deposits

Conglomerate of postNorth Park(?) age

North Park(?) formation

Browns Park(?) formation

Steele shale

Niobrara formation

Frontier formation

Mowry shale

Thermopolis shale

Cloverly formation

Morrison formation

Jurassic rocks 

undivided

Precambrian rocks 

undivided

Approximate 

thickness 

(feet)

1-15

100±

1000±

850±

2500±

1200±

650±

350±

100±

150±

250±

225±

?

Description

and gravel; found along major 

streams.

Unconsolidated pediment deposits 

consisting of poorly sorted silt, sand, 

gravel, cobbles, and boulders; found 

on relatively flat upland surfaces.

Poorly cemented conglomerate composed of rounded rock fragments up 

to 2 ft. across in matrix of poorly 

sorted sandstone; exposed only along 

Jack Creek. Mapped with North 

Park(?) formation.

Sequence of fine-grained sandstone; 

white- to yellowish-gray tuff; lightgray cherty limestone, bentonitic 

claystone and marlstone; and volcanic ash.

Basal conglomerate and overlying 

sequence of gray to white finegrained sandstone with thin beds of 

cherty limestone, marlstone, claystone, and green to gray volcanic 

ash. Basal conglomerate may be 

absent but is 100 ft. thick locally.

Sequence of gray soft shale with 

numerous thin fine-grained sandstone beds in upper part; contains 

marine fossils.

Sequence of smoky-gray limy shale 

and light-gray argillaceous chalky 

limestone; contains marine fossils.

Gray thin-bedded sandstone interbedded with gray to black silty and 

sandy shale; contains marine fossils.

Black hard siliceous shale, which 

weathers to distinctive silver gray. 

Contains a few thin bentonite beds 

and fish scale impressions.

Dark-gray to black soft shale in the 

lower part and interbedded black 

shale and gray ferruginous sandstone 

(Muddy sandstone member) in 

upper part; mapped with Mowry 

shale.

Clean light-gray sparkling sandstone 

with beds and lenses of chert pebble 

conglomerate in lower part and darkgray to black shale partings near top; 

some shale partings are carbonaceous.

Greenish-gray and variegated shale, 

claystone and siltstone with thin 

beds of gray, green, and pink nodular 

limestone and silty sandstone.

Dull pink to light-gray noncalcareous 

sandstone (Nugget sandstone of 

Lower Jurassic age) at base and an 

overlying sequence of gray finegrained calcareous nonglauconitic 

sandstone and greenish-gray glauconitic shale and sandstone; limited 

exposures in the Saratoga area.

Granite, granite gneiss, and schist.

466354 69 2
326 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

AGE AND NOMENCLATURE OF THE TERTIARY BOCKS

In a description of the Tertiary strata in central Carbon County, 

Wyo., Veatch (1907) included about 4,500 feet of white ashy beds, 

cherty bands, and basal conglomerate in the North Park formation 

unconformably overlying about 1,200 feet of dark shales and shaly 

sandstone of the Fort Union formation. He designated the age of the 

formations as Tertiary.

Ashley (1948) states that the Tertiary strata in the Saratoga Basin 

have been mapped as the North Park(?) formation by several geologists. The name was queried because of the uncertain correlation 

between the Tertiary sequence in the Saratoga basin and the North 

Park formation as redefined by Beekly (1915) at North Park, Colo. 

On the basis of lithologic characteristics, Ashley divided his North 

Park(?) formation into two parts. The lower part, predominantly 

gray, consists of a basal conglomerate overlain by persistent beds of 

sandstone, limestone, chert, clay, and volcanic ash. The upper part, 

characteristically buff, consists of lenticular beds of conglomerate, 

sandstone, limestone, clay, and volcanic ash. According to Ashley, 

vertebrate fossils collected in the vicinity of Saratoga establish the 

age of the lower part of the North Park(?) formation as used by him as 

early Miocene and the upper part as early Pliocene. He suggested 

tentatively that in the Saratoga basin the Miocene-Pliocene boundary 

be drawn at the color change from gray to buff.

McGrew (1951) also recognized the two lithologic units present in 

the vicinity of Saratoga and referred to the lower unit as the Browns 

Park formation of middle Miocene age and the upper unit as the North 

Park formation of early Pliocene age. Subsequently, a larger vertebrate fauna was obtained from the area by Montagne (1954). Study 

of this fauna led McGrew (1953) to consider the North Park formation 

of the Saratoga area as Barstovian in age or uppermost Miocene in 

age in accordance with the classification of these rocks by the Committee on Nomenclature and Correlation of the North American Continental Tertiary. The writers follow the usage of the Geological Survey 

in referring to the Browns Park formation as Miocene (?) in age and to 

the North Park formation as Pliocene (?) in age.

The Tertiary formations shown on plate 39 of this report are queried 

because of the uncertainty of the age relations and the correlation of 

the rocks in the Saratoga Valley with those at the type localities at 

Browns Park and North Park, Colo. Contacts have been modified 

from those shown in previous work (Love and others, 1952; Weitz 

and Love, 1952) on the basis of lithologic characteristics observed 

during a general reconnaissance in the area, but no supporting fossil 

evidence was found.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 327 

BROWNS PABK(P) FOBMATION

Rocks in which Miocene fossil vertebrates have been found crop 

out east of the North Platte River 5 miles north of Saratoga. The 

sequence consists of gray sandstone and siltstone with thin beds of 

gray cherty limestone and very light-gray clay, marlstone, and volcanic ash. The rocks are massive, usually poorly bedded, and weather 

drab to dull gray. The strata have a general dip of from 5° to 15° 

to the east. The cherty limestone beds usually form dip slopes of small 

cuestas that can be traced for several miles southwest of Saratoga 

where they are truncated and covered by pediment gravels. The 

base of the Browns Park(?) formation is not exposed in the area 

investigated, but several miles north of Saratoga along the North 

Platte River a basal conglomerate as much as 100 feet thick unconformably overlies the Mesaverde formation of Late Cretaceous age.

NOBTH PABK(P) FOBMATION

Rocks thought to represent the North Park(?) formation crop out 

east of the North Platte River north of Saratoga. The rocks consist 

of pale-yellowish-brown sandstone and siltstone, light-gray cherty 

limestone, and white chalky marlstone and volcanic ash. They 

usually have fairly well-developed bedding and on weathering appear 

thin layered. The weathered colors are chalky white, light gray, and 

pale yellowish brown. The strata in general dip about 2° to the east.

No continuous horizon on which to draw the base of the North 

Park(?) formation was observed. The color change as noted by 

Ashley (1948) and McGrew (1951) along the North Platte River 

several miles north of Saratoga could not be traced to the south. 

Ashley (1948) states that at many localities the base of the upper part 

of his North Park(?) formation is marked by a calcareous conglomerate, and J. D. Vine and G. E. Prichard (written communication, 

1956) have mapped such a conglomerate at the base of the North 

Park(?) formation in the Miller Hill area west of Saratoga. In most 

areas the contact between the Browns Park(?) and North Park(?) 

formations appears to be conformable and gradational, but locally the 

difference in attitude of the rocks indicates a probable unconformable 

relation. The nature of the contact was not studied in detail.

In the vicinity of Jack Creek (western half of T. 17 N., R. 85 W.) 

a poorly cemented conglomerate composed of rounded rock fragments 

as much as 2 feet in. diameter, but averaging less than 1 foot, in a 

matrix of poorly sorted sandstone overlies the truncated edges of 

tilted Mesozoic rocks. The conglomerate is as much as 100 feet 

thick. At one exposure about 5 feet of well-cemented conglomerate 

composed of fragments of quartz, chert, and igneous rock is exposed 

between the Mesozoic rocks and the poorly cemented conglomerate 

above. The entire thickness of the lower conglomerate is not ex-
328 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

posed because of talus cover at the base of the upper conglomerate. 

According to N. M. Denson (oral communication, 1954) the lower 

conglomerate is similar to that mapped by J. D. Vine and G. E. 

Prichard (written communication, 1956) as the base of the North 

Park(?) formation in the Miller Hill area. The thick, poorly cemented conglomerate overlying the well-cemented conglomerate is 

probably post-North Park(?) hi age and may be equivalent to the 

gravel of post-North Park(?) age described by Vine and Prichard in 

the southeastern part of the Miller Hill area. An inferred boundary between the Browns Park(?) and the North Park(?) formations 

has been sketched in this area to indicate the possible presence of

both formations.

PEDIMENT DEPOSITS

Much prospecting has been carried on hi the pediment gravels 

west of State Highway 130 from 4 to 7 miles south of Saratoga. 

Carnotite has been found in the gravel and underlying rocks. The 

pediment deposits consist of a very poorly sorted mixture of silt, sand, 

pebbles, cobbles, and boulders. The rock fragments are usually less 

than 1 foot in diameter and are well rounded. Fragments of many 

rock types including sandstone, limestone, chert, granite, schist, and 

basic igneous rocks are present, and pods of gypsum are common. 

The deposits are unconsolidated and massive.

URANIUM OCCURRENCES

In the Saratoga area, uranium in small quantities occurs in both the 

Browns Park(?) formation and the North Park(?) formation and in 

the overlying Quaternary pediment gravels. No commercial deposits have been found to date. Carnotite, KjCUCMsCVOiVl-SHaO, 

the only uranium mineral identified was found at localities 22 and 30 

(plate 39),where it occurs as a calichelike deposit coating sandstone 

and limestone in the North Park(?) formation directly beneath 

pediment gravel, as disseminated specks in the overlying pediment 

gravel, and as a coating on pebbles and boulders in the pediment gravel. 

At the other localities the uranium is disseminated in chert, limestone, 

sandstone, siltstone, or volcanic ash, but no uranium minerals were 

seen. Table 3 shows the equivalent uranium and uranium contents of 

the rocks collected in the area.

Most of the uranium in the Browns Park(?) formation occurs in 

layers and irregular masses of chert in thin hard dense medium-lightgray limestone beds that contain only minor amounts of uranium. 

Figure 31 and plate 40A show a typical example of this type of occurrence. The limestone beds range from 1 to 5 feet in thickness and 

usually form dip slopes on small cuestas. Because of the hard and 

resistant character of the limestone beds, few prospect pits have been 

dug; only a few samples of fresh rock could be obtained. The amount
GEOLOGICAL SURVEY BULLETIN 1040 PLATE 40

A, PIT IN THE BROWNS PARK(?) FORM \TIO.N 3 MILES WEST OF SARATOGA

'I lie pit is at locality 7 (sec. 20, T. 17 N., R. 81 W.). A radioactive cherty limestone bed 

(limestone appears lifiht and chert dark) overlies siltstone (lower light area). Base of cherty 

limestone is near center of hammer handle. See figure 31 for description and analyses.

R, BULLDOZED CUT ON PEDIMENT SURFACF 6 MILES SOUTH OF SARATOGA

'.trnolitu dialings occur on both the pediment gravel and their limestone lenses in the underlying 

sandstone of the North Park(?) formation. The cut is at locality 30 (sec. 13, T. 16 N., 

R. 81 W.K Base of the pediment gravel is just above the hammer handle. Hammer is resting 

on one of the limestone lenses. See figure 33 for description and analyses.

URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 329

of radioactivity of the limestone beds appears to be directly proportional to the amount of chert present; and, since the amount of chert 

varies considerably along the outcrop, the radioactivity of the beds is 

erratic. The limestone contains both dusky-yellow-brown and medium-light-gray chert, usually in the same bed. In general, the darker 

chert has the most uranium. An exception to this generalization is a 

medium-light-gray chert at locality 14 which contains the most uranium found in the Browns Park(?) formation in this area (0.027 

percent). Other rock types in the Browns Park(?) formation have 

only minor amounts of uranium. Sandstone contains as much as 

0.002 percent of uranium; siltstone, as much as 0.003 percent of 

uranium; and calcite, as vein filling in sandstone, as much as 0.005 

percent of uranium.

Uranium and equivalent uranium in percent

.005

 I 

.OIO 

 » 

.015 

 h-

.OZO 

 I

Scale Color Rock type 

in teet HT-I

6-

5-

4 

2-

0 

EXPLANATION

B

gray

Greenish gray Dusky 

yellow brown

Silicified limestone

Chert

Calcareous 

clayey siltstone

Calcareous 

sandy siltstone

Percent chemical uranium

 Percent equivalent uranium

FIGURE 31. Stratlgraphle section to the Browns Park(?) formation showing uranium and equivalent uranium contents of rocks at locality 7.
330 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

In the North Park(?) formation, uranium occurs in small quantities 

in several rock types in addition to chert and limestone as described 

above. At locality 10 a blocky pale-yellow-brown limestone 0.2 feet 

thick contains 0.017 percent of uranium, and a carbonaceous shale 0.1 

foot thick overlying the limestone contains 0.006 percent of uranium. 

A light-gray fine-grained limy sandstone 1 foot thick at locality 16 

contains 0.017 percent of uranium. At locality 18 a light-gray soft 

volcanic ash 1.7 feet thick contains from 0.019 to 0.026 percent of 

uranium (fig. 32). A light-gray clayey siltstone at the same locality

Scale c 

in feet ^

8 1

1 '-'*

f

1

6-t

1 5 1

1

/

4 ^

3 ~

2 -

',.

0 

«or

^

^'',

',

'/'/.

'/'/

\

\

i

\$\

Rock type

 : :-:¥xjxo:::

 : : :+: : : : : 

iz^§z

Y A Y A Y A Y 

Y AY IY A Y

YAYAYAY

YA Y A Y A Y 

YA Y A Y A Y 

Y A Y A Y A Y

i;:^;:^::::^:::

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i "y!'i'iy'x*yi*i*

* X* *I*^'I*I*X

t Ar L-MlilM 1 Iwli

r M v/;/\ [_ Light gray \///\ Po'e yellowish brown

Y Y Y "IvM-lvMY A Y A Y Volcanic ash i-SS:^- Sandstone

Y^Y'AY volcanic ash ^ErlE Clayey siltstone

 Siv^i? Tuffoceous ( Chemical uranium, 

;: *;£*; sandstone | percent

 Equivalent uranium, 

__ _J percent

J

_ _ Uranium and equivalent uranium, in percent

0 .005 .010 .015 020 .085

FIGURE 32. Stratigraphic section in the North Park(?) formation showing uranium and equivalent uranium contents of rocks at locality 18.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 331

contains 0.019 percent of uranium. At locality 30 a sandstone 4.5 

feet thick with many carnotite-coated lenses of light-gray limestone 

up to 2 inches in thickness, contains as much as 0.004 percent of 

uranium (fig. 33 and pi. 405).

The highest uranium content in pediment gravel in the area was 

found at locality 30 (fig. 33 and pi. 405). Carnotite is visible as

Scale Color Rock type

in feet

8 

Uranium and equivalent uranium in percent

.005 .010 .015 D20

-

4 

3 

2 

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L_| Light gray

~~ rrrm Hllli Yellowish gray

Y/yh Pale yellowish brown

^wO Pediment gravel

 : : ; : : : : : : : sandstone

"^^ Limestone lenses

__ <^ 

^^^ Gypsum pods

FICJUBE 33. Stratigraphic section.showing uranium and equivalent uranium contents in pediment gravel 

and partjof the North Park(?) formation at locality 30.
332 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

coatings on the rock fragments and as disseminated specks in the 

finer grained matrix. A selected sample of the gravel at this locality 

contains 0.011 percent of uranium.

URANIUM CONTENT OF WATER

Fifty-six samples of natural waters were collected in the Saratoga 

area in an effort to outline areas in which the rocks have high concentrations of uranium. Water was collected from 36 springs, 14 wells, 

3 seeps, 2 reservoirs, and 1 stream. Sample localities are shown on 

plate 39 and plate 41, and individual analyses are given in table 4. 

Although some of the wells are located on alluvium, the source of 

water in them is from formations at depth. The uranium content and 

pH for each source of water are summarized in the following table.

TABLE 2. Summation of analyses of water samples from the Saratoga area 

[Analysts: H. Bivens, R. Denting, J. Johnson, D. Stockwell, and J. Wilson, U. S. Oeological Survey}

Source of water sample

North Park(?) formation_____

Browns Park(?) formation.... 

Cloverly formation _______ __

Precambrian rocks ___ ____

Saratoga hot springs. _____

Unknown. ________________

Number of 

samples

5 

35

7 

2 

4 

2 

1

Uranium content 

(parts per billion)

Range

1-31 

1-80 

1-21 

1-3 i-e

1-3 

1

Average

12 

14 

8 

2 

3 

2 

1

PH

Range

7. 5-7. 9 

6. 8-8. 9 

7. 4-8. 0 

7. 0-7. 1 

7. 1-7. 8 

6. 9-7. 0 

7.7

Average

7.7 

7.5 

7.7 

7. 1 

7.6 

7.0 

7.7

Because analyses of the water samples were not available before 

fieldwork was discontinued, no detailed investigations were undertaken in areas where the water had a high uranium content. It is believed that the rocks in these areas may contain uranium in even 

higher concentrations than were found during the present investigation. If detailed work was undertaken in these areas, water sampling 

might serve as a useful prospecting tool in searching for higher grade 

deposits.

LOCALIZATION OF URANIUM

Data obtained in the Saratoga area are inadequate to formulate a 

definite theory for the source of the uranium. The formation of the 

carnotite in calichelike occurrences in sandstone, limestone, and 

pediment gravel can best be explained by solution and redeposition 

by ground water. The source for the uranium hi the water is not 

known, but it may be from tuffaceous beds in Tertiary rocks or from 

existing uranium occurrences.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 333

At other localities where uranium is present but no minerals can be 

seen or identified, the uranium may be either syngenetic or epigenetic. 

Uranium might have been deposited in favorable host rocks by water 

which leached uranium from tuffaceous beds in the Browns Park(?) 

and North Park(?) formations. Where uranium is concentrated in 

chert in limestone beds, possibly the uranium and chert were introduced simultaneously by ground water sometime after the deposition 

of the limestone. It is also possible that the uranium was adsorbed 

from uranium-bearing water by the chert after the deposition of both 

the limestone and chert or that it was deposited with the chert at the 

time of deposition of the chert and limestone. Conclusive evidence to 

substantiate any one of these possibilities was not observed.

No evidence for a hydrothermal origin of the uranium was seen, but 

such an origin should not be excluded because of the inadequate data 

obtained in the area. Tertiary intrusive rocks occur about 20 miles 

to the southwest in the Battle Mountain and Elkhead Mountains 

area, but none were recognized in the Saratoga area. Faults, along 

which uranium-bearing solutions could move, occur in the area, but 

none of the observed uranium occurrences appear to be associated 

with the faults.

TABLE 3. Analyses of rock samples from the Saratoga area, Carbon County, Wyo. 

[Analysts: S. Furman, M. Fincb, H. Lipp, and J. Wilson, U. S. Geological Survey]

Locality 

(see 

pi. 39)

1

1

2

2

3 

3

3 

4

4

4

4

6

5 

5 

5

6 

6

Laboratory 

sample

212196

212197

212198

212199

212193 

212194

212195 

212174

212173 

212172

212171

212178

212177 

212176 

212175

212189 

212188

Thickness 

of inter va 

sampled 

(feet)

1.0

2

2

1.5 

1.5

1.5

1± 

1±

1±

2± 

2±

2±

3±

5±

Equivalent 

uranium 

(percent)

0.005

.001

.001

.001

.009 

.010

.003 

.005

.002 

<.001

.001

.003

.002 

.002 

.001

.012 

.009

Uranium 

(percent)

0.005

.009 

.010

.002 

.006

<.001

.001

.003 

.002

.013 

009

Formation

 ..do.-. ... ....

.....do....-. .-.

.... .do... .... 

.....do--... .....

 ..do-.- ... 

... . .do...- .....

 ..do. 

.....do...- .....

Browns Park(?).... 

.....do. ......... 

.....do...... ....

.... .do... .... . 

,,...do,.,,.,, -

Description

ceous. 

Limestone, medium-light-gray; silicifled, contains buff chert. 

Limestone, medlum»light-gray,

nonsiliclfled; about 8 ft below 

sample 212198. 

Chert, light-brownish-gray; found 

in silicified limestone bed. 

Chert, dusky yellow-brown; found 

m silicified limestone bed about 

20 ft below sample 212193. 

Limestone, medium-light-gray; 

same bed from wbtcn sample 

212194 was taken. 

Chert, dusky-yellow-brown; debris

on ridge top. 

Sandstone, ligat-gray, clayey, micaceous. 

Limestone, light-gray, some lightgray chert, sillcifled. 

Limestone, light-gray, nonsilicified. 

Soil.

Limestone, light-gray, slightly 

silicified. 

Limestone, medium-light-gray, siliclfied. 

Limestone, light-gray, nonsflMfied. 

Limestone, medium-light-gray, silicified. Limestone, medium-light-gray, silicified, contains dusky-yellowbrown chert as layers and irregular masses.
334 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 3. Analyses of rock samples from the Saratoga area, Carbon County, Wyo. 

Continued

Locality 

(see 

pi. 39)

6 

6 

6 

6

7

7 

7 

7

7

7 

7 

8

8 

8

9

9 

9 

10 

10

10

10 

10 

10

11 

11

12

12 

13

13

14 

14 

14

14 

14 

15 

. 15

15 

16 

16

16

Laboratory 

sample

212192 

212191 

212190 

212187

212182

212186 

212184 

212181

212180

212179 

212183 

212218

212217 

212216

212219

212221 

212220 

212265 

212264

212263

212262 

212261 

212260

212205 

212206 

212207

212208 

212209

212210

212211 

212212 

212213 

212214 

212215 

212222 

212223

212224 

212226 

212227 

212228

Thickness 

ofinterval 

sampled 

(feet)

.4 

.4 

.4 

1.0

1.3

.3 

.3 

.6

2.4

2.0

3

1

1 

2 

2.4 

0.6

.7

.2 

.1 

.2

4

3

2 

1

Equivalent 

uranium 

(percent)

.019 

.007 

.015 

.002

.013

.011 

.013

.008

.003

.003 

.001

.013 

.002 

.001

.014

.013 

.002 

.002 

.002

.003

.005 

.008 

.012

.007 

<.001 

.008

.002 

.010

.011

.016 

.003 

.032 

.002 

.028 

.002 

001

.001

.003 

.002 

.013

Uranium 

(percent)

.017 

.006 

.015 

.002

.015

.012 

.014 

.010

.003 

.003

.014 

.001

.012

.013 

.001 

<.001 

<.001

.004

.003 

.006 

.014

.007

.006

.003 

.007

.010

.012 

.002 

.027 

.001 

.022 

.001

,002 

,001 

.017

Formation

Browns Park(?)_._ 

.....do.... 

.... .do 

 do 

.... .do.... ... ... 

.... .do... 

 .do 

 ..do ... 

... ..do-- 

 do.- -

 do.. ..

 .do 

 do 

 -do..... -.

 do. 

-- do.... -

 do. 

North Park(?) 

 -do - 

 do.. ... ... ..

.... .do. - 

 -do.- -- 

 do 

 do ... 

.... .do... .-- 

 .do ___

 do 

 do 

 do... ... .

Browns Park(?) ... 

... ..do. ... ... .

 .do 

 do... 

 do.. 

North Park(?> 

 do .... ....

 dO.,. 

Description

Upper 0.4 ft of bed sampled as No. 

212188 

Middle 6.4 ft of bed sampled as No. 

212188. 

Lower 0.4 ft of bed sampled as No. 

212188. 

Sandstone, greenish-gray, finegrained, calcareous. Undeilies 

bed sampled as No. 212188. 

Limestone, silicified 30 pe cent. 

Dusky yellow-brown chert in 

layers and irregular masses 70 

percent. 

Upper 0.3 ft of bed sampled as No. 

212182. 

Lower 0.3 ft of bed sampled as No. 

212182. 

Chert and interbedded limestone 

layers, directly below bed sampled as No. 212182. 

Siltstone, greenish-gray, clayey, 

calcareous, micaceous. 

Siltstone, sandy, calcareous. 

Limestone, nonsilicified. 

Chert, dusky-yellow-brown, found 

in silicified limestone bed. 

Chert, medium-light-gray, from 

same bed as 212218. 

Limestone, medium-light-gray, 

nonsilicified, about 10 ft below 

bed 212217 and 212218. 

Chert, dusky -yellow-brown, found 

in medium-light-gray limestone 

bed. 

Chert, dusky-yellow-brown, in 

limestone bed 10 ft below 212219 

Limestone with medium-light-gray 

chert, 10 ft below 212221. 

Sandstone, ironstained yellowbrown, fine-grained, argillaceous. 

Sandstone, yellow-gray, fine- to 

medium-grained, irregularly 

bedded. 

Shale, yellow-gray; contains limy 

zones. 

Shale, yellow-gray, limy zones. 

Shale, carbonaceous. 

Limestone, light-brownish-gray, 

blocky. 

Chert, dusky-yellow-brown; found 

in medium-light-gray limestone. 

Limestone, medium-light-gray, 

nonsilicified. 

Chert, dusky-yellow-brown, in 

silicified limestone bed. 

Limestone, nonsilicified. 

Chert, medium-light-gray, in silicified limestone bed. 

Chert, dusky-yellow-brown in 

same limestone as 212209. 

Chert, dusky-yellow-brown. 

Limestone, nonsilicified. 

Chert, medium-light-gray. 

Limestone, partially silicified. 

Chert, light-resinous-brown. 

Alluvium in center of dry lake bed. 

Alluvium about 15 ft from center of 

dry lake bed. 

Alluvium about 25 ft from center of 

dry lake bed. 

Sandstone, limy, exposed in bulldozed pit. 

Mndstone, sandy, exposed in bull- 

. . dozed pit. 

Sandstone, limy, exposed in creek 

bed.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 335

TABLE 3. Analyses of rock samples from the Saratoga area, Carbon County, Wyo. 

Continued

Locality 

(see 

pi. 39)

17

17

17

17

17

f C

f C

1R

1R

18

to

1ft

1C

19

20

20

20

21

99

99

93

23

24

OK

26

26

26

27

27

27

27

28

28

28

28

no

29

30

30 

30

30

30

30

31

31

31

Laboratory 

sample

212237

212236

212235

212234

212233

212253

212251

212252

212250

212249

212248

212247

212246

212245

212244

212243

212242

212254

212255

212256

212240

212241

214206

214205

214209

214208

214207

214212

214211

214214

214213

214219

214218

214217

214216

214215

212257

212259

212258 

139083

139084

139085

139086

214229

214230

214231

Thicknes 

ofinterva 

sampled 

(feet)

1

2

.5

1.2

1.2

2

.9

4

.6

.5

.6

.6

.8

1

.3

1

1

1

1

1.5

2

2

1.5

3.5

1.5

2

3

.5

2

5

2

2

.4

.4

2

1

1

4.5 

1

1

1

4

2

1

Equivalent 

uranium 

(percent)

.001

.003

.001

.001

.001

.005

.015

.003

.016

.020

.016

.005

.003

.002

.004

.004

.005

.003

.002

.002

.001

.005

.002

.001

.001

.001

.002

.001

.001

.002

.001

.005

.004

.003

.003

.002

.001

.009

.002 

.002

.004

.002

.002

.002

.002

.002

Uranium 

(percent)

<.001

.002

.019

.001

.019

.026

.019

.003

.001

<.001

.003

.002

.002

.002

<.001

<.001

.004

.007

.003

.011

.001 

.002

.004

.001

.002

Formation

North Park (?)-..

 -do 

. -do..... .... .

 do. _

-.-do.. ..........

.do

 ..do... .

... -do.. - . 

. .do

. .do. 

.. do. 

 -do. ... . ....

.. do ... . .

 do..... .....

... _.do. .... ... _.

 do 

do

 do ------

 -do 

 do- ---

 -do 

 .do - 

 do. 

do

 . do. 

 .do ...

do

North Park (?) __

 -do... ..... ...

 .do- ------

North Park(?)_ 

... .do.. 

 do. 

 -do.. -

North Park(?)_ 

 do. .

 do -

 do. 

 do ... 

 do. 

North Park(?)_ .

Description

ous.

Limestone, sandy, nodular.

Sandstone, brown.

Limestone, nodular.

Siltstone. light-gray, clayey, thinbedded. 

Sandstone, pale-yellowish-brown,

cross-laminated. 

Ash, light-gray.

Ash, light-gray, silicified.

carbonaceous. 

Sandstone, fine-grained, tuffaceous,

carbonaceous. 

Limestone, silicified.

Coaly silicified material.

Conglomerate, silicified.

Sandstone, silicified, with chunks

from y* in. to Ji in. of soft charcoal. 

Conglomerate, silicified.

Sand, yellow-green, unconsolidated.

dated.

Limestone, silicified.

Soil and gravel of pediment surface.

Soil, fine sand and gravel of pediment surface.

pebbles and boulders and gypsum. 

Fine unconsolidated sand, calcareous, some pebbles. 

Soil, sand and gravel of pediment

surface.

Siltstone, pale-green, laminated.

Soil, sand and boulders of pediment

surface. 

Sand and gravel with lenses of

green sandy Siltstone, unconsolidated. 

Sandstone, olive-green, silicified,

fine-grained. 

Gypsum.

grained. 

Sand and gravel of pediment surface. 

Sand, gravel and gypsum of pediment surface, contains carnotite, 

as coating on gravels and as disseminated specks. 

Sandstone with layers and lenses of 

limestone from \i in. to 2 in. in 

thickness, contains carnotite as 

coating material on limestone. 

Upper 1 ft of unit sampled as 212258.

Second 1 ft from top of unit sampled

as 212258. 

Third 1 ft from top of unit sampled

as 212258. 

Gypsum.

Soil, sand and gravel of pediment

surface. 

Gravel and boulders of pediment

surface. 

Silty sandstone, light-green, finegrained.
336 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 3. Analyses of rock samples from the Saratoga area, Carbon County, Wyo.

Continued

Locality 

(see 

pi. 39)

32

32

32

32 

32

32

32

32

32

Laboratory 

sample

214225

214224

214223

214222 

214221

214220

214223

214227

214226

Thickness 

of interval 

sampled 

(feet)

0-2

.5

.5

1.0 

1.5

.5

20

15

15

Equivalent 

uranium 

(percent)

.002

.001

.001

.004 

.001

.002

.005

.003

.003

Uranium

(percent)

.002

.001

Formation

North Park(?)..._.

.....do.. - 

..... do . ...

..... do...... ..... ... 

.....do ....

... ..do...... ... .... .

.....do. ........

... ..do.... ... ...

.....do... ...... .

Description

Sandstone, fine- to coarse-grained,

cross-laminated. 

Clay, dark-green, nonbedded, gypsum pods. 

Sand, yellow-gray, fine-grained,

unconsolidated. 

Siltstone, pale-green, tuffaceous, 

planar-bedded. 

Siltstone, light-gray, tuffaceous,

planar-bedded, contains gastropods. 

Siltstone, light-olive-green, tuflaceous, calcareous.

massive- to cross-bedded with 

silicifled conglomeratic zones.

masslve-to cross-bedded with 

silicified conglomeratic zones. 

Sandstone, fine- to coarse-grained,

massive- to cross-bedded with 

silicified conglomeratic zones.

TABLE 4. Analyses of water samples from the Saratoga area, Carbon County, Wyo. 

[Analysts: H. Bivens, R. Deming, J. Johnson, D. Stockwell, and J. Wilson, IT. S. Geological Survey]

Location 

(see pi. 39 and 41)

NW 4 26-18N 86W...... 

SW 4 36-18N-85W--. 

SE 4 36-18N-85W. ...

NE 4 7-18N-84W-..-.-

NE 4 18-18N-84W-. _ -

NE424-18N-84W.......

SW 4 25-18N-84W - ...

SW 4 25-18N-84W ....

NW 4 3&-17N-87W ...

SE 436-17N-87W ....

SE 4 16-17N-86W- ......

NW 4 19-17N-86W...... 

NE421-17N-86W.......

NE 4 27-17N-86W.......

SW 4 31-17N-86W.......

NE 4 33-17N-86W.......

NW 4 34-17N-86W......

NW 4 35-17N-86W _ ... 

NW 4 35-17N-86W... 

SW 41&-17N-85W.......

SW 4 17-17N-85W.......

SE419-17N-85W.......

Laboratory 

sample

213340 

210637

210638

213338

213339

213347

213344

213345

210655

210654

210648

210649 

210647

210646

210653

210644

210645

210651 

210650

210639

210640

210642

Type of 

sample

Spring ..

Well.. ...

Well.. 

Stream- ....

Seep. . 

Well 

U content 

(ppb)

6 

21

15

6

5

5

19

16

13

7

19 

9

10

26

16

<1

6

7

7

3

pH

7.8 

7.5

8.0

7.5

7.6

7.8

7.7

7.4

8,0

7.0

7.4

7.9

7.4

7.4

7.5

7.2

7.3

7.1 

7.5

7.6

7.0

7.0

Description

Browns Park(?) formation. 

Browns Park(?) formation.

water from spring sampled as no. 

210637. 

No report of depth of well or rock type

which contains water. Probably 

flood plain deposits of North Platte 

River.

North Platte Kiver.

William N. Eaton Ranch. 

Water probably from North Park(?)

formation. Frank Schilt Ranch. 

Well depth 35 ft.

North Park(?) formation. Frank 

Schilt Ranch. 

North Park(?) formation.

(?) formation. 

North Park(?) formation.

Perennial stream draining area of 

North Park(?) formation.

North Park(?) formation.

North Park(?) formation. 

North Park(?) formation. Well reported to be 50 ft deep and water 

from conglomerate at bottom. Paul 

Boden Ranch.

North Park(?) formation.

Iron Spring.
URANIUM OCCURRENCES IN CARBON COUNTY, WYO. 337

TABLE 4. Analyses of water samples from the Saratoga area, Carbon County, Wyo. 

Continued

Location 

(see pi. 39 and 41)

NW420-17N-85W 

SW 420-17N-85W.. _

NE 4 5-17N-84W .... .

NE 4 5-17N-84WSW412-17N-84W..... __

NW 4 13-17N-84W .

NW 4 14-17N-84W... ...

NW418-17N-84W......

NW 4 25-17N-84W ...

NW 4 16-17N-83W......

NW 4 23-17N-83W 

SE433-17N-82W-.. .

SW 4 15-16N-88W.. 

NW 4 22-16N-88W.____.

SE 4 27-16N-88W -. .._

NW 4 28-16N-88W... .__

SW 4 8-16N-87W-. - -

SW 4 4-16N-86W........

SW 4 11-16N-85W.. 

NE 4 15-16N-85W ..

NE 420-16N-85W-.. 

NW 4 28-16N-85W .

NE 4 33-16N-85W 

SE 4 33-16N-85W. ......

NE 4 9-16N-84W........

NE 4 17-16N-84W __

SW 4 31-16N-83W __

SW431-16N-83W .-

NW49-15N-88W.......

NE 4 17-15N-88W._____.

NW 4 23-15N-S5W...... 

SW44-15N-84W........

SE 4 7-15N-84W. ...

NW 4 6-15N-83W 

Laboratory 

sample

210643

210641

213341

213342

210657

210656

210681

213343

213348

210680

210678

210679

210661

210660

210659

210662

210658

210652

210668

210667

210669

210670

210671

210672

213349

210673

213350

213351

210663

210664

210674 

210676

210675

213352

Type of 

sample

Well. ....

WeU 

Well 

Well 

Well.... .

Well. 

WeU. ... .

Spring.. ....

Well. 

WeU. 

WeUSpring.. _ .

Well. 

U eontent 

(ppb)

7

1

3

31

3

<1

<1

11

<1

16

6

6

3

3

4

Q

1Q

01

i

<i

3

80

<1

5

">4

4

g

1

55

49

pH

7.5

7.1

7.9

7.6

7.0

fi Q

7.9

7.4

7.8

7.7

7.7

7.8

7.1

7.2

7.0

7.0

fi Q

7.3

7.7

7.8

8.1

7.6

7.1

7.7

7.7

7.7

8.0

7.5

6.8

7.2

7.8

7.7

8.9

7.6

Description

North Park(?) formation.

to be artesian well drilled to depth of 

60 ft. Four Bar Ranch.

Hot water spring probably associated 

with faulting.

Hobo Pool. Hot water spring probably associated with faulting.

plain of North Platte River.

(?) formation.

ported to be drilled to depth of 110 ft. 

North Park(?) formation. Well reported to be 47 ft deep. 

North Park(?) formation. Well reported to be 50 ft deep.

mation.

tion.

tion.

tion.

formation.

Abandoned oil test. Source of water 

unknown.

North Park(?) formation.

tion. 

Browns Park(?) formation. Well reported to be 225 ft deep. 

North Park(?) formation. Well at

house on Throwbridge Ranch. Reported to be dug to depth of 81 ft. 

Bottom in conglomerate. 

North Park(?) formation. Well at

dairy farm on Throwbridge Ranch 

reported to be drilled to depth of 34 

ft. May be alluvium.

tion.

Precambrian rocks undivided.

North Park(?) formation. 

North Park(?) formation. Irrigation

well on Throwbridge Ranch. Reported to be drilled to depth of 

101 ft.
338 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

REFERENCES CITED

Ashley, W. H., 1948, The Tertiary of the Saratoga basin, Carbon County, Wyoming: Soc. of Vertebrate Paleontology Third Ann. Field Conf. Guidebook, 

p. 25-26.

Beekly, A. L., 1915, Geology and coal resources of North Park, Colorado: U. S. 

Geol. Survey Bull. 596.

Blackstone, D. L., Jr., 1953, Notes on the tectonic map on a portion of southern 

Wyoming and northern Colorado: Wyoming Geol. Assoc. Eighth Ann. Field 

Conf. Guidebook, p. 85-86.

Henderson, J. R., 1954, Airborne radioactivity survey of part of Saratoga NW 

quadrangle, Carbon County, Wyoming: U. S. Geol. Survey open file report.

Love, J. D., 1953, Preliminary report on uranium deposits in the Miller Hill area, 

Carbon County, Wyoming: U. S. Geol. Survey Circ. 278.

Love, J. D., Weitz, J. L., and Hose, R. K, 1952, Geologic map of Wyoming: U. S. 

Geol. Survey.

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