Reconnaissance for 

Uranium in AsphaltBearing Rocks in the 

Western United States

GEOLOGICAL S,U*R VEY BULLETIN 1046-E

This report concerns work done on behalf 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission

Reconnaissance for 

Uranium in AsphaltBearing Rocks in the 

Western United States

By W. J. HAIL, Jr.

CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

GEOLOGICAL SURVEY BULLETIN 1046-E

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 : 1957
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

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

Washington 25, D. C. - Price 200 (paper cover)
CONTENTS

Page

Abstract__________-____________ ___________..________-__________ 55

Introduction-____ _______________________________________________ _-_ 55

Field work___________________________________ 57

Deposits________________________________________________________ 58

Summary___________________________________________________ 58-

California. ____________________________________________________ 61

Point Arena area__________..___________-_-______--___-___-- 61

Santa Cruz area___________.._______________________________ 61

Chalone Creek and San Lorenzo Creek areas-_________________ 61

San Ardo area__________________________________________.<: 62

Bradley area__-___________________________________________ 62

McKittrick area___________________________________________ 62

Edna area_--______---________-_______-______-_----__--__- 62

Casmalia area_______-__-__-_______________________________ 64

Los Alamos area_________________________________________ 64

Other areaS-__-____--_-_-_________________________-___-_-_ 65

Utah_______________________________________________-_________ 67

Vernal area____-___--_____._______________________________ 67

Sunnyside area____________________________________________ 68

Other areas---_-____-----__-____-__-__-____-_______-_____- 68

Wyoming__ _________________________________________________ 70

Muddy Creek area_________________________________________ 70

Janieson Ranch area_-----_____-_-______________-_--_-_-__- 70

Montana Red Dome area. ____________________________________ 71

New Mexico Santa Rosa area__________________________________ 71

Texas Uvalde area_ __________________________________________ 72

Oklahoma-_____________________________________________ 72

Sulphur area______________________________________________ 73

Cameron area.____________________________________________ 73

Other areas---______-----_________-_______________________ 73

Missouri______________________________________________________ 76

Ellis area__-______________________________________________ 76

Other areas_________-_____________________________________ 76

Origin of the asphalt__-_-_________--________________________-______ 77

Origin of the uranium____________________________________________ 79

References..-_____________________________________________________ 82

Index. _____.__.________________________________ 85

ILLUSTRATIONS

Pake

FIGUBE 14. Map of the Western United States showing areas examined for

uranium in asphalt-bearing rocks______________________ 56

15. Geologic map of part of the Edna area, San Luis Obispo

County, Calif__________________________ 63

m
IV CONTENTS

TABLES

Page

TABLE 1. Asphalt-bearing formations sampled for uranium in the Western

States.. _________________________________ 58

2. Summary of data on uranium in asphalt-bearing rocks 59

3. Analyses of samples from areas in California____ _____. 65

4. Analyses of samples from areas in Utah._________________ 69

5. Analyses of samples from areas in Wyoming..... _______ 70

6. Analyses of samples from the Red Dome area, Montana____ 71

7. Analyses of samples from the Santa Rosa area, New Mexico _ 72

8. Analyses of samples from the Uvalde area, Texas _ _ 72

9. Analyses of samples from areas in Oklahoma. _ 74

10. Analyses of samples from areas in Missouri.. . 76
CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

RECONNAISSANCE FOR URANIUM IN ASPHALT-BEARING 

ROCKS IN THE WESTERN UNITED STATES

BY W. J. HAIL, JR.

ABSTRACT

An appraisal of asphalt-bearing rocks as potential sources of uranium was made 

during 1953 and 1954 in 45 areas in California, Utah, Wyoming, Montana, New 

Mexico, Texas, Oklahoma, and Missouri. A total of 202 samples from these areas 

was analyzed for uranium. The oldest rocks sampled are Ordovician in age, and 

the youngest are Recent. Although none of the deposits are of value at this time 

as a source of uranium, some of the deposits may constitute a low-grade uranium 

resource, but recovery of the uranium will depend upon the primary use of the 

asphalt.

Significant amounts of uranium in the ash of oil extracted from these rocks were 

found in samples from 7 of the 45 areas examined. These areas are Chalone 

Creek, McKittrick, Edna, and Los Alamos, Calif.; Vernal, Utah; Sulphur, Okla.; 

and Ellis, Mo. The average uranium content in the ash of the extracted oil of 

samples from these 7 areas ranges from 0.028 to 0.376 percent. All except the 

Chalone Creek area contain large estimated reserves of asphalt-bearing rock, 

ranging from 15 million to almost 2 billion tons. The average uranium content 

of samples from 13 additional areas ranges from 0.020 to 0.068 percent in the ash 

of the extracted oil. Many of these areas contain very large reserves of asphaltbearing rocks.

It is believed that most of the asphalt deposits are oil residues, and that the 

uranium was introduced during or after the late stages of oil movement and loss 

of the lighter oil fractions.

INTRODUCTION

The term "asphalt-bearing rocks" as used here designates surface 

and near-surface rocks which contain a wide variety of naturally occurring solid, semisolid, and liquid petroliferous organic materials variously termed asphalt, asphaltite, gilsonite, bitumen, tar, brea, heavy 

oil, and others. This report presents the results of field investigations 

of uranium in asphalt-bearing rocks, together with laboratory analyses

55
56 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

of the samples collected. These investigations were carried on during 

1953 and 1954 by the U. S. Geological Survey, on behalf of the Division 

ot Raw Materials of the U. S. Atomic Energy Commission. Previous 

work by the Geological Survey (Erickson, Myers, and Horr, 1954) 

showed that the uranium content of the ash of natural asphalt and oil 

extracted from petroliferous rock is significantly higher than that of 

crude oil, sea water, and granitic rock. This suggested that some of 

the numerous deposits of asphalt-bearing rock of the Western United 

States might contain appreciable amounts of uranium. Selected deposits of asphalt-bearing rocks were examined and sampled in eight 

Western States to evaluate this type of rock as a possible source of 

uranium (fig. 14).

w v ° M i N e |

Point Arena 

Santo Cruz 

Cholone Creek 

Son Lorenio Creek 

Son Ardo 

Bradley 

McKittnck 

Edna

Goleta 

UTAH

Whiterocks Canyoi

Bonanza 

PR Sprinjs 

Sunnyside

/ 

/

(" e "-o-/ ^'t 1 r- 

^ \ / °r«»t: r -A.

 -" \ / / COL °RAoo I KANSAS"!

19. Muddy Creek 

20 Jomeson Ranch

MONTANA 

21. Red Dome 

NEW MEXICO 

2 2. Santo Rosa

TEXAS 

2 3. Uvolde

OKLAHOMA 

24. Parker 

25 Elgin

26. velnto

27. Baseline

OKLAHOMA (com) 

2 6. YMwdtord

29. Oougherty

30. Ado 

3 1. FllzhuoJi 

3 2 Sulphur 

33. Brotcher 

3 4. Morgon 

3 5 Lone Gimt 

36.0.1 C'ly

37. Asphairum

38. Frisco Crwk

39. Comeron

40. Lowlon Township

MISSOURI 

4 I. Oeerlield

42. EHi>

43. Sheidon Eos'

44. SlKldon North

45. Dry Wood Creek

MISSOURI

>**'ZOH A !

I NEW MEXICO

*" " "1 OKLAHOMA V " ~ "i-

«30 | ;

frTz" (ARKANSAS/

"1__ '

14. Map of the Western United States showing areas examined for uranium in asphalt-bearing

rocks.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 57

Analyses of asphalt-bearing rocks by Erickson, Myers, and Horr 

(1954, p. 2215) showed that the uranium is concentrated in the ash of 

the oil and not in the rock. Similar analyses of the extracted asphalt 

from several selected samples collected during the present study also 

showed that the uranium is concentrated in the ash of the asphaltic 

portion of the sample. Significant amounts of uranium occur only in 

the ash of the oil extracted by solvents from the asphalt-bearing rocks, 

and these amounts constitute only a minute fraction of the bulk sample. For example, the most highly uraniferous sample collected contained 1.9 percent uranium in the ash of the extracted oil but this represents only about 0.0005 percent uranium in the bulk sample.

The descriptions of the deposits are based on many published reports, in addition to direct field observations. Estimates of reserves 

of asphalt-bearing rocks, taken from published reports, are given 

where available.

Analyses of samples were furnished by A. T. Myers, C. A. Horr, and 

M. C. Curtiss of the Geological Survey. The samples of asphaltbearing rocks were crushed and the oil was exhaustively extracted with 

a hot mixture of 75 parts benzene, 15 parts acetone, and 10 parts 

methanol. The extract was evaporated to reduce possible loss of ash 

by rapid burning of the benzene-acetone-methanol mixture and then 

was dry ashed with final ignition at 500°C under oxidizing conditions. 

The ash was weighed, ground in an agate mortar, and analyzed chemically for uranium by standard fluorimetric methods. The uranium 

content of the oil was calculated from the amounts of oil ash and 

uranium in the oil ash.

FIELD WORK

Asphalt-bearing rocks were examined in 45 selected areas in California, Utah, Wyoming, Montana, New Mexico, Texas, Oklahoma, 

and Missouri. Many of the areas examined contain easily accessible 

deposits from which asphalt has been produced commercially. The 

individual deposits contain reserves ranging from a few thousand to 

about 2.8 billion tons. A total of 202 representative samples from the 

45 areas was analyzed for uranium and for oil content. These samples 

were taken from 23 geologic formations of Ordovician, Pennsylvanian, 

Permian, Triassic, Jurassic, Cretaceous, Eocene, Miocene, Pliocene, 

Pleistocene, and Recent age. (See table 1.)

All the rocks sampled were tested for radioactivity with a scintillation counter or Geiger counter and none was noticeably radioactive.
58 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 1. Asphalt-bearing formations sampled for uranium in the Western States

State

California .......

Utah...........

Age

cene(?).

 do. . 

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

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

- do... 

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

do

 do... .. .

 -do.... . ...

 do 

Stratigraphic unit

stone.

formations.

of Mesaverde formation.

Oherokee shale.

Predominant lithologic character of formation in areas 

examined.

terial.

Gravel consists of siliceous 

shale, chert, granite, and 

quartzite.

pebble conglomerate.

stone.

stone, diatomaceous sandstone, sandy and silty shale, 

diatomaceous shale, siliceous 

shale, and chert.

stone, micaceous siltstone, 

and claystone.

stone, porcelaneous diatomite, siliceous shale, and 

sandstone.

and conglomerate.

amounts of limestone.

erate.

and limestone. 

Do.

Do.

DEPOSITS

SUMMARY

Uranium was found in asphalt-bearing rocks in all of the 45 areas 

examined; average concentrations range from 0.001 to 0.376 percent in the ash of the extracted oil. The uranium content of the extracted oil ranges from 0.03 to 70.3 parts per million, and the uranium 

content of the ash of the extracted oil ranges from 0.001 to 1.9 percent. 

The average uranium content of the extracted oil is 2.0 parts per 

million, and the average uranium content of the ash of the extracted 

oil is 0.037 percent. None of the areas contains asphalt deposits of 

value as a source of uranium at this time. Whether any of the deposits may provide a low-grade source of uranium in the future 

probably depends upon recovery methods in the utilization of the 

asphalt for other purposes. Table 2 summarizes analytical data and 

other information on the asphalts from all the areas examined.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 59 

TABLE 2. Summary of data on uranium in asphalt-bearing rocks

Locality

number on

fig. 14

Area Stratigraphlc unit Age

Number of

samples

Average oil

in samples

(percent)

Average ash

in oil

(percent)

Average U

in ash

(percent)

Average U

in oil

(ppm)

California

1 .

2 _ .

3 

4. _ ...

6 _ 

7 

8 _ .

9 

10 

11 

12 _ ...

13.. .

14 

15 

16.. .

17 

18 __ 

19......

20-.-..

21 ...

22 . 

23......

Creek.

Whiterocks 

Canyon.

Uvalde ___ ..

stone.

tion. 

 .do,....... .

sandstone.

tion.

tion.

tion. 

 do 

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

. __ do_ _ ......

Navajo sandstone.

Uinta formations.

mation.

Wasatch formations.

tion.

member of 

Mesaverde formation.

tion.

stone.

Anacacho limestone.

 .do. 

.....do.- ..

 -do. .

Pleistocene(?).

Pliocene. 

 ..do. 

 do 

. do _

 .do. 

Utah

Jurassic and 

Jurassic(?).

 do.. 

 .do.... .

.... .do.. _

Wyoming

Montana

Vew Mexico

Texas

Cretaceous.. ..

6

8

3

3

2

1

5

7

3

1

7

1

2

4 

21

7

10

11

4

2

6

11

4.13

10.34

11.18

10.54

6.24

10.49

26.91

6.29

29.57

17.88

12.40

23.32

18.94

5.59 

8.10

100.00

6.55

5.38

6.04

3.81

4. Q1

3.99

8.52

0.80

.39

.48

.23

.49

.44

1.66

.56

.19

.23

.78

1.04

2.05

0.66 

2.68

.48

1.11

1.10

0.36

.59

0.60

1.24

0.43

0.030

.027

.182

.032

.068

.045

.047

.376

.040

.009

.081

.002

.023

0.009 

.028

.003

.014

.021

0.040

.023

0.010

0.025

0.002

2.4

1.0

8.7

.7

3.3

2.0

7.8

21.1

.8

.2

.2

4.7

0.6 

7.5

.1

1.6

2.3

1.4

1.4

0.6

3.1

0.1

429173 57-
60 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM 

TABLE 2. Summary of data on uranium in asphalt-bearing rocks Continued

Locality

number on

fig. 14

Area Stratigraphic unit Age

Number of 

samples

Average oil in samples

(percent)

Average ash

in oil 

(percent)

Average U

in ash 

(percent)

Average U 

in oil

(ppm)

Oklahoma

24 _ ...

25 _ ... 

26 

27 

28 

29 

30 

31 

32 

33 

34 _ ...

35 _ 

36 

37 

38. 

39 

40 

Elgin- ___ ..- 

Velma

Fitzhugh. __ .

Oil City -

Frisco Creek ...

ship.

 -do 

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

 -do .

. do. 

tion.

 .do... 

-.-do . ...

 do.. 

- do ..... ...

 do ....

 -do. 

 do 

..... do... 

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

 do .. 

 -_do_. _ 

 -do. 

 -do.. .

 do 

 do ..... -

 . do 

1

1 

1

2

3

4

2

7

3

1

5

2

1

1

2.16

1.76 

.94

.98

2.79

3.18

3.29

1.35

4.56

8.72

5.71

.87

12.28

6.15

2.08

5.70

1.19

1.62

1.98 

1.68

2.85

4.95

.66

1.95

2.00

.70

.59

.76

3.31

4.49

1.60

10.39

2.06

3.14

0.004

.006 

.001

.005

.010

.001

.014

.002

.043

.008

.005

.010

.002

.007

.004

.054

.020

0.6

1.2 

.2

1.4

4.9

.07

2.7

.4

3.0

.5

.4

3.3

.9

1.1

4.2

11.1

6.3

Missouri

41 

42 _ 

43 

44 

45 

Deerfield-- _

Ellis 

Sheldon North

Bartlesville(?)

sand zone. 

 do... ...... 

 do .

 -do ..

 do 

 -do 

.....do 

 do.. 

. do 

7

3

3

16

4.63

4.64

3.99

1.43

2.30

0.79

.62

1 4fi

1.27

1.58

0.006

.145

.016

.004

.004

0.5

9.0

2.3

.5

.6

Deposits in seven of the areas yielded individual samples with a 

significantly high uranium content in the ash of the extracted oil. 

These areas (with the uranium content of then- richest samples) are 

Chalone Creek (0.50 percent), McKittrick (0.15 percent), Edna (1.9 

percent), and Los Alamos (0.33 percent), Calif.; Vernal, Utah (0.15 

percent); Sulphur, Okla. (0.22 percent), and Ellis, Mo. (0.40 percent). 

The average uranium content of ash of the oil ranges from 0.028 percent in the Vernal area to 0.376 percent in the Edna area. All the 

deposits except those in the Chalone Creek area contain large estimated reserves of asphalt-bearing rock, ranging from 15 million to 

almost 2 billion tons. The most uraniferous deposits found are in 

the Edna area.

The average uranium content of samples from 13 other areas ranges 

from 0.020 to 0.068 percent in the ash of the extracted oil. These 

areas are Point Arena, Santa Cruz, San Lorenzo Creek, San Ardo, 

Bradley, Casmalia, and Goleta, Calif.; Sunnyside, Utah; Muddy 

Creek and Jameson Ranch, Wyo.; Santa Rosa, N. Mex.; and Cameron 

and Lawton Township, Okla. Reserves of asphalt-bearing rocks in 

these 13 areas range from a few thousand tons to about 2.8 billion tons.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 61

CALIFORNIA

The asphalt-bearing rocks in California generally appear to be 

more favorable for the occurrence of uranium than those examined 

in the other Western States. In 11 of the 13 California areas, the 

average uranium content in the ash of the extracted oil ranged from 

0.023 percent to 0.376 percent (table 2). Almost all the California 

asphalts examined occur in formations of Miocene or Pliocene age, 

and it is probable that the asphalt in most of these formations originated in bituminous marine shales of Miocene age, represented mainly 

by the Monterey shale and equivalent formations (Hoots, 1943, p. 

270-275). Table 3 shows analyses of samples from areas in California.

POINT ARENA ABBA

Asphalt-bearing sandstone beds in the Monterey shale of Miocene 

age crop out on the seacoast just west of the town of Point Arena, 

Mendocino County. A sequence of interbedded shale, siltstone, and 

sandstone, 500 feet thick, contains 6 asphalt-bearing sandstone beds 

ranging in thickness from 1 to 30 feet. The beds crop out along 

parts of the east and south rim of a small northwestward-plunging 

syncline and underlie an area of less than one-half a square mile. 

Reserves of asphalt-bearing sandstone are estimated to be about 3.2 

million tons (Holmes, Page, and Duncan, 1951).

SANTA CRUZ AREA

Asphalt-bearing sandstone beds in the Vaqueros sandstone and 

Monterey shale of Miocene age crop out about 5 miles west of Santa 

Cruz, Santa Cruz County. The two deposits in the area underlie 

about 3 square miles. The asphalt-bearing beds occur in a transition 

zone between the Vaqueros sandstone and the overlying Monterey 

shale. These formations vary greatly in thickness and lithology and 

lie unconformably on siliceous quartz diorite of pre-Cretaceous age. 

The asphalt-bearing beds are discontinuous and occur both as bedded 

sandstone and as sandstone "dikes" intruded into overlying shale 

beds. Total reserves of asphalt-bearing sandstone are estimated to 

be about 1.6 million tons (Page, Williams, Henrickson, and others, 

1945). There is no production at the present tune.

CHALONE CREEK AND SAN LORENZO CREEK AREAS

Asphalt-bearing arkose crops out along a small tributary of Chalone 

Creek, San Benito County, and along a small tributary of San Lorenzo Creek, Monterey County. The arkose in both areas is the 

basal part of a marine Pliocene formation which is in fault contact 

with pre-Cretaceous granite from which the arkose was derived 

(Bramlette and Daviess, 1944).
62 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

In the Chalone Creek area the asphalt-bearing arkose bed dips 

40° E. and crops out for a distance of about a quarter of a mile along 

both sides of the valley. The bed is 37 feet thick on the west side 

of the valley and 21 feet thick in a small abandoned quarry on the 

east side of the valley.

In the San Lorenzo Creek area the asphalt-bearing arkose beds are 

as much as 30 feet thick and dip about 14° SW. Two abandoned 

quarries and several prospect pits mark the line of outcrop.

SAN ARDO AREA

Asphalt-bearing sandstone crops out 2 to 3 miles west of San Ardo, 

Montcrey County. The asphalt-bearing beds may be as much as 

125 feet thick and extend for 5 miles (Eldridge, 1901, p. 410). They 

occur in a transition zone between the Monterey shale and the Santa 

Margarita sandstone, both of Miocene age (Bramlette and Daviess, 

1944). The beds dip eastward and crop out along the east flank of 

the hills bordering the Salinas River. At the sampled locality a 

22-foot-thick bed of asphalt-bearing sandstone is exposed and dips 

12° E.

BRADLEY AREA

Asphalt occurs in the basal bed of marine Pliocene rocks, which 

unconformably overlie the Monterey shale, about 6 miles southwest 

of Bradley, Monterey County (Eldridge, 1901, p. 411-12; Bramlette 

and Daviess, 1944). The asphalt-bearing bed crops out on both 

sides of the San Antonio River and dips about 12° NE. It is mainly 

a fine- to medium-grained sandstone, but some layers are conglomeratic. Part of the outcrop is obscured by slvmp, but the asphaltbearing bed appears to be about 15 to 20 feet thick.

MCKITTRICK AREA

Large deposits of asphalt in the form of asphalt-bearing sandstone, 

asphalt-bearing alluvium, oil seeps, and vein asphalt, crop out near 

McKittrick, Kern County. The deposits occur in a number of rock 

types in the Monterey shale of Miocene age, the Etchegoin formation 

of Pliocene age, the Tulare formation of Pliocene and early Pleistocene^) age, and Recent alluvium. The rocks in the area are highly 

folded and faulted, and the asphalt deposits, as well as a small producing oilfield, are associated with these structures. The total 

reserves in the area are about 15.7 million tons of asphalt-bearing 

rock (Page, Henrickson, Williams, and others, 1945).

EDNA AREA

The deposits of asphalt-bearing sandstone in the Edna area, San 

Luis Obispo County, contain the highest concentration of uranium 

of all the deposits examined in the Western States. The uranium 

content of 7 samples collected in the Edna area ranges from 0.035 to
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 63

1.9 percent and averages 0.376 percent in the ash of the extracted oil. 

Localities from which samples were collected and the extent of the 

asphalt-bearing rocks are shown on the geologic map of part of the 

Edna area (fig. 15).

Geology adapted from U.S. Geological Survey Oil and Gas Investigations preliminary map 16, 

by B. M. Page, M. D. Williams, E. L Hendrickson.and others

2000 0 4000 Feet

EXPLANATION

Alluvium, terrace gravel, 

and landslide material

Pismo formation 

(Asphalt-bearing sandstone, Tpa)

Monterey shale

Axis of anticline, 

approximately located

Axis of syncline 

approximately located

4-

Oil well

0.24Q

Sample locality

(Number indicates percent uranium 

in ash of extracted oil)

FIGURE 15. Geologic map of part of the Edna area, San Luls Obispo County, Calif.
64 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

The asphalt occurs in the Pismo formation of late Miocene and 

Pliocene age, which unconformably overlies the Monterey shale of 

Miocene age. The Monterey shale in the Edna area consists of tuff, 

diatomaceous and siliceous shale, and chert. The Pismo formation 

consists of varied rock types including conglomerate, arkosic sandstone, diatomaceous sandstone, sandy and silty shale, diatomaceous 

shale, siliceous shale, and chert. The asphalt is irregularly distributed 

in lenticular and discontinuous beds of arkosic sandstone which range 

in thickness from a few feet to almost 300 feet. The irregular distribution appears to be related to the variation in the permeability of the 

sandstone.

The largest deposits of asphalt-bearing sandstone crop out on the 

northeast flank of a northwestward-trending syncline near Pismo 

Creek. The total reserves of asphalt-bearing sandstone are about 

280 million tons (Page, Williams, Henrickson, and others, 1944). 

No asphalt-bearing sandstone is being produced at the present time.

CASMALJA AREA.

A deposit of asphalt-bearing diatomaceous mudstone is'exposed 

about 4 miles north of Casmalia, Santa Barbara County, at the 

N. T. U. open-pit mine, now abandoned. Similar beds crop out half 

a mile northeast of the N. T. U. mine and in the Schumann area, 3 

miles to the southeast; the asphalt-bearing beds may be continuous 

throughout these areas.

The asphalt impregnates northeastward-dipping beds of diatomaceous mudstone in the upper part of the Sisquoc formation, of 

Miocene and Pliocene age. The asphalt-bearing beds are as much 

as 20 feet thick at the N. T. U. mine, but the extent of downdip 

impregnation is not known. Estimated reserves at the mine are 

only about 100,000 tons of asphalt-bearing rock (Williams and Holmes, 

1945), but reserves for the entire area are undoubtedly much greater.

LOS ALAMOS AREA

Thick beds of asphalt-bearing sandstone crop out along the front 

of the San Rafael Mountains in the vicinity of Asphaltum and La 

Zaca Creeks, about 9 miles northeast of Los Alamos, Santa Barbara 

County (Eldridge, 1901, p. 429-39). The asphalt-bearing sandstone 

beds are in the Sisquoc formation, of Miocene and Pliocene age. An 

angular unconformity separates the Sisquoc formation from the 

underlying Monterey shale of Miocene age, which is composed mainly 

of porcelaneous diatomite and siliceous shale. The Sisquoc formation in this area is composed mainly of medium- to fine-grained sandstone, with thin beds of conglomerate containing pebbles of chert and 

silicified shale similar to that in the underlying Monterey shale.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 65

In the cliffs southeast of Asphaltum Creek, the exposed asphaltbearing beds have an aggregate thickness of about 225 feet, and the 

intervening barren zones an aggregate thickness of about 35 feet. 

The asphalt-bearing beds extend about 5 miles along their outcrop 

and probably underlie an area of at least 5 square miles.

OTHER AREAS

Deposits of asphalt-bearing rocks were also examined in the Schumann, Gaviota, and Goleta areas, Santa Barbara County. In the 

Schumann area, about 2 miles north of Casmalia, asphalt occurs 

throughout a section of diatomaceous mudstone reported to be as 

much as 340 feet thick. These beds are in the Sisquoc formation of 

Miocene and Pliocene age, and the occurrence is similar to that in 

the Casmalia area, 3 miles to the northwest.

Beds of shale in the Monterey shale of Miocene age contain seeps 

of asphalt along bedding planes and joints in exposures on the seacoast 

at the mouth of Gaviota Canyon, Santa Barbara County. A bed of 

asphalt-bearing sandstone is associated with the shale.

Asphalt-bearing siltstone in the Monterey shale of Miocene age 

crops out along the seacoast at Goleta Beach County Park, about 5 

miles west of Santa Barbara, Santa Barbara County. Several beds 

of lenticular asphalt-bearing siltstone, the thickest of which is 20 feet, 

occur within a section about 100 feet thick.

TABLE 3. Analyses of samples from areas in California

Sample

No.

Oil

(percent)

Ash In

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Point Arena

97756 

97757 

97758 

97759. ...

97761 .

97762 

4.21

3.34

3.67

5.52

3.71

6.08

0.52

.77

.64

.72

1.06

1.10

0.039

.022

030

.016

.044

2.0

1.7

1.7

2.2

1.7

4.8

Just north of Arena Cove

Coast Guard Station.

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

 -.do,. _ 

. do 

 - do.... .... 

 do .. 

Base of 15-ft.-thiek bed.

Middle of 15-ft.-thick bed.

Top of 15-ft.-thick bed.

Base of 30-ft.-thick bed.

16 ft. above base of 30-ft.-thick

bed.

26 ft. above base of 30-ft.-thick

bed.

Santa Cruz

97763 

97764 

97765 

97766 

97767 

97768 

97769 

97770 

6.01 

9.62

16.20

9.75

7.03

9.25

14.43

11.40

0.37 

.59

.42

.27

.43

.28

.45

.31

0.031 

.012

.096

.011

.005

.015

.024

.026

1.1

.7

4.0

.3

.2

.4

1.1

.8

About 5 miles west of 

Santa Cruz. 

. do ._ . .-..

 do _ ._ _ 

 do .- . __ .

- do . _

 do 

 . do ... ... 

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

Sylva quarry; 6 ft. above base 

of 28-ft.-thick bed. 

18 ft. above base of 28-ft.-thick

bed. 

Top of 28-ft.-thick bed.

of 32-ft.-thick bed. 

16 ft. above base of 32-ft.-thick

bed. 

22 ft. above base of 32-ft.-thick

bed. 

Top of 32-ft.-thick bed.

Sylva quarry; 3-inch-thick vein

in Monterey shale.
66 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 3. Analyses of samples from areas in California Continued

Sample 

No.

OU (percent)Ash in 

oil (percent)

Uin 

ash 

(percent)

Uin 

oil 

(ppm)

Location Remarks

Chalone Creek

97772....

97773 . 

97745 

10.89

13.40 

5.70

0.44

.21

.80

0.010

.036 

.50

0.4

.8 

40.0

SE}4 sec. 29, T. 19 S., R. 

8 B. 

_ .do.... _ 

 do _ 

8 ft. above base of 37-ft.-thick bed.

4 ft. above base of 21-ft.-thick bed. 

19 ft. above base of 21-ft.-thick bed.

San Lorenzo Creek

97746 

97747 . 

97748 

8.57 

14.41 

8.63

0.15 

.26

.28

0.043 

.037 

.017

0.6 

1.0 

.5

SE}4 sec. 15, T. 19 S., R. 

9B. 

 -do 

 do -- 

Middle of 13-ft.-thick bed.

25 ft. above base of 30-ft.-thick 

bed. 

4 ft. above base of 30-ft.-thick bed.

San Ardo

97749 

97750 

3.58 

8.90

0.60 

.39

0.072 

.064

4.3

2.5

SEJ4 sec. 13, T. 22 S., R. 

9 E. 

. _ do .-. .

16 ft. above base of 22-ft.-thick 

bed. 

4 ft. above base of 22-ft.-tb.ick bed.

Bradley97751 10.49 0.44 0.045 2.0 SWH sec. 35, T. 24 S., 

R. 10 E.

5ft. above base of 15-ft. -thick bed.

McKittrick

97752 .

97753 .

97754 .

97755....

255611 1 .

5.27

79.50

39.00

5.65

5.13

3.32

.51

1.54

2.85

.19

0.060

.019

.006

.002

.150

19.9

1.0

.9

.6

2.8

SWH sec. 28, T. 30 S.,

R. 22 E.

 _ do ._

NEJ4 sec. 29, T. 30 S.,

R. 22 E.

 do 

 ..do- -- .. .

Middle of 6-ft.-thick bed of

asphalt-bearing sandstone.

Asphalt seep in alluvium.

Do.

Edna

99133 .

99134 

99135 

99136 -

99137 .

99138 .

99139 

99140 

99141 .

99142 

3.16

4.86

7.60

10.15

6.48

4.80

7.01

27.80 

29.20

31.70

1.00

.76

.37

.14

.70

.46

0.18 

.22

.18

0.195

1.9

.132

.053

.035

0.014 

.033

.047

19.5

6.0

70.3

1.8

3.7

1.6

0.7 

.7

.8

_____ do.... _

 do . _-_

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

- do. 

.....do-.. - .

 . .do..... 

Casmalia

N. T. U. mine, sec. 3, 

T. 9N., R. 35 W. 

 -do . .

.-..do ___... _.___.. .

100 ft. thick.

300 ft. thick.

probably between 50 and 100 ft.

thick. 

Base of 120-ft.-thick bed.

Lower part of 230-ft.-thick bed.

Base of 20-ft.-thick bed. 

Middle of 20-ft.-thick bed.

Upper part of 20-ft.-thick bed.

i Sample submitted by P. D. Snavely.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 67 

TABLE 3. Analyses of samples from areas in California Continued

Sample

No.

Oil

(percent)

Ash in

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Los Alamos

99148. ... 

99149....

99150... .

99151....

99152....

99153... .

99154... .

3.20 

10.81

14.60

15.70

16.10

17.50

8.90

1.75 

.83

.57

.28

.68

.05

1.34

0.038 

.330

.073

.059

.010

.036

.023

6.6 

27.4

4.2

1.7

.7

.2

3.1

About 2 miles northeast of 

junction of Foxen Canyon and Alisas Canyon 

roads. 

 . _do. . 

. .do........ 

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

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

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

. do . 

Thickness of bed not known. 

8 ft. above base of 93-ft.-thick bed.

Middle of 33-ft.-thick bed.

95 ft. above base of 99-ft.-thick

bed. 

42 ft. above base of 99-ft.-thick

bed. 

5 ft. above base of 99-ft.-thick bed.

Schumann

99146 17.88 0.23 0.009 0.2 Airox quarry, 2 miles 

north of Casmalia.

158 ft. above base of 200-ft.-thick 

bed.

Gaviota

99156 . 23.22 1.04 0.002 0.2 Mouth of Gaviota Canyon.

Seep in shale joints.

Goleta

99157 ... 

99158 .

16.18 

21.70

2.00 

2.11

0.023 

.024

4.6 

5.1

Sec. 20, T. 4 N., R. 28 W._ 

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

Middle of 20-ft.-thlck bed. 

Top of 15-ft.-thick bed.

UTAH

All five of the asphalt-bearing areas sampled in Utah are in the 

Uinta Basin in the east-central part of the State. The deposits in the 

Vernal, Bonanza, PR Springs, and Sunnyside areas are in the Wasatch, 

Green River, and Uinta formations of Eocene age, and the deposit in 

the Whiterocks Canyon area is in the Navajo sandstone of Jurassic 

and Jurassic (?) age. The asphalt deposits in the Bonanza area are 

gilsonite, and the deposits in the other areas are asphalt-bearing 

sandstone. Table 4 shows analyses of samples from areas in Utah.

VERNAL, AREA

The asphalt hi the Vernal area, Uintah County, was the most uraniferous of those examined in Utah. The uranium content of 21 samples 

ranges from 0.001 to 0.150 percent and averages 0.028 percent in the 

ash of the extracted oil.

The deposits occur mainly in the Uinta formation of Eocene age, 

exposed along Asphalt Ridge, just west of Vernal. The asphalt impregnates lenticular sandstone beds ranging in thickness from a few 

feet to 190 feet within a section which may be as much as 300 feet 

thick. Most of the asphalt-bearing beds are in the basal part of the 

Uinta formation, but some of the lowest beds may be in the upper

429179 57 3
68 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

part of the Mesaverde formation of Cretaceous age. The Uinta formation lies unconformably on the Mesaverde in this area. The Uinta 

formation consists of red and cream-colored shale and sandstone and 

coarse siliceous conglomerate. The upper part of the Mesaverde 

formation consists mainly of medium-grained buff sandstone. Where 

they contain asphalt, the sandstones of the two formations are indistinguishable. Estimated reserves of asphalt-bearing sandstone in the 

area are. 1.97 billion tons (Spieker, 1930, p. 96-97). One quarry was 

operating hi 1953 and the product was us'ed locally for road construction.

The Vernal deposits were sampled by Vine and Moore (1952) and 

by Vine and Flege (1953), who took 12 samples from 9 localities along 

most of the 14-mile length of Asphalt Ridge. Nine additional samples 

were collected in 1953 for the present investigation.

SUNNYSIDE AREA

One of the largest known asphalt-bearing sandstone deposits in the 

United States is that near Sunnyside, Carbon County (Holmes, Page, 

and Averitt, 1948). The total measured, indicated, and inferred 

reserves in beds more than 10 feet thick are about 2.8 billion tons of 

asphalt-bearing sandstone. The asphalt occurs in lenticular sandstone beds ranging in thickness from a few inches to 350 feet within a 

stratigraphic interval of about 1,000 feet in the lower part of the Green 

River formation and in the upper part of the Wasatch formation of 

Eocene age. The beds dip northeastward and crop out for a distance 

of about 9 miles along the steep scarp of the Book Cliffs, which form the 

south rim of the Uinta Basin. No asphalt-bearing sandstone has been 

produced from the Sunnyside area since about 1948, but quarrying and 

prospecting have been extensive in the past. The material was used 

for road paving.

OTHER AREAS

Deposits of asphalt-bearing sandstone were also examined in the 

PR Springs area, Grand and Uintah Counties, and the Whiterocks 

Canyon area, Uintah County; deposits of gilsonite were examined in 

the Bonanza area, Uintah County. Samples collected from these 

areas had a generally low uranium content.

The asphalt of the PR Springs area is in sandstone beds in theJower 

part of the Green River formation of Eocene age (W. B. Cashion, 

oral communication), and the occurrence is similar to that ha the 

Sunnyside area. The asphalt of the Whiterocks Canyon area impregnates sandstone beds of the Navujo sandstone of Jurassic and Jurassic (?) age, which in this area is about 936 feet thick (Kinney and 

Romin^er, 1947). The gilsonite of the Bonanza area occurs in veins 

chiefly in the Wasatch, Green River, and Uinta formations of Eocene 

age (Cashion and Brown, 1956).
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 69 

TABLE 4. Analyses of samples from areas in Utah

Sample 

No.

Oil (percent)Ash in 

oil (percent)

Uin 

ash (percent)

Uin 

oil 

(ppm)

Location Remarks

Vernal

85728 

85729.... 

85730 

85731.... 

85732.... 

85733.... 

85734.... 

85735.... 

85736.... 

85737.... 

85738 

85739 

96056 

96057.... 

96058 

96059 

96061.... 

96062 

96063.... 

96064.... 

96065 

16.0 

11.4 

3.1 

12.3 

13.0 

10.8 

11.6 

6.6 

10.0 

7.4 

8.0 

9.4 

1.35 

1.85 

5.50 

2.09 

.98 

7.04 

4.76 

8.63 

10.10

1.77 

5.90 

.96 

6.31 

3.82 

3.68 

8.42 

1.35 

2.66 

3.45 

2.75 

3.24 

2.46 

2.04 

2.21 

.49 

.83 

1.50 

.93 

1.13 

.53

0.002 

.001 

.021 

.001 

.005 

.007 

.001 

.026 

.001 

.005 

.017 

.002 

.013 

.034 

.005 

.177 

.008 

.015 

.150 

.141 

.010

0.4 

.6 

2.0 

.6 

1.9 

2.6 

.8 

3.5 

.3 

1.7 

47 

.6 

3.2 

6.9 

1.1 

8.6 

.7 

2.2 

13.9 

15.9 

.5

Sec. 25, T. 4 S., R. 20 E... . 

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

 -do 

Sec. 11, T. 48., R. 20 E 

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

Sec. 30, T. 4 S., R. 21 E 

Sec. 31, T. 4 S., R. 21 B... 

 do 

Sec. 4, T. 58., R. 21 E. 

Sec. 9, T. 58., R. 21 E. 

Sec. 23, T. 5 S., R. 21 E... 

Sec. 25, T. 58., R. 21 E... 

Sec. 29, T. 48., R. 21 B... 

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

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

 do 

Sec. 32, T. 4 S., R. 21 E... 

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

 do 

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

Sec. 20. T. 4 S., R. 21 E...

See Vine and Flege (1953). 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Lower part of 12-ft-thick bed. 

Upper part of 55-ft-thick bed. 

Lower part of 55-ft-thiek bed. 

Upper part of 66-ft-thick bed. 

Upper part of 26-ft-thick bed. 

Middle of 19-ft-thick bed. 

Lower part of 38-ft-thlck bed. 

Lower part of 7-ft-thick bed. 

Mill pile.

Sunnyside

94103....

94102.... 

94101.... 

94100 

94106 

94105 . 

94104.... 

94108 

200931... 

94109.... 

94107 

1.80

6.17 

6.93 

10.65 

5.46

1.56 

3.10 

6.05 

5.88 

9.60 

1.97

1.17

.90 

1.59 

.75 

3.68

.83 

1.27 

.45 

.30 

.30 

.87

0.046

.041 

.012 

.020 

.010

.014 

.005 

.003 

.048 

.015 

.015

5.4

3.7 

1.9 

1.9 

3.7

1.2 

.6 

.1 

1.4 

.4 

1.3

NEH sec. 15, T. 14 S., R.

14 E.

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

 ..do.. ..- 

 do. 

NWH sec. 10, T. 14 S., R. 

14 E. 

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

 . -do . . 

Sec. 4, T. 148., R. 14 E... 

 ..do... 

 -do 

 -do ... ... .

Upper part of 45-ft-thlck bed.

Lower part of 28-ft-tblck bed. 

Middle of 50-ft-thick bed. 

Lower part of 18-ft-thick bed. 

Middle of 25-ft-tblck bed.

Middle of 60-ft-thick bed. 

Middle of 30-ft-thick bed. 

17 ft below top of 82-ft-thick bed. 

33 ft below top of 82-ft-thick bed. 

77 ft below top of 82-ft-thick bed. 

Lower part of 22-ft-thick bed.

PR Springs

96044.... 

96045.... 

96046.... 

96047 

96048.... 

96050 

96051.... 

96053 . 

96054 

96055....

12.0 

9.50 

7.13 

9.86 

499 

4.22 

445 

476 

3.82 

4.89

0.24 

.55 

.37 

3.05 

1.40 

.73 

1.08 

1.46 

.76 

1.46

0.011 

.063 

.025 

.005 

.009 

.006 

.003 

.009 

.004 

.009

0.3 

3.5 

.9 

1.5 

1.3 

.4 

.3 

1.3 

.3 

1.3

Sec. 5, T. 15^ S., R. 23 E._ 

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

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

- do 

 - do .-. ._. .

Sec. 36, T. 15 S., R. 23 E 

 -do - . _ 

..-.do .. _ ...........

- do 

 -do.. 

Base of 22-ft-thick bed. 

5 ft above base of 22-ft-thick bed. 

10 ft above base of 22-ft-thick bed. 

15 ft above base of 22-ft-thick bed. 

20 ft above base of 22-ft-thick bed. 

9 ft above base of 52-ft-thick bed. 

18 ft above base of 52-ft-thick bed. 

36 ft above base of 52-ft-thick bed. 

45 ft above base of 52-ft-thick bed. 

Top of 52-ft-thick bed.

Whiterocks Canyon

94110 . 

94111 ....

94112.... 

94113....

5.60 

9.72

2.93 

413

0.72 

.24

1.00 

.68

0.024 

.003

.005 

.003

1.7 

.1

.5 

.2

Sec. 18, T. 2 N., R. 1 E ....

Sec. 19, T. 2 N., B. 1 E __

 do 

 do 

Lower part of 936-ft-thick section. 

300 ft above base of 936-ft-tliick 

section. 

600 ft above base of 936-ft-thick 

section. 

800 ft above base of 936-ft-thiek 

section.

Bonanza

96037-... 

96038 

96039 

96040 . 

96041.... 

96042.... 

96043 

100 

100 

100 

100 

100 

100 

100

0.31 

1.02 

.45 

.49 

.56 

.31 

.23

0.003 

.004 

.004 

.002 

.001 

.005 

.003

.1 

.4 

.2 

.1 

.1 

.2 

.1

Sec. 7, T. 9 S.. R. 25 E ....

Sec. 16, T. 9 S. R. 25 E ... 

Sec. 30, T. 98. R. 25 E... 

Sec. 25, T. 98. R. 24 E-- 

Sec. 25, T. 98. R. 24 E... 

Sec. 35, T. 98. R. 24 E... 

Sec. 24, T. 11 S., R. 24E-.

Qilsonite, Cowboy vein. 

Do. 

Gilsonite, Tabor vein. 

Gilsonite, Independent vein. 

Gilsonite, Ohepetta vein. 

Gilsonite, Wagonhound vein. 

Gilsonite, Rainbow vein.
70 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

WYOMING

MUDDY CREEK AREA

Lenticular beds of highly weathered asphalt-bearing sandstone in 

the Wasatch formation of Eocene age (J. D. Love, written communication) crop out near Muddy Creek about 17 miles south of Creston, 

Carbon County (Jamison, 1912, p. 47). In this area the Wasatch 

formation dips about 4° SW. The asphalt occurs irregularly in a 

section of sandstone about 100 feet thick. The richest impregnation 

is in the lower 15 to 30 feet and in a 5-foot-thick zone in the upper 

part of the section. The outcrop of asphalt-bearing sandstone 

extends about 2 miles along U. S. Highway 789 in sees. 3, 10, and 15, 

T. 17 N., R. 92 W. The most compete exposures are in several 

outliers forming low hills a few hundred feet east of the highway* 

The westward underground extent of the asphalt-bearing beds is not 

known. Table 5 shows analyses of samples from the Muddy Creek 

area.

JAMESON RANCH AREA

The Teapot sandstone member of the Mesaverde formation of 

Cretaceous age is saturated with asphalt along its outcrop in sees. 

4, 5, and 9, T. 33 N., R. 87 W., Natrona County (Hares, 1917, p. 247). 

The asphalt-bearing sandstone forms a prominent hogback which 

dips about 24° NE. on the east flank of the Rattlesnake Range. 

The outcrop extends about a quarter of a mile and has a maximum 

exposed thickness of about 50 feet. The asphalt is highly weathered 

and is now represented only by brown staining throughout the 

exposed beds. No similar exposures of the asphalt-bearing Teapot 

sandstone member have been reported in this area. Table 5 shows 

analyses of samples from the Jameson Ranch area.

TABLE 5. Analyses of samples from areas in Wyoming

Sample

No.

Oil

(percent)

Ash in

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Muddy Creek

213818...

213819 

213820 

213821 

6.35

5.70

6.00

6.11

0.29

.42

.34

.38

0.091

.032

.021

.015

2.6

1.3

 .7

.6

NEH sec. 5, T. 17 N.,

R. 92 W.

NEH sec. 10, T. 17 N.,

R. 92 W.

.....do.. 

NJ4 Sec. 3, T. 17 N.,

R. 92 W.

Lower part of 15-ft-thick bed.

Upper part of 30-ft-thick bed.

Middle of 5-ft-thick bed.

Top of 15-ft-thick bed.

Jameson Ranch

213827... 

213828...

400 

3.62

0.84 

<u

0.014 

.032

1.2 

1.1

Sec. 5, T. 33 N., R. 87 W.. 

__ do _ . ____ . _ .

27 ft above base of 50-ft-thick bed. 

7 ft above base of 50-ft-thick bed.
URANIUM IN" ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 71

MONTANA BED DOME AREA

Asphalt-bearing sandstone in the Chugwater formation of Triassic 

age crops out along the rim of the breached top of Red Dome, Carbon 

County (Knappen and Moulton, 1930, p. 58). The asphalt contains 

relatively small amounts of uranium. The Chugwater formation is 

exposed in an irregular area of about one and one-half square miles at 

the crest of Red Dome. The asphalt impregnates the top 20-27 feet 

of the uppermost sandstone of the Chugwater immediately below 

clay of the Suiidance formation of Jurassic age. Asphalt-bearing 

sandstone is exposed only along the steep inner rim of the dome; the 

underground extent of the beds is unknown. Table 6 shows analyses 

of samples from the Red Dome area.

TABLE 6. Analyses of samples from the Red Dome area, Montana

Sample

No.

213834 

213837 

213838 

on

(percent)

4.74

6.60

2.45

6.60

4.16

Ash in

oil (percent)

0.58

.50

.66

.45

.81

Uin

ash

(percent)

0.012

.013

.003

.012

.009

Uin

oil

(ppm)

0.7

.6

.2

.5

.7

Location

Ei-4 sec. 20, T. 78., R.24E.

 -do-_ 

 -do--. --.

WW sec. 20, T. 7 S.,

R. 24 E.

SWJi sec. 20, T. 7 S.,

R. 24 E.

Remarks

5 ft above base of 27-ft-thick bed.

Middle of 27-ft-thick bed.

Top of 27-ft-thick bed.

5 ft above base of 19-ft-thick bed.

Middle of 20-ft-thick bed.

NEW MEXICO SANTA ROSA AREA

Beds of asphalt-bearing sandstone in the Santa Rosa sandstone of 

Triassic age crop out in northern Guadalupe County at the abandoned 

quarries of the New Mexico Construction Co., about 10 miles north 

of Santa Rosa. The asphalt occurs in the upper and middle sandstone members of the Santa Rosa sandstone. The Santa Rosa 

sandstone is overlain unconformably by the Chiiile formation, also 

of Triassic age, and underlain unconformably by the San Andres 

formation of Permian age. The rocks dip generally southwestward 

at a low angle. The average thickness of the Santa Rosa sandstone 

is 250 feet. The beds of asphalt-bearing sandstone range in thickness 

from 4 to 41 feet in quarry exposures and are 100 feet thick in a core 

hole. The total reserves of asphalt-bearing sandstone are 102 

million tons (German and Robeck, 1946). None has been produced 

since 1939. Table 8 shows analyses of samples from the Santa Rosa 

area.
72 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 7. Analyses of samples from the Santa Rosa area, New Mexico

Sample

No.

94094....

94095....

QdflQfi

94097 

94098....

94099....

Oil

(percent)

1.73

2.63

3.58

5.12

8.42

2.44

Ash in

oil (percent)

3.13

1.08

.70

1.31

.15

1.12

Uin

ash

(percent)

0.002

.008

.052

.012

.051

.025

Uin

oil

(ppm)

0.6

.9

3.6

1.6

.8

2.8

Location

__ . do ________ - _

Mill pile.

Remarks

12 ft. above base of 20-ft.-thick bed.

2 ft. above base of 20-ft.-thick bed.

23 ft.above base of 41-ft.-thick bed.

Base of 41-ft.-thick bed.

TEXAS UVALDE AREA

Large deposits of asphalt-bearing limestone in the Anacacho 

limestone of Late Cretaceous age crop out in an area of about 60 

square miles in the vicinity of Blewett in the western part of Uvalde 

County. The uranium content of the asphalt is exceptionally low, 

ranging from 0.001 to 0.004 percent, and averages 0.002 percent in 

the ash of the extracted oil.

The asphalt impregnates porous coquina beds which range in 

thickness from 10 to 135 feet in quarry exposures and are as much 

as 200 feet thick in drill holes. The distribution of the asphalt in the 

limestone is highly variable both horizontally and vertically. Two 

companies were quarrying the rock in 1953. The total reserves of 

minable asphalt-bearing limestone in the area are about 340 million 

tons (German and Robeck, 1945). Table 8 shows analyses of samples 

from the Uvalde area.

TABLE 8. Analyses of samples from the Uvalde area, Texas

Sample 

No.

99579 .... 

99580 

99581 

99582 

99583 

99584 

99585 

99586 .

99587 

QQRQQ

99590 -

on (percent)

12.16

8.02

5.75

7.53

8.82 

10.42 

9.18

7.65

5.54

8.93

9.39

Ash in 

oil (percent)

0.28 

.63

.22

.56

.42 

.37 

.43

.55

.22

.69

.35

Uin 

ash 

(percent)

0.002 

.002

.002

.002

.001 

.002 

.002

.001

.002

.004

.004

Uin 

oil 

(ppm)

0.06 

.1

.04

.1

.04 

.07 

.09

.05

.04

.3

.1

Location

Original No. 1 quarry .....

East end of Qato quarry. . 

West end of Gato quarry.. 

White's Uvalde Mines 

quarry.

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

. .do . 

Remarks

Thickness of bed not known.

Top of 80-ft.-thiek bed.

Base of 80-ft.-thick bed. 

Base of 80-ft.-thick bed. 

18 ft above base of 40-ft.-thick 

bed. 

Base of 40-ft.-thick bed.

Mill concentrate.

Middle of 130-ft.-thick bed.

OKLAHOMA

The 17 asphalt deposits examined in Oklahoma occur in formations 

of Ordovician, Pennsylvanian, and Permian age. One of the deposits 

occurs hi limestone; the remainer are in quartzose sandstones. Most 

of the areas examined do not contain above-average amounts of 

uranium in the ash of the extracted oil. Only the Sulphur, Cameron, 

and Ada areas yielded samples containing appreciable amounts of
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 73

uranium. Asph,alt-bearing limestone from the Dougherty area is 

exceptionally low in uranium. Table 9 shows analyses of samples 

from areas in Oklahoma.

SUXiPHUR AJtEA

Asphalt-bearing sandstone and limestone beds crop out about 5 

miles south of Sulphur, Murray County, over an area of about 1 

square mile. Most of the asphalt occurs in the Oil Creek formation 

of Ordovician age. The major structure in the area is a complexly 

faulted northeastward-trending anticline. Surface exposures of 

asphalt-bearing sandstone range in thickness from about 6 to 90 feet, 

although asphalt-bearing beds are fully exposed in few places. A well 

drilled hi the northern part of the area is reported to have penetrated 

242 feet of asphalt-bearing sandstone beginning at a depth of 101 feet 

(Gorman, Flint, Decker, and Ham, 1944). Some asphalt was produced in 1953 by the Southern Kock Asphalt Sand Mines.

CAMERON AREA

Asphalt-bearing sandstone is exposed in an abandoned quarry or 

prospect pit just across the road from Cameron College, Comanche 

County. The bed is 5 feet thick and lies between beds of barren 

sandstone in the Wichita formation of Permian age. The lateral 

extent of the asphalt-bearing bed is not known but it probably does 

not extend over a very large area.

OTHER AREAS

Deposits of asphalt were also examined in 15 other areas in Oklahoma, but most of the samples from these deposits contained relatively 

small amounts of uranium. A sample representing a 1-foot-thick 

bed of asphalt-bearing sandstone in the Ada area, Pontotoc County, 

contained 0.042 percent uranium hi the ash of the extracted oil. 

The Dougherty area, Murray County, contains large deposits of 

asphalt-bearing limestone in the Viola limestone of Ordovician age 

(Gorman and Flint, 1944), but the uranium content of the asphalt is 

exceptionally low. Asphalt-bearing sandstone of Pennsylvanian age 

was sampled in the Ada and Fitzhugh area (Ada formation), Pontotoc 

County; in the Bratcher and Morgan areas (Deese formation), Carter 

County; and in the Woodford area (Springer formation), Carter 

County. Asphalt-bearing sandstone in the Wichita formation of 

Permian age was sampled in the Parker, Elgin, Frisco Creek, and 

Lawton Township areas, Comanche County; in the Velma area, 

Stephens County; in the Baseline area, Garvin County; hi the Lone 

Grove and Oil City areas, Carter County; and in the Asphaltum area, 

Jefferson and Stephens Counties. The Ada, Bratcher, Woodford, 

and Asphaltum areas probably contain large reserves of asphaltbearing sandstone; the other areas contain only small reserves.
74 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

TABLE 9. Analyses of samples from areas in Oklahoma

Sample

No.

Oil

(percent)

Ash in

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Sulphur

201556... 

201557 

201588...

99599 

99601 

99603 

99591 

99592 . 

99593 . 

99594 .

99596 . 

99597 

201571 

200933 

201572...

201569 

4.00 

2.44

5.70

3.92 

3.63 

2.00

4.08 

1.87 

3.00 

4.20

1.68 

1.02

9.58 

7.29 

9.30

5.71

1.12 

.61

2.06

0.42

.52 

1.04

4.09 

.81 

2.13

.75

1.85 

2.16

0.77 

.91 

.09

0.76

.002 

.004

0.054

0.001 

.001 

.001

0.002 

.005 

.042 

.007

0.003 

.001

0.015 

.005 

.003

0.005

.2 

.2

11.1

0.04 

.05 

.1

0.8 

.4 

8.9 

.5

0.6 

.2

1.2 

.5 

.03

0.4

NWJ4 sec. 22, T. 1 S., R. 3 

E., Griffith No. 1 pit. 

NWJ4 sec. 22, T. 1 S., R. 3 

E., East Kirby pit.

Cameron

NEM sec. 34, T. 2 N., R. 

12 W.

Dougherty

SEJ4 sec. 25, T. 1 S., R. 

2E. 

SWM sec. 30, T. 1 S., R. 

3 E. 

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

Ada

NWM see. 6, T. 3 N., R. 

6E. 

NWM sec. 1, T. 3 N., R. 

5E. 

SWM sec. 19, T. 4 N., R. 

6E. 

NWi sec. 36, T. 4 N., R. 

6 E.

Fitzhugh

Sec. 32, T. 3N., R. 5E___ 

Sec. 5, T. 2 N., R. 5 E ._

Bratcher

SWM sec. 16, T. 4 S., R. 

1 E. 

NWM sec. 21, T. 4 S., R. 

IE. 

_____do-.._ ~

Morgan

NEM sec. 14, T. 5 S., R. 

IE.

Middle of 20-ft.-thick bed. 

Thickness of bed not known.

Middle of 5-ft.-thick bed.

40 ft. above base of 80-ft.-thick 

bed. 

75 ft. above base of 80-ft.-thick 

bed. 

Upper part of lOO-ft.-thick bed.

6 ft. above base of 16-f t.-thick bed. 

Lower part of 12-ft.-thick bed. 

l-ft.-thick bed. 

Thickness of bed not known.

Thickness of bed not known. 

2-ft.-thick bed.

Quarry dump. 

Upper part of 22-ft.-thick bed. 

Quarry dump.

Middle of 6-ft.-thick bed.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 75 

TABLE 9. Analyses of samples from areas in Oklahoma Continued

Sample 

No.

201574... 

201575 

201576 

201593 

201592...

201590 

201591 

201589 

201586...

201558 

201560 

201573 

201577 

201579... 

201580 

201581 

200934 

201584...

Oil (percent)

2. 26 

4.44

1.66

2.16

1.76

1.57 

2.58

1.19

0.94

0.79 

1.17

0.87

12.28

4.27 

7.47

9.72

8.07 

1.21

Ash In 

oil (percent)

6.49 

6.60

1.77

1.62

1.98

2.96 

17.83

3.14

1.68

2.71

2.98

3.31

4.49

1.64

.66

2.08

.97 

2.64

Uin

ash 

(percent)

0.017 

.010

.004

0.004

0.006

0.005 

.002

0.020

0.001

0.007 

.002

0.010

0.002

0.006 

.002

.006

.013 

.006

Uin 

oil

(ppm)

11.0 

6.6

.7

0.6

1.2

1.5

6.3

0.2

1.9 

.6

3.3

0.9

1.0 

.1

1.2

1.3 

1.6

Location

Woodford

Sec. 3, T. 3 S., R. 1 W.._ __ 

... do.. .

SWM sec. 11, T. 3 S., R. 

1 W.

Parker

SWM sec. 15, T. 4 N., R. 

11 W.

Elgin

SWM sec. 26, T. 4 N., R. 

11 W.

Frisco Creek

SWM sec. 9, T. 3 N., R. 

11 W. 

 do

Law ton Township

NWM sec. 21, T. 2 N., R. 

12 W.

Velma

SEM sec. 36, T. 1 S., R. 

5W.

Baseline

EJ4 sec. 36, T. 1 N., R. 

3 W. 

NWM sec. 17, T. 1 N., R. 

3W.

Lone Grove

NWM sec. 32, T. 4 S., R. 

1 W.

Oil City

Sec. 21, T. 3 S., R. 2 W __

Asphaltum

SEM sec. 23, T. 3 S., R. 

5 W. 

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

- do.. . 

NWM sec. 25, T. 3 S., R. 

5W. 

NWM sec. 11, T. 4 S., R. 

4W.

Remarks

Middle of 60-ft. -thick bed. 

Middle of 40-ft.-thick bed.

Prospect dump.

2-ft.-thick bed.

Upper part of 5-ft.-thick bed.

Base of 18-ft.-thick bed.

4-ft.-thick bed.

Thickness of bed not known.

4-ft.-thick bed. 

Lower part of 5-ft.-thick bed.

3-ft.-thick bed.

Lower part of 8-ft.-thick bed.

Lower part of 30-ft.-thick bed. 

Middle of 30-ft.-thick bed.

Upper part of 30-ft.-thick bed.

20 ft. above base of 30-ft.-thick 

bed. 

3-ft.-thick bed.
76 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

MISSOURI

The asphalt deposits in all five areas examined in Vernon County, 

Mo., occur in one or more lenticular sandstone beds in the Cherokee 

shale of Pennsylvanian age. These sandstone beds probably correlate 

with the Bartlesville sand zone of the midcontinent oilfields (Greene 

and Pond, 1926, p. 45), which is the subsurface equivalent of the 

Bluejacket sandstone member of the Boggy formation in Oklahoma 

(Dane and Hendricks, 1936, p. 312, and Bass, Leatherock, Dillard, 

and Kennedy, 1937, p. 40). The rock containing the asphalt is mainly 

fine-grained micaceous quartzose sandstone. Where asphalt is absent 

the sandstone is quite friable. Large reserves of asphalt-bearing 

sandstone under shallow cover extend over a wide area in Vernon 

County. Most of the samples collected in Missouri did not contain 

above-average amounts of uranium. One sample from the Ellis area, 

however, yielded 0.40 percent uranium in the ash of the extracted 

oil. Table 10 shows analyses of samples from areas in Missouri.

ELLIS AREA

Asphalt-bearing sandstone is exposed in an abandoned waterfilled 

quarry at Ellis, Vernon County. The quarry is about 160 feet wide 

and 265 feet long, and the exposed thickness of the asphalt-bearing 

bed ranges from 15 to 30 feet. The base of the bed is covered by 

water in the quarry; the top is obscured by soil. The quarry has 

been operated so recently that the asphalt-bearing rock is not greatly 

weathered.

OTHER AREAS

Deposits of asphalt-bearing sandstone were also examined in the 

Deerfield, Sheldon East, Sheldon North, and Dry Wood Creek areas, 

Vernon County. Exposed asphalt-bearing beds in these areas range 

from 1 to 9 feet in thickness. The exposures in the Deerfield, Sheldon 

East, and Dry Wood Creek areas are in abandoned quarries, indicating 

some production of asphalt-bearing rock hi the past. The exposure 

in the Sheldon North area is in a road cut.

TABLE 10. Analyses of samples from areas in Missouri

Sample

No.

Oil

(percent)

Ash In

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Ellis

91576 

207078 

224923 

5.38

4.08

4.47

0.75

.70

.40

0.40

.013

.011

30.0

.9

.4

SEH sec. 10, T. 35 N., R.

32 W.

. _ .do.... _____ .. ....

- .do.... . .-. 

Collected by N. W. Bass and H.

J. Hyden.

Do.

Collected by N. W. Bass and N.

M. Denson.
URANIUM INT ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 77 

TABLE 10. Analyses of samples from areas in Missouri Continued

Sample

No.

Oil

(percent)

Ash in

oil (percent)

Uin

ash

(percent)

Uin

oil

(ppm)

Location Remarks

Deerfleld

219691 

219692 

219693 

219694 

219695 

219696 

219697 

4.73 

465

5.54

4.37

4.57

4.56

3.96

0.44 

.44

.68

.78

.93

.84

1.43

0.010 

.010

.006

.003

008

.002

002

0.4 

.4

.4

.2

.7

.2

.3

SWH sec. 6, T. 35 N., R. 

32 W. 

 ..do... -_-. 

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

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

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

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

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

1 ft above base of 9-ft-thick bed.

Middle of 11-ft-thick bed.

Sheldon East

219661 

219662 

219663 

219665 

219668 

4.56

3.00

3.75

4.63

5.58

1.45

1.95

1.22

1.21

.26

0.033

.013

.009

.008

.008

4.8

2.5

1.1

1.0

.2

NWMsec.33,T.34N., R.

30 W.

 do....... __._ 

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

 do... . . 

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

Upper part of 2-ft-thick bed.

Lower part of 2-ft-thick bed.

1-ft-thick bed.

2-ft-thick bed.

Lower part of 6-ft-thick bed.

Sheldon North

219669 

219670 

219671 

1.58

1.12

1.60

1.58

1.59

.65

0.002

.005

.006

0.3

.8

.4

W^ sec. 15, T. 34 N., R.

31 W.

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

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

Upper part of 8-ft-thick bed.

Middle of 8-ft-thick bed.

Diy Wood Creek

219673 

219674 

219675 

219677- .

219678 

219679 

219680 

219681...

219682. .

219683 

219684 

219685 

219686 

219687 

219688 

219689 

1.73 

.98

2.24

2.60

1.74

1.23

1.66

2.60

5.42

2.58

4.07

3.79

2.32

1.37

3.41

4.23

1.15 

1.35

1.09

1.36

1.20

1.11

1.14

1.94

.74

2.26

3.06

3.40

1.59

1.45

.91

1.50

0.002

.004

.007

.009

.002

.004

.005

.001

.001

.004

.001

.001

.003

.005

.006

.003

0.2 

.5

.8

1.2

.2

.4

.6

.2

.1

.9

.3

.3

.5

.7

.5

.4

SE}4 sec. 24, T. 35 N., R. 

33 W. 

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

 _.do_. ...... ..

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

 do.___ _ 

- .do. -.. ...

... -do.... .-._._. 

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

... do .....

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

 ..do _ -. . ...

. ..do. ._.. 

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

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

 .do. ___ 

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

Middle of 3^-ft-thick bed. 

Middle of 2^-ft-thick bed.

Upper part of 5-ft-thick bed.

Middle of 4-ft-thick bed.

Middle of 6-ft-thick bed.

Middle of 5}4-fUhick bed.

Middle of 5-ft-thick bed.

Middle of 6^-ft-thick bed.

Base of 6^-ft-thick bed.

Lower part of 6^-ft-thick bed.

ORIGIN OF THE ASPHALT

The asphalt described in this report may have originated within 

the present host rocks essentially in its present form, or it may be 

residue of petroleum which moved into the host rocks from other 

source beds. The author believes that two or three of the deposits 

herein described may represent asphalt which originated in the host 

rocks, but that most of the deposits are residues of petroleum which 

moved into the host rocks from other source beds.

The deposits believed to have originated in the present host rocks 

are those in the Casmalia, Schumann, and Gaviota areas in California. 

Asphalt in these deposits occurs in richly organic shales. Even so, 

the occurrence of free oil in the Casmalia (N. T. U. mine) deposit
78 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

appears to be controlled by the permeability of the host rocks (Williams and Holmes, 1945), indicating movement of oil within the 

source rocks.

The other California deposits occur predominantly in sandstone and 

other coarse clastic rocks. The occurrence of these deposits is in no 

way different from that of nearby oil-producing rocks except that they 

are exposed at the surface. Their occurrence is controlled by the 

same structural and stratigraphic features and proximity to source 

beds that control the occurrence of oil-producing rocks. Oil has been 

recovered from two of the deposits, Edna and McKittrick, at depth. 

The rock of the productive oil zones in the Edna area is identical to the 

asphalt-bearing rock exposed at the surface (Krueger, 1943, p. 452). 

That movement of oil has and is taking place in the Edna area is indicated by a record of continuous production over a period of 50 years. 

In the McKittrick area some of the asphalt saturation occurs in fluviatile gravels of the Tulare formation of Pliocene and Pleistocene (?) age, 

and in Recent alluvium, which are not likely source beds for oil 

formation.

The Los Alamos asphalt deposits occur in sandstone in the lower 

part of the Sisquoc formation, which is a producing horizon of the four 

nearby oilfields (West Cat Canyon, Doheny-Bell, East Cat Canyon, 

and Gato Ridge). All the other California asphalt deposits are in 

sandstone or other clastic rocks closely associated with, or within, the 

Monterey shale, which was probably the source of the oil from which 

the asphalt deposits formed. Hoots (1943, p. 274-275) regards the 

Monterey shale as the likely source of oil for the Santa Maria district 

oilfields, and Bramlette and Daviess (1944) regard the Monterey as 

the probable source of the oil in the Salinas Valley.

The occurrence of asphalt deposits in other states likewise appears 

to be identical with that of typical oil-producing rocks; the only difference is that they are exposed at the surface. For example, the Red 

Dome, Mont., deposit occurs at the crest of a breached anticline. The 

Sulphur and Dougherty, Okla., deposits are clearly associated with 

faults. The Sunnyside, Utah, deposits occur in interfingering fluviatile and lacustrine sandstone beds. Oil shale in the lacustrine sequence is the probable source of the oil. The fact that asphalt impregnates both fluviatile and lacustrine sandstone suggests that 

permeability, which implies movement, was the controlling factor in 

the emplacement of the original oil. The asphalt-bearing sandstone 

beds of Pennsylvanian age in Vernon County, Mo., are typical of oilbearing beds described as "shoestring sands" (Bass, Leatherock, Dillard, and Kennedy, 1937) that derive their oil from the enclosing marine 

shale, and Bass (oral communication, 1956) believes that the asphalt 

in the Vernon County deposits is petroleum residue.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 79

ORIGIN OF THE URANIUM

On the basis of the small amount of available evidence, conclusions 

bearing on the origin of the uranium in asphalt are necessarily speculative. The uranium content of crude oil is consistently low (Erickson, Myers, and Horr, 1954, p. 2211-2212; H. J. Hyden, written 

communication) whereas the uranium content of asphalt is generally 

high relative to that of crude oil. The uranium content of the least 

uraniferous asphalt samples listed in this report may be accounted for 

by normal processes of concentration from crude oil by loss of the 

lighter fractions. The uranium content of the more uraniferous 

samples, however, is so much higher than that of crude oil that it 

cannot be accounted for by simple concentration, and some other explanation must be postulated.

Erickson, Myers, and Horr (1954, p. 2212) suggested that discrepancies in uranium content of asphalt and crude oil may be due to 

the retention of uranium-bearing oil fractions as insoluble coatings on 

sand grains of the reservoir rocks. No information bearing on this 

explanation is available from the present study, but the possibility 

does not seem likely for many of the samples collected during the present investigation inasmuch as the asphalt does not merely coat the 

sand grains but thoroughly impregnates the host rock and may be 

readily separated from the constituent grains.

Another possible explanation of the difference in uranium content 

of asphalt and crude oil is based on the assumption that the asphalt 

is formed in place in the present host beds (thus it is not oil residue) 

and, therefore, may have a uranium content comparable to that of 

closely associated marine organic shale which has a relatively high 

uranium content.

The author, however, believes that most of the asphalt in deposits 

described in this report is oil residue, and that the uranium, at least in 

those samples with above-average uranium content, was introduced 

during or after the late stages of oil movement and loss of the lighter 

oil fractions. The source of the uranium is believed to be the rocks in 

which the asphalt came to rest. It is believed that the uranium was 

emplaced by adsorption directly from the host rocks by the oil after 

the loss of most of the lighter fractions. Some addition of uranium 

to the asphalt by circulating uranium-bearing ground water is possible 

where such water could come into contact with asphalt-bearing beds, 

but this mechanism could not account for the emplacement of uranium 

within an asphalt-saturated rock. Breger and Deul (1955, p. 184) 

in their investigations of the Temple Mountain, Utah, uranium deposits showed that heavy oil, probably from a common source, moved 

through uranium ore-bearing rocks and adsorbed uranium from these 

rocks.
80 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Although the following comparisons of the ash and uranium contents of crude oil with those of asphalt derived from crude oil cannot 

be expected to furnish a completely accurate indication of the oilasphalt concentration factor, and of the uranium enrichment factor, 

it is believed that such comparison does furnish at least an indication 

of the order of magnitude of these factors.

Detailed considerations regarding the origin of uranium in asphalt 

are given to the Edna, Calif., area because it yielded asphalt samples 

relatively high in uranium and because more data on this area are 

available. A sample of crude oil (Serial No. 235033, K. G. Bell, 

written communication) was collected from the Edna area and may 

be compared directly with the Edna asphalt samples, inasmuch as it 

is a composite sample of crude oil produced at depth from the Edna 

deposits. This crude oil sample contains 0.0536 percent ash, 0.0003 

percent uranium in the ash, and 0.0016 parts per million uranium in 

the oil (calculated). The average ash content of the Edna asphalt 

is 0.563 percent, and the average uranium content of the original 

asphalt is 16.44 parts per million.

The apparent oil-asphalt concentration factor for the Edna deposits 

is about 10.5. However, a comparison of the uranium content of 

the crude-oil sample with the average uranium content of the Edna 

asphalt samples shows the asphalt samples to be enriched in uranium 

by a factor of about 10,000 rather than 10.5. For all 7 Edna asphalt 

samples this factor ranges from 1,125 to 43,750. If it is assumed that 

the Edna asphalt derived its uranium by concentration from the 

parent crude oil, the relative uranium contents of crude oil and asphalt 

should not be expected to differ by more than the concentration 

factor of 10.5. The Pismo formation in the Edna area contains many 

rock types such as arkosic sandstone, diatomaceous sandstone and 

shale, and siliceous shale, which are known to have a relatively high 

uranium content.

Although the available data do not permit a direct comparison of 

ash and uranium contents of oil and asphalt from other California 

areas, and from some Utah, Oklahoma, and Missouri areas, indirect 

comparisons may be made which demonstrate the magnitude of the 

discrepancy between apparent oil-asphalt concentration factors, and 

apparent uranium enrichment factors.

Comparison of the average ash content (0.047 percent) and uranium 

content (0.0036 parts per million, calculated) of 7 samples of California 

crude oil (H. J. Hyden and K. G. Bell, written communications) with 

the average ash and uranium content of asphalt samples from each 

of the other California areas (Edna area excluded), as shown in table 2, 

indicates apparent oil-asphalt concentration factors ranging from
URANIUM EST ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 81

about 4 to 40, and apparent uranium enrichment factors ranging 

from about 55 to 2,400.

Five crude-oil samples (H. J. Hyden, written communication) from 

the Uinta Basin, Utah, produced from reservoir rocks of Eocene age, 

may be compared with the asphalt samples collected from the Vernal, 

Bonanza, PR Springs, and Sunnyside areas in the Uinta Basin. The 

5 crude-oil samples contain an average of 0.093 percent ash, and an 

average of 0.001 parts per million uranium (calculated). A comparison of average ash content of these crude-oil samples with asphalts 

from each of the Uinta Basin areas (see table 2) shows apparent oilasphalt concentration factors ranging from 5 to 29. Corresponding 

apparent uranium enrichment factors, however, range from 100 to 

7,500.

Ten samples of crude oil (H. J. Hyden, written communication) 

collected from Kansas and Oklahoma, and produced from reservoir 

rocks of Pennsylvanian age, contain an average of 0.019 percent ash 

and 0.0007 parts per million uranium (calculated). A comparison of 

these figures with the average ash and uranium content of asphalt in 

Oklahoma and Missouri occurring in rocks of Pennsylvanian age (see 

table 2) shows apparent oil-asphalt concentration factors ranging from 

about 30 to 260, and corresponding apparent uranium-enrichment 

factors ranging from about 570 to 12,580. It is noteworthy that the 

uranium content of the crude oil of Pennsylvanian age does not reflect 

the relatively high uranium content of the marine shale of Pennsylvanian age, from which much of the oil presumably was derived.

The relation of the uranium content of the asphalt to the lithologic 

character of the host rocks is indicated by the unusually low average 

uranium content of samples from the Bonanza, Utah, the Uvalde, 

Tex., and the Dougherty, Okla., areas. Asphalt from the Bonanza 

area is pure gilsonite which is not intermixed with any mineral or rock 

material, but occurs as joint fillings in the surrounding rock. The 

low uranium content of the gilsonite probably reflects the absence of 

any rock or mineral material from the gilsonite. The Uvalde and 

Dougherty asphalt deposits occur as impregnated porous limestone 

beds, and the low uranium content of these deposits is probably due 

to the low uranium content of limestone (Bell, 1954, p. 109-110). All 

the other deposits, except those believed to have originated in place, 

are asphalt which impregnates clastic rocks such as sandstone, siltstone, and arkose. The uranium content of these deposits probably 

gives a rough indication of the uranium content of the host rocks. 

Relatively pure quartz sandstone is low in uranium, but sandstone 

and other clastic rocks containing such material as volcanic ash, 

arkose, or diatomite may have relatively large uranium contents.
82 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Bell (1954, p. 104) points out that the uranium content of clastic 

sediments ranges from a small fraction of a part per million to tens 

of parts per million. These amounts are of the same order of magnitude as the uranium in the asphalt described in this report.

REFERENCES

Bass, N. W., Leatherock, Constance, Dillard, W. R., and Kennedy, L. E., 1937, 

Origin and distribution of Bartlesville and Burbank shoestring oil sands in 

parts of Oklahoma and Kansas: Am. Assoc. of Petroleum Geologists Bull., 

v. 21, p. 30-66.

Bell, K. G., 1954, Uranium and thorium in sedimentary rocks in Faul, Henry 

(editor), Nuclear geology: New York, John Wiley and Sons, p. 98-114.

Bramlette, M. N., and Daviess, S. N., 1944, Geology and oil possibilities of the 

Salinas Valley, Calif.: U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 24.

Breger, I. A., and Deul, Maurice, 1955, Geochemistry of uranium-bearing carbonaceous rocks, 47i Geologic investigations of radioactive deposits Semiannual progress report, Dec. 1, 1954, to May 31, 1955: U. S. Geol. Survey 

TEI-540, p. 183-186, issued by U. S. Atomic Energy Comm. Tech. Inf. 

Service, Oak Ridge, Tenn.

Cashion, W. B., and Brown, J. H., Jr., 1956, Geology of the Bonanza-Dragon oilshale area, Uintah County, Utah, and Rio Blanco County, Colo.: U. S. Geol. 

Survey Oil and Gas Inv. Map OM 153.

Dane, C. H., and Hendricks, T. A., 1936, Correlation of Bluejacket sandstone, 

Oklahoma: Am. Assoc. Petroleum Geologists Bull., v. 20, p. 312-314.

Eldridge, G. H., 1901, The asphalt and bituminous rock deposits of the United 

States: U. S. Geol. Survey 22d Ann. Rpt., 1900-1901, p. 209-452.

Erickson, R. L., Myers, A. T., and Horr, C. A., 1954, Association of uranium and 

other metals with crude oil, asphalt, and petroliferous rock: Am. Assoc. of 

Petroleum Geologists Bull., v. 38, p. 2200-2218.

German, J. M., and Flint, G. M., Jr., 1944, Geologic map of the Dougherty 

asphalt area, Murray County, Okla.: U. S. Geol. Survey Oil and Gas Inv. 

Prelim. Map 15.

German, J. M., Flint, G. M., Jr., Decker, C. E., and Ham, W. E., 1944, Geologic 

map of the Sulphur asphalt area, Murray County, Okla.: U. S, Geol. Survey 

Oil and Gas Inv. Prelim. Map 22.

German, J. M., and Robeck, R. C., 1945, Asphalt deposits near Uvalde, Tex.: 

U. S. Geol. Survey Open File Rpt.

 1946, Geology and asphalt deposits of north-central Guadalupe County, 

N. Mex. U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 44.

Greene, F. C., and Pond, W. F., 1926, The geology of Vernon County: Mo. Bur. 

Geology and Mines, v. 19, ser. 2.

Hares, C. J., 1917, Anticlines in central Wyoming: U. S. Geol. Survey Bull. 

641-1.

Holmes C. N., Page, B. M., and Averitt, Paul, 1948, Geology of the bituminous 

sandstone deposits near Sunnyside, Carbon County, Utah: U. S. Geol. 

Survey Oil and Gas Inv. Prelim. Map 86.

Holmes, C. N., Page, B. M., and Duncan, D. C., 1951, Bituminous sandstone 

deposits of Point Arena, Mendocino County, Calif.: U. S. Geol. Survey Oil 

and Gas Inv. Map OM 125.

Hoots, H. W., 1943, Origin, migration, and accumulation of oil in California, in 

Jenkins, 0. P., Geologic formations and economic development of the oil 

and gas fields of California: California Div. Mines Bull. 118, p. 253-276.
URANIUM IN ASPHALT-BEARING ROCKS, WESTERN UNITED STATES 83

Jamison, C. E., 1912, The Muddy Creek oil field, Carbon County, Wyo.: Wyo. 

Geol. Survey Bull. 3, ser. B, p. 43-50.

Kinney, D. M., and Rominger, J. F., 1947, Pre-Tertiary geology of the Whiterocks River-Ashley Creek area, Uintah County, Utah: U. S. Geol. Survey 

Oil and Gas Inv. Prelim. Map 82.

Knappen, R. S., and Moulton, G. F., 1930, Geology and mineral resources of 

parts of Carbon, Big Horn, Yellowstone, and Stillwater Counties, Mont.: 

U. S. Geol Survey Bull. 822-A.

Krueger, M. L., 1943, Arroyo Grande (Edna) oil field, 471 Jenkins, O. P., Geologic 

formations and economic development of the oil and gas fields of California: 

Calif. Div. Mines Bull. 118, p. 450-452.

Page, B. M., Henrickson, E. L., Williams, M. D., and Moran, T. G., 1945, Asphalt 

and bituminous sandstone deposits of part of the McKittrick district, Kern 

County, Calif.: U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 35.

Page, B. M., Williams, M. D., Henrickson, E. L., and others, 1944, Geology of the 

bituminous sandstone deposits near Edna, San Luis Obispo County, Calif.: 

U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 16.

 1945, Bituminous sandstone deposits near Santa Cruz, Santa Cruz County, 

Calif.: U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 27.

Spieker, E. M., 1930, Bituminous sandstone near Vernal, Utah: U. S. Geol. 

Survey Bull. 822-C.

Vine, J. D., and Flege, R. F., Jr., 1953, Reconnaissance during 1952 for uraniumbearing carbonaceous rocks in parts of Colorado, Utah, Idaho, and Wyoming: 

U. S. Geol. Survey TEI 336, issued by U. S. Atomic Energy Comm. Tech. 

Inf. Service, Oak Ridge, Tenn.

Vine, J. D., and Moore, G. W., 1952, Reconnaissance for uranium-bearing rocks 

in northwestern Colorado, southwestern Wyoming, and adjacent parts of 

Utah and Idaho: U. S. Geol. Survey TEI 281, issued by U. S. Atomic Energy 

Comm. Tech. Inf. Service, Oak Ridge, Tenn.

Williams, M. D., and Holmes, C. N., 1945, Geology of oil-impregnated diatomaceous rock near Casmalia, Santa Barbara County, Calif.: U. S. Geol. Survey 

Oil and Gas Inv. Prelim. Map 34.

INDEX

Page 

Acknowledgments- -- 57

Ada formation_ -_ -- - --- 73 

Anacacho limestone.__ 72 

Analyses. See under State names. 

Areas studied..------_ 57, 58 (table), 59-70 (table)

See also under State names. 

Asphalt, denned ------ 55

origin.._______ __ . 77-78 

Asphaltite .__..._. ----- ----- 55

Bitumen-...-..._---....-------__-...._ 55

Brea-._ 55

California, analyses of samples..------ 65-67 (table)

Asphaltum Creek..-------------------- 64,65

Bradley.---------.---------------------- 60,62

Casmalia____._____ _ -__ __ 60,64,77 

Chalone Creek..__----------- 60,61-62

Edna -- --- -- 60,62-64,78,80 

formations sampled.. .. - 58 (table) 

Gaviota..-------------------------- 65,77

Goleta.... _ 60,65

LaZaca Creek ----------------------- 64

Los Alamos-...._. - 60,64-65,78

McKittrick.-. - 60,62,78 

N. T. U. mine _______________ 64, 77 

Point Arena..-----------------.-------- 60,61

San Antonio River.._______-___ 62

SanArdo.____________ _____ 60,62

San Lorenzo Creek_.___--_.--.__ 60,62

San Rafael Mountains..__- __--._ 64

Santa Cruz______________ ___ 60,61

Schumann..__..__.___-_ - 64,65,77

summary of data-..-..__ . 59 (table)

Cherokee shale...___._.-.._.--- - 76

Chugwater formation_____--__ .. 71

Deese formation --------- - _ 73

Etchegoin formation....________--__ 62

Formations sampled-___ 58 (table), 59-60 (table) 

See also formation names and under State

names. 

Gilsonite- - -- ------ 55,68,81

Green River formation...__..-._ -_. 68 

Heavy oil.. _ .. 55 

Host rocks..--.___.--.______..- 58 (table)

See also descriptions of each area. 

Laboratory procedure. _ - 57

Mesaverde formation-_________------ 68,70

Missouri, analyses of samples....-_- 76-77 (table)

Deerfield ------------- - --- 76

Dry Wood Creek ------------------ 76

Bills - 60,76

formations sampled..----------.----- 58 (table)

Sheldon East-------------------------- 76

Sheldon North..__ -._______.- 76

summary of data... _-_. .__. 60 (table)

Montana, analyses of samples ---------- 71 (table)

formations sampled... ------------ 58 (table)

Red Dome..________.________ 71,78 

summary of data_---------_..._ 58 (table)

Montereyshale . ----- --- 61,62,64,65,78

Navajo sandstone-.-.--.----__.-.__.-. 68

New Mexico, analyses of samples. _ 72 (table) 

formations sampled.... . __ 58 (table)

Santa Rosa.-------------.- ------- 60,71 j

summary of data_--------_-..._ 59 (table) I

Page

Oil Creek formation_______________ 7$

Oklahoma, Ada.- ___--__-__-... 73

analyses of samples________ 74-75 (table)

Asphaltum.- ____-______ 73

Baseline_..______________ 73

Bratcher...____._______.. 73

Cameron..--...________________ 60,73 

Dougherty- --- - - 73,78,81 

Elgin... -... ..- ...... 73

Fitzhugh.- - -. _...... 7»

formations sampled..--.-.___-_ 58 (table) 

Frisco Creek..._____...___...._ 73

Lawton Township__.-..._______ 60,73 

Lone Grove..___-----_____-__ 73

Morgan.. .. ..______________ 73 

Oil City -- - 73

Parker....._____________.__ 73

Sulphur.--- 60,73,78

summary of data.___________ 60 (table) 

Velma, ............... .. .. ....... 73

Woodford-.-__ .. -. --.... 73

Pismo formation.________________ 64,80- 

Recent alluvium...____..--__-_.._ 62,78 

References.....__________________ 82-8*

Reserves, summary_________...__ 60

See also descriptions of each area. 

Santa Margarita sandstone.-------___... 62

Santa Rosa sandstone..__ __._____ 71 

Sisquocformation....- . . -...- 64,65,78

Springer formation..-._..__________ 7& 

Tar.....- - . .- -._.__ 55

Texas, analyses of samples... _ ---. __ 72 (table) 

Blewett- ---- _ 72

formations sampled-__--__ _ 58 (table) 

summary of data_. _________ 59 (table) 

Uvalde' 72,81

Tulare formation________________ 62, 78 

Uinta formation-________________ 67,68 

Uranium, origin. __. _ _ __________ 79-82" 

summary of data..___...__.-- 59-60 (table) 

Uranium content. See analyses under State

names.

Utah, analyses of samples_ - - 69 (table) 

Asphalt Ridge --------_.. .. 67,68

Bonanza...______.__.__._____ 68,81 

Book Cliffs 68.

formations sampled. - _ _.---.-. _ 58 (table) 

PR Springs 68,81

summary of data_..---._ ____ 59 (table) 

Sunnyside -------------------- 60,68,78,81

Vernal 60,67-68,81

Whiterocks Canyon_____..___ 68 

Vaqueros sandstone. __ 61

Viola limestone. ---- - - 73

Wasatch formation . ____ __ - __ 68,70- 

Wichita formation...-----___...__---. 73-

Wyoming, analyses of samples. __ 70 (table) 

formations sampled..... 58 (table)

Jameson Ranch...___ _ 60,70- 

Muddy Creek..-.-. 60,70

Rattlesnake Range.--.-------.-.----- 70

summary of data.. - . 59 (table)

o

85