Stratigraphic Divisions and 

Geologic History of the 

Laney Member of the 

Green River Formation in 

the Washakie Basin in 

Southwestern Wyoming

GEOLOGICAL SURVEY BULLETIN 1372-E

Stratigraphic Divisions and 

Geologic History of the 

Laney Member of the 

Green River Formation in 

the Washakie Basin in 

Southwestern Wyoming

By HENRY W. ROEHLER

CONTRIBUTIONS TO STRATIGRAPHY

GEOLOGICAL SURVEY BULLETIN I372-E

The Laney Member is divided 

into the Hartt Cabin, Sand 

Butte, and LaClede Beds

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1973
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary

GEOLOGICAL SURVEY 

V. E. McKelvey, Director

Library of Congress catalog-card No. 72-600333

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

Washington, D.C. 20402. Price: 35 cents, domestic postpaid; 25 cents, GPO Bookstore

Stock No. 2401-00282

CONTENTS

Page

Abstract ______________________________________ _ El

Introduction ____________________________ __ _ 1

Nomenclature ____________________________________ 2

Laney Member of the Green River Formation __ 4

LaClede Bed ________________________________ 5

Sand Butte Bed ________________________________ 7

Hartt Cabin Bed _______________________________ 8

Age _ ____ 9

Electric-log correlations ________________________ 10

Geologic history ______________________________ 10

Stratigraphic sections ____________________________ 15

References cited _________________________________ 27

ILLUSTRATIONS

Page

FIGURE 1. Geologic map showing the areal distribution of

the LaClede, Sand Butte, and Hartt Cabin Beds of

the Laney Member in the Washakie Basin E3

2. Nomenclatural correlation chart for the Laney Member 

of the Green River Formation and adjacent formations 

in the Washakie Basin _____ 4

3. Generalized west-east restored section of the Laney 

Member of the Green River Formation across the 

Washakie Basin __________ ___ ____ 6

4. Electric log of the Shell Oil Co. 1 Shell Creek Unit well

in the Washakie Basin _______________ _ 11

5. Paleogeographic map of the Washakie Basin area and 

adjacent areas in southwestern Wyoming and northwestern Colorado ________ _ _ 13

6. Paleogeographic map showing the areal distribution of

the Sand Butte Bed of the Laney Member _ 14

7. Paleogeographic map of the Washakie Basin area and 

adjacent areas in southwestern Wyoming and northwestern Colorado __ _ ___ __ _ 15

III
CONTRIBUTIONS TO STRATIGRAPHY

STRATIGRAPHIC DIVISIONS AND

GEOLOGIC HISTORY OF THE

LANEY MEMBER OF THE GREEN RIVER

FORMATION IN THE WASHAKIE BASIN

IN SOUTHWESTERN WYOMING

By HENRY W. ROEHLER

ABSTRACT

The Laney Member, formerly the Laney Shale Member, of the Eocene 

Green River Formation in the Washakie Basin in southwestern Wyoming is 

herein divided into three new rock-stratigraphic units: a basal oil-shale section named the LaClede Bed; a middle wedge of tuffaceous sandstone and 

siltstone named the Sand Butte Bed; and an upper sequence mainly of 

mudstone alternating with sandstone, limestone, and shale named the Hartt 

Cabin Bed. The fossil and strati graphic records indicate that the LaClede 

Bed was deposited in Lake Gosiute in the early middle Eocene during a 

stage when the lake had great areal extent, that the introduction of air-laid 

volcanic ash later in the early middle Eocene initiated a southeastward retreat and shallowing of the lake during the deposition of the Sand Butte 

Bed, and that the lake dried up and disappeared near the end of the middle 

Eocene during the deposition of the Hartt Cabin Bed. The thickness, areal 

distribution, stratigraphic relations, age, and geologic histories of the beds 

are discussed and illustrated in a cross section and by maps, and the lithologies are described in type sections.

INTRODUCTION

Since 1968, I have investigated the Green River Formation in 

southwestern Wyoming as part of a program by the U.S. Geological Survey to evaluate oil-shale deposits located on federally 

owned lands. Geologic mapping and stratigraphic studies of oil 

bearing shales in the Washakie Basin have shown that the Laney 

Shale Member of the Green River Formation, called in this report

El
E2 CONTRIBUTIONS TO STRATIGRAPHY

the Laney Member, can be divided into three rock-stratigraphic 

units: a basal 150- to 500-foot-thick sequence that is mainly oil 

shale, a middle 0- to 900-foot-thick wedge that is mainly tuffaceous 

siltstone and sandstone, and an upper 0- to 700-foot-thick heterogeneous sequence that is mainly mudstone, alternating with 

sandstone, limestone, and shale. In ascending order, these units 

are herein named the LaClede Bed, the Sand Butte Bed, and the 

Hartt Cabin Bed. The three beds have dissimilar lithologies, diverse geologic histories, and partly unconformable contacts, and 

the oil shale in the LaClede Bed is a valuable resource; these 

facts make it desirable to recognize these units formally and to 

map each one separately.

NOMENCLATURE

The Laney Member was named the Laney Shale Member by 

Schultz (1920, p. 27) for exposures of "white and green shale, 

limestone and sandstone" along Laney Rim, a large ridge that 

parallels the northern part of the Washakie Basin. (See geologic 

map, fig. 1.) Schultz (1920, p. 27-28) reported that in the basin 

the Cathedral Bluffs Tongue of the Green River Formation (now 

placed in the Wasatch Formation) is overlain nearly everywhere 

by "fine, fissile Laney shales, 100 to 800 feet thick, which in turn 

is capped in places, as at Pine Bluffs [Pine Buttes], by reddish 

or cream-colored coarse-grained sandstone that is probably equivalent to the Tower sandstone." (The fine, fissile shales are now 

classified "oil shale.") Schultz (1920, p. 25) referred the rocks 

overlying the Tower Sandstone to the plant beds, a unit that was 

previously recognized by Powell (1876) along the crest of White 

Mountain in the Green River Basin about 40 miles west of the 

Washakie Basin. On a geologic map at the scale of 1:250,000, 

Schultz (1920, pi. 1) included the Tower Sandstone and plant 

beds in the Laney Shale Member in the Washakie Basin, but he 

showed a dashed and queried contact nearly everywhere for the 

Laney Shale Member with the overlying Bridger Formation. The 

LaClede Bed, Sand Butte Bed, and Hartt Cabin Bed are believed 

to correspond, respectively, to the Laney Shale Member, Tower 

Sandstone, and plant beds of Schultz, as he recognized them in 

the Washakie Basin; but subsequent stratigraphic revisions make 

the names as they were applied by him unusable.

Bradley (1945; 1959) made several nomenclatural changes for 

the Green River Formation in southwestern Wyoming. On a 1945 

geologic map of the Washakie Basin at the scale of about 

1:200,000, he recognized the Tower Sandstone (fig. 1), but he 

substituted the name Morrow Creek Member for the combined
LANEY MEMBER, GREEN RIVER FORMATION E3

R. 95 W.

R. 100 W.

FIGURE 1. Geologic map showing the area! distribution of the LaClede 

(shaded), Sand Butte (dotted), and Hartt Cabin (dashed). Beds of the 

Laney Member in the Washakie Basin. X, type section for the Sand Butte 

Bed; Y, type section for the Hartt Cabin Bed; and Z, type section for 

the LaClede Bed. X-Y, line of section shown in figure 3.

plant beds and Tower Sandstone of Schultz (1920) ; he retained 

Laney Shale Member for the basal oil-shale beds. On the 1945 

map, Bradley explained that "around the Washakie basin the 

Laney shale member and the overlying Morrow Creek member 

of the main body of the Green River formation were not mapped 

separately." In 1959, Bradley (p. 1074) abandoned the name 

Morrow Creek Member (he believed the Morrow Creek Member 

in the Green River Basin was the rock-stratigraphic equivalent 

of the Laney Shale Member in the Washakie Basin), and he 

placed all the beds lying between the Cathedral Bluffs Tongue and 

the Bridger Formation (or Washakie Formation in the Washakie 

Basin) in the Laney Shale Member.

The name Tower Sandstone was abandoned as a formal stratigraphic term by Culbertson (1962, p. C54).
E4 CONTRIBUTIONS TO STRATIGRAPHY

The Laney Shale Member has been divided into three beds in 

the Washakie Basin in preference to other nomenclatural alternatives because the term Laney Shale Member as it was inclusively 

applied by Bradley (1959) is now widely accepted for use in the 

adjacent Green River and Great Divide Basins in southwestern 

Wyoming and in the Sand Wash Basin in northwestern Colorado. 

However, inasmuch as the type locality of the Laney Shale Member is in the Washakie Basin and as the rocks to which the name 

is now applied are not exclusively shale, it is here proposed that 

the word "shale" be dropped and that the unit be henceforth 

named the Laney Member of the Green River Formation.

Changes in the nomenclature of the Laney Member in the 

Washakie Basin are shown in a correlation chart (fig. 2).

Schultz(1920)

Bridger 

Formation

Plant beds t

(0 

_Q

0

Tower J2 

Sandstone £

LL. 

G)

>

ir 

Laney Shale £;

Member (type) * O

Cathedral Bluffs 

Red Beds Member 

of Green River 

Formation

Bradley (1945)

Bridger 

Formation

c 

o Morrow Creek +:

Member "£ £

t*

-° « 

c > 

'ro ce

k C 

V 

V

Laney Shale £j 

Member

Cathedral Bluffs 

Tongue of Wasatch 

Formation

Bradley (1959)

Bridger 

Formation

Laney Shale 

Member 

of 

Green River 

Formation (part)

Cathedral Bluffs 

Tongue of Wasatch 

Formation

This report

Adobe Town 

£ Member

Q)

 Jjj Kinney^s,. 

£ Rim,^""^ c

| ^>Hartt - 1 

_3 Cabin £ £ 

^~~7 Bed -Q %

Sa r~~~2' « fc 

Butte ^~~~7 \> 

Bed_J^ / g-*-

^-^ TO S

_i j,

O 

LaClede Bed

\

Cathedral Bluffs 

Tongue of Wasatch 

Formation

FIGURE 2. Nomenclatural correlation chart for the Laney Member of the 

Green River Formation and adjacent formations in the Washakie Basin.

LANEY MEMBER OF THE GREEN RIVER FORMATION

Outcrops of the Laney Member encircle the Washakie Basin in 

a band of brown-, gray-, and tan-weathering ridges and valleys 

that is 3-10 miles wide. The outer boundary of the outcrop band 

describes an unevenly circular area nearly 40 miles in diameter. In 

most places the outer beds, the basal part of the member, weather
LANEY MEMBER, GREEN RIVER FORMATION E5

to drab rims above red beds of the upper part of the Cathedral 

Bluffs Tongue of the Wasatch Formation. The largest of these 

rims, Laney Rim, in the northern part of the basin, and its 

counterpart, Kinney Rim, in the western part of the basin, stand 

several hundred feet high. They slope gently basinward across 

minor ridges and valleys to the contact of the upper part of the 

Laney with the overlying Washakie Formation in the interior of 

the basin. The Laney Member varies in thickness from 900 to 

1,200 feet in the western part of the basin, where the LaClede 

and Sand Butte Beds are present, and from 500 to 900 feet in 

the eastern part of the basin, where the LaClede and Hartt Cabin 

Beds are present. The member has a maximum known thickness 

of about 1,800 feet in the vicinity of the Shell Oil Co. 1 Shell 

Creek Unit dry hole located in the south-central part of the basin. 

The location of this dry hole and the areal distribution of the 

named beds composing the Laney Member are shown in figure 1. 

Intertonguing, thickness, and lithologic relations of the LaClede, 

Sand Butte, and Hartt Cabin Beds of the Laney Member are 

shown in a west-east section across the basin (fig. 3).

LACLEDE BED

The name LaClede Bed of the Laney Member is here proposed 

for a sequence 145-455 feet thick, mainly of oil shale, that overlies the Cathedral Bluffs Tongue of the Wasatch Formation in the 

Washakie Basin. The LaClede Bed is typically exposed along 

Laney Rim north of the ruins of LaClede Stage Station on the 

Overland Trail, which are located in the NE^4 sec- 26 > T- 17 N., 

R. 98 W. The LaClede Bed is generally well exposed in a band 

of outcrops that varies in width from less than 1 mile to more 

than 5 miles; this band encircles the Washakie basin (fig. 1). The 

bed characteristically weathers to tan and drab brown sparsely 

vegetated ridges that have gentle dipslopes on the basin side and 

steep, commonly cliff-forming slopes on the outward-facing side.

The LaClede Bed is composed of at least 70 percent tan to 

dark-brown finely varved oil shale. Interbedded with the oil shale 

are beds of tan tuffaceous siltstone and sandstone and minor thin 

beds of tan oolite, algal limestone, and ostracodal limestone. 

Laminae of gray coarsely crystalline analcime and gray acicular 

calcite are common along the west margin of the basin. The oil 

shale is classified as marlstone by some geologists; however, the 

term "shale" seems more appropriate inasmuch as the rock is 

generally fissile to papery; the composition of most of it is no 

more than 20 percent calcite and dolomite, and it does not readily 

effervesce in cold dilute hydrochloric acid. Oil yields of weathered

493-697 O - 73 - 2
E6 CONTRIBUTIONS TO STRATIGRAPHY

LANEY MEMBER

OF GREEN R(VER

Hartt Cabin Bed

(Timaeepiiis olive-green a

ay mutfstoneiantfi sandstone)

(Green ajid brdwrvsalMd mudBtone; 

: sandstone and limestone; sparse oil shale)

(Tan tuffaceous sandstone and siltston 0

CATHEDRAL BLUFFS TONGUE 

OF WASATCH FORMATION

-35 MILES

FIGURE 3. Generalized west-east restored section of the Laney Member of 

the Green River Formation across the Washakie Basin showing thickness, 

intertonguing, and unconformable relations of the LaClede, Sand Butte, 

and Hartt Cabin Beds. The section was constructed from stratigraphic 

sections X and Y, measured on the west and east edges of the Washakie 

Basin, respectively, and from subsurface data not shown. The line of section X-Y is shown on the geologic map, figure 1.

oil-shale samples from the rocks called here the LaClede Bed in 

sec. 18, T. 14 N., R. 99 W., in the southwestern part of the basin, 

were listed and discussed by me previously (Roehler, 1969, fig. 5, 

p. 205-206). Facies distributions of montmorillonite and zeolites 

in the LaClede Bed that were believed to relate to the paleogeography and paleosalinity of Lake Gosiute were also previously 

described (Roehler, 1972a).

Oil shale and other lacustrine rocks in the lower 350 feet of 

the LaClede Bed intertongue eastward across the basin with 

fluviatile red, green, and gray mudstone and gray sandstone that
LANEY MEMBER, GREEN RIVER FORMATION E7

compose the upper part of the Cathedral Bluffs Tongue of the 

Wasatch Formation (fig. 3). As here defined, the contact of the 

LaClede Bed and the Cathedral Bluffs Tongue is the base of the 

lowermost oil shale in the LaClede Bed. When the contact is thus 

positioned, thin lacustrine algal limestone and oolite that normally 

characterize the basal part of the LaClede Bed may at a few 

places be included in the upper part of the Cathedral Bluffs 

Tongue.

The LaClede Bed has within it three important stratigraphic 

markers. Two of these, called informally the buff marker and the 

green shale marker, are easily recognized in outcrops by their 

distinctive colors. The buff marker (figs. 3, 4) varies in thickness 

from about 6 to 66 feet in outcrops along the western part of the 

Laney Rim and along Kinney Rim (fig. 1). Composed of tan 

tuffaceous siltstone, the buff marker commonly weathers to a 

light-buff band within darker weathering oil-shale strata. The 

buff marker thins eastward across the basin and grades into the 

Cathedral Bluffs Tongue of the Wasatch Formation, losing its 

distinctiveness as a lithologic unit. The green shale marker, 7-20 

feet thick, is composed of dark-green fissile to flaky clay shale 

or, locally, dark-green blocky mudstone. A yellow-brown silty 

dolomite less than 1 foot thick is commonly present near its 

center. The green shale marker constitutes the uppermost bed in 

the LaClede Bed in the eastern part of the Washakie basin. The 

third marker is a 3-inch to nearly 1-foot-thick bed of light-tangray limy siltstone that contains a small, low-spired gastropod, 

Gyraulus militarus, and sparse unidentified ostracodes. Small 

pebbles of the Gyraulus marker are found in talus that commonly 

covers slopes on weathered surfaces of the upper part of the 

LaClede Bed. The Gyraulus marker has been identified in outcrops everywhere in the basin, except in the poorly exposed rocks 

in northeastern part.

SAND BUTTE BED

The name Sand Butte Bed is proposed in this report for tuffaceous sandstone and siltstone that cap Kinney Rim in the western 

part of the Washakie Basin. The lower part of the bed is particularly well exposed on Sand Butte, a part of Kinney Rim, and 

from this feature in sec. 21, T. 16 N., R. 100 W., the bed takes 

its name.

The Sand Butte Bed has a maximum thickness of nearly 900 

feet along Antelope Creek in Tps. 16 and 17 N., R. 99 W., in the 

northwestern part of the basin, but it thins and wedges out southeastward across the basin, partly by stratigraphic thinning and
E8 CONTRIBUTIONS TO STRATIGRAPHY

partly by intertonguing with the LaClede and Hartt Cabin Beds 

(fig. 3). A pronounced eastward thinning and wedging out of the 

bed is apparent on aerial photographs of the northern part of 

the basin in Tps. 17 and 18 N., R. 97 W.

The Sand Butte Bed is composed of at least 90 percent gray to 

brown tuffaceous sandstone and siltstone along Kinney Rim and 

along the western part of Laney Rim. The remaining parts of the 

bed are composed of thin beds of gray coquinal siltstone and 

coquinal sandstone, gray partly coquinal limestone, tan and gray 

algal limestone, light-gray to tan-gray tuff, gray to brown shale, 

brown oil shale, and gray and green mudstone. The Sand Butte 

Bed weathers overall to tan brown.

The contact between the Sand Butte Bed and the underlying 

LaClede Bed is unconformable in the outcrops on the west side 

of the basin (Schultz, 1920, p. 26 and pi. IV-B) ; as much as 350 

feet of the LaClede Bed was eroded before the deposition of the 

Sand Butte Bed. Maximum erosion on this surface is in sec. 31, 

T. 17 N., R. 99 W., where thick tuffaceous sandstone and siltstone 

beds occupy channels scoured into the buff marker in the LaClede 

Bed. The unconformity apparently dies out eastward across the 

basin; no discordance has been noted in laterally equivalent beds 

that crop out along the east side of the basin.

The contact of the Sand Butte Bed and the Hartt Cabin Bed 

changes stratigraphic position across the basin because the beds 

are intertongued; it is arbitrarily located where dominantly tuffaceous sandstone and siltstone that compose the Sand Butte Bed 

change to dominant shale, mudstone, sandstone, and limestone 

that compose the Hartt Cabin Bed. Vertical cutoffs are used at 

the wedging out of the major tongues.

Where the Sand Butte Bed is overlain by the Kinney Rim Member of the Washakie Formation, the two units are transitional 

through an interval 100-300 feet thick in which fluvial olivegreen mudstone and gray crossbedded sandstone characteristic 

of the Kinney Rim Member are interbedded with beds of lacustrine gray sandstone and gray limestone characteristic of the 

Sand Butte Bed. The contact is arbitrarily placed within the 

transitional sequence at the base of a persistent and easily recognized bed of light-gray limy tuff informally called the white ridge 

marker. This tuff bed weathers chalky white and caps ridges on 

the lower east slopes of Kinney Rim and along the south slopes 

of Laney Rim.

HARTT CABIN BED

The name Hartt Cabin Bed is proposed for a sequence of interbedded sandstone, siltstone, mudstone, shale, oil shale, tuff, lime-
LANEY MEMBER, GREEN RIVER FORMATION E9

stone, and dolomite that compose the uppermost stratigraphic unit 

of the Laney Memlber in the Washakie Basin. The Hartt Cabin 

Bed is well exposed and is 625 feet thick near the head of Hartt 

Cabin Draw in the northwestern part of T. 14 N., R. 93 W., and 

from there eastward to the slopes of Flat Top Mountain in T. 14 

N., R. 93 W., and T. 15 N., R. 93 W. In most other places in the 

Washakie Basin, the Hartt Cabin Bed is not well exposed. Along 

the northern and eastern parts of the basin it weathers to flat 

plains that are generally covered by sand dunes and alluvial 

deposits interrupted locally by low sandstone ridges and small 

areas of badlands. Along Cherokee Ridge in the southern part of 

the basin the bed is poorly exposed in fault blocks that place it 

in juxtaposition with either the Washakie Formation or the 

Browns Park Formation. The bed is laterally equivalent to the 

Kinney Rim Member of the Washakie Formation and the Sand 

Butte Bed of the Laney Member (figs. 1, 3).

The Hartt Cabin Bed rests conformably upon the LaClede Bed 

in the eastern part of the basin. In that area, the contact of the 

two units is placed at the top of the green shale marker. At this 

horizon, underlying strata in the LaClede Bed weather drab 

brown, and overlying strata in the Hartt Cabin Bed weather 

chalky gray brown. The contact of the Hartt Cabin Bed with the 

overlying Adobe Town Member of the Washakie Formation is 

unconformable along the eastern edge of the basin, where 300- 

500 feet of the Hartt Cabin Bed was eroded before the Adobe 

Town was deposited (fig. 3).

Where the upper part of the Hartt Cabin Bed intertongues 

with the laterally equivalent Kinney Rim Member in a north-south 

band across the basin (figs. 1, 3), the contact of these units is 

arbitrarily placed at stratigraphic levels where the rocks change 

from fluvial olive-green and gray mudstone and sandstone (the 

Kinney Rim Member) to lacustrine green and brown shale and 

mudstone and gray sandstone and limestone (the Hartt Cabin 

Bed). Vertical cutoffs are used at the wedging out of major 

tongues, but in local areas where the intertonguing is complex 

and unmappable, minor thin tongues of one or the other unit are 

included within the unit that has the dominant lithology.

AGE

The Laney Member is of middle Eocene age, as determined by 

dating of fossil mammals. Although I have found fossil mammals at only one locality within the member, in a black chert 

layer near the base of the Hartt Cabin Bed in the northeastern 

part of the basin in the SE^ sec. 36, T. 18 N., R. 95 W. (USGS
E10 CONTRIBUTIONS TO STRATIGRAPHY

Fossil Vertebrate Catalog No. D777), fossils are abundant in the 

overlying Washakie Formation (Roehler, 1972b), and they are 

occasionally found in the underlying Cathedral Bluffs Tongue of 

the Wasatach Formation (Morris, 1954). The fossils indicate 

that the Laney Member in the Washakie Basin is Bridger A-B 

(Wood and others, 1941) in the lower part and Bridger C-D (Wood 

and others, 1941) in the upper part. The fossil dating, moreover, 

indicates that Lake Gosiute, in which the Laney Member was deposited, dried up in the Washakie Basin area, and probably 

throughout southwestern Wyoming, in the late middle Eocene.

ELECTRIC-LOG CORRELATIONS

Electric-log correlations of beds within the Laney Member in 

the Washakie Basin are difficult to make, partly because oil and 

gas test wells are sparse and widely spaced and partly because of 

abrupt thickness changes and intertonguing of units. An electric 

log that illustrates resistivity curves generally typical of the 

member was recorded in the Shell Oil Co. 1 Shell Creek Unit 

well (fig. 4). Oil shale and tuff composing the LaClede Bed are 

consistently the most easily recognized and correlated strata in 

the Laney Member. The oil shale exhibits high resistivity; the 

tuffs show low resistivity. The buff marker, the stratigraphic 

interval that includes the Gyraulus marker, and the green shale 

marker can be identified on the logs of most wells by their distinctive resistivity curves. The Sand Butte Bed is characterized 

by moderately strong resistivity in logs of wells located along 

the west side of the basin, but as the bed thins and wedges out 

southeastward, the curve flattens and loses its distinctive character. The Hartt Cabin Bed is composed of many lenticular strata, 

and the bed intertongues extensively with the Kinney Rim Member of the Washakie Formation and with the Sand Butte Bed, a 

relation that commonly makes consistent correlations impossible 

in that part of the section. In the 1 Shell Creek Unit well (fig. 4), 

the contact of the Hartt Cabin Bed with the overlying Kinney 

Rim Member is marked by a change from high to low resistivities, 

but in other wells in the basin the contact is impossible to locate 

consistently without supporting lithologic data from drill samples.

GEOLOGIC HISTORY

The deposition of the LaClede, Sand Butte, and Hartt Cabin 

Beds of the Laney Member in Lake Gosiute most likely began 

when the lake reached its maximum size and continued during 

the period when the lake began to shrink and withdraw southeastward across southwestern Wyoming, and finally ended when 

the lake dried up and disappeared.
LANEY MEMBER, GREEN RIVER FORMATION

Spontaneous Depth NORMAL 

Potential (ft) LONG NORMAL

Ell

WASHAKIE 

Kinney Rim FORMATION 

Member

3000

CATHEDRAL BLUFFS TONGUE 

OF WASATCH FORMATION

FIGURE 4. Electric '.og of the Shell Oil Co. 1 Shell Creek Unit well in the 

Washakie Basin illustrating resistivity curves of the Hartt Cabin, Sand 

Butte, and LaClede Beds. The geographic location of the well is shown in 

figure 1.

During the late early and very early middle Eocene the climate 

in southwestern Wyoming was hot and dry; the saline rocks that
E12 CONTRIBUTIONS TO STRATIGRAPHY

compose the Wilkins Peak Member of the Green River Formation 

were deposited in the Green River Basin to the west and the 

fluvial rocks that compose the Cathedral Bluffs Tongue of the 

Wasatch Formation were deposited upon the flood plains that 

encircled the lake. The depositional center of the lake at this time 

was in the southern part of the Green River Basin. At a later 

time during the middle Eocene the climate changed from hot and 

dry to hot and humid, as shown by unpublished fossil-plant data, 

and Lake Gosiute expanded to an area of more than 10,000 square 

miles. Moderately saline lake waters inundated most of the Green 

River, Great Divide, Washakie, and Sand Wash Basins and all 

of the Rock Springs uplift (fig. 5). Lake Gosiute at this time 

probably reached its maximum size and depth, although it competes for this distinction with its stage during the period of 

deposition of the Tipton Shale Member of the Green River Formation. The thick beds of varved oil shale and the few beds of 

air-laid tuff that were deposited in the expanded lake are preserved now as the LaClede Bed. If the thickest strata were deposited in the deepest parts of the lake, the depositional axis must 

have been situated toward the south shore, north of and generally 

parallel to the Uinta Mountains (see fig. 5), near the southwest 

edge of the Washakie Basin.

Minor thin tuffs were deposited in early Eocene time in the 

Washakie basin, but during the early middle Eocene a volcanic 

disturbance of major proportions abruptly introduced large quantities of air-laid volcanic ash that dramatically changed the basin 

landscape. The large lake in which the LaClede Bed was deposited 

rapidly began to fill with the volcanic sediments that now compose the Sand Butte Bed. Although the volcanic ash was originally air-laid, much of it was later reworked and water deposited, 

as evidenced by the thin interbedded mollusk-bearing limestone 

and algal limestone and by the sedimentary structural features 

typical of shallow-water and shoreline deposits. The center of 

the distant volcanic activity is unknown, but a northwest-source 

direction is indicated by the abrupt thinning and wedging out of 

the Sand Butte Bed in a southeasterly direction across the Washakie Basin (figs. 1, 3, 6); possibly the center of activity was 

in the Absaroka Range in northwestern Wyoming.

The unconformable contact of the LaClede Bed and the Sand 

Butte Bed in outcrops along the western part of the basin indicates a gentle uplift and erosion of the western part of the basin 

near the end of the period of deposition of the LaClede Bed in 

the early middle Eocene, and a penecontemporaneous southeast-
LANEY MEMBER, GREEN RIVER FORMATION E13

111° 110° 109° 108° 107°

42'

41'

20

I

40

I

60 MILES

I

FIGURE 5. Paleogeographic map of the Washakie Basin area and adjacent 

areas in southwestern Wyoming and northwestern Colorado showing the 

areal extent of Lake Gosiute during the deposition of the LaClede Bed 

of the Laney Member of the Green River Formation. Areas of lacustrine 

deposition are patterned; the approximate depositional center of the lake 

is shown by a line and arrows.

ward shift of the center of deposition in the basin. The two events 

probably were brought on (1) by a change in the topography of 

the lake floor resulting from rapid deposition of volcanic sediments in the northwestern part of the basin and slower deposition of fluvial clastic sediments in the southeastern part and (2) 

by isostatic adjustment to the accumulation of low-density volcanic sediments in the northwestern part of the basin as compared to higher density clastic sediments in the southeastern 

part of the basin. Climatic changes, possibly resulting from volcanic activity, may also have helped shrink the lake. Air-laid 

volcanic ash accumulation and basin tilting must be considered 

as the primary factors involved in the drying up and withdrawal 

of Lake Gosiute from southwestern Wyoming.

The Eocene climate became cooler and drier after the deposition of the Sand Butte Bed (unpub. fossil plant data); and Lake
E14 CONTRIBUTIONS TO STRATIGRAPHY

111° 110° 109° 108° 107°

41° -

20

I

40

I

60 MILES

I

FIGURE 6. Paleogeographic map showing the areal distribution of the Sand 

Butte Bed of the Laney Member of the Green River Formation in the 

Washakie Basin area and adjacent areas in southwestern Wyoming and 

northwestern Colorado. The area of Sand Butte deposition is patterned; 

a suggested source direction for air-laid volcanic ash that composes most 

of the bed is shown by the arrow.

Gosiute was reduced in size until it occupied only the Washakie 

Basin area in southwestern Wyoming and parts of the Sand 

Wash Basin area of northwestern Colorado (fig. 7). The terminal 

stages of Lake Gosiute are recorded in the stratigraphic sequence 

composing the Hartt Cabin Bed. Interbedded fluvial and lacustrine rocks attest to intermittent flooding and drying up of large 

areas. Volcanic sediments continued to enter the basin from the 

northwest, but they intermixed with clastic sediments derived 

mainly from the plutonic core of the Sierra Madre. Fluvial sediments that encroached upon the withdrawing lake are preserved 

in the Kinney Rim Member of the Washakie Formation (fig. 3). 

In the final stages, the lake was characterized by scattered freshwater ponds and small interconnected shallow lakes that supported prolific populations of mollusks. In many ways the terminal stages of Lake Gosiute recapitulated in reverse the embry-
LANEY MEMBER, GREEN RIVER FORMATION E15

111° 110° 109° 108°

42°

41'

20

I

40 60 MILES

FIGURE 7. Paleogeographic map of the Washakie Basin area and adjacent 

areas in southwestern Wyoming and northwestern Colorado showing the 

areal extent of Lake Gosiute during the deposition of the Hartt Cabin Bed 

of the Laney Member of the Green River Formation. Areas of lacustrine 

deposition are patterned; the approximate depositional center of the lake 

is shown by a line and arrow.

onic stages of Lake Gosiute described for the southwestern part 

of the Rock Springs uplift (Roehler, 1965, p. 145).

STRATIGRAPHIC SECTIONS

Type section for the LaClede Bed of the Laney Member, Green River

Formation

[The section was measured on Laney Rim in sees. 14, 15, and 23, T. 17 N., R. 98 W. The 

LaClede Bed is overlain at this locality by several hundred feet of gray tuffaceous siltstone and sandstone that compose the Sand Butte Bed of the Laney Member]

Green River Formation (part) :

Laney Member (part) :

Sand Butte Bed.

Unconformity.

LaClede Bed:

55. Oil shale, brown, silty, blocky; a few thin beds of 

gray blocky limy hard siltstone; not well exposed

54. Tuff, light-gray, silty, firm; scattered plant and leaf 

fragments; weathers to light-gray band in outcrops ___________-________________

Thickness 

(ft)

30.0

4.5
E16 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the LaClede Bed of the Laney Member, Green

River Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

LaClede Bed Continued Thickness i/*/

53. Oil shale, brown, flaky, soft; poorly exposed __- 11.2 

52. Calcite, gray, hard; a persistent bed of vertical acicular crystals; exhibits some cone-in-cone structure _____________________________ .05 

51. Oil shale, brown, flaky, soft; poorly exposed ___ 1.4 

50. Siltstone, tan-gray, limy, hard; scattered ostracodes 

and sparse Gyraulus militaris. The Gyraulus 

marker _________________________ .9

49. Oil shale, brown, papery, soft; some silty laminae- 73.0 

48. Algal limestone, tan, gray; onionskin type ____ 1.8 

47. Oil shale, brown, flaky, soft; poorly exposed ___ 9.0 

46. Siltstone, tan, hard, limy, platy, and thin interbeds of tan algal limestone; wavy-banded 

colonies _______________________ 1.3

45. Oil shale, brown, flaky, soft; poorly exposed ___ 7.8 

44. Tuff, light-gray, blocky, hard _____________ .3 

43. Oil shale, brown, flaky, soft; poorly exposed ___ 2.8 

42. Algal limestone, gray; rounded brain-type colonies .4 

41. Ostracodal limestone, light-brown, silty, hard ___ .2 

40. Siltstone, tan, very tuffaceous, finely bedded, hard_ 5.3 

39. Oil shale, brown, papery, soft; some flaky and

brittle __________________________ 12.5 

38. Siltstone, tan, limy, hard ________ ___ .7 

37. Oil shale, black, flaky, hard, brittle ________ 2.7 

36. Siltstone, tan, very tuffaceous, finely bedded, platy; 

weathers to prominent buff band in outcrop. The 

"buff marker" bed __________________ 36.0 

35. Algal limestone, tan, silty, very hard; the upper 

part is mainly algal fragments in a coarsegrained sandstone matrix; the lower part is thin 

beds of algal colonies ___ ._ _ 3.6 

34. Oil shale, brown, papery, firm ___ ___ 15.0 

33. Siltstone, tan, very tuffaceous, blocky, firm _____ 2.9

32. Ostracodal limestone, tan, very hard; weathers

rust brown _____ _ .1 

31. Oil shale, brown, papery, soft _ 4.7 

30. Analcimized tuff __________________ .2

29. Oil shale, brown, papery, soft ___-___ ___ 11.0 

28. Oolitic limestone, tan, siliceous, hard; weathers to

spongy texture _______________ ___ .3 

27. Oil shale, brown, flaky, silty, firm; scattered carbonaceous plant fragments ________ ___ 1.8

26. Pisolite, tan, silty, hard; caps distinct ledge in

outcrops; top 0.2 ft exhibits algal banding___ 1.1 

25. Oil shale, brown, papery to flaky, firm; some thin 

laminae very dolomitic; sparse thin laminae of 

tan firm siltstone _______--- --- __ 12.3
LANEY MEMBER, GREEN RIVER FORMATION E17

Type section for the LaClede Bed of the Laney Member, Green River

Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

LaClede Bed Continued Thickness

(ft/ 

24. Algal limestone, gray; onionskin type .3

23. Oil shale, dark-brown, papery, firm; thin dolomitic

laminae; sparse thin laminae of analcime -- 11.3

22. Algal limestone, tan, silty; mostly algal fragmented 

limestone at the base, grading upward into wavybanded colonies at the top; weathers to a small 

ledge __________________________ 1.0

21. Oil shale, brown, papery to flaky, hard; thin laminae of dolomitic shale; a few thin laminae of 

calcite and analcime ____-____--__ 5.6

20. Sandstone, gray, very fine grained, soft, very

biotitic; appears analcimitic __ _ __ .2

19. Siltstone, tan, gray, tuffaceous, firm; some claystone inclusions; weathers to a groove in cliff 

face _____________________________ 1.7

18. Oil shale, brown, papery, firm ___ 4.5

17. Algal limestone, tan; brain and onionskin types;

weathers to small, persistent ledge .7

16. Oil shale, brown, papery, soft __ 5.2

15. Oolite, tan, silty, hard; evenly bedded; sparse

ostracodes ________________ __ _ .15

14. Oil shale, brown, papery, soft ____ 2.4

13. Algal limestone, tan, hard, and interlaminated

ostracodal tan hard limestone _______ - .6

12. Oil shale, brown, papery, soft; several thin laminae

of gray coarsely crystalline analcime 4.5

11. Oolite, tan, hard; evenly bedded ___-___-_-- .3

10. Mudstone, green, sandy, blocky, firm at the base, 

and gray limy hard finely laminated to varved 

siltstone at the top; a few thin laminae and 

flattened colonies of algae _______ __ 2.7

9. Algal limestone, tan, oolitic at the base; fragmented algal limestone in the middle; wavybanded algal limestone at the top ___ 1.2 

8. Mudstone, gray, fissile to blocky, silty, firm; very

finely bedded at the top; weathers brown _-_ 3.5 

7. Oil shale, brown, flaky, firm _______________ 1.3

6. Ostracodal limestone, tan, silty, hard _______ .3 

5. Oil shale, brown, papery to flaky, firm; abundant

ostracodes ___ _________ _ 8.2

4. Algal limestone, tan; persistent even beds of fragmented brain-type colonies at the top; thin interbedded algal limestone and tan limy siltstone at the base ___________________ .7

3. Oil shale, brown, papery, soft ___________ 5.4
E18 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the LaClede Bed of the Laney Member, Green River

Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

LaClede Bed Continued Thickness

\jt) 

2. Algal limestone, tan, silty, hard, siliceous in part;

persistent beds of brain-type algae at the base, 

with fine wavy laminated bedding at the top 1.1 

1. Oil shale, brown, papery, soft _ _ ____ _ 4.0

Total thickness LaClede Bed (rounded) __ 320 

Cathedral Bluffs Tongue of the Wasatch Formation.

Type section for the Sand Butte Bed of the Laney Member, 

Green River Formation

[Measured on Kinney Rim in the NE% sec. 19, NV2 sec. 20, and NW% sec. 21, T. 14 N., R. 

99 W. The Sand Butte Bed is overlain at this locality by the mostly olive-green mudstone and 

gray erossbedded brown-weathering sandstone that compose the Kinney Rim Member of 

the Washakie Formation]

Washakie Formation (part) :

Kinney Rim Member (part) : Bed 5 ft thick of light-gray limy

tuff (white ridge marker). 

Green River Formation (part) :

Laney Member (part) :

Sand Butte Bed: Thickness

(ft) 

62. Algal limestone gray, silty, hard, rounded colonies

of brain type as much as 1.5 ft in diameter 

and gray, very finely crystalline, silty, platy, 

hard limestone between the algal colonies _____ 4.1

61. Mudstone, dark-olive-green and gray, silty to sandy,

blocky, firm _______________________ 17.8

60. Sandstone, gray, very fine grained, some finegrained, poorly sorted, subangular; very calcareous in part; soft to hard __________--_ 16.7

59. Mudstone, gray-brown, silty to very sandy, blocky,

firm _____________________________ 4.0

58. Limestone, tan-gray, very finely crystalline, silty,

platy, hard __________________ __,. 1.1

57. Sandstone, light-gray, very fine grained, very

argillaceous biotitic, calcareous, hard _ ____ 4.0

56. Sandstone, gray, fine to very coarse grained, poorly 

sorted, subangular, biotitic, calcareous, firm; 

scattered pebbles and lenses of conglomerate 

pebbles are rounded and somewhat flattened gray 

mudstone and gray siltstone; unit is crossbedded 41.9

55. Conglomerate subrounded gray sandy mudstone 

galls as much as 0.2 ft in diameter in a matrix 

of gray, coarse-grained, poorly sorted, biotitic, 

very calcareous, hard sandstone; abundant poorly 

preserved fossil wood fragments _ 3.0

54. Sandstone, medium-gray, very fine grained, fairly 

well sorted, subangular; colored grains; very 

calcareous; crossbedded; nonresistant to weathering _ _____ __ __ _ ____ 5.0
LANEY MEMBER, GREEN RIVER FORMATION E19

Type section for the Sand Butte Bed of the Laney Member, 

River Formation Continued

Green River Formation (part) Continued 

Laney Member (part) Continued

Sand Butte Bed Continued Thickness

53. Mudstone, medium-gray, silty to sandy, blocky,

firm; becomes very sandy at the top _____ _ 2.5

52. Sandstone, medium-gray, very fine grained, fairly 

well sorted, subangular; colored grains; very calcareous; hard; weathers to ledge _ 2.5

51. Sandstone, gray, very fine to fine-grained, fairly 

well sorted, micaceous; abundant colored grains; 

firm; friable; nonresistant to weathering; and 

thin interbedded, dark-gray-green, silty to sandy, 

blocky, firm mudstone _-_-__-_________ 28.0

50. Limestone, light-gray, very finely crystalline, hard, 

dense; weathers to peculiar spongy texture and 

forms a distinct gray ledge; large talus blocks 

from a distance appear to be a flock of sheep__ 4.9

49. Sandstone, light-gray, very fine to very coarse 

grained, poorly sorted, subangular; abundant 

colored grains; soft; friable; crossbedded; conglomerate lens near the base has clay galls as 

much as % in. in diameter; abundant fossil wood 

fragments _____________________ _ 56.0

48. Sandstone light-gray, mostly very fine grained, 

some fine-grained, calcareous, firm and interbedded dark-gray-green, sandy, soft mudstone __ 20.0

47. Siltstone, light-gray, calcareous, argillaceous, hard 1.0

46. Limestone, gray, sandy, hard; sparse fish bones and 

a few mollusk shell fragments including those 

of Goniobasis sp _______________ __ .3

45. Algal limestone, tan, platy; small rounded heads

as much as 1.0 ft in diameter _________ .4

44. Sandstone, gray, very fine grained, soft, friable;

nonresistant to weathering ___________ 7.8

43. Sandstone, gray, fine- to coarse-grained, poorly 

sorted, subangular; abundant colored grains; 

soft; friable; becomes calcareous the top 3.0 ft; 

weathers gold brown _____________ 18.5

42. Limestone, medium-gray, silty, hard; weathers to

ledge __________________________ 1.5

41. Sandstone, gray-brown, fine- to medium-grained, 

subangular, soft, friable, tuffaceous; some calcareous streaks; abundant colored grains; 

weathers to nonresistant slopes __________ 23.8

40. Tuff, tan-gray, silty, hard _______________ 1.5

39. Siltstone, tan, gray, tuffaceous, calcareous, firm, 

and sparse interbedded gray, very fine grained, 

calcareous tuffaceous, hard sandstone ______ 49.3

38. Mudstone, gray-green, silty, blocky, soft to firm__ 2.8
E20 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the Sand Butte Bed of the Laney Member, 

River Formation Continued

Green River Formation (part) Continued 

Laney Member (part) Continued

Sand Butte Bed Continued Thickness

37. Sandstone, gray, very fine to fine-grained, poorly 

sorted, subangular; colored grains; soft; friable; 

calcareous; becomes very silty in the top 1 ft 9.1

36. Sandstone, gray, very fine grained, poorly sorted,

tuffaceous, calcareous; colored grains; hard- _ 1.0

35. Mudstone, gray-brown, blocky, firm; possible low

kerogen content _____________________ 10.5

34. Tuff, white, hard ___________________ .4

33. Sandstone, gray, very fine grained, slightly calcareous, fairly well sorted, firm; and interbedded 

gray, calcareous, tuffaceous, firm siltstone ___ 14.5

32. Sandstone, gray, very fine grained, very limy, very

hard; weathers gray brown __-____________ 1.3

31. Siltstone, tan-gray, tuffaceous, calcareous, hard, 

and occasional thin beds of light-gray, very fine 

to fine-grained, tuffaceous, calcareous, hard 

sandstone _________________________ 21.6

30. Oil shale, brown, flaky, firm; some silty; some very

limy; estimated oil yield 5 gallons per ton 5.0

29. Siltstone, gray, hard, tuffaceous, calcareous; abundant clay galls; weathered blocks form talus 

slope ____________________________ 7.5

28. Sandstone, light-gray, very fine grained, poorly 

sorted, silty, tuffaceous, hard; weathers rust 

brown __________________________ 6.5

27. Siltstone, light-gray, tuffaceous, calcareous, hard; 

scattered plant impressions; and thin interbedded, 

Iigh1>gray, very fine grained, tuffaceous, calcareous, hard sandstone __________________ 38.0

26. Coquinal sandstone, gray, fine- to medium-grained, 

very limy, very hard; contains Goniobasis sp. 

and Lampsills sp _________ _ _ 1.0

25. Siltstone, pink to maroon, calcareous, tuffaceous,

firm ___________________________ 2.5

24. Siltstone, gray, maroon, brown, tuffaceous, calcareous, hard; interlaminated and interbedded with 

light-gray, tan, very fine to medium-grained, 

poorly sorted, subangular, tuffaceous, calcareous, 

firm sandstone __ _____ ______ _ 35.5

23. Coquinal limestone, gray, shaly, hard; contains 

poorly preserved shell fragments of Goniobasis 

sp., Lampsilis sp., and Viviparus, sp _ .4

22. Limestone, tan, brown, silty, ostracodal, hard; and 

finely interlaminated to interbedded brown, silty, 

blocky, hard oil shale; estimated oil yield 5 

gallons per ton ___________ 9.8
LANEY MEMBER, GREEN RIVER FORMATION E21

Type section for the Sand Butte Bed of the Laney Member, 

River Formation Continued

Green River Formation (part) Continued 

Laney Member (part) Continued

Sand Butte Bed Continued Thickness (ft)

21. Siltstone, tan, gray, some maroon tinted, tuffaceous, 

calcareous, hard; with shale partings; and interlaminated to interbedded gray, red-tinted, 

very fine grained, tuffaceous, calcareous, hard 

sandstone; some mud cracks ___ __ _ - 19.0

20. Sandstone, tan-gray, very fine to medium grained, 

poorly sorted, subangular; abundant colored 

grains; calcareous; firm; weathers to ledge --- 4.8

19. Siltstone, gray, some maroon-tinted, calcareous, 

tuffaceous, hard, thin-bedded, platy; some green 

shale partings, and a few thin beds of gray, very 

fine grained sandstone; scattered aquatic plant 

impressions _______________ 8.0

18. Oil shale, dark-brown, silty, ostracodal, hard; becomes very silty the top 1.5 ft; oil yield of 

weathered surface sample 11.6 gallons per ton 5.4

17. Sandstone, gray, red, brown, very fine to finegrained, fairly well sorted, subangular, very 

calcareous, hard; abundant green shale partings, 

and some interbedded brown, gray, tuffaceous, 

calcareous, hard siltstone ______ _ 10.0

16. Sandstone, gray, green, very fine grained, poorly 

sorted, tuffaceous, calcareous, hard; a few shaly 

streaks; abundant worm borings; weathers to 

ledge ____________________________ 3.0

15. Sandstone, light-gray, brown, some red tinted, fineto coarse-grained, poorly sorted, subangular, tuffaceous; abundant colored grains; crossbedded; 

and some interbedded gray, very tuffaceous, calcareous, firm siltstone; weathers to a series of 

rust-brown ledges ________________ 131.0

14. Siltstone, tan, argillaceous, tuffaceous, firm, and 

interlaminated, light-gray, very fine grained, 

tuffaceous; and calcareous firm sandstone __-_ 9.0

13. Oil shale, brown, flaky, ostracodal, soft; estimated

oil yield 10 gallons per ton ________ ___ _ 7.5

12. Siltstone, gray, tan, some red-tinted, argillaceous, 

tuffaceous, some shaly streaks, and interlaminated to interbedded light-gray, very fine 

grained, calcareous, tuffaceous, firm, finely bedded 

sandstone; not well exposed _________- 65.5

11. Oil shale, tan-brown, fissile, some flaky, ostracodal,

soft; estimated oil yield 3 gallons per ton _____ 13.3

10. Sandstone, light-gray, fine- to coarse-grained, 

poorly sorted, subangular, tuffaceous, calcareous, 

hard; weathers to nearly flat slope; sparse very
E22 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the Sand Butte Bed of the Laney Member, 

River Formation Continued

Green River Formation (part) Continued 

Laney Member (part) Continued

Sand Butte Bed Continued Thickness 

poorly preserved twigs and wood, mostly replaced by limonite _____-______ _ _ 2.0

9. Sandstone, light-gray, very fine grained, subangular, tuffaceous, hard; and interbedded light-gray, 

tuffaceous, firm siltstone; 2 ft dark-gray, fissile, 

soft shale, about 5 ft from the top ________ 18.4

8. Sandstone, light-gray, very fine grained, subangular, poorly sorted, calcareous, tuffaceous, firm__ 3.2

7. Siltstone, light-gray, tuffaceous, hard; and sparse 

thin laminae of gray very fine grained sandstone. 

Some outcrops of this unit are, very locally, 

oxidized red. Cinder fragments suggest that oil 

shales in the underlying LaClede Bed may have 

burned __________________________ 9.6

6. Sandstone, light-gray, fine-to coarse-grained, subangular, poorly sorted; abundant colored grains; 

calcareous; tuffaceous, broadly crossbedded; 

weathers to rust brown and caps ridge - - - 4.5

5. Siltstone light^gray, argillaceous, tuffaceous, firm;

disseminated plant impressions _ __ 1.9

4. Sandstone, light-gray, fine- to coarse-grained, poorly sorted, subangular to subrounded; abundant 

colored grains; calcareous; limonitic; weathers 

to smooth rust-brown slope; top of unit contains abundant Goniobasis sp _____ __ ____ 4.2

3. Siltstone, light-gray, argillaceous, tuffaceous, firm; 

and sparse thin laminae of light-gray, very fine 

grained, tuffaceous, firm sandstone; surface of 

unit contains casts of Goniobasis sp _________ 7.7

2. Sandstone, light-gray, fine- to coarse-grained, poorly sorted, subangular to subrounded; abundant 

colored grains; calcareous; firm; weathers 

rust brown ____________ 19.2

1. Silstone, gray, tuffaceous, firm, finely bedded; platy 

in part; and finely interlaminated to interbedded, 

light-gray, very fine grained, tuffaceous, firm, 

friable sandstone; scattered small plant fragments ___________________________ 19.8

Total thickness Sand Butte Bed (rounded) ___ 850 

Unconformity. 

LaClede Bed.
LANEY MEMBER, GREEN RIVER FORMATION E23

Type section for the Hartt Cabin Bed of the Laney Member, 

Green River Formation

[Units 1-42 were measured in sees. 30, 31, and 32, T. 15 N., R. 93 W., and units 43-82 

were measured in sec. 6, T. 14N. , R. 93 W.]

Washakie Formation.

Adobe Town Member. 

Unconformity. 

Green River Formation (part) :

Laney Member (part) :

Hartt Cabin Bed: Thickness

(ft)

82. Sandstone, gray, very fine grained, fairly well 

sorted, tuffaceous, firm; and interbedded gray, 

finely bedded, hard siltstone _____ 13.0

81. Siltstone, gray, tuffaceous, calcareous, finely 

bedded; and interbedded medium-brown, very 

silty, firm oil shale _ 19.0

80. Shale, gray-brown, flaky, soft __________ _ 2.5

79. Siltstone, gray-brown, tuffaceous, firm; scattered

ostracodes ________________-__ 2.7

78. Siltstone, light-gray, calcareous, very tuffaceous,

hard, massively bedded; weathers to small ledge 1.5

77. Mudstone, dark-gray-green, silty, blocky, firm 5.2

76. Tuff, light-gray, sandy, hard ______ .8

75. Siltstone, gray, calcareous, tuffaceousjfinely bedded,

firm; weathers to a small ledge _-- 7.4

74. Mudstone, dark-gray, dark-gray-green, silty, blocky, 

firm; and a few beds of gray, very fine grained, 

argillaceous sandstone; soft at the base --- 15.3

73. Sandstone, gray, fine-grained, fairly well sorted, 

subangular; abundant black grains; calcareous; 

hard; crossbedded _ _ 1.6

72. Mudstone, dark-gray-green, silty, blocky, firm; 

and interbedded dark-gray-brown, fissile to flaky, 

firm, shale; a few thin beds of tan, calcareous, 

platy siltstone; one thin bed of brown, carbonaceous shale about 8 ft below the top _________ 24.0

71. Shale, medium-brown, fissile, carbonaceous, very

soft _____________________________ 2.5

70. Mudstone, dark-gray, dark-gray-green; black at the

top; silty; blocky; firm ________________ 32.7

69. Siltstone, gray-brown, limy, finely bedded, platy; 

abundant ostracodes. Laterally the base of this 

unit grades into a siliceous coquina containing 

the gastropod Goniobasis tenera _________ 8.6

68. Sandstone, gray, very fine to fine-grained, poorly 

sorted, subangular; abundant colored grains; 

abundant biotite; argillaceous, becoming tuffaceous and calcareous in the top 3 ft; the upper 

part weathers to a gray ledge; the lower part 

weathers brown ___ __ _____________ 6.8

67. Oil shale, brown, fissile, flaky, firm; sparse

ostracodes ________________________ 4.4
E24 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the Hartt Cabin Bed of the Laney Member, 

Green River Formation Continued

Green River Formation (part) Continued 

Laney Member (part) Continued

Hartt Cabin Bed Continued Thickness

(ft)

66. Shale, tan-gray, very fissile, flaky, soft 1.4

65. Oil shale, medium-brown, very silty, flaky, firm; 

some inter laminated medium-brown, shaly, very 

finely bedded siltstone; abundant ostracodes ____ 7.6

64. Sandstone, gray-brown, very fine to fine-grained, 

poorly sorted, subangular, calcareous in part, 

argillaceous, soft _________________- 2.5

63. Coquinal sandstone, gray, very fine grained, limy,

hard; abundant specimens of Goniobasis sp ___ .9

62. Sandstone, gray-brown, very fine to fine-grained, 

argillaceous, subangular, poorly sorted; abundant 

colored grains; abundant biotite; weathers to 

steep slope _________________________ 17.5

61. Mudstone, dark-gray-brown, silty, blocky, firm; and 

thin interbedded gray, very fine grained, calcareous, firm sandstone ____________________ 9.0

60. Tuff, white, silty, firm, finely bedded; weathers to

a chalky ledge. The "flat top white layer" ___ 2.7

59. Sandstone, gray-brown, very fine to fine-grained, 

argillaceous, firm; banded calcareous zones; a 

few tuffaceous layers; weathers dark brown near 

the center; forms a nearly vertical cliff; abundant ostracodes in the upper 2 ft; most of a turtle 

carapace near the center ______ _ 30.4

58. Sandstone, gray, very fine grained, fairly well 

sorted, finely bedded, tuffaceous, firm; scattered 

small plant fragments ________ _ 3.4

57. Siltstone, gray, sandy, calcareous, finely bedded;

abundant small plant fragments _ _ .9

56. Mudstone, gray, gray-brown, silty, calcareous, firm;

some very small plant fragments along partings 5.3

55. Algal limestone, gray, silty, hard; slightly undulating brain-type colonies _ _ -_ .6

54. Shale, medium-gray-brown, flaky, soft 3.2

53. Mudstone, gray-green, silty, blocky, firm; grades 

upward into firm, gray, calcareous, argillaceous 

siltstone _____________ _____________ _ _ 3.5

52. Siltstone, gray, sandy, finely bedded, very calcareous; weathers to small, thin plates __ __ .8

51. Shale, gray-green, flaky, firm _ _ _ .9

50. Sandstone, gray, very fine grained, calcareous, firm,

crossbedded; forms ledge; weathers dark brown__ 2.1

49. Sandstone, gray-brown, very fine to mediumgrained, poorly sorted, subangular; abundant 

colored grains; biotitic; argillaceous; firm; and 

interbedded gray, very sandy, argillaceous, firm
LANEY MEMBER, GREEN RIVER FORMATION E25

Type section for the Hartt Cabin Bed of the Laney Member,

Green River Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

Hartt Cabin Bed Continued Thickness

(ft) 

mudstone; the interval is at least 75 percent

argillaceous sandstone; weathers to steep graybrown slope ________________________ 28.7

48. Sandstone, gray-brown, very fine to mediumgrained, poorly sorted, subangular; abundant 

colored grains; abundant biotite; argillaceous; 

friable; crossbedded; most of unit nonresistant 18.3

47. Mudstone, gray, sandy, soft, and thin interbedded 

gray, very fine grained, very argillaceous, soft 

sandstone and gray, argillaceous, calcareous, firm 

siltstone ________________________ 10.0

46. Oil shale, dark-green-brown, flaky, firm ___ 3.2

45. Ostracodal limestone, gray, finely bedded, platy,

silty, firm - .4

44. Mudstone, green, very sandy, firm; and interbedded gray-brown, some green-tinted, very fine 

grained, fairly well sorted, very argillaceous, 

colored-grained, firm sandstone __ 8.3

43. Sandstone, gray-brown, some green tinted; very fine 

grained, fairly well sorted, very argillaceous; 

abundant colored grains; firm; a few very shaly 

streaks __________________________- 24.9

42. Siltstone, gray, argillaceous, tuffaceous, calcareous,

firm; weathers to ledge _--- 6.2

41. Mudstone, dark-gray-green, silty to sandy, blocky, 

firm; and interbedded gray, argillaceous, tuffaceous, firm siltstone ________ - 14.3

40. Siltstone, gray, very argillaceous, tuffaceous, platy,

calcareous; weathers to ledge __ --_-- 2.1

39. Shale, gray-brown, very fissile to flaky, firm; very

low kerogen content __-______ ___ 6.5

38. Sandstone, gray, very fine grained, argillaceous, 

soft; and interbedded gray, calcareous, firm siltstone; grades upward into gray-green firm mudstone __________________________ 12.5

37. Siltstone, gray, calcareous, platy, hard __ .8

36. Shale, dark-gray, very fissile to flaky, firm ___ 6.3

35. Dolomite, tan, finely crystalline, very silty, finely

bedded, platy, hard _________________- .6

34. Mudstone, dark-green, silty, flaky, firm; and interbedded gray, argillaceous, platy, calcareous siltstone __________________________ 20.3

33. Siltstone, gray, argillaceous, platy, firm; weathers

to small ledge _____ _______ ___ 1.8

32. Siltstone, gray, argillaceous, calcareous, hard, finely 

bedded; grades upward into gray, very silty, 

flaky, firm shale ___________________ 3.4
E26 CONTRIBUTIONS TO STRATIGRAPHY

Type section for the Hartt Cabin Bed of the Laney Member,

Green River Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

Hartt Cabin Bed Continued Thickness \j*}

31. Mudstone, green, sandy, blocky, firm 5.9

30. Sandstone, gray-green, very fine grained, fairly well 

sorted, calcareous, firm; abundant Goniobasis 

sp.; some Australorbis sp., and Lampsilis sp .7

29. Mudstone, dark-green, silty, blocky, firm _ 6.3

28. Dolomite, gray, finely crystalline, very silty, finely

bedded, platy, hard __-_ _ .5

27. Shale, gray, very silty, flaky; and thin, finely interbedded gray, calcareous, finely bedded, platy, 

hard siltstone _________ _ __ _ 5.3

26. Siltstone, gray, calcareous, finely bedded, platy,

hard; abundant syneresis cracks _ ___ _ - 1.3

25. Shale, dark-gray-green, flaky, clayey, firm __ 4.1

24. Shale, gray; very silty at the base, grading upward 

into gray, very fine grained, argillaceous, limonitic, soft sandstone ____ __ _________ 7.5

23. Siltstone, gray, very calcareous, argillaceous; sparse

plant fragments _______ _________ 1.2

22. Sandstone ,gray, very fine grained, very argillaceous; sparse small, carbonaceous plant fragments 1.3

21. Sandstone, gray, fine-grained, fairly well sorted,

argillaceous, soft, limonitic, nonresistant ____ 6.5

20. Sandstone, gray, fine-grained, fairly well sorted, 

angular to subangular, calcareous; abundant 

colored grains; abundant biotite; crossbedded __ 1.6

19. Sandstone, gray, very fine to fine-grained, fairly 

well sorted, argillaceous, soft, friable, nonresistant; and interbedded gray-green, gray, flaky to 

blocky, firm mudstone; two very thin carbonaceous layers in the lower part _ 51.9

18. Mudstone, dark-gray, silty, carbonaceous, firm, becoming shaly the top 0.4 ft _ 1.1

17. Shale, brown, flaky, soft ________ 6.0

16. Mudstone, dark-gray-green, silty to sandy, blocky,

soft; deeply weathered; not well exposed __ _ 15.0

15. Sandstone, gray, very fine to fine-grained, fairly 

well sorted; abundant colored grains; soft; friable; argillaceous; weathers distinctive orange 

brown _________________ ___ 5.2

14. Mudstone, dark-gray-green, partly very silty to

very sandy deeply weathered _ 20.4

13. Dolomite, tan, silty, platy, very hard 1.4

12. Shale, gray, fissile, silty; firm at the base, grading 

upward into dark gray-green, clayey, soft mudstone; deeply weathered _ 14.0

11. Oil shale, medium- brown, very silty, calcareous; 

firm, grading upward into medium brown, very
LANEY MEMBER, GREEN RIVER FORMATION E27

Type section for the Hartt Cabin Bed of the Laney Member,

Green River Formation Continued 

Green River Formation (part) Continued 

Laney Member (part) Continued

Hartt Cabin Bed Continued Thickness (ft)

shaly, hard, platy siltstone; abundant ostraoodes 

and fish bones; unidentified gastropod shell fragments _____________ _ 6.1

10. Siltstone, medium-brown, calcareous, platy, hard; 

abundant ostracodes; weathers to large white 

plates _ _____-____ 4.0

9. Shale, medium-brown, very silty, flaky, brittle, tuffaceous; very low kerogen content 10.2 

8. Oil shale, dark-brown, papery, soft _ 5.4 

7. Oil shale, dark-brown, slightly silty, firm; and interbedded medium-brown, shaly, flaky to platy, 

tuffaceous siltstone; unit weathers very light 

gray _ __ 12.5 

6. Siltstone, brown, shaly, platy, tuffaceous, calcareous, firm; sparse ostracodes; very sparse 

Musculium sp __________ ___ 3.3 

5. Oil shale, medium-brown, very silty, firm 5.3 

4. Siltstone, medium-brown, limy, hard; and interbedded brown, very silty, firm oil shale; abundant 

ostracodes _____________-__ _ 5.0 

3. Siltstone, medium-brown, limy, hard, tuffaceous,

very platy; weathers white _ 3.0 

2. Oil shale, brown, flaky, soft ______________ 3.8 

1. Dolomite, gray, finely crystalline, silty, hard;

weathers yellow brown _______ .8

Total thickness Hartt Cabin Bed (rounded) __ 625 

LaClede Bed (part) : Bed 7 ft thick of dark-green flaky 

shale (green shale marker).

REFERENCES CITED

Bradley, W. H., 1945, Geology of the Washakie Basin, Sweetwater and Carbon Counties, Wyoming, and Moffat County, Colorado: U.S. Geol. Survey Oil and Gas Inv. Prelim. Map 32.

 1959, Revision of stratigraphic nomenclature of Green River formation of Wyoming: Am. Assoc. Petroleum Geologists Bull., v. 43, no. 5, 

p. 1072-1075.

Culbertson, W. C., 1962, Laney Shale Member and Tower Sandstone Lentil 

of the Green River Formation, Green River area, Wyoming, in Geological Survey research 1962: U.S. Geol. Survey Prof. Paper 450-C, p. C54- 

C57.

Morris, W. J., 1954, An Eocene fauna from the Cathedral Bluffs tongue of 

the Washakie Basin, Wyoming: Jour. Paleontology, v. 28, no. 2, p. 195- 

203.

Powell, J. W., 1876, Report on the geology of the eastern portion of the 

Uinta Mountains and a region of county adjacent thereto: U.S. Geol. 

and Geog. Survey Terr., 218 p.
E28 CONTRIBUTIONS TO STRATIGRAPHY

Roehler, H. W., 1965, Early Tertiary depositional environments in the Rock 

Springs uplift area, in Wyoming Geol. Assoc. Guidebook 19th Field 

Conf., Sedimentation of Late Cretaceous and Tertiary outcrops, Rock 

Springs uplift, 1965: p. 140-150.

 1969, Stratigraphy and oil-shale deposits of Eocene rocks in the 

Washakie basin, Wyoming, in Wyoming Geol. Assoc. Guidebook 21st 

Field Conf., Tertiary rocks of Wyoming, 1969: p. 197-206.

 1972a, Zonal distribution of montmorillonite and zeolites in the 

Laney Shale Member of the Green River Formation in the Washakie 

Basin, Wyoming, in Geological Survey research 1971: U.S. Geol. Survey 

Prof. Paper 800-B, p. B123-B126.

1972b, Stratigraphy of the Washakie Formation in the Washakie

Basin, Wyoming: U.S. Geol. Survey Bull., 1369 (in press). 

Schultz, A. R., 1920, Oil possibilities in and around Baxter Basin in the

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

Bull. 702, 107 p. 

Wood, H. E., 2d, and others, 1941, Nomenclature and correlation of the

North American continental Tertiary: Geol. Soc. America Bull., v. 52,

no. 1, p. 1-48.

U.S. GOVERNMENT PRINTING OFFICE: 1973 O 493-697