DEPARTMENT OF THE INTERIOR
US. GEOLOGICAL SURVEY

CONTOUR INTERVAL 40 FEE
TED LINES REPRESENT 20-FOOT CON

NATIONAL GEODETIC VERTICAL DATUM OF 1929

y'HAY CANYON JUNC. 28 MI.
y

R21E. R226, 10

Su (ae

Geology mapped in 1983-19;

19

14374000.)

84

METERS
2134

1829

1524

1220

CORRELATION OF MAP UNITS

Qai_ |} Holocene }QUATERNARY
==

Tgp
|»

Td Eocene TERTIARY

Tw

DESCRIPTION OF MAP UNITS

ALLUVIUM AND COLLUVIUM (HOLOCENE)--Includes

unconsolidated gravel, sand, silt, and clay
jn alluvial, colluvial, and fan deposits

GREEN RIVER FORMATION (EOCENE)

Parachute Creek Member--Consists mostly of
siltstone and claystone, as well as barren
marlstone, sandstone, altered tuff beds,
slightly bituminous sandstone, and a few
beds of oi] shale. Unit generally weathers
light gray to tan in rounded slopes and
hills; lower part forms cliffs and ledges in
western and southern parts of quadrangle.
Unit becomes less sandy and contains more
marlstone and siltstone to northeast.
Mahogany ledge (Mahogany zone in
subsurface), which contains richest oil-
shale beds in Parachute Creek Member, is
basal unit of member. Consists of dark-gray
to black oi] shale interbedded with thin
tuff beds and medium- to dark-gray silty
marlstone. Mahogany ledge is about 19 ft (6
m) thick in northern and western parts of
quadrangle; that part which has an average
shale-oil yield of 25 gallons per ton (104
liters per metric ton) is about 11 ft (3 m)
thick and thins to southeast to 3 ft (1
m). Bituminous sandstone beds occur above
and below Mahogany ledge. Only lowermost
350 ft (107 m) of Parachute Creek Member
exposed in northwestern corner of quadrangle
Horse Bench Sandstone Bed--Base of a fine-
grained tuffaceous sandstone and siltstone
unit within Parachute Creek Member.
Weathers brownish tan to yellowish orange.
Forms prominent bench in northwestern part
of quadrangle. Uneven base and smooth
top. Top of Horse Bench Sandstone Bed is
approximately 360 ft (110 m) above base of
Parachute Creek Member. Ranges in thickness
fron 3 to 23 ft (1 to 7 m)

Top of Mahogany bed--Richest oil-shale bed
within Mahogany ledge. Consists of dark-
gray to black oi] shale interbedded with
thin tuff beds. Weathers light gray to
brown. Basal contact of Parachute Creek
Member lies 13 to 15 ft (4 to 4.5 m) below
top of Mahogany bed and is not shown on
map. Thickness of Mahogany bed ranges from
about 5 ft (1.5 m) in northwestern part of
quadrangle to 3 ft (1 m) in southeastern
corner

Tgd Douglas Creek Member--Consists of fine-grained

to very fine grained grayish-brown
sandstone, dark-brown bituminous sandstone,
gray siltstone, green and maroon mudstone,
stromatolitic and ostracodal limestone, and
a few thin dark-gray oil-shale beds. Most
sandstone and limestone beds are ledge
formers, whereas siltstone and mudstone beds
form slopes and reentrants. Unit includes
in its lower part alluvial sandstone and
siltstone beds previously mapped as part of
the Renegade Tongue of the Wasatch Formation
by Cashion (1967). Upper 800 ft (244 m) of
member exposed in quadrangle. Thickness of
Douglas Creek Member fron geophysical logs
is approximately 1,900 ft (580 m)

WASATCH FORMATION (EOCENE)
Tw Wasatch Formation--Shown on cross section

only. Irregularly bedded sandstone,
siltstone, and shale. Intertongues with
Green River Formation

CONTACT--Dashed where approximately located

—7OOO— STRUCTURE CONTOURS--Drawn on top of Mahogany

—6900—
e!

62 DRY
$e GAS

Cashion, W.B., 1967, Geology and fuel resources of the Green

OIL-

bed. Dashed where Mahogany bed eroded.
Contour interval 100 ft (30 m). Datum is
mean sea level ‘

SHALE CORE HOLE--Results of drilling shown
in Cashion (1981). Number keyed to list of
drill holes

HOLE--Number keyed to list of drill holes
WELL--Includes shut-in, producing, and

abandoned wells at time of mapping (1983-
1984). Number keyed to list of drill holes

REFERENCES CITED

River Formation, southeastern Uinta Basin, Utah and

Colorado:
548, 48

U.S. Geological Survey Professional Paper

p.

1981, Results of core drilling in the Mahogany zone

and some
Winter Ri

adjacent beds of the Green River Formation,
dge area, southeastern Uinta Basin, Utah:

U.S. Geological Survey Open-File Report 81-175, 27 p.

MISCELLANEOUS FIELD STUDIES
MAP MF-1839

DRILL HOLES IN THE WOLF POINT QUADRANGLE, UINTAH COUNTY, UTAH
LUSGS, U.S. Geological Survey. Leaders (--), data not available.

1 ft=0.304 m ]
Drill hole
number Drilling company Drill hole name! bias i
(on map)
1 USGS--------------- USGS WR-1 (No. U94)-- - 100
2: Continental O71 Co. Bull Canyon No. 2-- -- 4,205
3 Coseka Resources--- Pine Spgs. No. 6-7-14-22-- --
4 Pine Spgs. No. 12-18-14-22 --
5 USGS WR-2 (No. U95)------- 100
6 Wolf Point No. 1 10,300
7 USGS WR-7 (No. U100)- 98
8 Coseka Resources--- Federal No. 3-11-15-21- --
9 Coseka Resources--- Federal No. 7-15-15-21- --
10 Coseka Resources--- Federal No. 6-14-15-21---- --
ql) Coseka Resources--- Federal No. 5-13-15-21-: --
12 USGS--------------- USGS WR-3 (No. U96)------- 160

lyumbers in parentheses are keyed to USGS data-bank file.

A A’
FEET an USGS WR-i Top USGS WR-2 —_- FEET METERS
4 <i , Tap 7000 2134
7000 = e .
SP + m Willow Creek m m
6000 —- Tad f- 6000 1829
Tgd Tgd
5000 — 5000 1524
Tw Tw Tw |
Bott f i
4000 omniot ‘section 4000 1220

Surficial deposits not shown on cross section

No vertical exaggeration

PRELIMINARY GEOLOGIC MAP OF THE WOLF POINT QUADRANGLE, UINTAH COUNTY, UTAH

By

Richard W. Scott, Jr, and Michael P. Pantea

1986

INTERIOR—GEOLOGICAL SURVEY, RESTON, VIRGINIA— 1986

For sale by Branch of Distribution, U.S. Geological Survey,
Box 25286, Federal Center, Denver, CO 80225