Plate 1. Detailed west to east structural cross section across the Piceance Basin

Core hole and identifier

Cross section

108° 30' 108°

0 12 18 MILES

0 6 12 18 KILOMETERS

6

0 1 3 4 5 6 7 8 9 10 MILES

0

2

EXPLANATION

COLORADO

40°

39° 30'

White River

White River

Meeker

Rangely

Rifle

Rio Blanco

DeBeque

Parachute

Colorado River

Creek

Creek

GARFIELD

GARFIELD

RIO BLANCO

MESA

Roan

Parachute

Creek

Piceance

C0183

C0466

INDEX MAP

R 103 W R 102 W R 101 W R 100 W R 99 W R 98 W R 97 W R 96 W R 95 W R 94 W R 93 W

T 8 S

T 7 S

T 6 S

T 5 S

T 4 S

T 3 S

T 2 S

T 1 S

T 1 N

T 2 N

Rich oil shale zones—Carbonate rich 

EXPLANATION

Oil yield—In gallons per ton

Volcaniclastic rocks 

Contact— Dashed where location approximate

Mostly lean oil shale with some volcaniclastic

material

Lithology

Fish bones or fish scales

Limestone

Pelcypod

Climbing ripples

Symmetrical ripples

Horizontal stratification

Irregular stratification

Contorted stratification

Claystone, clayshale

or mudstone

Siltstone

Sandstone

Large-scale lateral

accretion

10

11

12

Mainly climbing ripples

Buff to white

Light gray/green

Medium gray/green

Maroon

Dark gray/green

Black

Purple

Pebbles and cobbles

Coarse sand

Medium sand

Fine sand

Very-fine sand

Silt

Clay

Covered

 Irregular

scour surface

 Pinches out

along outcrop Thins along outcrop

Partially covered

Unweathered color Lithology Grain-size range Internal characteristics

Measured section

Lithologies above Mahogany zone

Core hole identifier and location

Description of saline interval

Hundreds

of feet

Calcareous or dolomitic 

rock

Ostracodes

Gastropods

Oolites

Thin beds of dolomite Oncolites

Cross-stratification, 1 to 3 ft high

Cross-stratification, greater than 3 ft high

Indistinct laminae

Evidence for leaching of 

nahcolite and halite

Marlstone and oil shale

(Above Mahogany zone only)

Sandstone and siltstone

(Above Mahogany zone only)

Lean oil shale zones—Carbonate rich 

Saline mineral interval

Core hole

Saline minerals present

VERTICAL EXAGGERATION ×45

Rich oil shale zones—Clay rich 

Lean oil shale zones—Clay rich 

Mahogany bed

Mahogany bed

Nahcolite

Halite

C0306

Carter Oil Co.

Upper Willow 2 & 2A

1,900’ FEL. 700’ FNL

sec. 27, T. 3 S., R. 97 W.

GL 6,690’

300

600

500

0

100

200

800

900

Oil yield, in

gallons per ton

0 20 40 60 80

Total depth in feet

400

700

Oil shale

Area underlain by the Mahogany bed

Boundary of area underlain by the

 Mahogany bed

139

139

64

13

13

64

A A ́

70

1 2 3 4 5 6 7 8 9 10 KILOMETERS

Saline minerals leached

Saline minerals leached boundary

WEST

EAST

Development, Evolution, and Destruction of the Saline Mineral Area of Eocene Lake Uinta, Piceance Basin, Western Colorado

By

Ronald C. Johnson and Michael E. Brownfield

2015

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not

imply endorsement by the U.S. Government 

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary

between electronic plotters and between X and Y directions on the same plotter, and paper may change

size due to atmospheric conditions; therefore, scale and proportions may not be true on plots of this map. 

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225,

1–888–ASK–USGS 

Digital files available at http://dx.doi.org/10.3133/sir20135176/

Suggested citation: Johnson, R.C., and Brownfield, M.E., 2015, Development, evolution, and destruction

of the saline mineral area of Eocene Lake Uinta, Piceance Basin, western Colorado: U.S. Geological

Survey Scientific Investigations Report 2013–5176, 76 p., 2 pl., http://dx.doi.org/10.3133/sir20135176 

.

ISSN 2328-0328 (online)

http://dx.doi.org/10.3133/sir20135176

U.S. Department of the Interior

U.S. Geological Survey Scientific Investigations Report 2013–5176

Plate 1 of 2

Marlstone at Duck Creek 

Marlstone at Duck Creek 

Black Sulfur Tongue of Green River Formation

Alluvium

Alluvium?

C0291

U.S. Geological Survey

CR–2 (WRD TH75–17B)

sec. 36, T. 1 N., R. 97 W.

GL 6,100

C0329

Carter Oil Co.

Opportunity 2

sec. 28, T. 1 N., R. 96 W.

GL 7,080

C0330

Carter Oil Co.

Square S No. 1

45 ft FEL, 2,625 FSL

sec. 21, T. 1 S., R. 97 W.

GL 6,160

C0533

Exxon Co.

Cole Gulch 1A

300 ft fwl, 350 ft fsl

sec. 11, T. 1 S., R. 97 W.

KB 6,000

C0007

Pan American Oil Co.

Saterdal 1

sec. 31, T. 1 S., R. 97 W.

GL 6,460

C0299

U.S. Bureau of Mines

CH 02–A

sec. 29, T. 1 S., R. 97 W.

GL 6,224

C0331

U.S. Bureau of Mines

CH 01

2,233’ FEL, 63’ FSL

sec. 31, T. 1 S., R. 97 W.

GL 6,254

A-Groove

B Groove Mahogany zone

L–1

R–2

L–2

R–3

L–5

R–6

R–1

L–0

R–0

R–5

L–4

R–4

L–3

900

1,000

1,200

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,500

2,600

2,800

2,900

3,000

500

800

900

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,400

2,500

2,600

2,700

400

600

500

700

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,200

2,300

600

500

700

800

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,500

600

500

700

800

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,500

0

100

200

300

400

600

500

700

800

900

1,100

1,000

1,600

1,700

1,800

1,900

2,000

Parachute Creek Member Garden Gulch Member 

Green River Formation (part)

0

100

200

300

400

600

500

0

100

200

300

400

+200

+100

600

500

700

0

100

200

300

400

+100

+400

+300

+200

C0177

Shell Oil Co.

22X–1

2,610‘ FEL, 2,260’ FNL

sec. 1, T. 2 S., R. 98 W.

GL 6,414 

0

100

200

300

400

0

100

200

300

+300

+200

+100

400

+300

+200

+400

+500

+100

Uinta Formation

Yellow Creek

Member

C0179A

Shell Oil Co.

23X–2

1,580’ FWL, 2,325’ FSL

sec. 2, T. 2 S., R. 98 W.

GL 6,520

C0012

Pan American Oil Co.

Peterson 1

sec. 04, T. 2 S., R. 98 W.

GL 6,710 C0005

Juhan–Joe T.

Juhan 4–1

sec. 4, T. 2 S., R. 98 W.

GL 6,661

C0174

Humble Oil & Refining Co.

Ryan Ridge 1

sec. 3, T. 2 S., R. 98 W.

GL 6,691

C0272

Rio Blanco Oil Shale Co.

C–14

810 ft FWL, 3,800 FSL

sec. 10, T. 2 S., R. 99 W.

GL 7,081

C0239

Amoco Production Co.

CH–4

1,734 ft FEL, 1,837 ft FNL

sec. 10, T. 2 S., R. 99 W.

GL 7,135

C0199

Occidental Petroleum Co.

 Stake Springs Draw 1

1,650’ FEL, 600’ FNL

sec. 12, T. 2 S., R. 99 W.

GL 6,570

A Groove

B Groove

500

700

800

1,100

1,000

1,200

1,400

1,800

1,900

2,000

200

300

600

700

800

1,100

1,000

2,000

0

100

200

400

500

800

900

1,000

1,300

1,600

1,800

2,000

800

1,000

1,200

1,300

1,600

1,700

1,800

1,900

2,000

2,100

2,300

2,500

1,100

1,000

1,400

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,500

2,700

2,900

3,000

1,100

1,000

1,200

1,300

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,500

2,600

2,900

3,000

3,100

3,200

800

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,600

2,700

2,800

2,900

3,000

800

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,300

2,400

2,500

2,600

2,700

2,800

800

900

1,100

1,000

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

2,400

2,500

0

100

200

300

+100

400

600

700

900

100

200

400

600

500

700

800

900

300

300

400

600

500

700

0

100

200

300

0

100

0

100

0

100

100

200

0

100

200

300

400

600

500

+200

+100

700

100

200

400

0

100

200

300

+400

+300

+100

0

1,500

Parachute Creek Member (part) Garden Gulch Member 

Green River Formation (part)

C0466

Shell Oil Co.

Dillon Pipeline Section

sec. 34, T. 2 S., R. 100 W.

C0509

Phillips Petroleum Co.

P–06

1,151 ft FEL, 2,511 ft FSL

sec. 16, T. 2 S., R. 100 W.

GL 8,552

C0310

Shell Oil (Ertl claims)

42X–10

sec. 10, T. 2 S., R. 100 W.

GL 8,241

C0515

Phillips Petroleum Co.

P–15

669 ft FWL, 1,618 ft FNL

sec. 13, T. 2 S., R. 100 W.

GL 7,853

C0516

Phillips Petroleum Co.

P–16

1,617 ft FWL, 1,139 ft FSL

sec. 07, T. 2 S., R. 99 W.

GL 7,555

C0309

Shell Oil (Ertl claims)

32–7

sec. 7, T. 2 S., R. 99 W.

GL 7,428

100

200

500

700

800

900

1,000

0

100

400

600

500

1,100

1,000

1,200

1,300

1,400

100

200

400

700

1,300

1,400

1,500

1,600

1,800

300

700

800

1,000

1,500

1,600

1,800

2,000

500

800

900

1,100

1,700

1,900

2,100

300

400

600

700

800

900

1,100

1,000

1,200

1,300

1,400

1,600

1,800

1,900

2,000

100

200

300

400

+400

+300

+200

+100

600

700

800

1,100

1,300

1,400

1,500

900

1,600

1,800

A-Groove

B-Groove Mahogany ledge

L–1

R–2

L–2

R–3

L–3

R–4

L–4

R–5

L–5

R–6

R–1

L–0

R–0

Tommy’s Draw

secs. 2, 3, 4, 10, 11, T. 3 S., R. 100 W.

100

200

300

400

600

500

700

800

C0213

Cameron Engineers

CE-708

975 ft FEL, 1,250 ft FNL

sec. 5, T. 2 S., R. 99 W.

Gl 6,918

Marlstone at Mare Canyon of Green River Formation

Dry Fork Tongue of Green River Formation 

Wasatch

Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Uinta Formation

Yellow Creek Tongue of Green River Formation

unnamed tongue of Green River Formation

Thirteenmile Creek Tongue

of Green River Formation

Thirteenmile Creek Tongue

 of Green River Formation

Dry Fork Tongue of Green River Formation

Yellow Creek Tongue of Green River Formation

17

16

15

14

13

12

11

10

19

20

?

?

some thin s.s. beds

sharp base and top

sharp base

abundant shells

Dolomitic, slightly fissile

Grad. contacts, fissile

Dolomitic, fissile

Dolomitic, sli. fissile Dolomitic, sli. ssile

Laminae not well developed

Dolomitic, mod. fissile

Some dol. beds, fissile

fissile

fissile

Dolomitic, fissile

Mostly indistinct laminae

All symetrical ripples

Sltst., l.s., Dolomitic

Dolomitic bed w/ ost.

Dolomitic, some thin oil sh beds

A few dolomitic beds

thin dolomitic beds

laminated oil sh. ripups

Small dolomitic ripups

ripups, nahcolite vug

gradational base

Nahcolite vugs

22

?

?

0

fissile

fissile

fissile

fissile

fissile

non-fissile

fissile

fissile

fissile

fissile

very fissile

9

18

21

23

2.0 MILES

3.05 MILES

Fissile, some thin ostracode beds

ost. l.s. beds are from 1”-10” thick

interlayed kerogen rich and kerogen poor shale

2.5” thk. poss. tuff 2.5’ from top. 4” thk ost. l.s. just below poss. tuff

Dolomitic, fissile

Dolomitic, fissile

Dolomitic

Dolomitic

Dolomitic

Dolomitic

Dolomitic

Dolomitic

Dolomitic

Dolomitic ripups

ripups

ripups

ripups

Dolomitic

Dolomitic, convolute upper surface. pass. algal

Dolomitic, star- shaped fractures to 1” diameter on bedding surface

Dolomitic, star- shaped fractures on bedding surface

Dolomitic, fissile

Dolomitic ripups

Discont. dolomitic beds

Dolomitic ripups

Dolomitic

Some lean oil sh. zones

Dolomitic ripups

Rich beds have irreg. lam. and dol. ripups. leaner beds are well laminated

Rich oil shale beds have sharp base and grade up to lean oil sh.

Brecciated dolomitic bed

ripups

laminated oil sh. ripups

2” thk. tuff, even tkness

2” thk. tuff, even tkness

Some very lean oil shale

2” thk. tuff, irreg. tkness

ripups, soft sediment thrust fault

3” thk. tuff, even tkness

ripups

6” thk. tuff, irreg tkness

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

20 40 60 80

Oil yield, in

gallons per ton

Oil yield, in

gallons per ton

20 40 60 80

0 20 40 60 80 100

FEET FEET

8,800

8,700

8,600

8,500

8,400

8,300

8,200

8,100

8,000

7,900

7,800

7,700

7,600

7,500

7,400

7,300

7,200

7,100

7,000

6,900

6,800

6,700

6,600

6,500

6,400

6,300

6,200

6,100

6,000

5,900

5,800

5,700

5,600

5,500

5,400

5,300

5,200

5,100

5,000

4,900

4,800

4,700

4,600

4,000

3,900

3,800

3,700

3,600

4,500

4,400

4,300

4,200

4,100

3,500

3,400

8,800

8,700

8,600

8,500

8,400

8,300

8,200

8,100

8,000

7,900

7,800

7,700

7,600

7,500

7,400

7,300

7,200

7,100

7,000

6,900

6,800

6,700

6,600

6,500

6,400

6,300

6,200

6,100

6,000

5,900

5,800

5,700

5,600

5,500

5,400

5,300

5,200

5,100

5,000

4,900

4,800

4,700

4,600

4,000

3,900

3,800

3,700

3,600

4,500

4,400

4,300

4,200

4,100

3,500

3,400

WEST

EAST

Vertical coordinate information is referenced to sea level

shells scattered throughout

slightly fissile

very fissile, droopy ledge

600

400

300

0

Total depth 1,700 feet

Elevation 8,250 feet

Total depth 1,763 feet

Total depth 1,764 feet

Total depth 2,106 feet

Total depth 1,908 feet

Total depth 1,345 feet

Total depth 1,794 feet

Total depth 1,990feet

Total depth 1,597 feet

Total depth 2,738 feet

Total depth 2,621 feet

Total depth 3,232 feet

Total depth 2,699 feet

Total depth 2,660 feet

Total depth 2,745 feet

Total depth 2,369 feet

Total depth 2,665 feet

Total depth 2,300 feet

Total depth 2,358 feet

Total depth 2,395 feet

Total depth 1,963 feet

1.50 MILES

1.55 MILES

200

300

700

800

900

1,500

0

300

500

800

900

1,000

1,100

1,200

1,700

200

400

600

500

600

900

1,100

1,200

1,300

1,400

1,700

1,900

1.35 MILES

0.52 MILE

1.70 MILES

1.70 MILES 

0.83 MILE

300

600

700

1,000

1,200

1,300

1,400

1,500

1,600

1,800

2,000

200

500

1,500

1,700

0 100

Oil yield, in

gallons per ton

500

900

1,000

1,200

0 4020 60 80 100

400

500

1,200

1,300

1,400

1,500

1,700

1,900

No vugs or breccias

400

600

900

1,300

1,500

1,600

1,700

1.71 MILES 

0 100

300

600

700

1,100

1,200

1,400

1,500

1,700

1,900

2.38 MILES 

0

900

1,100

1,400

1,500

2,400

2,600

0.78 MILE

0

1,200

1,300

1,500

1,600

2,400

2,600

2,800

0.98 MILE

0

900

1,400

2,700

2,800

0.83 MILE

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

20 40 60 80

Oil yield, in

gallons per ton

0 100

+200

500

2,500

1.04 MILES

1.19 MILES

+300

0.41 MILE

2,300

700

800

1,100

1,300

2,700

1.14 MILE

+500

600

700

1,100

2,300

2.07 MILE

?

+200

800

2,400

2,500

1.91 MILE

3.36 MILE

3.11 MILE

Green River

Formation (part)

2,200

2,100

1,500

1,400

1,300

1,200

+100

C0310

C0516

C0213

C0272

C0239

C0012

C0005

Tommy’s Draw

C0331

C0174

C0007

C0299

C0330

C0533

C0329

C0291

C0177

C0179

C0199

C0309

C0515

C0466

C0509