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://pubs.usgs.gov/sir/2012/5041/

Suggested citation: Johnson, R.C., 2012, The systematic geologic mapping program and a 

quadrangle-by-quadrangle analysis of time-stratigraphic relations within oil shale-bearing rocks of the 

Piceance Basin, western Colorado: U.S. Geological Survey Scientific Investigations Report 2012–5041, 

28 p., 2 pls., CD-ROM, also available at http://pubs.usgs.gov/sir/2012/5041/.

Tu

Tw

Tws

Tgp

Tgd Tgu

Tgds Tga

Tgg

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2012–5041

Plate 1

Illitic phase of Lake Uinta

Carbonate phase of Lake Uinta

Infilling phase of Lake Uinta

EXPLANATION 

Depositional phases 

Eocene stratigraphic units

?Tuh

Evacuation Creek Member (Tge)

Tgp

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgg

Tgg

c c

48.8 Ma

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zone R-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Pizolite ledge (pz) Pizolite ledge (pz)

Lower ostracodal limestone (lo) Lower ostracodal limestone (lo)

Tgpu

Tgp

Tgp

Tgp

Tgp

Yellow tuff bed (yt) Yellow tuff bed (yt)

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone

Mahogany zone

R-6 zone

R-6 zone

L-5 zone

L-5 zone

R-5 zone

R-5 zone

L-4 zone

L-4 zone

R-4 zone

R-4 zone

L-3 zone L-3 zoneR-3 zone

R-3 zone

L-2 zone L-2 zoneR-2 zone

R-2 zone

L-1 zone L-1 zone R-1 zone

R-1 zone

R-0 zone

R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-grooveBed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-grooveBed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Mahogany ledge (M) Mahogany ledge (M)

B-groove (B) B-groove (B)

Mahogany ledge (ml)

Blue marker (b)

Orange marker (o)

Top of Mahogany ledge (m)

Top of Mahogany ledge (m) Top of Mahogany ledge (m)

Tua

Tub

Tuc

Tud

Mahogany ledge (ml) Mahogany ledge (ml) Mahogany ledge (ml)

Tu

Tu

Tu

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tud

Tuf

 Mahogany ledge (ml) Mahogany ledge (ml) Mahogany ledge (ml)

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove base of main oil shale zone (m) Bed 44-Bed 66 A-groove-Bed 44 Mahogany Zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove Base of main oil shale zone (m)

Top of Mahogany oil-shale zone (M) Top of Mahogany ledge (m) Top of Mahogany ledge (m)

Base of yellow-orange

weathering tuffaceous

 sequence (t)

0 20 40 60 80 100

C0012

Pan American Oil Co.

Peterson 1

Sec 04, T02S, R098W

500

1,000

1,500

2,000

2,500

3,000

0 20 40 60 80 100

C0037

U.S. Bureau Land Management

Triangulation Station, 

Sec 24, T07S, R097W

500

1,000

0

Oil yield in gallons per ton

Oil yield in gallons per ton

Garden Gulch Member 

Tu

Marlstone at Barnes Ridge

and Stewart Gulch (Tgbs)

Dimpled algal zone (DA)

L2 zone (L2)

Tgg

Tgd

Tgd

Tgd Tgd Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Evacuation Creek Member (Tge) Evacuation Creek Member (Tge)

Tge Tge

Tgp

Tgp

Tgp

Tu

Tuff bed at Kimball 

Mountain (km)

Tuff bed at Kimball 

Mountain (km)

Tuff bed at Kimball 

Mountain (km)

 Kimball Mountain 

Tuff Bed (km)

 Kimball Mountain 

Tuff Bed (km) Tuff bed at Kimball 

Mountain (km)

Long Point Bed (lp)

Tue

Tud

Tuc

Tu6

Tu6 Tu6

Tu5 Tu5 Tu5

Tu4 Tu4

Anvil Points Member unit 3 (Tga3)

Anvil Points Member unit 2 (Tga2) Anvil Points Member unit 2 (Tga2)

Anvil Points Member unit 1 (Tga1) Anvil Points Member unit 1 (Tga1) Tgg Tgg

Tgg Tgg

Tgg Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp Tgp

Tgpu

Tgpu

Tu

Tgp

Tgp

Top of 

Mahogany ledge (ml)

Top of 

Mahogany ledge (ml)

Tongue of Parachute

Creek Member (Tgpa)

Tongue of Parachute

Creek Member (Tgpt)

Tongue of Evacuation

Creek Member (Tgea)

Tg2

Tg3

Tg1

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgm

Tgtc

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsk

Tgt

Tgd

Tgy Tgy

Tgm

Tgtc Tgtc Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt Tgt Tgt Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd Tgd Tgd

Tgy Tgy Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Dessicated concretion zone (c)

Tga

Anvil Points Member lower part (Tgal) Anvil Points Member lower part (Tgal)

Tgg

Tgg

Tgg

Tgg

Tgg

Anvil Points Member upper part (Tgau) Anvil Points Member 

upper part (Tgau)

Second algal zone (2A)

P-ledge (P)

F-ledge (F)

First algal zone (1A) First algal zone (1A)

Garvey Canyon

(R.C. Johnson, unpublished mapping)

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgl

Tgl

Tgl

Tgl

Tgl

Tgl

Tgl

Lower unit (Tgl)

Upper unit (Tgu)

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Lower ostracode limestone (lo)

L1zone (L1) L1zone (L1)

High algal zone (HA)

Tucb

Tu1 Tua Tua Tu2

Tu6

Tu3 Tu4

Tu5

Tu7

Tud

Tue

Unnamed Tongue A(Tgua)

Tub

Tuc

Tuf

Tug

Tu (note: some Green River Formation

tongues present but not mapped)

Tgt

Tgm Tgm

Tgtc

Tgua

Tub Tuc

Tud

Garden Gulch Member

upper part (Tggu)

Garden Gulch Member

lower part (Tggl)

Intertonguing Uinta and Green

River Formations (Tiug)

?

? ?

?

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

?

?

?

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgt Tgt

Tgd Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb Tgb Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd Tgd Tgd

Tgy Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb Tgb Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb Tgb

Tgb (only top is mapped)

Tgc 5 (Tgc)

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt Tgt Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgb

Tgc

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgc

Tgc

Tgs Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc Tgc

Tgs Tgs Tgs

Tgb Tgbr Tgb

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgc

Tgs Tgs

Tgb Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc Tgc

Tgs Tgs

Tgbr

Tgsl, Tgj

Tgsk Tgsk Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Tgsk

Tu2 Tu2

Tu1 Tu3

Tu3 Tu3

Tu1 Tu2

Marlstone at Duck Creek (Tgdc) Marlstone at Duck Creek (Tgdc) 

Uinta Fm. channel ss.(Tuc)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp

Mahogany oil-shale bed (m) Mahogany bed (m) Mahogany bed (m)

Tu5 Tu5

Tu6 Tu6

Tgu

Tgu

Tu4 Tu4

? Tu1

Tu5

Tu6

Tgu

Tgp

Uinta Fm. units 6 and 5

undivided (Tuu)

Upper marker bed (Tuh)

(Note: only bases of Tgd, Tgt, Tgb, and Tuh

are mapped on MF-570)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgj

Tu

Tu

Tuh

Tu

Tu

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgj Tgj

Tgj Tgj

Tu

Tu Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tga Tga Tga

Tga Tga

Tga Tga

Tga Tga

Tga Tga

Tga Tga

Tga Tga

Tga

Tga

Tga

Tga

Tga

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp

Tgp

Tgp

Tgp

Tgp

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

(Note: only top of Black Sulphur and 

Coughs Creek Tongues are mapped)

Marlstone at Bull Fork Marker bed at Bull Fork

Tub

Tua

Tus

Tua

Tua

Tub

Tub

Tuc

Tud

Tgs

Tgc

Tgj

Tgp Tua Tua

Tub Tub

Tuc Tuc

Tud

Tgsl

Tuff bed at Kimball Mountain (km)

Sandstone bed

at Long Point (lp)

Sandstone bed

at Long Point (lp)

Marker bed

at Long Point (lp)

Marker bed

at Long Point (lp)

Long Point Bed (lp)

Tgg

Tgg Tgg Tgg

Tgg Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgg Tgg

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Mahogany oil-shale bed (mb) Mahogany bed (m) Mahogany oil-shale bed (m)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgpl

Tgpl

Parachute Creek

Member lower

part (Tgpl)

Tgpl

Tgpl

Tgpm Tgpm

Tgpm

Tgpm Tgpm

Tgpm 

Parachute Creek Member

Parachute Creek Member middle part (Tgpm)

middle part (Tgpm)

Tgpm Tgpm

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgsl

Tgss

Tue

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd Tgd Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Channel sandstone (c)

Tu Tu Tu Tu Tu

Parachute Creek Member, 

upper part (Tgpu) Parachute Creek Member, 

upper part (Tgpu)

Tgds

Tgds Tgds

Tgds

Tgdm

Tgdm

Tgd Tgd

Tgd Tgd

Tgd Tgd

Tgd Tgd

Stillwater oil-shale zone (s)

Tu

Tu

Tu

Tu Tu

Tgp

Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgdu

Tgdm

Tgdm

Tgdm

Tgdm

Tgdm

Tgdm

Tgdl

Tgdl

Tgp

Tgp

Tgsl, Tgj

Douglas Creek Member upper part (Tgdu) Douglas Creek Member upper part (Tgdu)

Douglas Creek Member middle part (Tgdm) Douglas Creek Member middle part (Tgdm)

Douglas Creek Member lower part (Tgdl) Douglas Creek Member lower part (Tgdl)

Tgdu

Tgdm

Tgdm

Tgdm

Tgdm

Tgdm

Tgdm

Tgdl

Tgdl

Tgu

Tgu

Tgu

Tgu Tgu

Tgu Tgu

Tgu Tgu

Tgu

Tgu Tgu

Tgu Tgu

Tgu Tgu

Tgu

Tgu

Evacuation Creek Member (Tge)

Evacuation Creek Member (Tge)

Tgp

Tgp

Tgp Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgu

Tgu

Tgu

Tgu

Tgu

Tgg

Tgg

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgu

Tgu

Tgu

Tgu

Tgu

Tgg

Tgg

Mahogany oil-shale ledge (ml)

Mahogany oil-shale bed (m) Mahogany-oil shale bed (m) Mahogany oil-shale bed (mb) Mahogany oil-shale bed (mb)

(Note: only top of Black Sulphur Tongue

is mapped)

(Note: only top of Black Sulphur Tongue

is mapped)

Mahogany bed (mb)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp

Tgp

Mahogany bed (m) Mahogany bed (m)

Tu Tu Tu

 

Tw

 Tws

 Tws

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tga Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga Tga

Tga

Tgp

Tgp

Tgp

Mahogany oil-shale bed Mahogany oil-shale bed

Mahogany oil-shale bed

Mahogany oil-shale bed

Tgp

Tu Tu

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgp

Tgp

Tgp

Tgp

Tu

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgdm Tgdm

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

lp

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

 Base of Mahogany oil-shale bed (m)

Tu

Tgi

Tgi

Intertonguing

unit (Tgi)

Tgi

Tgi

Evacuation Creek Member (Tge)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgg

Tgd

Evacuation Creek Member (Tge)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Mahogany oil-shale bed (m)

Douglas Creek Member

upper part (Tgdu)

Douglas Creek Member

middle part (Tgdm) Douglas Creek Member

middle part (Tgdm)

Douglas Creek Member upper part (Tgdu)

Douglas Creek Member upper part (Tgdu)

Douglas Creek 

Member upper 

part (Tgdu)

Tua

Tua

Tua

Tua

Garden Gulch Mbr. of Bradley (1931)

Douglas Creek Member of Bradley (1931), modified by Johnson (1984)

Parachute Creek Member of Bradley (1931)

Type section Anvil Points Member (Donnell, 1953, 1961)

Tuc

?

Tg4

Mahogany bed (mb)

Tub

Tuffaceous bed (a)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek

Marlstone at Trail Canyon

Marlstone at Calamity Ridge

Top Bed 44

Black Sulfur

Coughs Creek

Marlstone at Mare Canyon

Yellow Creek Tongue

Dry Fork Tongue

Stuart Gulch Tongue

Marlstone at Barnes Ridge

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge

Tgt

Tgd

Tgy

Tgm

Tgtc

Tggc

Tgcr

Tgb

Tgc

Tgs

Tgbr

Tgsl, Tgj

Marlstone at Skinner Ridge Tgsk

Thirteenmile Creek Tongue

Basal sandstone Basal sandstone member (Tgb)

member (Tgb)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top Bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Marlstone at Greasewood Creek (Tggc)

Marlstone at Trail Canyon (Tgtc)

Marlstone at Calamity Ridge (Tgcr)

Top bed 44

Black Sulphur Tongue (Tgb)

Coughs Creek Tongue (Tgc)

Marlstone at Mare Canyon (Tgm)

Yellow Creek Tongue (Tgy)

Dry Fork Tongue (Tgd)

Stuart Gulch Tongue (Tgs)

Marlstone at Barnes Ridge (Tgbr)

Marlstone at Sleepy Ridge, Marlstone at Jackrabbit Ridge (Tgsl, Tgj)

Marlstone at Skinner Ridge (Tgsk)

Thirteenmile Creek Tongue (Tgt)

Tongue of Uinta

Foramtion (Tut)

Tgal Tgal

Tgal Tgal

Unnamed Tongue B

(Tgub)

Unnamed Tongue 

C (Tguc)

Rich unit no. 8 (R-8)

Thirteenmile Creek Tongue lower part (Tgtl) Thirteenmile Creek Tongue upper part (Tgtu) Thirteenmile Creek Tongue upper part (Tgtu)

Thirteenmile Creek Tongue 

upper part (Tgtu)

Thirteenmile Creek 

Tongue equivalent (Tgte)

Base of orange-yellow

tuffaceous unit (t)

Mahogany oil shale ledge (M)

Mahogany oil-shale ledge (m)

Long Point Bed (lp) Long Point Bed (lp)

Long Point Bed (lp) Long Point Bed (lp)

Mahogany oil-shale bed (mb) Mahogany oil-shale bed (mb) Mahogany oil-shale bed (mb) Mahogany oil-shale bed (mb)

Unnamed unit (Tgu)

Unnamed unit (Tgu)

 Tws Tws Tws

 Tws Tws

Mahogany oil-shale bed

Long Point Bed (lp)

Long Point Bed (lp)

Kimball Mountain

tuff bed (km)

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Green River Formation

unnamed tongue (Tgu)

Green River Formation 

unnamed unit (Tgu)

Green River Formation 

unnamed unit (Tgu)

Marker bed

at Long Point (lp)

Base of tuffaceous 

beds (t)

m

Anvil Points Member of Green River Formation (Tga), 

 Douglas Creek Member of Green River Formation, sandy part (Tgds)

Douglas Creek Member of Green River Formation (Tgd), 

 unnamed member of Green River Formation (Tgu)

Parachute Creek Member, also used for tongues of Green River

 Formation intertonguing with the Uinta Formation

Uinta Formation

Wasatch Formation

Shire Member

Green River Formation

Collbran, MF-1825

(Donnell and others,1985)

Molina, MF-1784

(Donnell and others, 1985)

Mesa, MF-1698

(Donnell and others, 1984)

Corcoran Peak

(R.C. Johnson, unpublished mapping)

Winter Flats, MF-1777

(Johnson, 1985b)

Wagon Track Ridge, MF-1182

(Johnson and Douglas, 1980)

DeBeque, MF-2201

(Donnell and others,1992b)

Housetop Mountain, MF-1965

(Donnell and others,1987)

Hawkhurst Creek, MF-2026

(Donnell and others,1988)

South Mamm Peak, MF-2113

(Donnell and others, 1990)

Rulison, MF-2060

(Yeend and others, 1988)

North Mamm Peak, MF-2093

(Donnell and others,1989)

Grand Valley, MF-1883

(Donnell and others,1986)

Red Pinnacle, MF-2202

(Donnell and others, 1992a)

Long Point, MF-688

(Johnson, 1975)

The Saddle, MF-829

(Johnson, 1977a)

Middle Dry Fork, MF-1215

(Johnson, 1980)

Douglas Pass, MF-1772

(Nuccio, 1985)

Calf Canyon, GQ-1086

(Roehler, 1973a) Henderson Ridge, GQ-1113

(Roehler, 1973b)

Desert Gulch, MF-1328

(Johnson, 1981b)

Mount Blaine, MF-984

(Hail, 1978) Circle Dot Gulch, MF-1293

(Hail, 1982)

Forked Gulch, MF-1953

(O’Sullivan and Hail, 1987)

Anvil Points, MF-1882

(O’Sullivan,1986)

Baxter Pass, MF-1813

(Johnson, 1985c)

Rio Blanco, MF-1816

(O’Sullivan, 1985)

McCarthy Gulch, MF-860

(O’Sullivan and others, 1981)

Cutoff Gulch, MF-691

(Hail, 1975)

Bull Fork, MF-830

(Hail, 1977)

Figure Four Spring, MF-912

Razorback Ridge, GQ-1019 (Johnson, 1977b)

(Roehler, 1972b)

Brushy Point, GQ-1018

(Roehler,1972a)

East Evacuation Creek, MF-2220

(Pantea, 1993) 

Davis Canyon, MF-1933

(Pantea, 1987)

Thirteenmile Creek, MF-1789

(O’Sullivan and Smith,1985)

No Name Ridge, MF-1989

(O’Sullivan,1987)

Black Cabbin Gulch, GQ-812

(Cashion, 1969)

Yankee Gulch, MF-758

(Duncan, 1976c)

Jessup Gulch, MF-756

Texas Mountain, MF-2321 (Duncan1976e)

(Barnum and others,1997)

Texas Creek, MF-2134

(Scott and Pantea,1990)

Rock School, MF-757

(Duncan, 1976a) Dragon, MF-1777

(Scott and Pantea,1985)

Segar Mountain, MF-570

(O’Sullivan, 1974) Square S Ranch, MF-754

(Duncan, 1976b)

Greasewood Gulch MF-755

(Duncan, 1976d)

Wolf Ridge, MF-753

(Duncan,1976f)

Sagebrush Hill, MF-1398

(Donnell, 1982)

Philadelphia Creek, MF-2216

(Johnson and Smith,1993)

Banta Ridge, MF-2308

(Pantea and Schmitt,1996)

Weaver Ridge, MF-824

(Cashion, 1977)

Rough Gulch, GQ-1195

(Hail, 1974a)

Smizer Gulch, GQ-1131

(Hail, 1973)

Indian Valley, MF-836

(Pipiringos and Rosenlund, 1977a)

White Rock, MF-837

(Pipiringos and Rosenlund, 1977b)

Divide Creek, MF-2232

(Hail and Barnum,1993)

Mellon Hill, GQ-835

(Cullins, 1969)

Citadel Plateau I-1532

(Izett and others, 1985)

(A) Time–Stratigraphic and (B) Thickness–Stratigraphic Columns for Oil Shale Area of Piceance and Easternmost Part of Uinta Basins, Western Colorado

By

Ronald C. Johnson

2012

Parachute Creek

Member lower part (Tgpl) Parachute Creek

Member lower part (Tgpl)

Parachute Creek

Member upper part (Tgpu)

Parachute Creek

Member upper part (Tgpu)

Depth in feet

Depth in feet

200 ft thick

Tge

Tgp

Tongue of Evacuation Creek

Member (Tgea)

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

R-6 zone L-5 zone R-5 zone R-4 zone

L-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone

L-5 zone R-5 zone

L-4 zone L-4 zone

L-4 zone

L-4 zone

L-4 zone

L-4 zone

L-4 zone

R-4 zone

R-4 zone

R-4 zone

L-3 zone

R-3 zone

R-3 zone R-3 zone

R-3 zone

R-3 zone

R-4 zone

R-4 zone

R-4 zone

R-5 zone

L-5 zone

L-2 zone

R-2 zone

R-2 zone

R-2 zone

R-3 zone

R-3 zone

R-3 zone

R-2 zone R-2 zone

R-2 zone

R-2 zone

R-2 zone

L-1 zone

L-1 zone

R-1 zone R-0 zone

L-0 zone

B-groove

R-6 zone L-5 zone R-5 zone

L-3 zone

L-3 zone

L-2 zone

L-0 zoneR-1 zone R-0 zone

L-0 zone

A-groove

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Mahogany zone R-6 zone L-5 zone R-5 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Mahogany zone R-6 zone L-5 zone R-5 zone

L-4 zone

L-4 zone L-4 zone

L-4 zone

L-4 zone

R-4 zone

R-4 zone R-4 zone

R-4 zone

R-4 zone

L-3 zone

L-3 zone

R-3 zone

R-3 zone

R-3 zone

R-3 zone

R-3 zone

L-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

B-groove

Mahogany zone R-6 zone L-5 zone R-5 zone

L-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

L-5 zone R-5 zone

L-3 zone

L-2 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

R-6 zone L-5 zone R-5 zone

L-3 zone

L-1 zone R-1 zone R-0 zone

L-0 zoneB-groove

R-6 zone

L-5 zone R-5 zone

L-4 zone

L-4 zone

L-4 zone

R-4 zone

R-4 zone

R-4 zone

L-3 zone

R-3 zone

R-3 zone

R-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

B-groove

R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zoneR-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone L-0 zone

A-groove

A-groove

A-groove

B-groove

Mahogany zone R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zone R-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

R-6 zone L-5 zone R-5 zone

L-4 zoneR-4 zone

L-3 zone

L-3 zone

R-3 zone

R-3 zone

L-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

R-6 zone R-5 zone

L-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

R-6 zone R-5 zone

R-4 zone

R-4 zone

L-3 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

R-6 zone L-5 zone R-5 zone

L-4 zone

L-4 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone R-3 zone

R-3 zone

L-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

A-groove

A-groove

B-groove

B-groove B-groove

B-groove

R-6 zone

L-5 zone

L-5 zone

L-5 zone

R-5 zone R-4 zone

L-3 zone R-3 zone

L-2 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone L-5 zone R-5 zone R-4 zone

L-3 zone

L-2 zoneR-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

A-groove-Bed 44 R-6 zone L-5 zone R-5 zone

L-4 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

A-groove-Bed 44 R-6 zone

R-5 zone

L-3 zone

L-2 zone

L-1 zone R-1 zone

R-0 zone

B-groove

A-groove-Bed 44 R-6 zone L-5 zone R-5 zone

L-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

B-groove

A-groove-Bed 44 R-6 zone

L-5 zone

L-5 zone

L-5 zone

R-5 zone

L-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone L-0 zone

L-0 zone

A-groove

A-groove

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone L-5 zone R-5 zone

R-4 zone

R-4 zone R-4 zone

R-4 zone

L-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone L-5 zone R-5 zone

L-4 zone

L-4 zone

L-4 zone L-4 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

R-3 zone

R-2 zone

R-3 zone

R-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone L-5 zone R-5 zone

L-4 zone R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

R-2 zone

R-3 zone

R-2 zone

R-2 zone R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Mahogany 

zoneR-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

R-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Mahogany

 zone

Mahogany

 zone

R-6 zone L-5 zone R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

A-groove-Bed 44

Mahogany 

zoneR-6 zone L-5 zone R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

A-groove-Bed 44

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

R-6 zone L-5 zone R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

R-6 zone L-5 zone R-5 zone L-4 zone R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

First algal zone (1A) pz, pizolite ledge

Lower ostracodal limestone (lo)

Lower ostracodal limestone (lo)

Yellow tuff (yt)

Yellow tuff (yt)

Parachute Creek

Member lower part (Tgpl)

Parachute Creek

Member lower part (Tgpl)

Parachute Creek

Member lower part (Tgpl)

Parachute Creek

Member upper part (Tgpu)

Parachute Creek

Member upper part (Tgpu)

Parachute Creek

Member upper part (Tgpu)

R-1 zone R-0 zone

L-0 zone

Bed 44-

Bed 76

A-grooveBed 44R-6 zone

L-5 zone

L-2 zone L-2 zone L-1 zone L-1 zone R-1 zone R-0 zone

A-groove

B-groove

Bed 44-

 Bed 76

A-grooveBed 44 R-6 zone

L-5 zone

R-5 zone

R-5 zone

L-1 zone

L-2 zone

L-4 zone

L-4 zone

L-3 zone

L-3 zone

R-3 zone

R-3 zone

R-3 zone

R-2 zone

R-2 zone

R-2 zone

R-4 zone

R-4 zone

R-1 zone R-0 zone

L-0 zone

L-0 zone

A-groove

B-groove

L-1 zoneR-1 zone R-0 zone

R-1 zone R-0 zone

L-0 zone

L-0 zone

L-3 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

Bed 44-Bed 76 A-groove-Bed 44 Mahogany zone R-6 zone L-5 zone R-5 zone R-1 zone R-0 zone

A-groove

B-groove

R-6 zone

L-5 zone

R-5 zone

L-2 zone

L-1 zone

L-1 zone L-1 zone R-1 zone R-0 zone

A-groove

B-groove

R-6 zone

L-5 zone

R-5 zone

L-4 zone L-4 zone

L-4 zone

L-4 zone

L-5 zone

R-4 zone R-4 zone

R-4 zone

R-4 zone

R-4 zone

R-4 zone

R-5 zone

L-2 zone

L-3 zone L-3 zone

R-2 zone R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-2 zone

R-3 zone R-3 zone R-3 zone

R-3 zone

R-3 zone

R-3 zone

L-3 zone

L-2 zone

L-2 zone

L-2 zone

L-3 zone

L-3 zone

R-1 zone R-0 zone

L-0 zone L-0 zone L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany Zone R-6 zone

L-3 zone

L-3 zone

R-2 zone

R-2 zone L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 R-6 zone

L-5 zone

L-5 zone

L-5 zone

R-5 zone

R-5 zone

R-5 zone

L-4 zone

L-4 zone

L-4 zone

R-4 zone

R-4 zone

R-4 zone

L-3 zone R-3 zone

R-3 zone

R-3 zone

L-2 zone

L-2 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany Zone R-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 76

Bed 44-Bed 76

Bed 44-Bed 76

Bed 44-Bed 76

A-groove-Bed 44

A-groove

-Bed 44

A-groove

-Bed 44

A-groove

-Bed 44

Mahogany

zone

Mahogany

zone

Mahogany

zone

Mahogany

zone

Mahogany

zone

R-6 zone L-5 zone R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 76 A-groove-Bed 44

Mahogany 

zoneR-6 zone L-5 zone R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 76 R-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 76

A-groove-Bed 44

Mahogany 

zone

Mahogany 

zone

R-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

L-5 zone R-5 zone

L-3 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

Bed 44-Bed 76 A-groove-Bed 44 R-6 zone

R-3 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

B-groove

R-6 zone L-5 zone R-5 zone

L-3 zone

L-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

B-groove

R-1 zone R-0 zone

L-0 zone

Bed 44-Bed 76

R-4 zone

R-4 zone

L-3 zone

L-3 zone

R-3 zone

R-3 zone

L-2 zone

L-2 zone

R-2 zone

R-2 zone

L-1 zoneR-1 zone

R-0 zone

L-0 zone

A-grooveBed 44 R-6 zone

L-5 zone

R-5 zone

L-4 zoneL-1 zone R-1 zone

L-0 zone

B-groove

A-groove

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove-Bed 44 R-6 zone

L-5 zone

R-5 zone

R-3 zone

L-2 zone

L-1 zone R-1 zone R-0 zone

L-0 zone

A-groove

B-grooveR-1 zone

L-0 zone

A-groove

Bed 44-Bed 66 R-6 zone

R-6 zone

L-3 zone R-3 zone

L-2 zone

L-2 zone

R-2 zone

R-2 zone

L-1 zone

L-1 zone

R-1 zone

R-0 zone R-0 zone

L-0 zone

A-groove

B-groove

B-groove

L-3 zone

L-2 zone

R-1 zone R-0 zone

L-0 zone

A-groove

B-groove

Bed 44-Bed 66 A-groove-Bed 44 Mahogany Zone R-6 zone L-5 zone R-5 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove

L2 zone (L2)

Dimpled algal zone (DA)

R-6 zone L-5 zone L-0 through R-5 R-0 zone B-groove

Mahogany ledge (M)

Mahogany ledge (M)

B-groove (B)

B-groove (B)

Blue marker (b)*

Orange marker (o)*

Tgte

Tgtu

Tgtu

Tgtu

Mahogany oil shale ledge (m)

Top Mahogany ledge (m)

Top of Mahogany oil-shale zone (M)

Top of Mahogany ledge (m)

Top of Mahogany ledge (m)

Top of Mahogany ledge (m)

Top of Mahogany ledge (m)

Mahogany ledge (ml)

Mahogany ledge (ml)

Mahogany ledge (ml)

Tu

Tu Tu

Tu

Tgp

Tgp

Tgp

Tgp

Tgp

Tud

Tuf

Mahogany ledge (ml)

Mahogany ledge (ml)

Mahogany ledge (ml)

R-6 zone Bed-44-Bed 76 A-groove-Bed 44 L-5 zone R-5 zone

L-3 zone

L-3 zone

L-2 zone

L-2 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

B-groove m, base of main oil shale zone Bed 44-Bed 66 A-groove-Bed 44

Mahogany 

zoneR-6 zone L-5 zone R-5 zone

L-3 zone

R-3 zone

R-2 zone

R-4 zone

L-4 zone

L-1 zoneR-1 zone R-0 zone

L-0 zone

A-groove

B-groove Base of main oil shale zone (m)

A-groove-Bed 44 R-6 zone

R-5 zone

R-5 zone

R-5 zone

L-3 zone

L-2 zone

L-1 zone R-1 zone

R-0 zone

B-groove

L-5 zone

L-5 zone

L-5 zone

L-0 zone

A-groove

R-4 zone

R-3 zone

R-4 zone

R-4 zone

L-4 zone

L-4 zone

L-4 zone

R-3 zone

L-3 zone R-3 zone

R-2 zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone Mahogany 

zone

Mahogany 

zone

Top Bed 44

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Mahogany 

zone

Tg1

Top of Mahogany

ledge (ml)

Top of Mahogany

ledge (ml)

L-2 zone

R-3 zone

A-groove

A-groove

Mahogany zone Mahogany zone

Mahogany

zone

Bed 44-

Bed 76

Bed 44-

Bed 76

Bed 44-

Bed 76

A-grooveBed 44

A-grooveBed 44

A-grooveBed 44

Mahogany zone

Mahogany zone

Thirteenmile Creek Tongue

upper part (Tgtu)

Thirteenmile Creek Tongue

upper part (Tgtu)

Thirteenmile Creek 

Tongue

lower part (Tgtl)

1

2

Tgpu

Tgpu

Tgp

Tgp

Tgp

Tgp

Tgp

Pizolite ledge (pz)

Mahogany 

zone

Mahogany 

zone

R-6 zone

L-5 zone

R-5 zone

L-4 zone

B-groove

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone

L-0 zone

R-0 zone

R-6 zone

L-5 zone

R-5 zone

L-4 zone

R-4 zone

R-3 zone

R-2 zone

L-1 zone

Tgg

Tgg

Tgg

Tgd

Tgd

Tgd

Tgd Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Kimball Mountain

tuff bed (km)

Tuff bed at Kimball

Tuff bed at Kimball Mountain (km)

Mountain (km) Tuff bed at Kimball

Mountain (km)

Tud

Tuc

Tu6

Tu6

Tu6 Tu5

Tu5

Tu5

Tu4

Tu3

Tu4

Unnamed

tongue C

Tguc

Anvil Points Member unit 2 (Tga2)

Anvil Points Member unit 2 (Tga2)

Anvil Points Member unit 3 (Tga3)

Rough Gulch, GQ-1195

(Hail, 1974a)

Smizer Gulch, GQ-1131

(Hail, 1973)

Buckskin Point, MF-651

(Pipiringis and Johnson,1975)

Barcus Creek SE GQ-1613

(Hail, 1988)

Barcus Creek, GQ-1578

(Hail, 1984) 

Basal sandstone 

Member (Tgb) Basal sandstone 

Member (Tgb)

Tgg Tgg

Tgg Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tongue of Parachute Creek

Member (Tgpa)

Tgpu

Tgpu

Tgp

Tgp

Tgp

Tgt

Tgl

Tgl

Lower unit (Tgl)

Upper unit (Tgu)

Tg2

Tg3

Tg4

Tgtc

Tgp

Tgp

Tgm

Mahogany bed (mb)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgy

Tgtc

Tgtc

Tgt

Tgt

Tgt

Tgd

Tgd

Tgy

White River City, MF-736

(Pipiringis and Johnson,1976)

Anvil Points

Member upper

part (Tgau)

Anvil Points

Member upper

part (Tgau)

Dessicated concretion zone (c)

Dessicated concretion zone (c)

Tga Tga1

Anvil Points Member lower part (Tga1)

Anvil Points Member lower part (Tga1)

Tga1

Tga1

Tga1

Tgg

Tgg

Tgg

Tgg

Second algal zone (2A)

P-ledge (P)

F-ledge (F)

First algal zone (1A)

Indian Valley, MF-836

(Pipiringos and Rosenlund, 1977a)

White Rock, MF-837

(Pipiringos and Rosenlund, 1977b)

Citadel Plateau I-1532

(Izett and others, 1985)

Divide Creek, MF-2232

(Hail and Barnum,1993)

Calamity Ridge, MF-1690

(Donnell and Hail, 1984)

Gillam Draw, MF-2314

(Barnum and Hail, 1996)

Segar Mountain, MF-570

(O’Sullivan, 1974)

Square S Ranch, MF-754

(Duncan, 1976b)

Greasewood Gulch MF-755

(Duncan, 1976d) Wolf Ridge, MF-753

(Duncan,1976f)

Sagebrush Hill, MF-1398

(Donnell, 1982)

Philadelphia Creek, MF-2216

(Johnson and Smith,1993)

Banta Ridge, MF-2308

(Pantea and Schmitt,1996)

Black Cabbin Gulch, GQ-812

(Cashion, 1969)

Yankee Gulch, MF-758

(Duncan, 1976c)

Jessup Gulch, MF-756

(Duncan1976e)

No Name Ridge, MF-1989

(O’Sullivan, 1987)

Thirteenmile Creek, MF-1789

(O’Sullivan and Smith, 1985)

Rio Blanco, MF-1816

(O’Sullivan, 1985)

McCarthy Gulch, MF-860

(O’Sullivan and others,1981)

Cutoff Gulch, MF-691

(Hail, 1975)

Bull Fork, MF-830

(Hail, 1977)

Figure Four Spring, MF-912

(Johnson, 1977b)

Razorback Ridge, GQ-1019

(Roehler, 1972b)

Brushy Point, GQ-1018

(Roehler, 1972a)

East Evacuation Creek, MF-2220

(Pantea, 1993) 

Texas Mountain, MF-2321

(Barnum and others,1997)

Douglas Pass, MF-1772

(Nuccio, 1985)

Calf Canyon, GQ-1086

(Roehler, 1973a)

Henderson Ridge, GQ-1113

(Roehler, 1973b)

Desert Gulch, MF-1328

(Johnson, 1981b)

Mount Blaine, MF-984

(Hail, 1978) Circle Dot Gulch, MF-1293

(Hail, 1982)

Forked Gulch, MF-1953

(O’Sullivan and Hail, 1987)

Anvil Points, MF-1882

(O’Sullivan,1986)

Rulison, MF-2060

(Yeend and others, 1988)

North Mamm Peak, MF-2093

(Donnell and others,1989)

Grand Valley, MF-1883

(Donnell and others,1986)

Red Pinnacle, MF-2202

(Donnell and others, 1992a)

Long Point, MF-688

(Johnson, 1975)

The Saddle, MF-829

(Johnson, 1977)

Middle Dry Fork, MF-1215

(Johnson, 1980)

Garvey Canyon

(R.C. Johnson, unpublished mapping)

Corcoran Peak

(R.C. Johnson, unpublished mapping)

Winter Flats, MF-1777

(Johnson, 1985)

Wagon Track Ridge, MF-1182

(Johnson and Douglas, 1980)

DeBeque, MF-2201

(Donnell and others,1992b)

Housetop Mountain, MF-1965

(Donnell and others,1987)

Hawkhurst Creek, MF-2026

(Donnell and others,1988)

South Mamm Peak, MF-2113

(Donnell and others, 1990)

Collbran, MF-1825

(Donnell and others,1985)

Molina, MF-1784

(Donnell and others, 1985)

Mesa, MF-1698

(Donnell and others, 1984)

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tga1

Anvil Points Member unit 1 (Tga1)

Anvil Points Member unit 1 (Tga1)

L1 zone (L1)

L1 zone (L1)

High algal zone (HA)

Tu1

Unnamed tongue A 

(Tgua)

Unnamed 

tongue B 

(Tgub)

Tua

Tu2

Tu3

Tu4

Tu5

Tu6

Tu6

Tu7

Tu8

Tud

Tub

Tub

Tua

Tuf

Tug

Tongue of Uinta Formation(Tut)

Tu (note: some Green River Formation

tongues present but not mapped)

Tgpt

Tgm

Intertonguing Uinta and

Green River Formation (Tiug)

?

?

Tgg Tgg

Tgg

Tgg

?

?

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgt

Tgt

Tgd

Tgb

Tgb

Tgd

Tgd

Tgy

Tgb

Texas Creek, MF-2134

(Scott and Pantea,1990)

Tgb

Tgb

Tgb

Tgt

Tgt

Tgc

Tgt

Tgb

Tgc

Tgc

Tgc

Tgs

Tgc

Tgc

Tgs

Tgs

Tgbr

Marker bed at Bull Fork (Tgbf)

Marker bed at 

Bull Fork (Tgbf)

Tgbr

Tgc

Green River Formation

unnamed tongue (Tgu)

Tgcr

Tgc

Tgs

Tgsk

Tgsk

Tgs

Tgc

Tu2

Tu1

Tu3

Tu3

Tu2

Tu1

Tu1

Marlstone at Duck Creek (Tgdc)

Marlstone at Duck Creek (Tgdc)

Tuc

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Mahogany bed (m)

Mahogany bed (m)

Tu5

Tu5

Tu6

Tu6

Green River Formation

unnamed tongue (Tgu)

Tu4

Tu4

Tu5

Tu6

Tgu

Tuh

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgj

Tu Tu

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgj

Tgj

Tgj

Tgj

Tu

Tu

Tu Tu

Tu

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tga

Tga Tga

Tga

Tga

Tga

Tga

Tga Tga

Tga Tga

Tga

Tga

Tga

Tga

Tga

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgp

Tgp

Tgp

Tgp

Tgp

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tub

Tua

Tus

Tua

Tua

Tub

Tuc

Tud

Tgs

Tgc

Tgj

Tgp

Tua

Tua

Tub

Tub

Tuc

Tuc

Tud

Tgsl

km

Tgg Tgg Tgg Tgg

Tgg

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tga Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Mahogany bed (m)

Mahogany oil-shale bed (m)

Mahogany oil-shale bed (mb)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgpl

Tgpl

Tgpl

Tgpm

Tgpm

Tgpm

Tgpm

Parachute Creek Member

middle part (Tgpm)

Parachute Creek Member

middle part (Tgpm)

Parachute Creek Member

upper part (Tgpu)

Parachute Creek Member

upper part (Tgpu)

Parachute Creek 

Member lower 

part (Tgpl)

Tgp

Tgsl

Tgss

Tue

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tu

Tu

Tu

Tgds

Tgds

Tgdm

Tgd Tgd

Tgd

Tgd

Tgd

Tgd

Kimball Mountain Tuff Bed (Km)

Marlstone at Barnes 

Ridge and Stuart

 Gulch (Tgbs)

Stillwater oil-shale zone (s)

Tu

Tu Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgdu

Tgdm

Tgdm

Tgdm

Tgdl

Tgdl

Mahogany 

zone

R-6 zone

L-5 zone

R-5 zone

L-4 zone

B-groove

R-4 zone

L-3 zone

R-3 zone

L-2 zone

R-2 zone

L-1 zoneR-1 zone

L-0 zone

R-0 zone

Tgp

Tgdu

Tgdm

Tgdm

Tgdl

Tgdl

Baxter Pass, MF-1813

(Johnson, 1985c)

Tgsk

Tgu

Tgu

Tgu

Tgu

Tgu Tgu

Tgu

Tgu

Tgu

Tgu

Tgu

Tgu

Tgu

Evacuation Creek Member (Tge)

Evacuation Creek Member (Tge)

Tgp Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgu

Tgu

Tgg

Mahogany oil-shale ledge (ml)

Mahogany oil-shale bed (mb) Mahogany oil-shale bed (mb)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgu

Tgu

Green River Formation 

unnamed unit (Tgu)

Green River Formation 

unnamed unit (Tgu)

Green River Formation 

unnamed unit (Tgu)

Green River Formation 

unnamed unit (Tgu)

Tgg

Rock School, MF-757

(Duncan, 1976a)

Mahogany bed (mb)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Mahogany bed (m)

Mahogany bed (m)

Tu

Tu Tu

Tw

Tw

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tgg

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgp

Tgp

Tgp

Tu

Tu

Tu

Tga

Tga

Tga

Tga

Tga

Tga

Tga Tga

Tga

Tga

Tga

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp Tgp

Tu

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tga

Tgdm

Tgdm

Tgdm

Tgdm

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Tgdu

Mahogany oil-shale bed (m) Mahogany oil-shale bed (m)

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Tgd

Dragon, MF-1777

(Scott and Pantea,1985)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Base of Mahogany oil shale bed (m)

Tu

Intertonguing

unit (Tgi)

Tgi

Tgi

Tgi

Weaver Ridge, MF-824

(Cashion, 1977)

Davis Canyon, MF-1933

(Pantea, 1987)

m

Walsh Knolls, MF-1013

(Cashion, 1978)

Banty Point, GQ-703

(Cullins, 1968)

Tge

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgdu

Tgdu

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgg

Tgd

Evacuation Creek 

Member (Tge)

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Tgp

Mahogany oil-shale bed (m)

Tua

Tua

Tua

Tua

Tu

Tua

Tub

Mellon Hill, GQ-835

(Cullins, 1969)

Garden Gulch Mbr. (Bradley, 1931)

Douglas Creek Member of Bradley (1931),

modified by Johnson 1984)

 Parachute Creek Member (Bradley, 1931)

Type section Anvil Points Member (Donnell, 1961)

2,500

2,550

2,650

Tuc

Tub

Top Bed 44

Top Bed 44

Top Bed 44

Top Bed 44

Top Bed 44

Top Bed 76

Top Bed 76

Top bed 76

Top Bed 44

Top Bed 44

Top bed 44

Max. Uinta: 850

Tu

Tu

Tu

Tu

Tu

Tua

Tub

Tuc

Tud

Tgs

Tgb

Tuh

Top Bed 44

Top Bed 44

Top Bed 44

Base of orange-yellow

tuffaceous uint (t)

?

Tu

Tu

Tu

Tu Tu

Tu

Top Bed 44

Top Bed 44

Top Bed 44

Tgb

Top Bed 44

Top Bed 44

Top Bed 44

Rich unit no. 8 (R-8)

t

Tgy

Tuc

Tud

Tucb Tu

Tu

Tu

Tu

Tu

Tub

Tgtc

Tgua

Mahogany ledge (ml)

Tgm

Tuc

Tuc

Lower ostracodal limestone (lo)

Tuffaceous bed (a)

Garden Gulch Member

upper part (Tggu)

Garden Gulch Member

lower part (Tggl)

Tgu

Long Point Bed (lp)

Evacuation Creek Member (Tge)

Long Point Bed (lp) Long Point Bed (lp)

Douglas Creek Member upper part (Tgdu)

Douglas Creek Member upper part (Tgdu)

Douglas Creek Member lower part (Tgdl)

Douglas Creek Member lower part (Tgdl)

Douglas Creek Member middle part (Tgdm)

Douglas Creek Member middle part (Tgdm)

Mahogany oil-shale bed (m)

Mahogany oil-shale bed (m)

Long Point Bed (lp) Long Point Bed (lp) Long Point Bed (lp)

Evacuation Creek Member (Tge)

Evacuation Creek Member (Tge)

Mahogany oil-shale bed (mb)

Mahogany oil-shale bed (mb)

Mahogany oil-shale bed Mahogany oil-shale bed

Tws Tws

Sandstone bed

at Long Point (lp)

Sandstone bed

at Long Point (lp)

Marker bed at

Long Point (Lp)

Long Point Bed (Lp) Marker bed at

Long Point (lp)

Long Point Bed (Lp)

Long Point Bed (Lp)

Douglas Creek Member

sandy facies (Tgds)

Douglas Creek Member

muddy facies (Tgdm)

Douglas Creek

Member

Sandy part (Tgds)

Kimball Mountain 

Tuff Bed (km)

Mahogany oil-shale bed

Mahogany oil-shale bed Mahogany oil-shale bed

Base of tuffaceous 

beds (t)

Douglas Creek Member

upper part (Tgdu)

Top Bed 44

5 (Tgc)

m

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,500

2,000

2,500

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0

500

1,000

1,500

2,000

2,500

3,000

3,500

Tuff bed at Kimball 

Mountain (km)

A Time-Stratigraphic Columns B Thickness-Stratigraphic Columns

Buckskin Point, MF-651

(Pipiringis and Johnson,1975)

Barcus Creek SE GQ-1613

(Hail, 1988)

Barcus Creek, GQ-1578

(Hail, 1984) 

White River City, MF-736

(Pipiringis and Johnson,1976)

Calamity Ridge, MF-1690

(Donnell and Hail, 1984)

Gillam Draw, MF-2314

(Barnum and Hail, 1996)

Walsh Knolls, MF-1013

(Cashion, 1978) Banty Point, GQ-703

(Cullins, 1968)

Tws

Tws

Tws

Tws

Tws

Tws

Tws

Tws

Tws

L-3 zone

R-3 zone

L-2 zone

Long Point Bed (lp)

Tgp

(A) Time-stratigraphic and (B) thickness-stratigraphic columns for sixty-nine 71⁄2-minute quadrangles and one 15-minute quadrangle that cover the oil shale area of the 

Piceance and easternmost Uinta Basins in western Colorado, showing how mapped stratigraphic units relate to the time-stratigraphic system of rich and lean oil shale zones 

defined by Cashion and Donnell (1972) for the Mahogany oil shale zone and below and Donnell (2010) for above the Mahogany oil shale zone. The quadrangles are positioned 

on the diagram in their proper east-west and north-south positions so that stratigraphic changes can be traced from one quadrangle to another. Only those stratigraphic units 

deposited in Eocene, saline Lake Uinta are shown. Older stratigraphic units mapped in these quadrangles are not included. The two representative oil shale core holes used to 

construct the rich-and lean-zone stratigraphy are shown in upper left of the time-stratigraphic columns (A). For convenience, the chart is subdivided into three different depositional intervals, in ascending order: (1) base R-0 through top L-1 (light gray), (2) base R-2 through Mahogany bed (tan), and (3) Mahogany bed to top of marlstone at Skinner 

Ridge, the highest mapped Green River Formation unit in the basin (pink). A single representative thickness for each zone from the R-0 through Mahogany zones is shown for 

each quadrangle on the thickness-stratigraphic columns (B). Varying thicknesses are shown for stratigraphic units above the Mahogany zone for each quadrangle as these 

units vary markedly in thickness across each quadrangle. Thickness in feet.