Green River and Wasatch Formations

Green River Formation (Thrust Belt) - Buff laminated marlstone and limestone, brown oil shale, and siltstone. Includes Angelo and Fossil Butte Members. Wasatch Formation (Thrust Belt) - Variegated mudstone and sandstone. Includes Tunp and Bullpen Members, other tongues and unnamed members, and main body (variegated red to gray, brown, and gray mudstone and sandstone; conglomerate lenses). Green River Formation (in southwest Wyoming) - Oil shale, light-colored tuffaceous marlstone, and sandstone. Wasatch Formation (in southwest Wyoming) - Drab to variegated claystone and siltstone, carbonaceous shale and coal, buff sandstone, arkose, and conglomerate. In northwestern part of Green River Basin is thick arkosic light-yellowish-tan sandstone intertonguing with pale-green to gray claystone and shale.
State Wyoming
Name Green River and Wasatch Formations
Geologic age Eocene
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale > Oil-shale
Sedimentary > Carbonate > Limestone
Sedimentary > Carbonate > Marlstone
Sedimentary > Clastic > Conglomerate
Sedimentary > Clastic > Siltstone
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone
Igneous > Volcanic (Pyroclastic-tuff)
NGMDB product
Counties Lincoln - Sublette - Uinta