Wells and Amsden Formations, Casper Formation, and Madison Limestone

Wells Formation (Thrust Belt) - Gray limestone interbedded with yellow limy sandstone. Amsden Formation (Thrust Belt) - Red and gray cherty limestone and shale, sandstone, and conglomerate. Casper Formation (North and South Wyoming) - Gray, tan, and red thick-bedded sandstone underlain by interbedded sandstone and pink and gray limestone. May include some Devonian(?) sandstone along east flank of Laramie Mountains. Madison Limestone (North and South Wyoming) - Includes Mission Canyon Limestone (blue-gray massive limestone and dolomite), underlain by Lodgepole Limestone (gray cherty limestone and dolomite).
State Wyoming
Name Wells and Amsden Formations, Casper Formation, and Madison Limestone
Geologic age Upper Mississippian-Permian
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Sandstone
Minor
Sedimentary > Carbonate > Dolostone
Sedimentary > Clastic > Conglomerate
Sedimentary > Clastic > Mudstone > Shale
References
NGMDB product
Counties Albany - Carbon - Converse - Fremont - Laramie - Lincoln - Platte - Sublette