Cloverly, Morrison, Sundance, and Gypsum Spring Formations

Cloverly Formation - Rusty sandstone at top, underlain by brightly variegated bentonitic claystone; chert-pebble conglomerate locally at base. Morrison Formation - Dully variegated claystone, nodular limestone, and gray silty sandstone. In southern Yellowstone and Jackson Hole areas the presence of Morrison is questionable. Sundance Formation (Js) - Greenish-gray glauconitic sandstone and shale, underlain by red and gray nonglauconitic sandstone and shale. Gypsum Spring Formation - Interbedded red shale, dolomite, and gypsum. In north Wyoming wedges out south in T. 39 N.
State Wyoming
Name Cloverly, Morrison, Sundance, and Gypsum Spring Formations
Geologic age Middle Jurassic-Lower Cretaceous
Lithologic constituents
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Claystone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Carbonate > Dolostone
Sedimentary > Clastic > Conglomerate
Sedimentary > Clastic > Mudstone > Claystone > Bentonite
Sedimentary > Chemical > Chert
Sedimentary > Chemical > Evaporite > Gypsum
NGMDB product
Counties Big Horn - Fremont - Hot Springs - Johnson - Park - Sheridan - Sublette - Teton - Washakie