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Cloverly, Morrison, Sundance, and Gypsum Spring Formations and Nugget Sandstone

CLOVERLY, MORRISON, AND SUNDANCE (Js), GYPSUM SPRING FORMATIONS, AND NUGGET SANDSTONE (J@n). 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--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. NUGGET SANDSTONE--Gray to dull-red, crossbedded quartz sandstone.
State Wyoming
Name Cloverly, Morrison, Sundance, and Gypsum Spring Formations and Nugget Sandstone
Geologic age Phanerozoic | Mesozoic | Triassic(?) Jurassic(?) Cretaceous-Early
Primary rock type fine-grained mixed clastic
Secondary rock type medium-grained mixed clastic
Other rock types carbonate; dolostone (dolomite)
Lithologic constituents
Minor
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Claystone
Sedimentary > Clastic > Conglomerate
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Dolostone
Sedimentary > Chemical > Evaporite > Gypsum
Incidental
Sedimentary > Clastic > Mudstone > Claystone > Bentonite
Sedimentary > Chemical > Chert
Map references
Love, J.D. and Christiansen, Ann Coe, 1985, Geologic Map of Wyoming: U.S. Geological Survey.
Unit references
Love, J.D. and Christiansen, Ann Coe, 1985, Geologic Map of Wyoming: U.S. Geological Survey.
Counties Fremont