Frontier Formation and Mowry and Thermopolis Shales (WYKft;0)

FRONTIER FORMATION (Kf) AND MOWRY (Kmr) AND THERMOPOLIS SHALES. FRONTIER FORMATION--Gray sandstone and sandy shale. In Northern Yellowstone area, Yellowish- to medium-gray sandstone; tuffaceous and carbonaceous in lower part. MOWRY SHALE (AGE 94 TO 98 Ma)--Silvery-gray hard siliceous shale containing abundant fish scales and bentonite beds. THERMOPOLIS SHALE--Black soft fissile shale; Muddy Sandstone Member at top.

State	Wyoming
Name	Frontier Formation and Mowry and Thermopolis Shales
Geologic age	Phanerozoic \| Mesozoic \| Cretaceous-Early Cretaceous-Middle(?) Cretaceous-Late
Original map label	Kft
Primary rock type	sandstone
Secondary rock type	shale
Other rock types	mixed clastic/volcanic
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale Sedimentary > Clastic > Sandstone Minor Sedimentary > Carbonate > Limestone Incidental Sedimentary > Clastic > Mudstone > Claystone > Bentonite Igneous > Volcanic > Sandstone (Pyroclastic, tuff)
Map references	Love, J.D. and Christiansen, Ann Coe, 1985, Geologic Map of Wyoming: U.S. Geological Survey. [http://pubs.er.usgs.gov/publication/ofr83802]
Unit references	Love, J.D. and Christiansen, Ann Coe, 1985, Geologic Map of Wyoming: U.S. Geological Survey. [http://pubs.er.usgs.gov/publication/ofr83802]
Geographic coverage	Albany - Carbon - Converse - Fremont - Hot Springs - Johnson - Laramie - Park - Sheridan - Sublette - Teton