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Meeteetse Formation and Lewis Shale

MEETEETSE FORMATION AND LEWIS SHALE. MEETEETSE FORMATION (AGE ABOUT 73 Ma) (Km)--Chalky-white to gray sandstone, yellow, green, and dark-gray bentonitic claystone, white tuff, and thin coal beds. LEWIS SHALE (AGE ABOUT 68 Ma) (Kle)--Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds.
State Wyoming
Name Meeteetse Formation and Lewis Shale
Geologic age Phanerozoic | Mesozoic | Cretaceous-Late
Primary rock type medium-grained mixed clastic
Secondary rock type fine-grained mixed clastic
Other rock types mixed clastic/volcanic; coal
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Clastic > Mudstone > Claystone
Incidental
Igneous > Volcanic (Pyroclastic, tuff)
Sedimentary > Coal
Sedimentary > Clastic > Mudstone > Claystone > Bentonite
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 - Natrona