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Greenhorn Formation and Belle Fourche Shale

GREENHORN FORMATION AND BELLE FOURCHE SHALE. GREENHORN FORMATION--Light-colored limestone, marl, and limy sandstone interbedded with gray concretionary shale. BELLE FOURCHE SHALE--Black soft bentonitic concretionary shale. CARLILE SHALE--Dark-gray sandy shale; Sage Breaks Member at top; Turner Sandy Member in middle.
State Wyoming
Name Greenhorn Formation and Belle Fourche Shale
Geologic age Phanerozoic | Mesozoic | Cretaceous-Late
Primary rock type mixed clastic/carbonate
Secondary rock type fine-grained mixed clastic
Other rock types mixed clastic/volcanic; medium-grained mixed clastic
Lithologic constituents
Minor
Sedimentary > Carbonate > Limestone
Unconsolidated > Marl
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale
Incidental
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 Niobrara - Weston