Lower Miocene Rocks

Northwest Wyoming (Bighorn Mountains): Gray soft poorly bedded to massive sandstone; Central Wyoming: Tuffaceous sandstone, siltstone, and white marl.
State Wyoming
Name Lower Miocene Rocks
Geologic age Lower Miocene
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Minor
Sedimentary > Clastic > Siltstone (Tuffaceous)
Sedimentary > Carbonate > Marlstone
References
NGMDB product
Counties Albany - Carbon - Converse - Johnson - Natrona - Washakie