Chugwater and Goose Egg Formations

Chugwater Formation (North Wyoming) - Red siltstone and shale. Alcova Limestone Member in upper middle part in north Wyoming. Thin gypsum partings near base in north and northeast Wyoming. Goose Egg Formation - Red sandstone and siltstone, white gypsum, halite, and purple to white dolomite and limestone. Chugwater Group or Formation (South Wyoming) - Red shale and siltstone containing thin gypsum partings near base. Group includes Popo Agie Formation (red shale and red, yellow, and purple siltstone; lenses of lime-pellet conglomerate), Crow Mountain Sandstone (red and gray, thick bedded), Alcova Limestone, and Red Peak Formation (red siltstone and shale). Chugwater Formation includes as members all the units listed above. Includes overlying Jelm Formation in Shirley and Seminoe Mountains and at northern end of Laramie Basin. Jelm Formation - Red sandstone.
State Wyoming
Name Chugwater and Goose Egg Formations
Geologic age Permian-Upper Triassic
Lithologic constituents
Sedimentary > Clastic > Siltstone
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Conglomerate
Sedimentary > Carbonate > Dolostone
Sedimentary > Chemical > Evaporite > Gypsum
Sedimentary > Chemical > Evaporite > Salt
NGMDB product
Counties Albany - Big Horn - Carbon - Johnson - Laramie - Natrona - Park - Platte - Sheridan - Washakie