Goose Egg Formation (CO*,MT*,SD*,WY*)
(alphabetical): Difficulty Shale Member (WY*), Ervay Limestone Member (WY*) or Ervay Member (WY*), Forelle Limestone Member (CO*,WY*), Freezeout Shale Member (WY*), Glendo Shale Member (CO,SD,WY*), Little Medicine Member (MT*,WY*), Minnekahta Limestone Member (CO*,MT*,WY*), Opeche Shale Member (MT*,WY*), Satanka Member (WY) or Satanka Shale Member (WY), Sybille Member (WY).
early to middle Permian (late Cisuralian to middle Guadalupian; Kungurian to Wordian) and Early Triassic (Scythian)*
Typical exposure near Goose Egg Post Office, in NW/4 sec. 12, T. 32 N., R. 81 W., Natrona Co., central WY (Burk and Thomas, 1956).
Denver basin*
Green River basin*
Powder River basin*
Wind River basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).