About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 56 (1972)

Issue: 3. (March)

First Page: 653

Last Page: 653

Title: Phosphate Deposition Seaward of Barrier Islands at Edge of Phosphoria Sea in Northwestern Wyoming: ABSTRACT

Author(s): R. P. Sheldon

Article Type: Meeting abstract


Four elongate tongues of the Shedhorn Sandstone of Permian age extend southeastward from the Yellowstone Park area into the Gros Ventre, Hoback, and Wyoming Range area. These tongues represent barrier-island complexes that built southwestward in the Phosphoria sea, creating a lagoon on their northeast side. The lagoonal facies includes algal laminated and ostracodal limestone and dolomite and a greenish-gray shale. The barrier island facies consists of crossbedded quartz sandstone which contains abraded thick-shelled fossils. The marine facies southwest of the barrier island facies includes chert, quartz sandstone, calcarenite containing a siliceous sponge, brachiopod, and bryozoan fauna, and phosphorite containing a brachiopod and fish fauna. Major phosphate deposition w s restricted to the marine environment seaward of the barrier islands, and was absent in the lagoonal environment.

End_of_Article - Last_Page 653------------

Copyright 1997 American Association of Petroleum Geologists