UW 3099/9A (Univ. WY, Laramie) (Carboniferous to of the United States)

Also known as Sando et al. South Pass Loc.22

Where: Fremont County, Wyoming (42.6° N, 108.7° W: paleocoordinates 0.7° N, 39.5° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Anthracospirifer welleri-shawi zone, Horseshoe Member (Amsden Formation), Chesterian to Chesterian (335.5 - 321.8 Ma)

• Shale 55 ft above base of Amsden Fm. "Carlinia amsdeniana subzone. Late Mississippian (Chesterian)."

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, red, silty, sandy, calcareous shale and gypsiferous, shelly/skeletal limestone

• horseshoe: predominantly fissile, platy or blocky siltstone, shale, and mudstone. weathers bright red to grayish red or purple. thin beds and lenses of platy, white to red, fine grained, commonly calcareous quartz sandstone occur sporadically throughout member. thin beds of silty, sandy, or argillaceous limestone are rare in central wy, significant proportion in western wy. dolomite is a rare constituent. limestone beds are either fine grained and unfossiliferous or fine to medium grained and contain a shelly fauna. anhydrite and gypsum present at several localities. represents offshore marine facies of the transgressing amsden sea.

Reposited in the UW

• "Collected by C.A. Biggs, 1950. Fossils listed by Burk, 1954, p.6, and Shaw, 1955 p.63, fig.1."

Primary reference: W. J. Sando, M., J.r. Gordon, and J. T. Dutro. 1975. Stratigraphy and geologic history of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming. United States Geological Survey Professional Paper 848A:1-83 [J. Alroy/M. Sommers/P. Wagner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 5688: authorized by John Alroy, entered by Mike Sommers on 15.11.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Strophomenata
 Productida - Productellidae
Carlinia amsdeniana
 Productida - Monticuliferidae
Ovatia croneisi
Rhynchonellata
 Spiriferida - Spiriferidae
Anthracospirifer welleri
 Athyridida - Athyrididae
Composita ? sigma
Composita ? sigma Gordon 1975
Bivalvia
 Cardiidia - Sanguinolitidae
Wilkingia terminalis, Sanguinolites sp.
Wilkingia terminalis Hall 1852 clam
Sanguinolites sp. M'Coy 1844 clam