UW 2997/6A (University of WY, Laramie) (Carboniferous to of the United States)

Also known as Sando et al. Beaver Creek Loc.19

Where: Fremont County, Wyoming (42.5° N, 108.5° W: paleocoordinates 0.6° N, 39.4° 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)

• Float 45 ft above base of Amsden Fm. "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

• "Collection evidently made from float because it includes a mixture of forms from 2 subzones and a coral from the Madison Limestone. Collected by C.A. Briggs, 1950. Fossils listed by Burk, 1954, p.6."

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 5685: 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
unclassified
  -
Antracospirifer shawi
Antracospirifer shawi
ssp. exoletus
Rhynchonellata
 Athyridida - Athyrididae
Composita sp.
Composita sp. Brown 1849