USGS 22207-PC (Carboniferous of the United States)

Also known as Sando et al. Amsden Creek Loc.64

Where: Sheridan County, Wyoming (44.9° N, 107.3° W: paleocoordinates 4.5° N, 34.3° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Ranchester Member (Amsden Formation), Morrowan (318.1 - 314.6 Ma)

• Limestone 96.5-97.5 ft above base of Amsden Fm. "Pennsylvanian (Morrowan)."

• bed-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified, lenticular, concretionary, gray, yellow, sandy, cherty/siliceous dolomite and green, red shale

• ranchester: heterogenous sequence of interbedded cherty dolomite and limestone, sandstone, and shale. carbonate rocks predominate; thin- to thick-bedded, fine grained to coarsely crystalling, yellowish-gray weathering dolomite and dolomitic limestone are generally much more abundant than thin-bedded, fine- to medium-grained, light-gray to purple weathering limestone. carbonate beds, particularly dolomites, contain abundant gray, brown or jasperoid chert in small nodules, irregular lenses and irregular networks. red and green shale in thin beds and partings are commonly interbedded with the carbonate rocks, particularly in the upper half, and may compose significant thicknesses of the member at some localities. thin beds of fine- to medium-grained, white to pink sandstone occur throughout the member but are most abundant in the upper half. quartz sand is also a minor constituent of some of the carbonate beds. anhydrite was reported as a minor constituent of some dolomite beds.

Reposited in the USGS

• "Collected by W.J. Sando and K.R. Moore, 1965."

Primary reference: W. J. Sando, M. Gordon, Jr., 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/M. Uhen]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 5729: authorized by John Alroy, entered by Mike Sommers on 17.11.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

cf. Palaeonubecularia sp. Reitlinger 1950
 Archaediscacea - Archaediscidae
 Fusulinoidea - Staffellidae
 Fusulinoidea - Eostaffellidae
Eostaffella sp. Rauser-Chernousova 1948
 Endothyroidea - Endothyridae
 Palaeotextularoidea - Biseriamminidae
 Miliolida - Cornuspiridae
Cornuspiridae indet. Schultze 1854