USGS 19241-PC (Carboniferous of the United States)

Also known as Sando et al. South Rock Creek Loc.53

Where: Johnson County, Wyoming (44.5° N, 106.9° W: paleocoordinates 4.0° N, 34.4° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Ranchester Member (Amsden Formation), Morrowan (323.2 - 318.6 Ma)

• Limestone 3-5 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 Helen Duncan and others, 1951."

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 5726: authorized by John Alroy, entered by Mike Sommers on 17.11.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Gastropoda
 Euomphalina - Euomphalidae
Straparollus sp.
Straparollus sp. de Montfort 1810 snail
 Murchisoniina - Gosseletinidae
Mourlonia sp.
Mourlonia sp. de Koninck 1883 snail
Bivalvia
 Trigoniida - Schizodidae
Schizodus alpinus
Schizodus alpinus Hall 1858 clam
 Cardiida - Kalenteridae
Permophorus sp.
Permophorus sp. Chavan 1954 clam
sp. A
 Carditida - Astartidae
Astartella concentrica
Astartella concentrica Conrad 1842 clam
 Pectinida - Aviculopectinidae
Aviculopecten spp.
Aviculopecten spp. M'Coy 1851 scallop
sp. B and other spp. indet.
 Nuculanida - Sareptidae
Paleyoldia sp.
Paleyoldia sp. Lintz 1958 clam
 Nuculida - Nuculidae
Nuculopsis sp.
Nuculopsis sp. Girty 1912 nut clam
sp. B
Strophomenata
 Orthotetida - Orthotetidae
Orthotetes sp.
 Productida - Productellidae
Antiquatonia cf. coloradoensis
 Productida - Linoproductidae
Linoproductus eastoni