Spruce Mountain SM-274 (Permian of the United States)

Where: Elko County, Nevada (40.5° N, 114.8° W: paleocoordinates 14.5° N, 36.6° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Gerster Formation (Park City Group), Wuchiapingian (259.9 - 254.2 Ma)

• 274 feet above base of Gerster Fm.

•Gerster Formation is correlated with the upper Phosphoria Formation (Rex Chert, Retort, Tosi) and other upper units in the Park City Group (Franson, Ervay). Those units are now Lopingian in age, following a latest Capitanian U/Pb age of 260.57 Ma in the upper Meade Peak Member. The upper age of the Gerster is unclear, and it may span much of the Lopingian, although the top is unconformable (overlying units are Smithian) so some or all of the Changhsingian may be missing. For now, all collections are assigned a Wuchiapingian age.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; limestone

Size class: macrofossils

Preservation: replaced with silica

Collection methods: bulk, chemical,

Primary reference: B. R. Wardlaw. 1977. The biostratigraphy and paleoecology of the Gerster Limestone (Upper Permian) in Nevada and Utah. U.S.G.S. Open File Report 77(470):1-125 [D. Bottjer/M. Clapham/M. Clapham]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 39504: authorized by David Bottjer, entered by Matthew Clapham on 30.05.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
"Ramose bryozoa"
Rhynchonellata
 Athyridida - Athyrididae
Composita mira Girty 1899
 Terebratulida - Dielasmatidae
 Spiriferinida - Pennospiriferinidae
 Rhynchonellida - Wellerellidae
Phrenophoria "n. sp. A" Cooper and Grant 1969
Strophomenata
 Productida - Productellidae
cf. Echinauris subhorrida Meek 1877
Written "Echinauris" subhorrida
 Productida - Linoproductidae
cf. Grandaurispina "n. sp. A" Muir-Wood and Cooper 1960
Written "Grandaurispina" n. sp. A
 Strophomenida - Rugosochonetidae
 Orthotetida - Derbyiidae
Derbyia sulca Branson 1930