Spruce Mountain SM-306 (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)

• 306 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; peloidal, shelly/skeletal, silty, cherty/siliceous wackestone

• silty, skeletal, pelletal wackestone (highly chertified)

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 39505: authorized by David Bottjer, entered by Matthew Clapham on 30.05.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Strophomenata
 Strophomenida - Rugosochonetidae