USGS loc. 15782-PC, Cottonwood Mountains (Carboniferous of the United States)

Where: Inyo County, California (36.8° N, 117.5° W: paleocoordinates 3.0° N, 46.9° W)

• coordinate estimated from map

When: Rest Spring Formation, Arnsbergian (326.4 - 318.1 Ma)

• McAllister (1952) and Gordon (1964) say this is the uppermost 10 ft and probably lower 5 ft of Rest Spring Shale

•If Perdido group, this would be the Mexican Spring Formation of Stevens et al., 1996

•Titus (2000) says this is lower Rest Spring Shale, but doesn't give any evidence. Says "the formational contact between the Rest Spring Shale and the underlying Mexican Spring Formation essentially coincides with the Pendleian-Arnsbergian boundary" making this Arnsbergian if Rest Spring, or Pendleian if Mexican Spring.

Environment/lithology: marine; fine-grained, gray limestone and calcareous siltstone

• In the Quartz Spring area the Early Mississippian Tin Mountain Limestone is overlain by a sequence of varied beds that consists of calcareous siltstone, sand- stone, conglomerate and interbedded chert, limestone, silty limestone, and siltstone having some shale. These constitute the Perdido Formation of McAllister (1952, p. 22-25), approximately 610 feet thick in its composite type section south of Perdido Canyon and south of Rest Spring.The topmost bed of this formation, a dark-gray fine-grained limestone, 6 to 12 inches thick, is crowded with fossils, mostly Cravenoceras hesperium Miller and Furnish. Four to five feet of very soft shale, grayish red to purplish gray, separate it from the gray locally sandy limestone below that carries productids, spirifers, and other brachiopods.

Size class: macrofossils

Collected by R. F. Johnson in Aug. 16, 1949; reposited in the USNM

Primary reference: M. Gordon, Jr. 1964. California Carboniferous cephalopods. United States Geological Survey Professional Paper 483-A:A1-A27 [J. Marcot/J. Marcot/J. Marcot]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 217081: authorized by Jonathan Marcot, entered by Jonathan Marcot on 22.01.2021

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Goniatitida - Glaphyritidae
Eosyngastrioceras quadratum n. sp. Titus 2000 ammonite
 Goniatitida - Delepinoceratidae
Delepinoceras californicum n. sp. Gordon 1964 ammonite
 Actinocerida - Carbactinoceratidae
 Pseudorthocerida - Pseudorthoceratidae