Cerro Prieto Fm., Cerro Rajon, Caborca Region, Mexico - Stewart et. al 1984 (Cambrian of Mexico)

Where: Mexico (30.4° N, 111.9° W: paleocoordinates 4.3° S, 102.8° W)

When: Cerro Prieto Formation (Bonnia-Olenellus Group), Dyeran (515.3 - 511.2 Ma)

• All lithology/stratigraphic details are based primarily on exposures of rocks in the Cerro Rajon area. Unit is 82.0m thick. The formations dark color and resistant weathering contrasts with the lighter colored and relatively nonresistant overlying and underlying Buelna and Arrojos Formations.

• group of beds-level stratigraphic resolution

Environment/lithology: lithified, gray limestone

• Represents a southern extension of the Cordilleran miogeocline, rocks may be offset 700 to 800km along a left- lateral fault.
• Limestone, light gray to mediuym gray, thin bedded. Abundant oncolites (Girvanella) in lower half, sparse in upper half.

Size classes: macrofossils, mesofossils

Preservation: trace

Collection methods: bulk,

Primary reference: J. Stewart, M. A. S. McMenamin, and J. M. Morales-Ramirez. 1984. Upper Proterozoic and Cambrian rocks in the Caborca Region, Sonora, Mexico - physical stratigraphy, biostratigraphy, paleocurrent studies, and regional relations. U. S. Geological Survey Professional Papers (1309)1-33 [M. Patzkowsky/P. Borkow]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 10686: authorized by Mark Patzkowsky, entered by Phil Borkow on 11.06.2001

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Hormogoneae
 Oscillatoriales - Girvanellaceae
Girvanella sp.
Girvanella sp. Nicholson and Etheridge 1878
Salterella
  - Salterellidae
Salterella sp.
Salterella sp. Billings 1861