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

When: Buelna 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 77.5m thick. Formation creates a conspicuous ridge or ledge in most areas. The broad facies included in the formation and a lack of information regarding the lithology containing the fossils prevents a single paleoenvironment from being selected.

• group of beds-level stratigraphic resolution

Environment/lithology: lithified, gray, green, yellow siltstone and lithified, brown, yellow sandstone

Size classes: macrofossils, mesofossils

Preservation: trace, original calcite

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 10684: authorized by Mark Patzkowsky, entered by Phil Borkow on 11.06.2001

Creative Commons license: CC BY (attribution)