Puerto Blanco, Unit 2, Cerro Rajon, Caborca Region, Mexico - Stewart et. al 1984 (Cambrian of Mexico)

Where: Mexico (30.4° N, 111.9° W: paleocoordinates 6.1° S, 105.0° W)

When: Unit 2 Member (Puerto Blanco Formation), Montezuman (520.0 - 515.3 Ma)

• All lithology/stratigraphic details are based primarily on exposures of rocks in the Cerro Rajon area. Unit is 173.0m thick. The formation changes facies markedly from one locality to another in the Caborca Region.

• group of beds-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; lithified, burrowed, gray, yellow siltstone and lithified sandstone

• Represents a southern extension of the Cordilleran miogeocline, rocks may be offset 700 to 800km along a left- lateral fault.
• Siltstone, yellow gray, dusty yellowm and grayish red, micaceous, abundant borrows, tracks, and traits. Quartzite, very fine grained, evenly laminated. Sparse limy siltstone to silty limestone beds.

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 10680: 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
Coeloscleritophora
 Chancelloriida - Chancelloriidae
Chancelloria eros
Chancelloria eros Walcott 1920
 Hyolithelminthida - Hyolithellidae
Hyolithellus sp.
Hyolithellus sp. Billings 1872
Helcionelloida
 Helcionellida - Helcionellidae
Helcionellidae indet.
Hyolitha
 Hyolithida - Hyolithidae
"Hyolithes aff. princeps" = Nevadotheca princeps
"Hyolithes aff. princeps" = Nevadotheca princeps Billings 1872
Kutorginata
 Kutorginida - Nisusiidae
Nisusiidae indet.
Nisusiidae indet. Walcott and Schuchert 1908
Trilobita
 Redlichiida - Fallotaspididae
cf. Fallotaspis sp.
cf. Fallotaspis sp. Hupé 1953 trilobite
Microdictyon
  -
Microdictyon sp.
Microdictyon sp. Bengston et al. 1981
 Ichnofossils -
Palaeophycus sp., Scolicia sp.
Palaeophycus sp. Hall 1847
(trace fossil)
Scolicia sp. de Quatrefages 1849
(trace fossil)