SDA-3:Quartz Bioclastic Packstone (Triassic of Mexico)

Where: Sonora, Mexico (30.7° N, 112.6° W: paleocoordinates 12.0° N, 53.9° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Antimonio Formation, Norian (228.0 - 208.5 Ma)

• The strata of the Monos and Antimonio Formations at Sierra del Alamo represents a nearly complete succession of marine sedimentary rock that ranges from Late Permian to Early Jurassic age.

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; lithified packstone

• The Sandy Limestone lithofacies lies above the lime-cemented sandstone and below and above the bedded pure limestone. This unit varies little in thickness ~ averaging 1m. It consists of limestone with abundant sand to silt-sized quartz grains. Profuse subparallel dissolution residues, stylolites, and geopetal structures are characteristic.

Size class: macrofossils

Primary reference: D. H. Goodwin. 1999. Paleontology, Paleoecology, and Depositional Environments Within the Upper Triassic (Norian) Carbonate Strata of the Antimonio Formation, Northwest Sonora, Mexico. University of Montana [D. Bottjer/N. Bonuso/N. Bonuso]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 41019: authorized by David Bottjer, entered by Nicole Bonuso on 05.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

 Vaceletida - Verticillitidae
Cinnabaria expansa Seilacher 1962 demosponge