Sierra del Álamo (SA) locality (Triassic of Mexico)

Where: Sonora, Mexico (30.7° N, 112.6° W: paleocoordinates 11.5° N, 54.0° W)

When: Rio Asunción Formation (El Antimonio Group), Late/Upper Triassic (237.0 - 201.4 Ma)

• Late Norian from ammonoid and bivalve biostratigraphy (Damborenea & González-León 1997 and references therein; González-León 1997).

• formation-level stratigraphic resolution

Environment/lithology: sand shoal; lithified grainstone and lithified rudstone

• Sand sheets and sand shoals, agitated water (lithoclastic echinoid–gastropod–sponge–peloid Grainstone to Rudstone).
• At Sierra del Álamo, the Rio Asunción Formation (upper part of the El Antimonio group succession, ca. 109 m), consists of shallow-marine limestone, siltstones to fine grained sandstones, some intercalated volcanics, and shales. A distinct carbonate interval, dated by ammonoid and bivalve biostratigraphy as Norian in age (Damborenea & González-León 1997 and references therein; González-León 1997), contains sponge-coral biostromes with algae.

Size class: mesofossils

Preservation: original aragonite, replaced with calcite

Primary reference: I. I. Bucur, S. Rigaud, N. Del Piero, A. Fucelli, E. Heerwagen, C. Peybernes, G. Peyrotty, C. Verard, J. Chablais and R. Martini. 2020. Upper Triassic calcareous algae from the Panthalassa Ocean. Rivista Italiana di Paleontologia e Stratigrafia 126(2):499-540 [W. Kiessling/T. Jujihara]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 234383: authorized by Wolfgang Kiessling, entered by Toshiro Jujihara on 10.04.2024

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Chlorophyceae
 Dasycladales - Dasycladaceae
Macroporella sp., Gyroporella sp., Salpingoporella sp.
Gyroporella sp. Gümbel 1872