Where: Baja California Sur, Mexico (27.0° N, 114.0° W: paleocoordinates 6.5° N, 55.6° W)
When: San Hipólito Formation, Sevatian (212.0 - 205.6 Ma)
• Late Norian
• formation-level stratigraphic resolution
Environment/lithology: platform or shelf-margin reef; lithified grainstone and lithified rudstone
•The San Hipólito Formation (ca 2400 m thick marine succession) is named after the nearby village and represents an arc-ophiolite assemblage (Busby 2004; Morán Zenteno et al. 1994) with basinal to slope facies spanning from the Norian to the Pliensbachian (Orchard et al. 2007). The formation comprises a limestone breccia (ca 105 to 260 m thick), which includes re-worked upper Norian shallow-water limestones. According to Heerwagen & Martini (2020), the breccia itself consists of volcaniclastic sandstones containing limestone clasts in a poorly sorted, massive to weakly bedded, fine to medium-coarse litharenite matrix. The size of the clasts ranges from several decimeters up to few meters in diameter. Lithologically, the limestone clasts are composed of light gray to gray, sometimes with a pinkish hue, micritic limestone. The macrofossil assemblage is dominated by brownish-weathered coral colonies; subordinate are fragments of thalamid sponges and fossil debris including echinoids, gastropods, bivalves, brachiopods, ostracodes, and foraminifers. Only in some samples red algae and dasycladalean algae, serpulids, bryozoans, coprolites, and fragments of calcimicrobe colonies were found. Less commonly found were blocks of micritic limestone that contain megalodontid bivalves
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 234363: authorized by Wolfgang Kiessling, entered by Toshiro Jujihara on 05.04.2024
Creative Commons license: CC BY (attribution)
Taxonomic list
Chlorophyceae | |
Gyroporella sp. Gümbel 1872 |