San Hipólito locality (Vizcaíno terrane): Sevatian, Mexico
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Chlorophyceae
- Dasycladales
- Dasycladaceae
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Gyroporella sp.
Gümbel 1872
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| see common names | |||||||
Geography
| Country: | Mexico | State/province: | Baja California Sur |
| Coordinates: | 27.0° North, 114.0° West (view map) | ||
| Paleocoordinates: | 6.5° North, 55.6° West |
Time
| Period: | Triassic | Epoch: | Late Triassic |
| Stage: | Norian | 10 m.y. bin: | Triassic 4 |
| Key time interval: | Sevatian | ||
| Age range of interval: | 213.2 - 208.5 m.y. ago |
Stratigraphy
| Formation: | San Hipólito | ||||
| Stratigraphic resolution: | formation | ||||
| Stratigraphy comments: Late Norian | |||||
Lithology and environment
| Primary lithology: | lithified grainstone |
| Secondary lithology: | lithified rudstone |
| Lithology description: In Baja California Sur, the studied algae come from the San Hipólito Formation on the Vizcaíno terrane. The Vizcaíno terrane is a northwest-southeast trending tectonostratigraphic unit, which constitutes the entire Vizcaíno Peninsula. However, its classification as a terrane is somewhat unclear (Heerwagen & Martini 2020 and references therein). 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 | |
| Environment: | platform/shelf-margin reef |
| Geology comments: Patch reef margin to back reef (echinoid lithoclast-peloid Grainstone to Rudstone and Wackestone) | |
Taphonomy
| Modes of preservation: | body,original aragonite,replaced with calcite |
| Size of fossils: | mesofossils |
Collection methods and comments
| Collection excludes: | all macrofossils |
| Reason for describing collection: | taxonomic analysis |
Metadata
| Database number: | 234363 | ||
| Authorizer: | W. Kiessling | Enterer: | T. Jujihara |
| Modifier: | P. Wagner | Research group: | marine invertebrate |
| Created: | 2024-04-05 12:47:50 | Last modified: | 2024-08-08 19:35:26 |
| Access level: | the public | Released: | 2024-04-05 12:47:50 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 87972. | 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] |