Bed 3, Section 17 - Carhuaz (Santa Fm): Valanginian, Peru
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Bivalvia
- Cardiida
- Cyrenidae
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Gastropoda
- Cassiopidae
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| see common names | |||||||
Geography
| Country: | Peru | State/province: | Ancash |
| Coordinates: | 9.3° South, 77.7° West (view map) | ||
| Paleocoordinates: | 11.8° South, 36.2° West (Wright 2013) | ||
| Basis of coordinate: | based on nearby landmark | ||
| Geographic resolution: | outcrop |
Time
| Period: | Cretaceous | Epoch: | Early Cretaceous |
| Stage: | Valanginian | 10 m.y. bin: | Cretaceous 1 |
| Key time interval: | Valanginian | ||
| Age range of interval: | 137.05 - 132.6 m.y. ago |
Stratigraphy
| Formation: | Santa | ||||
| Local section: | Carhuaz | Local bed: | 136 m | ||
| Local order: | bottom to top | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: Collection from a 25 m thick limestone unit, lying below the Carhuaz Formation (late Valanginian-Aptian) and above the Chimu Sandstone (early Valanginian). The Santa Formation is 341 m thick at this section. The formation was originally placed within the Barremian by Steinmann (1930) but the present author suggests it belongs within the Valanginian. | |||||
Lithology and environment
| Primary lithology: | concretionary,dolomitic,shelly/skeletal,brown,gray,yellow lithified "limestone" |
| Secondary lithology: | black,gray "shale" |
| Includes fossils? | Y |
| Lithology description: Limestone, dark gray, somewhat dolomitic, medium-bedded, platy, fossiliferous, with large limestone concretions and chert nodules, weathers yellow brown, and has interbeds of splintery, grayish black shale. | |
| Environment: | marginal marine indet. |
| Glacial or sequence phase: | transgressive |
| Geology comments: The Santa Formation represents a change from the non-marine conditions that prevailed during deposition of the Chimu sandstone to a shallow marine to brackish water environment. | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | selective quarrying,field collection |
| Reason for describing collection: | general faunal/floral analysis |
| Museum repositories: | AMNH |
| Collection method comments: Collections reposited at AMNH. | |
| Taxonomic list comments:Taxonomic list compiled by the author during 1951-1952. Nomenclature should therefore be somewhat antiquated, though systematics reflect supervision of Normal Newell, Columbia University and AMNH paleontologists. | |
Metadata
| Database number: | 56944 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2005-11-29 11:02:13 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2005-11-29 11:02:12 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 15338. | V.E. Benavides-Caceres. 1956. Cretaceous system in northern Peru. Bulletin of the American Museum of Natural History 108(4):1-493 [A. Miller/A. Hendy] |