Bed 6, Section 17 - Carhuaz (Carhuaz Fm) (Cretaceous of Peru)

Where: Ancash, Peru (9.3° S, 77.7° W: paleocoordinates 10.1° S, 44.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Carhuaz Formation, Valanginian (139.8 - 132.9 Ma)

• Collection from a 25 m thick limestone unit, lying below the Pariahuanca Formation (late Barremian-Aptian) immediately above the Santa Formation (Valanginian). The Carhuaz Formation is 1554 m thick at this section. The formation was originally placed within the Barremian by Steinmann (1930) athough the present author suggests it has a broader temporal range, spanning the late Valanginian-Aptian in places. The fossiliferous part of the formation largely appears to be late Valanginian to early Hauterivian. The section includes the types of the Inca, Yumugual, Mujuarrun, Romiron, Conor, and Cajamarca formations.

• group of beds-level stratigraphic resolution

Environment/lithology: marginal marine; lithified, shelly/skeletal, brown limestone and poorly lithified, gray shale

• After deposition of the underlying Santa Formation there was a withdrawal of the sea. Much of the Carhuaz Formation is non-marine to brackish.
• Shale, dark gray, laminated, soft, with interbeds of dark brown, platy, fossiliferous limestone and of brownish quartz-siltstone.

Size class: macrofossils

Reposited in the AMNH

Collection methods: quarrying,

• Collections reposited at AMNH.

Primary reference: 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]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 56941: authorized by Austin Hendy, entered by Austin Hendy on 29.11.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• 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.
Show authors, comments, and common names
Cephalopoda
 Ammonitida - Olcostephanidae
Valanginites broggii
Valanginites broggii Lisson 1937 ammonite
Bivalvia
 Trigoniida - Trigoniidae
Buchotrigonia gerthii