Lutitas Cocachacra, Isaacson collection (Devonian of Peru)

Where: Peru (17.1° S, 71.8° W: paleocoordinates 58.7° S, 94.0° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Lutitas Cocachacra Formation, Early/Lower Devonian (419.2 - 393.3 Ma)

• Authors tentatively suggest correlation with Emsian Floresta Fmn. in Colombia.

• member-level stratigraphic resolution

Environment/lithology: marine; fine-grained, micaceous sandstone and brown, cherty/siliceous siltstone

• "Devonian...consists of alower, conglomeratic unit...overlain by an upper unit of quartzite and finer-grained rocks, the "Lutitas Cocachacra"...the conglomeratic unit is polymictic...Above the conglomerate are quartzites and fine-grained, indurated and slabby beds of the Cocachacra lutites [about 30-40 m thick] [which] might represent reworked, silicified volcanic material [containing quartz, biotite, and muscovite]...The fossils occur in dark brown, flinty siltstone..."

Primary reference: A. J. Boucot, P. E. Isaacson, and G. Laubacher. 1980. An Early Devonian, Eastern Americas Realm faunule from the coast of southern Peru. Journal of Paleontology 54(2):359-365 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 36142: authorized by Michael Foote, entered by Michael Foote on 14.01.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

"? Pelecypoda indet." = Bivalvia
"? Pelecypoda indet." = Bivalvia Linnaeus 1758 clam
 Spiriferida - Acrospiriferidae
 Rhynchonellida - Trigonirhynchiidae