Also known as A 3576

Where: Baja California Sur, Mexico (27.1° N, 112.1° W: paleocoordinates 26.9° N, 110.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: San Marcos Formation, Early/Lower Pliocene (5.3 - 3.6 Ma)

• The San Marcos Formation includes clastic sediments as well as gypsum, and along the southeastern shore and southern contact of volcanic rocks the base of the formation consists of 100-150 feet of volcanic sandstone and interbedded volcanic conglomerate resting on and butting into the Comondu volcanics. Marine fossils occur in sediments conformably overlying the gypsum northeast and southwest of the main gypsum area. The lower part of the section is volcanic sandstone, while the upper part is calcareous conglomerate and pebbly limestones, locally quite fossiliferous. Collection from sandstone overlying congglomerate, and overlain by conglomerate containing pebbles of granite.

• bed-level stratigraphic resolution

Environment/lithology: marine; poorly lithified, gray, calcareous sandstone

Size class: macrofossils

Reposited in the UCMP

• Material reposited in the UCMP collections.

Primary reference: J. W. Durham. 1950. 1940 E.W. Scripps cruise to the Gulf of California. Part II - Megascopic paleontology and marine stratigraphy. Geological Society of America Memoir 43(2) [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 44035: authorized by Austin Hendy, entered by Austin Hendy on 31.08.2004

Creative Commons license: CC BY (attribution)