Also known as Loc. 32

Where: Baja California Sur, Mexico (26.2° N, 112.3° W: paleocoordinates 25.3° N, 105.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Ysidro Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• The Ysidro Formation consists of dirty-white sandstone, underlying the Comondu Formation. The formation varies in lithology from place to place and apparently becomes more tuffaceous towards the gulf coast. The formation can be subdivided into two members, a lower shale member and an upper sandstone member. Collection from exposures initially named the "Purisima Nueva Formation", but now assigned to the lower part of the Ysidro Formation. Collected from white calcareous beds of the lower part of the formation, below the yellow member. Heim (1922) reports that the collection has affinities to the Gatun Formation of Panama.

• bed-level stratigraphic resolution

Environment/lithology: marine; white, calcareous shale

Size class: macrofossils

Collection methods: quarrying,

• Collected, studied and determined by Arnold and Clark (1917), further analyses by T.W. Vaughan and C.W. Cooke (reported by Heim, 1922). No known repository.

Primary reference: C. H. Beal. 1948. Reconnaissance of the geology and oil possibilities of Baja California, Mexico. Geological Society of America Memoir 31 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 43803: authorized by Austin Hendy, entered by Austin Hendy on 26.08.2004

Creative Commons license: CC BY (attribution)