USGS MR 5062, Marin Headlands (M-6) (Jurassic of the United States)

Where: Marin County, California (37.8° N, 122.5° W: paleocoordinates 31.4° N, 60.8° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Bajocian (170.3 - 168.3 Ma)

• Assemblage MH-3: The possible range of assemblage MH-3 is considered to be Middle Jurassic (Bajocian to Callovian) and possibly lower Upper Jurassic (Oxfordian?, Kimmeridgian?). Restricted to Bajocian in Kohnen & Murchey, 1995.

• bed-level stratigraphic resolution

Environment/lithology: basinal (siliceous); lithified chert

Size class: macrofossils

Reposited in the USGS

Primary reference: B. Murchey. 1984. Biostratigraphy and lithostratigraphy of chert in the Franciscan complex, Marin Headlands, California. Franciscan Geology of Northern California Field Trip Guidebook 43, Society of Economic Paleontologists and Mineralogists, Pacific Section 51-70 [M. Clapham/M. Clapham]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 185296: authorized by Matthew Clapham, entered by Matthew Clapham on 18.04.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Nassellaria - Xitidae
Foremanina "sp. A" Empson-Morin 1981 radiolarian
 Spumellaria - Pantanelliidae
Pachyoncus sp. Pessagno and Blome 1980 radiolarian