USGS MR 5074, Marin Headlands (M-9) (Jurassic to of the United States)

Where: Marin County, California (37.8° N, 122.5° W: paleocoordinates 31.9° N, 62.4° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Bathonian to Bathonian (168.3 - 161.2 Ma)

• Assemblage MH-4: upper Middle Jurassic (Bathonian and (or) Callovian) and (or) lower Upper Jurassic (Oxfordian?, Kimmeridgian?). Bathonian to Early Callovian 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 185300: authorized by Matthew Clapham, entered by Matthew Clapham on 18.04.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

Radiolaria
 Nassellaria -
Tricolocapsa "sp. C" Haeckel 1881 radiolarian
 Nassellaria - Xitidae
Foremanina "sp. A" Empson-Morin 1981 radiolarian
 Nassellaria - Ultranaporidae
Napora "sp. A" Pessagno 1977 radiolarian
 Nassellaria - Parvicingulidae
Ristola turpicula Pessagno and Whalen 1982 radiolarian