ammonites
USGS Loc. D4536, San Juan Basn [Lewis Shale] (Cretaceous of the United States)

Where: New Mexico (36.6° N, 106.9° W: paleocoordinates 43.5° N, 78.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Lewis Shale Formation, Late/Upper Campanian (83.5 - 70.6 Ma)

• STRATIGRAPHIC RELATIONS: From the Lewis Shale, for which lithostratigraphic relations are not discussed. AGE: Late Campanian, on the ammonoid biostratigraphy; Didymoceras cheyennense zone. STRATIGRAPHIC POSITION: About unknown position within formation.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, concretionary, brown, gray, argillaceous, calcareous shale

• SPECIFIC LITHOLOGY: Gray weathering limestone concretions. LITHIFICATION: Lithified, assumed on the neighboring collections.

Size class: macrofossils

Preservation: concretion

Reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: Dane, Landis & Cobban, 1964. REPOSITORY: USNM.

Primary reference: W. A. Cobban, E. R. Landis, and C. H. Dane. 1974. Age relations of upper part of Lewis Shale on east side of San Juan Basin, New Mexico. New Mexico Geological Society Guidebook, 25th Field Conference, Ghost Ranch 279-282 [A. Hendy/A. Hendy/A. Hendy] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 88559: authorized by Austin Hendy, entered by Austin Hendy on 14.04.2009

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)