USGS D11424, Section 15 [Smoky Hill Shale Mbr, Niobrara Fm] (Cretaceous of the United States)

Where: Colfax County, New Mexico (36.3° N, 104.8° W: paleocoordinates 40.7° N, 72.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Smoky Hill Shale Member (Niobrara Formation), Santonian (86.3 - 83.6 Ma)

• STRATIGRAPHIC RELATIONS: From the Smoky Hill Shale Mbr of the Niobrara Fm, which regionally overlies the Fort Hays Limestone. AGE: Santonian, on the basis of inoceramid and ammonite biostratigraphy; Prionocyclus quadratus biozone. STRATIGRAPHIC POSITION: Bed 4, in the sandy unit, from near middle of section.

• bed-level stratigraphic resolution

Environment/lithology: coastal; lithified, gray, sandy limestone

• ENVIRONMENT: Shallow marine siliciclastic environment.
• SPECIFIC LITHOLOGY: Limestone, gray, weathers orange, platy, dense. LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Collected by Scott, Cobban, Merewether, Buckhorn in 1984; reposited in the UNSM

• COLLECTORS: Scott, Cobban, Merewether, and Buckhorn (1984). REPOSITORY: USNM.

Primary reference: G. R. Scott, W. A. Cobban, and E. A. Merewether. 1986. Stratigraphy of the Upper Cretaceous Niobrara Formation in the Raton basin, New Mexico. New Mexico Bureau of Mines and Mineral Resources Bulletin 115:1-34 [A. Hendy/A. Hendy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 82264: authorized by Austin Hendy, entered by Austin Hendy on 25.07.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Probably not exhaustive, but comprising representative and common bivalves and cephalopods. NOMENCLATURE: Not an authoritative publication, but with modern nomenclature, and identifications to species-level.
Bivalvia
 Myalinida - Inoceramidae
Inoceramus sp. Sowerby 1814 clam
 Ostreida - Ostreidae
 Ostreida - Pteriidae
Phelopteria sp. Stephenson 1953 pearl oyster
Cephalopoda
 Ammonitida - Scaphitidae
 Ammonitida - Baculitidae
Baculites codyensis Reeside 1927 ammonite