USGS 13513 - Nuevo Leon, Mexico (upper Jackson Formation) (Eocene of Mexico)

Also known as USGS 13513

Where: Nuevo Leon, Mexico (25.8° N, 99.2° W: paleocoordinates 26.9° N, 91.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Upper Member (Jackson Formation), Late/Upper Eocene (37.2 - 33.9 Ma)

• The Jackson Group of Mexico and the Gulf Coastal Plain is here considered as a formation. The Jackson Formation can be subdivided into three members, the basal "Roma Sandstone" and middle and upper members (no lithostratigraphic name). No comments are made on relations to Gulf Coastal Plain units, but the enterer considers that the Jackson Formation of this collection is equivalent in age (late Eocene) as the Jackson Group (Gulf Coastal Plain). Collection is from massive, heavily fossiliferous sandstone boulders.

• bed-level stratigraphic resolution

Environment/lithology: coastal; fine-grained, shelly/skeletal, gray sandstone

• Siliciclastic. Enterer considers the fauna to be an inner shelf assemblage. No paleoenvironmental data reported.
• Listed as "massive, heavily fossiliferous sandstone". Assumed to be similar to other collections in being fine-grained, gray.

Size class: macrofossils

Reposited in the USNM

Collection methods: quarrying,

• Collections reposited in USGS and USNM collections.

Primary reference: J. Gardner. 1945. Mollusca of the Tertiary formations of Northeastern Mexico. Geological Society of American Memoir 11 [M. Kosnik/M. Kosnik/M. Kosnik]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 43051: authorized by Austin Hendy, entered by Austin Hendy on 09.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca.
Gastropoda
 Opisthobranchia - Cylichnidae
Acteocina melinoides barrel-bubble
 Opisthobranchia -
Nucleopsis sp. Conrad 1865 snail
 Neogastropoda - Turridae
Pleurofusia ? collaris Casey 1903 turrid
 Neogastropoda - Nassariidae
"? Tritiaria zacatensis" = Nassarius (Tritiaria)
"? Tritiaria zacatensis" = Nassarius (Tritiaria) snail