ammonites
banner
Gateway to the Paleobiology Database
USGS 13564 - Nuevo Leon, Mexico (lower Laredo Formation) (Eocene of Mexico)

Also known as USGS 13564

Where: Nuevo Leon, Mexico (25.9° N, 99.2° W: paleocoordinates 27.9° N, 89.7° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Laredo Formation), Middle Eocene (48.6 - 37.2 Ma)

• The succession of Claiborne Group in northeastern Mexico is exceptionally thick and well correlated to those units of the same name in Texas on the basis of faunal similarity. The name Laredo Formation replaces the "Cook Mountain Formation" in the Rio Grande embayment. The Laredo Formation is divided into three members: lower, middle and upper. The collection is from the lower member.

• bed-level stratigraphic resolution

Environment/lithology: marine; shale

• Siliciclastic. No paleoenvironmental data reported.
• No concise lithological description of the lower Laredo Formation, although several collections are described similarly as coming from shales with associated limestones and concretionary horizons.

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 42991: authorized by Austin Hendy, entered by Austin Hendy on 07.08.2004

Creative Commons license: CC BY (attribution)