USGS 13584 - Tamaulipas, Mexico (Guajalote Formation) (Miocene of Mexico)

Also known as USGS 13584

Where: Tamaulipas, Mexico (24.9° N, 98.2° W: paleocoordinates 25.6° N, 94.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Guajalote Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• The Guajalote Formation is early Miocene age and can be correlated with the Tuxpam (or Tuxpan) Formations of southern Mexico, and have also been called San Rafael and San Fernandao Formation (Dumble's nomenclature). The Guajalote Formation has similar faunal composition to the Chipola and Shoal River formations of the Alum Bluff Group, Flordia. Field relations indicate that the fossiliferous beds of the Guajalote Formation lie some 2,500 feet above those of the upper Oligocene.

• bed-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified, shelly/skeletal sandstone

• Siliciclastic. No paleoenvironmental data reported. The lower Miocene was an interval of regression in the Gulf of Mexico.
• No specific lithologic description other than "fossiliferous sandstone".

Size class: macrofossils

Preservation: mold/impression

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 43075: authorized by Austin Hendy, entered by Austin Hendy on 10.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca.
Gastropoda
 Cerithioidea - Turritellidae
Turritella subgrundifera Dall 1892 turret shell
 Neogastropoda - Olividae
"Oliva cf. liodes" = Oliva (Omogymna) liodes
"Oliva cf. liodes" = Oliva (Omogymna) liodes Dall 1903 olive snail
 Neogastropoda - Nassariidae
"Uzita ? waltonensis" = Nassarius (Uzita) waltonensis
"Uzita ? waltonensis" = Nassarius (Uzita) waltonensis Gardner 1936 snail
Bivalvia
 Pectinida - Pectinoidae
"Chlamys (? Lyropecten) nicholsi" = Lyropecten, "Chlamys (Nodipecten) dumblei" = Lyropecten dumblei
"Chlamys (? Lyropecten) nicholsi" = Lyropecten scallop
Subspecies: Chlamys (Lyropecten?) sp. cf. nicholsi neotera
"Chlamys (Nodipecten) dumblei" = Lyropecten dumblei Gardner 1945 scallop
 Cardiida - Cardiidae
"Cerastoderma (Dinocardium) ? cabezai" = Dinocardium cabezai
"Cerastoderma (Dinocardium) ? cabezai" = Dinocardium cabezai Gardner 1945 cockle