Bol. Soc. Geol. Mexicana,  XXXVII, 60-83, 1976

El contacto Jurásico-Cretácico, la estratigrafía del Neocomiano, el hiato Hauteriviano Superior-Eoceno Inferior y las amonitas del pozo Bejuco 6 (Centro-Este de México).

Abelardo Cantú Chapa*

*Investigador del Instituto Mexicano del Petróleo.


Ammonites in 60 m of continuous core cut in the Bejuco 6 well southwest of Tampico, Mexico, separate the Jurassic from the Cretaceous, permit stage subdivision of the 40 m of Neocomian, and provide the first ammonite zoning for the Neocomian in eastem Mexico.

Six bentonite beds of Upper Tithonian-Upper Valanginian age intercalated with carbonate rocks of the Pimienta and Lower Tamaulipas Formations, have been dated.

Study of lithofacies of the Upper Tithonian amI Neocomian rocks, coupled with gamrna-ray logging, indicates an unconformity of Upper HauterivianLower Eocene age. Bejucoceras, a new genera of Ancyloceratidae, two new species of Neolissoceras, and new species of Haploceras, one new species of Proniceras, One new of Bochianites, are created.