Articles

Correlaciones multiestratigráficas en el límite Jurásico-Cretácico en el noreste de México

Thierry Adatte1, Wolfgang Stinnesbeck2, Hans Hubberten3, Jurgen Romane1

1Institut de Géologie, 11 rue, Emile Argand, 2007 Neuchâtel, Suiza
2Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León, Ap. Postal 104. 67700 Linares, N.L., México
3Alfred Wegener Institut für Polar-und Meerersforschung. Forschungsstelle Potsdam, Telegrafenberg A 43. 0-1561 Postdam. Alemania

 

Abstract

Four profiles, three of them in the Sierra Madre Oriental and one, 400 km farther NW in the Durango Basin, have been measured and sampled in detail, in order to ascertain the stratigraphic position of the boundary between the La casita and Taraises Formations. Calpionellids show that this boundary is diachronus, situated in the Lower Berriasian. Late Tithonian Mediterranean faunal elements are, however, largely (Crassicolaaria in the case of calpionellids) or completely missing (Saccocoma, Chitinoidella). Calpionellids are still more or less sporadic in the lower part of zone B, but become frequent its upper part. This indicates an important turnover in oceanographic conditions (currents and/or temperature), which appears also clearly in a change of the composition of clay-mineral associations (increase of chlorite, decrease of kaolinite). Analyses of stable isotopes point in the same directions, as well as the simultaneous appearance of Mediterranean ammonite genera. Calpionellid Zones C to D1 are reduced or incomplete in this part of the Sierra Madre Oriental.

The succession of calpionellid species corresponds perfectly to that known from Mediterranean realm. This allows precise transatlantic correlations, it appears that the ammonite genera Durangites and Hildoglochiceras extend to the lowermost Berriasian (lowermost Zone B), whereas Kossmatia and Substeueroceras extend farther up into the Berriasian.


Resumen    Abstract     HTML    PDF    Vol. 51, n. 1-2 (1991-1992)