Resumo

BERALDI-CAMPESI, Hugo  e  CEVALLOS-FERRIZ, Sergio R. S.. Microfossil diversity in the Tarahumara Formation, Sonora. Rev. mex. cienc. geol [online]. 2005, vol.22, n.2, pp.261-271. ISSN 2007-2902.

A great diversity of permineralized microfossils are found embedded in chert associated to stromatolites that crop out in the Huépac locality, an Upper Cretaceous (Turonian-Maastrichtian) volcano-sedimentary sequence of the Tarahumara Formation, in Sonora, Mexico. The diversity is represented by fossils of microalgae, pollen, spores, conidiospores, fragments of plants and arthropods, achritarchs and undefi ned structures of biological origin, refl ecting the type of organisms that lived asssociated to the water body and part of the surrounding biota. Our observations support the interpretation of a lacustrine depositional environment associated to magmatism in this portion of the Formation. This work documents part of the Upper Cretaceous microfl ora and microfauna of the northwestern Mexico.

Palavras-chave : microfossils; stromatolites; Tarahumara Formation; Cretaceous; Huépac; Sonora; Mexico.