Biostratigraphy of the Passa Dois Group in the São Paulo State

Abstract

The well drilling to get groundwater supply in São Paulo State has been carried by Instituto Geológico (ex-Instituto Geográfico e Geológico). It led not only to new stratigraphic data but also, to paleontologic observations which has enlarged broadly our knowledge on geology concerning to Passa Dois Group in São Paulo State. The following fossils found in Lara wells have been identified: Lycopodiopsis derbyi Renault; ? Thallites sp.; Pecopteris sp.; Unknown fossils plants; Leinzia froesi Mendes; Paulocaris pachecoi Clarke; Amaralia paulistana Kegel; Liocaris huenei Beurlen; Clarkecaris brazilicus (Clarke) Mezzalira; and others as fish scales and., spines from Paleoniscidea and Ostracoda. Then some considerations are done concerning to the biota fossil stratigraphic position in Passa Dois Group. The recent survey in this area led to the correlation between macro and microfossil, including the bioestratigraphic zoning. It has been suggested in experimental way the possible correlation and the respective zones which follow: Pinzonella neotropica Zone; Lycopodiopsis derbyi Zone; Zone I; Pinzonella ilIusa Zone; Zone II; in Estrada Nova Formation. It has been suggested in the underlying Iraty Formation which includes Serra Alta Member the Zone m; Leinzia froesi Zone; Barbosaia angulata Zone; Paulocaris pachecoi Zone; Mesosaurus brasiliensis Zone including Pygaspis brasiliensis Sub Zone and Clarkecaris brazilicus Zone.