REVISÃO ESTRATIGRÁFICA DA PARTE ORIENTAL DA BACIA BAURU (NEOCRETACEO)

This paper deals with the stratigraphy of the Bauru Basin based on regional investigation. The Bauru Basin was formed in the Late Cretaceous (Coniacian- Maastrichtian) as a result of subsidence of the central-southern part of the South-American Platform.This inner continental basin spreads over an area of approximately 370,000 km2 and is filled by a sandy sequence with maximum thickness of 300 meters at present. Its substratum is constituted by volcanic rocks (mainly basalts) of the Serra Geral Formation (1K) from which it is separated by a regional erosive surface. The studied area, with about 180,000 km , corresponds to the eastern part of the basin (west of Sao Paulo, southwest of Minas Gerais, northwest of Parana), and is located between the coordinates 18°S to 25° S and 47° W to 54° W. According to the distribution and interrelations of the units a stratigraphic revision was proposed for the basin. The Upper Cretaceous sequence is now divided in two groups, partially contemporaneous: Caiua Group (Rio Parana, Goio Ere and Santo Anastacio formations) and Bauru Group (Uberaba, Vale do Rio do Peixe, Aracatuba, Sao Jose do Rio Preto, Presidente Prudente, and Marilia formations, including the Taiuva analcimites).