FRANCISCO, NEPOMUCENO FILHO, NILO C. AZAMBUJA, and MARCIO R. MELLO, Petrobras, Rio de Janeiro, Brazil

ABSTRACT: Tectonic-Sedimentary Evolution of the Eastern Brazilian Marginal Basins: Implications in Their Petroleum Systems

A geological survey of eastern Brazilian marginal basins using sedimentological, tectonic and geochemical data has been carriet out. The almost 4000 km long set of basins can be classified as component of a typical divergent. mature Atlantic-continental margin. Based on their tectonic-sedimentary sequence, they can be linked to a single evolutionary history, which can be divided in three main stages: pre-rift, rift and drift.

The integration of all data allowed the characterization of two major petroleum systems that represent about 90% of the known Brazilian hydrocarbons reserves: (1) the rift (Early Cretaceous) and the drift (Late Cretaceous-Paleogene). With respect to the oil-in-place volume and production, the most significant one is the drift system associated with the siliciclastic deep water turbidites reservoirs deposited in bathyal environments. Such reservoirs are clearly controlled by a favorable relationship of stratigraphic and tectonic settings.

AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.