Bacia dos Parecis

Abstract

The analysis, interpretation, and integration of available geological data and information on central western Brazil's Phanerozoic sedimentary province, located between the Paraná and Solimões Basins, indicates the existence of a large basín marked by an extended subsidence of great  amplitude and sedimentary filling some 6,000 m thick from the Paleozoic, Mesozoic, and Cenozoic. Within the sequence labeled Paleozoic, it has been possible to identify radioactive carbonaceous shales (likely hydrocarbon source rocks); sandstones with good reservoir-rock characteristics; and shales, clayey siltstones, pebbly mudstones and gypsiferous horizons, all acting as sealing rocks. lmportant tectonic activity partly contemporaneous with Paleozoic sedimentation as well as tectonic reactivation as from the Neo-carboniferous Permian fostered the development of structural, stratigraphic, and combination traps. As defined herein, the Parecis Basin reveals similarities to the oil and gas-bearing Solimões and Amazonas Basins and although no direct evidence of gas or oil has been found, the Parecis may be considered an attractive alternative for hydrocarbon research.