Caracterização geoquímica de folhelhos betuminosos da formação Ipubi, bacia do Araripe, NE Brasil

Abstract

The Araripe Basin is characterized predominantly by continental sedimentary systems related to the fragmentation of Gondwana and formation of the South Atlantic Ocean. This study aims to characterize the organic matter of four samples of bituminous black shale from Ipubi Formation, collected in different mines of gypsum, using total organic carbon (TOC), Rock-Eval pyrolysis,liquid chromatography (LC) and gas chromatography-mass spectrometry (GCMS) in order to make an interpretation of the environmental conditions during the deposition event. The samples show high values of TOC, and data provided by pyrolysis show a very immature rock endowed with a large hydrocarbon generating potential and classified as Type I kerogen. Gas Chromatography-Mass Spectrometry data obtained from saturated and aromatic fractions, provided parameters and specific compounds that points to an imature organic matter deposited in lacustrine, anoxic and hypersaline environment, showing contribution of algae and higher plants.