Characterization of Jurassic Black Shales from Asturias (Northern Spain): Evolution and Petroleum Potential

The black shale levels for the Jurassic from the province of Asturias (Northern Spain) are mainly Pliensbachian age. They are composed of calcite, quartz, pyrite and illite as inorganic compounds while organic matter corresponds to a type II kerogen in which the autochthonous aquatic material (marine) predominates over that from the continental origin. The rank studies show a differential evolution for these sediments which corresponds to the diagenesis (represented by oil shales) and organic catagenesis (source-rocks of oil and gas) stages. This evolution seems to be linked to the tectonic of the region and to the presence of thermal flows which have occurred from the Paleozoic until after Jurassic sedimentation promoting the generation and migration of hydrocarbons.