Edad minima del gossan de Las Cruces: implicaciones sobre la edad del inicio de los ecosistemas extremos en la Faja Pirítica Ibérica

Abstract

The micropalaeontogical study of glauconite sands overlying Las Cruces massive sulfide deposit (Iberian Pyrite Belt) indicates an Upper Tortonian minimum age for oxidation and the gossan genesis. Sulfide oxidation, both natural and anthropic, give acid waters which are characterized by low pH values as well as high sulphate and metals concentration. Extreme environments, controlled by acidic waters, have been developed in the Iberian Pyrite Belt including the Rio Tinto ecosystem, which have been enhanced recently by an unexpected level of biodiversity, importance of such type of environments are related with the origin of life on Earth and even other Solar system scenarios. Time consideration for natural acidic water pollution at the Rio Tinto system have been suggested of about 0,5 m.y. However, the minimum age of the Las Cruces gossan predate on about 6 m.y the previously reported age for the Rio Tinto acidic ecosystem