Materia orgánica en la Fm. Arenas de Utrillas de Picofrentes (provincia de Soria): diagénesis mineral y orgánica

Abstract

By Rock-Eval pyrolysis method, fluorescence, microscopy and S.E.M. with E.D.A.X. analysis, the organic matter rich horizonts at the top of Utrillas Fm. in Picofrentes log were studied. Ail samples are potencially good source rocks for hydrocarbons and they show type I (lacustrine o.m.), being located in the inmature zone close to the oil window boundary. The reaction between the organic acids liberated in the o.m. decarboxylation process, in the intercalated lutites, leads to the diagenetic alteration of K-feldspar to kaolinite and gibbsite and the enhancement of the porosity in the arkosic sandstones