Caracterización y origen de las dolomías del sector sudeste de Picos de Europa (Norte de España)

Abstract

In this work we focus on the dolomitization processes which affected the southeastern sector of Picos de Europa Unit. The dolostones formed consequently with this process are rocks with a varied and irregular geometry, wich reminds that observed in intrusive rocks. Their chemical composition show a slight excess of calcium in relation to stoichiometric dolomite. Their iron and strontium contents are low in relation to other comparable dolomites. The abundance of dolostones is much bigger at the Frontal Unit than in upper structural Units. The dolomitization processes respond to an epigenetic dolomitization model and they are previous to the formation of Pb-Zn orebodies. We suggest a per ascensum dolomitization model tiggered by formation waters of the Pisuerga-Carrion Unit. With regard to age, the dolomitization was later than Lower Estephanian B and possibly earlier than some undetermined time during the Permian.