Significado geotectónico de la formación Gneises de La Morcuera

Abstract

In the Eastern Guadarrama (Sistema Central, Spain) crops out a gneissic formation, the Morcuera Gneiss, under metasedimentary preordovician terrains of the Buitrago Formation, probably Cambriam in age. The Morcuera Gneiss is made up of a basal augengneiss complex covered by a succession of several types of gneiss derived from volcanic and sedimentary rocks. In this paper are studied the pétrographie, stratigraphie, tectonic and chemical features of Morcuera Gneiss. The existence of ortogneiss derived from old porphyritic granites is ascertained and the tectonic signification of Morcuera Gneiss is finally discussed.