Tectónica del macizo Hercínico de Honrubia (provincia de Segovia)

Abstract

This work confirms that the Honrubia Massif is just the northwestern prolongation of the eastern part of the Spanish Central System. Departamento de Geomorfología y Geotectónica. * Departamento de Petrología y Geoquímica. Universidad Complutense. ** 441 On one side, one finds the continuation of the Berzosa ductile lowangle tbrust, and moreover a new ductile low-angle thrust- the Honrubia Fault- is described, whicb is considered equivalent to the basal thrust in the 1-liendelaencina antycline. These accidents are related to the F> of the Hercynian tectogenesis. Like in the Central System, F, and F2 face northeastward with gently diping axial planes, whilst F3 faces in the opposite direction with more inclined axial planes. Another discovered faut-the Risco high-angle thrust- played at the end of F>. This fault along with the Honrubia Fault are responsable for the great thinning of all thc area which in the Central System is comprised between the Berzosa and the Hiendelaencina thrusts. The rnetamorphic regional succession is similar to the Buitrago's region one aud confirms again the existence of a remarkable metamorphic inversion related to the syn-F2 thrusts, wbich is typical of collisional orogenic belts.