El granitoide de Manzaneda, marcador del acortamiento NE-SW en el arco hercínico

Abstract

The Manzaneda granite (NW Spain) is located at the southern sector of the Calida Variscan arc. It shows a NW-SE elongated shape, and covers ah area of about 400 Km2, within thè «P/ló de Sapo» anticlinorium.

It is a two-mica leucogranite, with feldspar phenocrysts (porphyritic fàcies) near the borders. The magmatic foliation within the massif shows a NW-SE strike, with variable dips, from horizontal to vertical. The northern and southern borders of the massif are occupied by two, granodioritic NW-SE-elongated bodies, with a NW-SE-striking, southward-dipping foliation. At both borders there are conjugate systems of C planes with subhorizontal lineation, whose obtuse bisector is NE-SW. The structures observed in the granitoid bodies and the country rocks .are consistent with a NE-SW flattening, which is consistent with a progressive changing of the shortening direction from E-W to NNE-SSW across the Variscan arc in NW Spain