The geology and petrology of the Artiès—Siguer—Valira del Norte Valleys, Aston-Hospitalet Massif (France-Andorra)

The stratigraphic sequence of the mapped area consists of Paleozoic rocks ranging from Cambro-Ordovician to Carboniferous. Part of this sequence occurs in a regional metamorphic state as schists and migmatites. A large body of a leucocratic gneiss with granites occurs in this metamorphic series, and probably represents an orthogneiss. The petrography of the non-pelitic, mainly calcareous rocks in the schists and migmatites is described. The relations between metamorphism and folding from the Serrat area are treated. A short description of the various structures is given in the last chapter. Pegmatites occurring abundantly in the metamorphics, are dealt with.