in a burial metamorphosed volcanic pile, central Chile M. VERGARA', B. L E V I 2 A N D R. V I L L A R R...Departamento of Geologia, Universidad de Chile, Casilla 73518, Santiago, Chile *Department of Geology and Geochemistry...S-10691 Stockholm, Sweden Codelco Chile, Divisi6n El Teniente, Rancagua, Chile ' ABSTRACT The Upper Cretaceous...by burial metamorphism. For example, in central Chile (between 32"" and 35"s), the Abanico Formation,...Abanico Hill area, located just east of a graben at Santiago (the longitudinal Central Valley), the alteration |