La glaciación del límite Ordovícico-Silúrico en el Altiplano de Perú: evidencias e implicaciones tectónicas

Abstract

The Lower Paleozoic strati graphic sequence cropping out immediately to the north of Ayaviri (Peruvian Altiplano) belongs to the Eastern Cordillera tectonostratigraphic domain, and includes the Sandia, San Gabán and Ananea formations. Clacially-striated and faceted clasts found within the diamictites of the San Gabán Formation provide the first evidence for the late Ashgill-Llandovery glaciation in the Peruvian Altiplano, an area where this unit was previously considered not to be deposited. The marked difference between the Lower Paleozoic sequences of the Altiplano and Eastern Cordillera tectonostratigraphic domains suggests important tectonic shortening along the boundary fault zone