The South American Ordovician System

Abstract

?The South American Ordovician System?. Deposits of Ordovician rocks in South America were controlled by the gradual cortical decrease that affected a great part of the Andean Cordillera and some pericratonic sectors of the Atlantic region since the end of the Upper Cambrian. The general distribution and litho-biostratigraphic characteres of the outcrops aid to interpret the paleogeography and structural controls that had an effect on deposits of the sedimentary series, development of metamorphic sequences and the insert of an early eruptivity in an cycle the magnitude of which ovarpasses the period (Famatinian cycle). The continental cratonized zone looses its integrity until the end of the periods, when it was fractured whith later expansion of the Amazonian area and similar regions of the Brazilian border and Argentinian central cratogene. The Paleozoic register of the statigraphic column from Argentina allows to describe it as the most complete from South America.