BASIN EVOLUTION OF THE PRECORDILLERA TERRANE (WESTERN ARGENTINA) DRIVEN BY ORDOVICIAN EXTENSIONAL TECTONICS

PERALTA, S H.

Neuquén

Congreso; XVIII Congreso Geológico Argentino; 2011

Asociación Geológica Argentina

Ordovician sedimentary rocks are widely distributed in the Argentine Precordillera (Cuyania) terrane, but they are scarce or absent in other geological regions of Argentina, such as Famatina, Puna, Eastern Cordillera and the Subandean Ranges. In the Ordovician Precordillera, carbonate rocks range from Tremadocian to Darriwilian (Global Stages from International Subcommission on Ordovician Stratigraphy, ICS, IUGS, 2009), and siliciclastics predominate from Darriwilian to Hirnantian, although there are also some carbonate and mixed rocks. A conspicuous feature of the Precordillera is the extensive occurrence of Upper Ordovician siliciclastic shelf deposits in the eastern flank of Central Precordillera and Western Precordillera (Peralta, et al., 2003; Basilici, 2005), which are frequently associated with coeval basic volcanic and intrusive rocks (figure 1). On the basis of tecto-sedimentary, biostratigraphic and stratigraphic data correlation, this contribution aims to show how extensional tectonic drives the Ordovician basin evolution,