THE GRENVILLIAN BASEMENT OF THE PRECORDILLERA/CUYANIA TERRANE AND THE FAMATINIAN MOBILE BELT.

BALDO, E.G.; CASQUET, C.; DAHLQUIST, J.; VAN STAAL, C.R.; VUJOVICH, G.

Mendoza

Conferencia; GONDWANA 12 CONFERENCE: GEOLOGICAL AND BIOLOGICAL HERITAGE OF GONDWANA.; 2005

C.W. Rapela (CONICET-UNLP) y L. A. Spalletti (CONICET-UNLP), Coordinadores-Editores.

The A3 pre-conference field trip is aimed at visiting key areas of Western Sierras Pampeanas (WSP) where much geological research has been made over the past few years. The WSP became notorious when Grenvillian age rocks were discovered in the Sierra de Pie de Palo. This fact led support the Precordillera (or Cuyania) terrane hypothesis that was put forward in the late 1980´ and developed in the 1990´. According to this hypothesis the Precordillera (or Cuyania) terrane was a fragment of Laurentia that detached from it in the Late Neoproterozoic to Early Cambrian to eventually collide with the western margin of pre-Andean Gondwana to produce the Famatinian orogeny in the Ordovician. The exotic Precordillera terrane consisted of a long enigmatic Cambrian to Early Ordovician carbonate platform sequence which outcrops in the Argentine Precordillera, to the west of the area dealt with in this field trip. In this hypothesis the WSP Grenvillian age rocks represented the basement of the platform carbonate sequence and were accordingly correlated with Grenvillian rocks of the Appalachian margin of Laurentia, i.e., the Ouachita embayment.