LITHOLOGY AND AGE OF THE CUSHAMEN FORMATION: DEVONIAN MAGMATISM IN THE WESTERN NORTH PATAGONIAN MASSIF, ARGENTINA

LÓPEZ DE LUCHI, M.G.; CERREDO, M.E.; MARTÍNEZ DOPICO, C.I.

BOLLETTINO DI GEOFISICA TEORICA ED APPLICATA

ISTITUTO NAZIONALE DI OCEANOGRAFIA E DI GEOFISICA

Lugar: Trieste; Año: 2010 vol. 51 p. 71 - 74

0006-6729

Accurate temporal constraints for the metamorphic peak conditions, granitoid emplacement, deformational events and cooling paths are a key issue for unraveling the tectono-metamorphic history of basement complexes such as the Cushamen Metamorphic Complex. One of the greatest difficulties in Rb-Sr dating on metamorphic rocks is the lack of evidence of complete re-homogenization and the assumption of a common initial Sr ratio. Magmatic units that were emplaced at different stages of the metamorphic evolution as indicated by deformation features could be satisfactorily dated with this method. In this paper we present two cooling ages for the Cushamen Metamorphic Complex.