40Ar/39Ar dating of Patagonian Jurassic volcanism: New constrains on Gondwana break up.

ALRIC VI; FERAUD G; BERTRAND H; HALLER MJ; LABUDIA C; ZUBIA M

Strassbourg

Congreso; European Union of Gesciences, Strasbourg 9-13 April 1995; 1995

European Union of Gesciences

Southern South America was affected by an intense magmatic activity during the Jurassic, which produced in surface ignimbrites and rhyolites extending from de Andean Cordillera to the Atlantic coast over more than 1100 km from North to South. We observed an age evolution from the NE (oldest ages) to the SW (youngest ages) which may be related to the extensional tectonics which is characterised by NNW trending half grabens. The data will allow to define a well constrained model of initial break up of Gondwana in time and space.