Cenozoic plutonism geochemistry in the extra-andean southern Patagonia as evidences of arc migration process

In this work, we present the results of a petrographic and geochemical study that involves seven Cenozoic plutons located in NS trending belt western Patagonia, south Chile Triple-Junction to east magmatic arc. Four were studied northern end, three southern part belt. The characteristics (major trace element contents, eNdt, 87Sr/86Sr initial ratios), these are different enough propose further classification for them: Only Monte Balmaceda intrusive complex end is alkaline (sensu stricto). Río de Las Nieves San Lorenzo area, Torres del Paine complex, area have “intra-plate transitional” calc-alkaline affinity. Paso Llaves Cerro Negro Ghío Donoso pluton show “arc character. “transitional” character, together with pluton’s location, their regional geological context, can be explained by Mio-Pliocene eastward arc migration coeval beginning Rise subduction. A slab flattening hypothesis favoured explain arc-migration, which length time arrival segments subduction zone, contributed heterogeneous geochemistry plutons.