Quaternary evolution of the El Tromen volcanic system, Argentina, based on new K-Ar and geochemical data: Insights for temporal evolution of magmatic processes between arc and back-arc settings
The new data coupled with those previously published highlight that, in the last 2 Ma, the Tromen Volcanic System (TVS) erupted transitional, alkali and rhyolitic lavas which built the Tilhué, Chapúa-Maipo-El Puente, Coyocho-Wayle and El Tromen volcanic groups. Four partial melting events have been...
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2019
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v90_n_p338_Pallares http://hdl.handle.net/20.500.12110/paper_08959811_v90_n_p338_Pallares |
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| Sumario: | The new data coupled with those previously published highlight that, in the last 2 Ma, the Tromen Volcanic System (TVS) erupted transitional, alkali and rhyolitic lavas which built the Tilhué, Chapúa-Maipo-El Puente, Coyocho-Wayle and El Tromen volcanic groups. Four partial melting events have been identified: first at 2.10 ± 0.13 Ma, second at 1.44 ± 0.08 Ma, third at 1.04 ± 0.06 Ma and the last at 0.488 ± 0.007 Ma. Partial melting rates of the TVS sources are about 7% and constant, where first events affected simultaneously a shallower spinel-bearing mantle and a lower continental crust, and later ones a deeper garnet-bearing mantle. The melting of shallower, spinel-bearing, mantle released melts with low and middle-Ni, while the melting of deeper, garnet-bearing mantle, released relatively high-Ni melts. The lower continental crust affected by the first partial melting event could have been of sedimentary origin, thus producing the peraluminous Tilhué evolved lavas. © 2018 Elsevier Ltd |
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