Resumo

SRUOGA, Patricia et al. Initial stage of the Neogene volcanic arc in the Cordillera Principal of Mendoza (35°S). Rev. Asoc. Geol. Argent. [online]. 2008, vol.63, n.3, pp.454-469. ISSN 0004-4822.

This is the first time that an integrated geological approach of the volcanic complex outcroping at Cordón del Burrero and surrounding areas, in Cordillera Principal of Mendoza province (35° S), is carried out. It constitutes a complex volcanic unit, encompassing lavas, dykes and subvolcanic intrusive bodies of basaltic, andesitic and rhyolitic composition. These rocks belong to high-K calc-alkaline series, showing high Ba, Sr, Rb and Cs contents, Nb, Ta and Hf depletion and moderate La/Yb ratios. The volcanics experienced regional burial and related very low grade metamorphism under zeolite and prehnite-pumpellyite facies conditions. In addition, another yuxtaposed thermal event was locally identified. The volcanic event took place during Middle Miocene times (~ 18 a 14 Ma) and represents the initial stage of the neogene volcanic arc in Argentina and it may be correlated to the lowest part of Farellones Formation, widespread in Chile at these latitudes.

Palavras-chave : Miocene; Volcanism; Cordillera Principal; Mendoza.

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