ESTUDIO GEOCRONOLÓGICO Y PETROLÓGICO DEL PLUTÓN ANCAJÁN, SIERRAS PAMPEANAS ORIENTALES

ZANDOMENI, P.; VERDECCHIA, S.; BALDO, E.; DAHLQUIST, J.; CASQUET , C.; BASEI, M.A.S.; MORENO, J.A.; PANKHURST, R.J.

Córdoba

Congreso; XIII CONGRESO DE MINERALOGÍA, PETROLOGÍA ÍGNEA Y METAMÓRFICA, Y METALOGÉNESIS; 2019

Asociación Geológica Argentina y Asociación de Mineralogía de Argentina

Geochronological and petrological study of the Ancaján pluton, Eastern Sierras Pampeanas. An elongate igneous body, known as the Ancaján pluton, crops out in Sierras de Ancaján, Eastern Sierras Pampeanas, Santiago del Estero, Argentina. A U-Pb zircon Concordia age of 372 ± 10 Ma (MSWD= 0.60; n=4) was obtained by LA-MC-ICP-MS, which represents the first report of Devonian age at this latitude (28°27?). Furthermore, SHRIMP and LA-MC-ICP-MS U-Pb zircon data reveal a high inheritance in this granite, represented by zircon populations with ages ranging from Paleoproterozoic to Ordovician (1826 ? 465 Ma). The pluton was emplaced in marbles and its magmatic assemblage consists of Qtz + Kfs + Pl + Bt with Ep, Ap, Zrn and Op as accessory minerals. Geochemically, the granitic rocks are weakly peraluminous, magnesian and calc-alkalic with SiO2 ranging from 66.13 to 73.26 wt.%.