GEOCRONOLOGÍA U/Pb DE CIRCONES DEL COMPLEJO VOLCÁNICO PAIRIQUE: INTERPRETACIONES PETROGÉNETICAS Y ERUPTIVAS

CAFFE, P.J.; SCHMITT, A.K.; JOFRE, C.B.; TRUMBULL, R.B.; PERALTA ARNOLD, Y.J.; MARO, G. .; SARCHI, C.

Congreso; XIII Congreso de Mineralogía Petrología Ignea Y Metamórfica Y Metalogénesis XIII MINMET- IV PIMMA; 2019

We present a reconnaissance study of U/Pb isotopic data on zircon crystals from the Pairique Volcanic Complex (PVC). Comparisons between zircon ages (averaging ~11 Ma) and previous Ar/Ar data (biotite) suggest that the magmatic system at PVC started to develop 70-800 ka before eruption. Some of the pervasively altered units at the eastern Bajo Pairique region yielded the youngest ages of PVC, which along with petrographic data and presence of skarn suggest that part of the Bajo Pairique Lavas is actually an intrusion. Abundance (~20 %) of xenocrystic zircon cores with Pampean-Famatinian ages and the overall peraluminous nature of PVC are interpreted as evidence for an origin via increasing contamination of typical APVC magmas with metasedimentary material/anatectic melts.