GEOLOGÍA Y PETRO-CALCOGRAFÍA DE UN DIQUE SUB-VOLCÁNICO DEL COMPLEJO VOLCÁNICO ANTILLA-SAN LORENZO, SALTA

FOGLIATA, A.; GROSSE, P.; ALDONATE, D.

Córdoba

Congreso; Congreso de Mineralogía, Petrología Ígnea y Metamórfica, y Metalogénesis: XIII MINMET y IV PIMMA; 2019

The Pliocene Antilla-San Lorenzo Volcanic Complex is the easternmost mafic back-arc volcanic complex of the southern Central Andes. Here, we present the geology and petro-chalcography of a sub-volcanic dyke from this complex. The dyke has an outcrop length of 380 m and an upper width of 15-20 m. It is sub-vertical and strikes N85º to N100º. It is characterized by large and abundant hornblende phenochrysts and abundant opaque minerals. A border and a central facies are distinguished. The border facies is richer in hornblende phenochrysts and poorer in augite and pigeonite phenocrysts. The central facies has a lighter color due to chlorite-calcite-quartz hydrothermal alteration. Both facies contain abundant magnetite > pyrite > ilmenite.