Caracterización de la mineralización en el área de Santa María - Proyecto Arenizo, Ayacucho - Perú

Abstract

The Arenizo Project in Santa María area is located between the district of Pullo Parinacochas Province of Ayacucho Region and the Quicacha District, Caraveli Province, Arequipa region, on western flank of Parinacochas synclinorium at 3600 m.s.n.m in the Coracora quadrangle, sheet 31-O of The National Charter of Peru. Lithologically is conformed of Quaternary alluvial deposits, the Huaylillas volcanic Tertiary upper is conformed of crystal tuffs and lapilli tuffs, Formation Huanca is conformed of deposits red molásicos, Formation Arcurquina Upper Cretaceous is conformed of Aguas Verdes member of carbonaceous limestones and member Arenizo of white limostine. The plutonic igneous rocks belong to the Coastal Batholith of Upper-Lower Cretaceous, the Tiabaya Superunitis is conformed of tonalite-granodiorite to diorite undifferentiated. There are young magmatic of age Paleogene, events that do not belong to the Coastal Batholith is conformed of horblende diorite and porphyry dacite.

There are regional faults from direction approximate EW, NW and NE; the regional Arenizo fault is the most affecting to the events of the magmatic activity of the intrusive rocks. Locally the Arenizo fault has direction average N15°W and has faults cross to the mineralization in the area project. The hydrothermal alterations present are: phyllic alteration (quartz-sericite-pyrite), argillic alteration (clay), propylitic alteration (chlorite-epidote-calcite) and silicification (SiO2). The contact metamorphism there is presence of skarn and marble. The main economic mineralization is observed in outcrops of the Anita Vein, Maria vein and type stock work veins. It has been identified iron oxides, sulfates (jarosite, barite), hosted in dacite porphyry and horblende diorite. The mineralization of the deposit is epigenetic, the scattering of the elements is primary, reported geochemical laws of economic importance in Au, Ag and Cu.