Geología y prospección geoquímica del prospecto Pisacca, Arequipa

Abstract

The prospect "Pisacca" comprises approximately 712 hectares of surface area, it is an area located between 3.0 and 5.0 km south of the Caylloma mining unit; area that became a target of exploration for the company due to anomalous results in Au obtained in samples of "chips", during a regional campaign executed years ago, as well as the presence of silicified structures. During the present work it was possible to identify the Orcopampa Formation in almost all the extension of the prospect, with predominance of vulcanoclastics and andesitic flows, covered by andesitic lavas of the Barroso Group. The silica-illite, silica- chalcedonic and argilization alteration are presented with great importance associated with the structural guidelines present in the area. The mineralogical assemblies of alterations found: kaolinite-silica and illite-smectite, the result of the fluid inclusion sample comprised between 200 and 400ºC and salinity between 2 and 10% eq. NaCl weight, and the geochemical results helped to understand the possible type of deposit, which may correspond to a mesothermal transition to an epithermal of intermediate to low sulfidization of Ag-Au and polymetallic veins. Consequently, considering the results of the lithostructural mapping, sampling results and the geochemical data treatment, it is recommended to continue with the geophysical studies and according to results continue with the diamond drilling, in order to define the economic potential of the prospect.