Petrografía y Geoquímica del Gabro Winchos y su Asociación con la Mineralización de Magnetita en el Prospecto Winchospunta - Carhuamayo - Junín, Perú

The Winchos Gabbro, located in the Winchospunta prospect, Carhuamayo, Junín, was studied to characterize its petrography, geochemistry, and mineralogy, as well as to determine its relationship with magnetite mineralization and its nature and origin. To achieve this, petrographic and geochemical analyses were integrated to establish the relationship between the igneous rock and iron mineralization. The methodology involved the analysis of 24 representative samples, including gabbros, volcanic rocks from the Mitu group, and limestone from the Chambará Formation. ICP-MS and ICP-AES techniques were used to determine the chemical composition of major, minor, and trace elements, along with petrographic studies of thin and polished sections. The obtained data were interpreted using geochemical and tectonic discrimination diagrams. The results revealed a mineralogical composition dominated by calcic plagioclases (44%) and pyroxenes (15.5%), with hydrothermal alterations reflected in the presence of chlorites, secondary biotite, and hematite. Geochemically, Fe₂O₃values ranged from 11.55% to 16.13%, while MgO varied between 3.78% and 12.07%, suggesting a hydrothermal evolution. Magnetite exhibited TiO₂concentrations between 2.09% and 3.28% and V up to 294 ppm, which are typical characteristics of hydrothermal deposits, distinguishing them from orthomagmatic ones. The application of the Ti vs. Ni/Cr diagram, following the Dare et al. (2014) model, confirmed the classification of magnetite as hydrothermal in origin.