Exploración de sistemas pórfidos utilizando la Alunita como vector de orientación en la Litocapa Los Tambos, región Ayacucho, Perú

The mining districts of Southern Peru located in the Tertiary volcanic belt host epithermal systems hosted by Lithocap that could be linked to porphyry systems. There are several tools to explore “hidden” porphyry systems and one of them are Alunites. The usefulness of Alunites is proposed as guidance towards a possible porphyry system related to the “Los Tambos” Lithocap located in the Ayacucho region. In the study area, volcano-sedimentary sequences, tuffs and domes of Miocene-Pliocene age emerge, with assemblages of advanced argillic alteration and local development of vuggy silica. Taking as reference the paper “Exploration Tools for Linked Porphyry and Epithermal Deposits: Example from the Mankayan Intrusion-Centered Cu-Au District, Luzon, Philippines” by Zhaoshan Chang, et al.; an orientation study was done to explore porphyry systems using only samples with Alunite. The study revealed a trend of increase in Na content in Alunite with a Northwest direction. The same occurs with Na/(Na+K) ratios and with values of La, Sr, La/Pb and Sr/Pb where anomalous contents of Cu and Mo are concentrated on these anomalies. Hg contents tend to decrease over anomalous areas of La and Sr in the Northwest sector of the Lithocap. Illite Crystallinity Index confirm an increase in temperature towards the Northwest. These directional indicators suggest the occurrence of a porphyry system below or beside of the Northwest end of the Lithocap, which is complemented by outcrops of a “patchy” texture and that would evidence a transition to a porphyry system. Los distritos mineros del Sur del Perú emplazados en la franja volcánica Terciaria albergan sistemas epitermales hospedados por litocapas que podrían estar ligados a sistemas pórfidos. Hay varias herramientas para explorar sistemas pórfidos “ocultos” y, una de ellas son las alunítas. Se propone la utilidad de las Alunitas como orientación hacia posible sistema pórfido relacionado a la Litocapa “Los Tambos” ubicada en la región Ayacucho. En el área de estudio afloran secuencias volcano-sedimentarias, tobas y domos de edad Mioceno-Plioceno, con ensambles de alteración argílica avanzada y desarrollo local de sílice residual. Tomando como referencia el articulo “Exploration Tools for Linked Porphyry and Epithermal Deposits: Example from the Mankayan Intrusion-Centered Cu-Au District, Luzon, Philippines” de Zhaoshan Chang, et al.; se hizo un estudio de orientación para explorar sistemas pórfido utilizando solo muestras con Al