Exploration of porphyry systems using Alunite as an orientation vector in the Los Tambos Lithocap, Ayacucho region, Peru

Abstract

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 sílica. 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.