Estudio mineralógico y paragenético de la veta Curi en la concesión minera La Romero , sector la Avanzada, cantón Santa Rosa

Abstract

Abstract: This study characterizes the Curi vein located in the La Romero mining concession, Santa Rosa Canton in terms of mineralogy and paragenesis, utilizing field observations, thin-section and polished-section petrography, and XRD and XRF analyses. The wall rock consists of quartz-sericite schist with subordinate chlorite, belonging to the metamorphic basement of the Amotape-Tahuin Block, and shows no pervasive hydrothermal alteration. The vein exhibits an assemblage of quartz, pyrite, arsenopyrite, pyrrhotite, chalcopyrite, sphalerite, galena, and gold, organized into four stages: early quartz; early sulfides (pyrite and arsenopyrite); main infill (pyrrhotite, chalcopyrite, and sphalerite); and a late phase (galena and gold). The predominance of polymetallic sulfides aligns the system with the intermediate- to low-sulfidation epithermal deposits of the Zaruma-Portovelo district; however, the metamorphic host rock, consistent presence of arsenopyrite, and absence of an alteration halo are characteristic of deposits hosted in metamorphic terranes. This classification is considered preliminary, and further resolution requires fluid inclusion and stable isotope data. A local paragenetic model applicable to exploration is presented.