Caracterización mineralógica, paragenética y estructural de las alteraciones hidrotermales: implicaciones para la determinación del tipo de sistema Epitermal y su potencial exploratorio en el sector Los Planes, cantón Chinchipe, Ecuador

Abstract

Abstract: This study characterizes the mineralogy, paragenesis, and structural controls of hydrothermal alteration in the Los Planes sector (Chito Parish, Chinchipe Canton) to determine the type of epithermal system present and to define criteria and vectors for precious and/or base metal exploration. The methodology integrated four lines of evidence: morphostructural and fractal analysis of lineaments using QGIS, SAGA GIS, and MATLAB; petrography and ore microscopy of two thin sections from a mineralized vein; SWIR spectrometry (TerraSpec data interpreted via continuum removal, technique normalizing the spectrum to highlight mineral absorption bands and TSG software); and multi-element geochemistry via ICP-MS and fire assay. The system exhibits discrete structural control over individual veins (D=1.0355, with no X- or Y-type intersection nodes). Paragenetic analysis reveals pyrite and arsenopyrite containing refractory gold. The interpretation is supported by an argillic-phyllic assemblage (illite-muscovite-paragonite ± montmorillonite, with subordinate calcite and chlorite) and a geochemical association of Au, As, and Sb transitioning laterally into a Pb-Zn zone. These results classify the Los Planes sector as a low-sulfidation epithermal system, while not ruling out an intermediate-sulfidation component.