Figure 1 – Left: Local geological map. Right: Geological sections. The principal economic minerals are sphalerite, tetrahedrite-tennantite (Ag-bearing, with As > Sb), chalcopyrite, and galena. Both the Sofía D and Sofía E orebodies exhibit well-defined vertical zoning, transitioning from Cu-rich (chalcopyrite-dominated) mineralization at the base to Zn–Pb–Ba-rich assemblages toward the top. Mineral reserves are currently estimated at 4.5 million metric tons, with average grades of 1.8 oz/t Ag, 0.82% Pb, 7.6% Zn, and 1.2% Cu. 2.1.3 Geomechanical characterization María Teresa mine has three main structural domains (SD): SD-II, SD-IIIA, and SD-IIIB. The zoning was established using the Bieniawski Rock Mass Rating (RMR) classification system. Within the deposit area, SD-IIIA and SD-IIIB predominate in the mineralized zone, with only minor presence of SD-IVA. In contrast, SD-IIIA is the prevalent domain in both the immediate and distant wall-rock zones (Figure 2). Figure 2 – Geomechanical zoning of Sofia D body (DCR Ingenieros S.R.L. Geomechanical study,2018) 2.1.4. Stope and pillar design parameters Based on the classification of mining geo-conditions, appropriate parameters were selected to determine the stope dimensions. Stope design was performed using the stability chart method
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