Summary:
The Yauli unit region shows mineralization related to polymetallic epithermal systems, replacement bodies and polymetallic vein systems, as well as porphyry mineralization and skarns, thus indicating the great potential of the area.
The San Cristobal-Andaychagua mining district, located in the southern part of the Yauli Dome, is a classical high-temperature, carbonate-hosted, massive sulfide replacement ore deposit district. Such deposits have been traditionally considered in terms of a single evolving hydrothermal fluid traveling differing distances from an intrusive center.
The San Cristobal-Andaychagua mining district includes only mantos and veins. The mantos are hosted by the Pucara limestone along the contact with the underlying Mitu Group, and occur mainly along the western flank of the Domo de Yauli. The veins are steeply dipping and crosscut rocks of the Mitu and Excelsior Groups, and locally the Chumpe and San Cristobal intrusions.
Andaychagua Vein is one of the producers in the San Cristobal district, is one of the most important veins on the southeast side of the Chumpe intrusive. The vein lies on the northeast side of the Chumpe Anticline. About three and a half kilometers southeast of the San Cristobal Vein system. The Andaychagma Vein strikes N 30° E and dips 85° northwest. The vein can be traced on the surface for about four kilometers, three of which are in Mitu volcanic rocks and one of which in Excelsior Phyllites. The structure continues on the surface across the axial zone to the southwest side of the Chumpe Anticline, but only as a fault structure without apparent mineralization. The Andaychagua Vein carries sphalerite, galena, and silver minerals.
Drilling campaigns
The 2023 and 2024 drilling campaigns aimed to enhance the geological certainty of mineral resources. Additionally, exploratory drilling sought to identify new economic resources and assess areas with promising geological and economic potential, thereby extending the longevity of the assets in the medium to long term.
In Andaychagua, efforts continued to increase the geological certainty of mining sectors by reclassifying indicated resources to measured and inferred to indicated. Additionally, new mineral resources with high grades of zinc, lead, and silver were incorporated in the extensions of the Salvadora Norte, Prosperidad Techo, Andaychagua, and Adriana bodies, as well as in the Barbara vein. Furthermore, economic mineralization with high silver content was confirmed in the Valentina vein, and the discovery of the Katherine vein with high grades of zinc, copper, and silver, as well as the Camila vein with high grades of zinc and silver were consolidated. Together, these new zones with economic mineralization ensure great operational performance in the coming years and the extension of the asset's life.