GREENFIELD EXPLORATION IN AU-CU-AG DEPOSIT THE CHICCHE – CAJAMARCA – PERÚ

The present work is a study in stage of Greenfield exploration by Au-Cu-Ag, referred to areas where are indications of mineralization; however, the territory has not yet been explored and no mineral deposit has been discovered until now (Bendezu, 2014), to define the presence of mineralization with profitable economic potential of metals such as Au, Cu and Ag, it has been carried out a mapping, sampling and geochemistry, where structures were identified that facilitated mobility to hydrothermal fluids and the type of host rock to contain the mineralization, as well as the alterations produced by changes in the physicochemical conditions associated with it; mapping of alterations present in the surface, providing a strong guide by the presence of Gossan (Taylor, 2011) where samples have been collected containing the following results: 3.7 Oz/Tn Au, 1.05% in Cu and 6.9 Gr/Tn in Ag respectively (see Table 1). The study area is located 18 km NE of the city of Cajamarca.

Geological and Structural Framework

The host rock belongs to the Huambos Volcanic Age Paleogene-Neogene, with its three events: andesitic lava flows in the floor, pyroclastic flows and pumice in the middle member and an upper one containing pyroclastics with blocks of adesites. To the north, intrusive bodies with diorite composition and some wok stock structures, characteristic of copper porphyries (type D and M veins), emerge. The predominant structural framework is mainly NE and NW orientation course failures.

Hydrothermal Alterations

Gossan or Iron Hat: predominant minerals are goethite, hematite and jarosite. Massive silica and Vuggy silica. In the distal zone there is propylitic alteration with its characteristic epidote – chlorite assemblages. Furthermore, garnets (andradite and grosularia) have been recognized, evidencing possible skarn mineralization towards distal areas.

Conclusions

Preliminary surface data indicate the presence of an important mineralization area with high economic potential, the fault lines are predominant NE and NW which are believe to control the mineralization. Laboratory analyzes indicate the concentration of metals in the “Gossan” zone, mainly contained in Goethite and Hematite minerals.