Atacama Copper Announces the Expansion of its License Area on the El Cofre Copper Project
The geology of the El Cofre area consists of a basement of quartz meta-sandstones and quartz-mica schists from the Chañaral Metamorphic Complex (Devonian - Early Carboniferous) that underlies to a sequence of marine, clastic and volcanic rocks from the Triassic to Early Jurassic epoch and also to
Late Jurassic volcanic rocks. Several intrusive units from Mid Jurassic to Early Cretaceous age intrude the above units. The most recent units in the region are fluvial, alluvial and littoral unconsolidated deposits of Quaternary age that covers the Huasco River valley, minor creeks, and foothills. An intense deformation zone named the Infiernillo Shear Zone appears in the contact zone between the intrusive units to the east and the metasedimentary unit to the west. This structural zone corresponds to the continuity of the well-known Atacama Fault System in this area that is related to several mining districts along its trend in Chile. El Cofre is an analogue of the San Juan copper, gold and cobalt mining district, located to the south-west from the northern section of the El Cofre concessions. The San Juan district was the principle Cobalt producing region of Chile up until the mid-1940s. Publicly reported exploration samples obtained from old tailings piles, small mine workings as well from outcrops from this district indicate cobalt concentrations of up to 1.95% (from 0.001%), Co together with variable contents of copper (7.9% -0.037%), gold (1.1 g/t - 0.1 g/t), silver (8.8 g/t - 0.5 g/t), nickel (0.49% - 0.023%) and cadmium (4.7 g/t -0.023 g/t). The historical mining production atEl Cofre was restricted to small artesian workings from veins that outcrop in the area. The exploration in the area commenced with International PBX Ventures Ltda. ("IPBX") during 2009. IPBX performed geophysics, including airborne ZTEM survey in the whole area and Induced Polarity (IP) concentrated in the northern sector, along with geochemical sampling of outcrops. On selected mineralized veins and in some artesian development stockpiles, samples showed a number of high-grade copper values. Finally, IPBX abandoned the concessions to concentrate their efforts in more advanced projects. The former owner staked the area in 2017. A geological and geochemical profiling program was executed in the northeastern El Cofre properties during 2018. The profiling work is composed of 18 profiles, separated by 400 m, with 50 m of geochemical sampling in each profile, in an area of 2,700 hectares that covers approximately 48% of the northern tenements (Fig. 5). The geochemical campaign shows several anomalous values in copper (Cu), gold (Au), cobalt (Co) and nickel (Ni). The Cu, Au and Co anomalies are concentrated mainly in the recognized mineralized structures, with average values of
0.34% Cu, 0.29 g/t Au & 73 ppm Co. The maximum values of these elements in veins are 1.75% Cu, 3.85 g/t Au and 0.03% Co.