The Mining Segment of CAP S.A. conducts its operations through its subsidiary, Compañía Minera del Pacífico S.A. (CMP). For management purposes, CMP is organized into four main units, one of which is the Valle de Huasco unit. This unit includes the operations of the Pellet Plant, Los Colorados mine, El Algarrobo, and the Puerto Guacolda II mines.
CMP is a limited liability Company. It has two main shareholders, the controller with 74.9% of shares, CAP S.A. and MC Inversiones LTDA., subsidiary of Mitsubishi Corporation.
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Summary:
The Los Colorados magnetite-apatite deposit is one of the largest and least altered Kiruna-type deposits in the Chilean iron belt.
The Los Colorados IOA deposit is formed at ~110 Ma and is hosted in andesitic to basaltic andesitic volcanic and volcaniclastic rocks of the Punta del Cobre Formation (Pichon, 1981; Oyazún and Frutos, 1984; Pincheira et al., 1990). Mine geologists estimate that the ore deposit formed 3 to 4 km beneath the paleosurface (CAP, pers. commun.). The deposit consists of two high-grade, massive tabular orebodies, as well as mineralized breccia bodies, and disseminated and veinlet mineralization.
The two tabular orebodies are referred to by mine geologists as the Western and Eastern dikes. The Western dike is dominated modally by massive magnetite (=90 vol %), with minor amounts of actinolite, pyrite, and apatite.
The Western dike strikes N10°–15° E to N-S, is approximately 1,500 m long, 500 m deep, and varies in width from 90 to 180 m. The orebody is hosted within the district-scale Los Colorados fault, which is part of the Atacama fault system, and was the structural control for ore fluid(s) (Knipping et al., 2015a; Reich et al., 2016).
The Eastern dike is a smaller, tabular orebody composed of massive magnetite (=85 vol %) with minor amounts of actinolite, apatite, and pyrite. This orebody measures about 780 m long, is about 500 m deep, 50 m wide, and the strike changes from N10°–15° W to N10°–15° E from the central to the northern portions of the orebody.
The Western and Eastern dikes each grade outward from massive magnetite to intergrowths of magnetite and large actinolite crystals, to disseminated mineralization in the volcanic and/or diorite host rocks. Disseminated mineralization, which consists of up to 5 vol % each of disseminated magnetite and pyrite, and minor amounts of chalcopyrite, extends for hundreds of meters to the east of the Eastern dike into a diorite intrusion. Veinlets comprised of actinolite, magnetite, and pyrite crosscut the diorite intrusion, as well as the Western and Eastern dikes.