Angélica Copper Deposit: Exotic Type Mineralization in the Tocopilla Plutonic Complex of the Coastal Cordillera, Northern Chile

Abstract

The Angélica copper deposit is situated at the southernmost sector of the Jurassic Tocopilla plutonic complex in the North Chilean Coastal Cordillera. This deposit occurs in monzonitic to monzodioritic rocks, and has platelike orebodies with no appreciable hydrothermal alteration nor sulfi de mineralization. The mineralized zones are located in the western side of the two main normal faults with NE and NW orientations, and are characterized principally by impregnation of supergene copper products of atacamite and minor amounts of chrysocolla, lavendulan and "black copper". Generally, chrysocolla is more abundant at a distal NE sector of the deposit. The black copper is Cu-Fe-Mn-Si-Cl-rich multimineral aggregates composed of atacamite with minor amounts of quartz, pseudomalachite, dioptase, neotocite, gypsum, paratacamite and melanothallite, and its surface exhibits nanometer-sized cylindrical morphologies. All these characteristics suggest an exotic origin for the Angélica copper deposit. A few vein-type copper deposits situated at the southwestern sector along the NE-oriented fault are inferred as the possible source of the Angélica copper deposit.

Extraction of Mn from Black Copper Using Iron Oxides from Tailings and Fe2+ as Reducing Agents in Acid Medium

“…Some examples of exotic deposits in Chile are Mina Sur in Chuquicamata [11], Damiana in El Salvador [7], Huanquintipa in Collahuasi [12], and La Cascada, Lomas Bayas Spence, El Tesoro [2], and Angélica in Tocopilla [13]. The copper and manganese of this type of deposit are often associated with oxidized minerals, mainly chrysocolla, which, in turn, are associated with gangue that can negatively affect leaching [11].…”

Contamination of urban soils in a historical mining town of northern Chile

“…Copper, Zn, and Pb showed the highest indices and rates suggesting that their enrichment in soils is largely due to anthropogenic sources. Lower indices for these elements were obtained using local volcanics when compared to intrusives as background (Table 7); these lower indices might reflect Cu deposits hosted by volcanics in this zone (Zambra et al 2007). Additionally, in the vicinity of Tocopilla, volcanics show enriched concentrations of Cu and Zn when compared to the UCC (Table 2).…”

Metalurgia prehispánica en las sociedades costeras del norte de Chile (quebrada Mamilla, Tocopilla)

“…Adicionalmente, en Tocopilla son frecuentes los yacimientos de cobre tipo vetas alojadas en rocas plutónicas del Jurásico Superior (dioritas, granodioritas y monzodioritas del Batolito de la costa de Tocopilla) que se introducen en la Formación La Negra (Boric et al 1990;Vivallo y Henríquez 1998;Maksaev y Zentilli 2002). También se ha informado la presencia de depósitos exóticos que ocurren en rocas monzoníticas y monzodioríticas y que provienen posiblemente de yacimientos tipo veta cercanos (Zambra et al 2007). Es así que este distrito destaca por ser uno de los más ricos en reservas de cobre, y por presentar yacimientos de alta ley y de fácil extracción en un contexto tecnológico prehispá-nico (Núñez 1987).…”