in - Porter, T.M. (Ed), 2002 - Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective,
The Productora prospect is situated 15 km SSW of the town of Vallenar in the Third Region, north-central Chile. It lies within the "Chilean Iron Belt" close to the north-trending Atacama Fault system. The belt contains a variety of Fe oxide ± Cu ± Au-bearing deposits including Candelaria (366 million tonnes averaging 1.08 % Cu, 0.26 g/t Au) which is situated in the Punta del Cobre region approximately 150 km north of Productora. The age, structural setting, alteration assemblages and styles of mineralization in the Productora area resemble those present at Candelaria, but Productora differs in its spatial association with intrusive rocks and its lack of skarn assemblages.
Productora includes a north-trending zone of hydrothermal alteration (Fe oxide-albite-K spar-tourmaline-sericite-silica) that exceeds 8 km in strike length and 3 km in width. This zone contains 13 small former mines, 8 of which were worked for magnetite and the remaining 5 for Cu-Au. In addition, there are over 80 shallow pits and surface occurrences containing some Fe oxide ± Cu ± Au ± U ± REE ± apatite mineralization. The mineralization and alteration are structurally and stratigraphically controlled. They are preferentially developed in more permeable tuffaceous units of a presumed Cretaceous package but also follow NW-striking and, to a lesser extent, N-trending structures related to the Atacama Fault system.
Hydrothermal alteration is mainly centered around two Early Cretaceous (c. 130 Ma) felsic intrusions, the Cachiyuyito and
Three styles of Fe-oxide dominant mineralization are identified, each of which tends to occur within a specific alteration zone. The most proximal and common of these is magnetite ± apatite veins and replacements hosted by
The second and most economically important style of mineralization is typified by the Cu-Au ± REE ± U ± Mo ± Co mineralization at the Productora and Santa Innes mines. It is more commonly associated with
The third style of mineralization is developed in the outermost parts of the Productora hydrothermal system
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