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Structural evolution of the Rio Blanco-Los Bronces district, Andes of central Chile: controls on stratigraphy, magmatism, and mineralization

Citation

Piquer, J and Skarmeta, J and Cooke, DR, Structural evolution of the Rio Blanco-Los Bronces district, Andes of central Chile: controls on stratigraphy, magmatism, and mineralization, Economic Geology, 110, (8) pp. 1995-2023. ISSN 0361-0128 (2015) [Refereed Article]

Copyright Statement

© 2015 Society of Economic Geologists.

DOI: doi:10.2113/econgeo.110.8.1995

Abstract

The late Miocene to early Pliocene mineralized centers of the Rio Blanco-Los Bronces porphyry copper cluster constitute the largest known copper concentration in the Earth’s crust. Based on new district-scale geological mapping and cross-section interpretation, this study describes the structural evolution of the Main Cordillera of central Chile in the Rio Blanco-Los Bronces district and its relationship with the emplacement of magmatic bodies and mineral deposits. The tectonic evolution of this Andean segment was strongly controlled by regional-scale fault systems, oriented oblique to the north-south axis of the orogen. These NW- and NE-striking faults were active as normal faults during the late Eocene-Oligocene, and controlled the compartmentalization of the Abanico volcanotectonic basin into individual subbasins with characteristic volcanosedimentary facies and thicknesses. The faults were selectively reactivated during Mio-Pliocene east-west contraction, with the NW-striking faults showing a composite reverse-sinistral movement and the NE-striking faults showing mainly dextral strike-slip movements. This reactivation occurred coeval with the deposition of the Farellones Formation and the emplacement of the Rio Blanco-San Francisco batholith, the last pulses of which are genetically related with the formation of the Rio Blanco-Los Bronces cluster. Magmatic and hydrothermal fluid flow was channeled and focused by both sets of preexisting oblique structures and, in turn, fault rupture was driven by high fluid pressures. A proper understanding of similar long-lived, regional-scale arc-oblique fault systems might clarify the structural controls on magmatism and mineralization in the broader Mio-Pliocene metallogenic belt of central Chile and also in other Andean segments.

Item Details

Item Type:Refereed Article
Keywords:porphyry, copper, geodynamics, structure, mineralization
Research Division:Earth Sciences
Research Group:Geology
Research Field:Ore Deposit Petrology
Objective Division:Mineral Resources (excl. Energy Resources)
Objective Group:Other Mineral Resources (excl. Energy Resources)
Objective Field:Mineral Resources (excl. Energy Resources) not elsewhere classified
Author:Piquer, J (Mr Jose Piquer Romo)
Author:Cooke, DR (Professor David Cooke)
ID Code:106996
Year Published:2015
Web of Science® Times Cited:8
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2016-02-29
Last Modified:2017-11-02
Downloads:0

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