Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile

José Piquer; Gonzalo Yáñez; Orlando Rivera; David R. Cooke

Keywords: central chile, Chile central, Basement fault intersections, Magma and hydrothermal fluid flow, Intersecci?n de fallas de basamento, Flujo de magmas y fluidos hidrotermales

Abstract

Long-lived, high-angle fault systems constitute high-permeability zones that can localize the upward flow of hydrothermal fluids and magma throughout the upper crust. Intersections of these types of structures can develop complex interference patterns, which constitute volumes of damaged rock (networks of small-scale faults and fractures) where permeability may be significantly enhanced. This is relevant for understanding regional-scale structural controls on the emplacement of hydrothermal mineral deposits and volcanic centers, and also on the distribution of areas of active upper-crustal seismicity. In the high Andes of central Chile, regional-scale geophysical (magnetic, gravimetric, seismic) and structural datasets demonstrate that the architecture of this Andean segment is defined by NW-and NE-striking fault systems, oblique to the N-S trend of the magmatic arc. Fault systems with the same orientations are well developed in the basement of the Andes. The intersections of conjugate arc-oblique faults constitute the site of emplacement of Neogene intrusive complexes and giant porphyry Cu-Mo deposits, and define the location of major clusters of upper-crustal earthquakes and active volcanic centers, suggesting that these fault systems are still being reactivated under the current stress regime. A proper identification of one-dimensional, lithospheric-scale high-permeability zones located at the intersections of high-angle, arc-transverse fault systems could be the key to understanding problems such as the structural controls on magmatic and hydrothermal activity and the patterns of upper-crustal seismicity in the high Andes and similar orogenic belts.

Más información

Título según WOS: Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile
Título según SCOPUS: Long-lived crustal damage zones associated with fault intersections in the high andes of Central Chile [Zonas de daño cortical de larga vida, asociadas con intersecciones estructurales en los altos andes de Chile Central]
Título según SCIELO: Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile
Título de la Revista: ANDEAN GEOLOGY
Volumen: 46
Número: 2
Editorial: SERVICIO NACIONAL GEOLOGIA MINERVA
Fecha de publicación: 2019
Página de inicio: 223
Página final: 239
Idioma: English
DOI:

10.5027/andgeoV46n2-3106

Notas: ISI, SCIELO, SCOPUS