Cenozoic Tectonics and Porphyry Copper Systems of the Chilean Andes

Reactivation of Fault Systems by Compartmentalized Hydrothermal Fluids in the Southern Andes Revealed by Magnetotelluric and Seismic Data

“…Second‐order NW trending transverse structural domains that crosscut the volcanic arc have been observed throughout the Andes and are considered to be pre‐Andean, inherited basement faults (e.g., Katz, 1971; Lara et al, 2006; Melnick & Echtler, 2006; Piquer et al, 2017; Yáñez et al, 1998). These seismically active ATF (Aron et al, 2015; Sielfeld et al, 2019; Stanton‐Yonge et al, 2016) accommodate part of the deformation arising from oblique convergence (Perez‐Flores et al, 2016; Stanton‐Yonge et al, 2016), are spatially and genetically associated with massive to medium scale ore deposits (e.g., Chernicoff et al, 2002; Mpodozis & Cornejo, 2012; Piquer et al, 2015), and are believed to control the seismic segmentation of the plate interface (Melnick et al, 2009).…”

“…The Andes comprise of a volcanically active mountain belt along the western margin of South America between latitudes 18-46°S, which have formed from the roughly eastward convergence and subduction of the oceanic Nazca Plate beneath the South American Plate since the Jurassic (ca. 180 Ma) (Charrier et al, 2007;Mpodozis & Cornejo, 2012;Pardo et al, 2009;Ramos, 2010). Since the Miocene (<20 Ma), orogenic uplift was coupled with intense volcanism and the formation of an eastward migrating volcanic arc.…”

Apatite (U–Th)/He thermochronology and Re–Os ages in the Altar region, Central Andes (31°30′S), Main Cordillera of San Juan, Argentina: implications of rapid exhumation in the porphyry Cu (Au) metal endowment and regional tectonics

“…The Early Oligocene-Late Oligocene "slow cooling" period observed at 30°S in the Elqui valley region (Lossada et al 2017) coincides, with the intense volcanic activity that gave rise to the Pelambres and Pachón formations and the Mondaca and Río Chicharra Strata which accumulated at the northern end of the Central Chile Abanico/Coya Machalí extensional intra arc basin (Charrier et al 2002(Charrier et al , 2005Mpodozis and Cornejo 2012). Volcanism occurred during a period of fast plate convergence rates (Jordan et al 2001) causing steady westward displacement of the South American Plate (Silver et al 1998;Kay and Copeland 2006) Fig.…”

“…U-Pb ages from Los Pelambres deposit are from Perelló et al (2012). U-Pb ages from Los Azules, Yunque and Rincones de Araya deposits are from Zurcher (2008) and Mpodozis and Cornejo (2012) Abbreviations: n.c: not calculated.…”

A Systematic Approach to Mapping Regimes of Earthquake‐Induced Static Stress Changes Acting on Magmatic Pathways

“…Unclamping of arc‐parallel pathways is therefore expected to be the main response, which will favor magma ascent, but the previously uninvestigated stress changes on arc‐perpendicular and horizontal pathways may also be important. Coseismic unclamping has previously been invoked to explain magmatism occurring along arc‐parallel structures that are unfavorably orientated within a compressive stress field with σ 1 perpendicular to the plate boundary (Acocella, 2014; Acocella et al., 2018; Bonali et al., 2013; Lara et al., 2006; Lupi & Miller, 2014; Mpodozis & Cornejo, 2012; Sepúlveda et al., 2005; Walter & Amelung, 2007).…”