Salar de Atacama basin: A record of compressional tectonics in the central Andes since the mid‐Cretaceous

Abstract

The Salar de Atacama basin lies in the inner fore arc of northern Chile. Topographically and structurally, it is a first‐order feature of the central Andes. The sedimentary fill of the basin constrains the timing and extent of crustal deformation since the mid‐Cretaceous. We have studied good exposures along the western edge of the basin and have correlated them with seismic reflection sections and data from an exploration well. Throughout most of its history, the basin developed in a foreland setting, during periods of thin‐skinned and thick‐skinned thrusting. Growth strata provide evidence for coeval sedimentation and thrust motions during mid‐Cretaceous, Paleogene, and Neogene times. Pre‐Neogene deformation was significant in the basin and in surounding areas of the early central Andes. Models that attempt to explain the current thickness of the central Andes should consider Late Cretaceous and Paleogene shortening, as well as the more obvious Neogene and Quaternary shortening.

Sources of surface water for the Soncor ecosystem, Salar de Atacama basin, northern Chile

“…The profiles were defined based on previously available data. These data included stratigraphic information obtained from wells (Harza 1978), and geophysical studies of electrical resistivity of the underground layers carried out using seismic profiles obtained from the work of Arriagada et al (2006). As an example, Fig.…”

Cenozoic tectonostratigraphic evolution and architecture of the Central Andes in northern Chile based on the Aquine region, Western Cordillera (19°-19º30’ S).

“…These compressive events include: the Early to Late Cretaceous "Peruvian" phase; the Late Cretaceous-early Cenozoic "K-T" phase; the middle Eocene "Incaic" phase; the late Oligocene-Early Miocene "Quechua" phase, and the late Miocene "Pehuenche" phase (e.g., Steinmann, 1929;Mégard, 1984;Jaillard, 1992;Gregory-Wodzicki, 2000;Cornejo et al, 2003;Arriagada et al, 2006;Hoke et al, 2007;Charrier et al, 2007Charrier et al, , 2009Charrier et al, , 2013Farías et al, 2010). The phases are interpreted as a product of changing plate convergence conditions through time, and consequent deformation of the leading edge of the continental plate (Charrier et al, 2007(Charrier et al, , 2013.…”

The Lautaro Basin: A record of inversion tectonics in northern Chile

“…In the other hand, the Paleogene deformation is more widely distributed across the Andes of northern Chile (Arriagada et al, 2000(Arriagada et al, , 2003(Arriagada et al, , 2006bTaylor et al, 2007). Eocene-Oligocene deformation was accompanied by tectonic shortening, mountain uplift and significant clockwise block rota tions (e.g., Hartley et al, 1992;Riley et al, 1993;Forsythe and Chisholm, 1994;Randall et al, 1996;Taylor et al, 1998;Arriagada et al, 2000;Somoza and Tomlinson, 2002;Arriagada et al, 2003Arriagada et al, , 2006bArriagada et al, , 2008. Fission track thermochronology indicates that tectonic uplift and erosion were mainly active during the EoceneEarly Oligocene 'Incaic Orogeny', when at least 4-5 km of rocks were eroded during exhumation of tectonic blocks of the Cordillera de Domeyko between ca.…”