Evolution of the West Andean Escarpment at 18°S (N. Chile) during the last 25 Ma: uplift, erosion and collapse through time

Wörner, Gerhard; Uhlig, Dieter; Kohler, Ingrid; Seyfried, Hartmut

doi:10.1016/s0040-1951(01)00212-8

Cited by 105 publications

(139 citation statements)

References 43 publications

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“…Separating the Central Depression from the Coastal Cordillera on the west and the Precordillera on the east are the Atacama Fault Zone and the West Andean Thrust, respectively, accommodating some of the differential uplift between the physiographic domains (Armijo et al, 2015; González et al, 2003; Muñoz & Charrier, 1996; Muñoz & Sepulveda, 1992; Victor et al, 2004). Most of northern Chilean (e.g., Isacks, 1988; Jordan et al, 2010; Wörner et al, 2002) and Peruvian (2.5° northward; e.g., Schildgen et al, 2007) Western Cordilleran uplift, however, is thought to have occurred by way of a crustal‐scale monocline of which the Precordilleran slope constitutes the limb.…”

Section: Field Settingmentioning

confidence: 99%

“…Repeated onset of hyperaridity since 14 Ma may be further responsible for ambiguous records and interpretations (Jordan et al, 2014). These transitions have been tied to (1) a coastal temperature inversion from the cold Humboldt current formed concurrent with the opening of the Drake Passage (Gregory‐Wodzicki, 2000; Lawver & Gahagan, 1998; Wörner et al, 2002), (2) an Andean rain shadow blocking off Atlantic moisture as a result of post‐Miocene uplift (e.g., Houston & Hartley, 2003; Rech et al, 2006, 2010), and (3) additional shut off from Pacific moisture blocked by the Coastal Cordillera(Rech et al, 2010). Present‐day precipitation rates are recorded as low as <1 mm/yr in the coastal cities of northern Chile (e.g., Schulz et al, 2012).…”

Section: Field Settingmentioning

confidence: 99%

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Slow Long‐Term Exhumation of the West Central Andean Plate Boundary, Chile

2018

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We present a regional analysis of new low‐temperature thermochronometer ages from the Central Andean fore arc to provide insights into the exhumation history of the western Andean margin. To derive exhumation rates over 10 million‐year timescales, 38 new apatite and zircon (U‐Th)/He ages were analyzed along six ~500‐km long near‐equal‐elevation, coast parallel, transects in the Coastal Cordillera (CC) and higher‐elevation Precordillera (PC) of the northern Chilean Andes between latitudes 18.5°S and 22.5°S. These transects were augmented with age‐elevation profiles where possible. Results are synthesized with previously published thermochronometric data, corroborating a previously observed trenchward increase in cooling ages in Peru and northern Chile. One‐dimensional thermal‐kinematic modeling of all available multichronometer equal‐elevation samples reveals mean exhumation rates of <0.2 km/Myr since ~50 Ma in the PC and ~100 Ma in the CC. Regression of pseudovertical age‐elevation transects in the CC yields comparable rates of ~0.05 to ~0.12 km/Myr between ~40 and 80 Ma. Differences between the long‐term mean 1‐D rates and shorter‐term age‐elevation‐derived rates indicate low variability in the exhumation history. Modeling results suggest similar background exhumation rates in the CC and PC; younger ages in the PC are largely a function of increased heat flow and consequently an elevated geothermal gradient near the arc. Slow exhumation rates are suggestive of semiarid conditions across the region since at least the Eocene and deformation and development of the Andean fore arc around this time.

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Section: Field Settingmentioning

confidence: 99%

Section: Field Settingmentioning

confidence: 99%

Slow Long‐Term Exhumation of the West Central Andean Plate Boundary, Chile

2018

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“…Estas rocas se extienden desde la Precordillera a una altura cercana a 1,5 km y tienen un manteo menor a 3º hacia el oeste, de modo que estas rocas en Arica y más al oeste de la línea litoral están bajo el nivel de mar evidenciando el basculamiento al oeste del antearco que involucra alzamiento en la zona de la Precordillera y subsidencia litoral. Trabajos más recientes (Wörner et al, 2002;Farías et al, 2005y Riquelme et al, 2007 demostraron que existe un basculamiento hacia el oeste del antearco en el norte de Chile durante el Neógeno que tuvo una importante contribución en el alzamiento andino, particularmente en la Precordillera, más que la actividad de fallas inversas de vergencia al oeste que tuvieron poca actividad durante el Plioceno. Las conclusiones de los trabajos anteriores (Karzulovic, 1968;Achurra, 2004;Le Roux et al, 2005a, b;Clift y Hartley, 2007;Wörner et al, 2002;Farías et al, 2005;Riquelme et al, 2007), confirman el planteamiento de Mortimer (1980) de un basculamiento al oeste del antearco que involucra subsidencia litoral y alzamiento andino (Precordillera y Cordillera Occidental) que ocurrió durante el Neógeno, particularmente durante el Plioceno.…”

Section: Origen Del Acantilado Costerounclassified

“…Trabajos más recientes (Wörner et al, 2002;Farías et al, 2005y Riquelme et al, 2007 demostraron que existe un basculamiento hacia el oeste del antearco en el norte de Chile durante el Neógeno que tuvo una importante contribución en el alzamiento andino, particularmente en la Precordillera, más que la actividad de fallas inversas de vergencia al oeste que tuvieron poca actividad durante el Plioceno. Las conclusiones de los trabajos anteriores (Karzulovic, 1968;Achurra, 2004;Le Roux et al, 2005a, b;Clift y Hartley, 2007;Wörner et al, 2002;Farías et al, 2005;Riquelme et al, 2007), confirman el planteamiento de Mortimer (1980) de un basculamiento al oeste del antearco que involucra subsidencia litoral y alzamiento andino (Precordillera y Cordillera Occidental) que ocurrió durante el Neógeno, particularmente durante el Plioceno. Esta subsidencia litoral debió ser moderada para permitir que la abrasión marina erosionara el relieve preexistente de la Cordillera de la Costa, formando el Acantilado Costero que retrocedió al este hasta ca.…”

Section: Origen Del Acantilado Costerounclassified

Efectos de la tectónica y el clima en la configuración morfológica del relieve costero del norte de Chile

Quezada

Cerdá

Jensen

2010

AndGeo

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RESUMEN.En este trabajo se analiza el relieve de la vertiente occidental de la Cordillera de la Costa del norte de Chile, la cual está caracterizada por la ocurrencia del gran Acantilado Costero. El objetivo central de este estudio es establecer los controles tectónico-climáticos en la configuración del relieve del borde costero del norte de Chile. La metodología utilizada consiste básicamente en un estudio detallado del relieve mediante índices geomorfológicos cuantitativos tales como grado de incisión, curvas e integrales hipsométricas, perfiles de thalweg e índice de sinuosidad. Estos índices se aplicaron a modelos de elevación digitales e imágenes satelitales. Los resultados más relevantes muestran que el relieve de la vertiente occidental de la Cordillera de la Costa exhibe creciente incremento de la intensidad de la erosión al aumentar la latitud. Este incremento no es uniforme; procesos relacionados con la tectónica como subsidencia/alzamiento litoral y actividad de fallas, y por otra parte la erosión de la paleotopografía de la Cordillera de la Costa debido a los procesos ligados a la construcción del Acantilado Costero y el aumento de la precipitación, afectan la morfología del relieve del borde costero del norte de Chile. La existencia y excelente preservación del Acantilado Costero resulta de un marcado desequilibrio entre las tasas de alzamiento y las tasas de erosión, cuya diferencia es de una a dos órdenes de magnitud, controlada por el marco climático de hiperaridez extrema del Desierto de Atacama que se ha mantenido por lo menos desde los últimos 2 Ma. Las variaciones en la intensidad de la erosión desde el norte hacia el sur se interpretan como resultado del incremento en la tasa de precipitación en un orden de magnitud en esa misma dirección. ABSTRACT. Tectonic and climatic effects in the morphologic configuration of the coastal relief of northern Chile.This work analyzes the morphological features of the western margin of the northern Chile Coastal Cordillera, characterized by the presence of a major Coastal Cliff. The main purpose of this research is to better understand the tectonic and climatic controls on the topography. The methodology used consists basically of a detailed study of the topography with quantitative geomorphic indexes such as incision grade, hypsometric curves and integrals, thalweg profiles and sinuosity index. These are applied to digital elevation models and satellite images. The main results show that the topography of the western margin of the Coastal Cordillera, exhibits an increasing intensity of the erosion with latitude. This increment is non uniform. The tectonic processes that produced coastal subsidence/uplift and fault activity, and the erosion of the paleotopography of Coastal Cordillera due to processes related with the construction of the Coastal Cliff and increasing rainfall, modify the morphology of the coastal border of northern Chile. The existence and conservation of the Coastal Cliff results from the existance of non-equilibrium between the uplift and...

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“…Despite their importance in terms of hazards, landslide maps remain rare (Guzzetti et al, 2012) and information on the type, age or distribution of individual landslides is often lacking. Only a few publications deal with landslide triggering and/or evolution in arid contexts such as the western Andean flank, where several gigantic scarps disrupt the forearc piedmont (Audin and Bechir, 2006;Pinto et al, 2008;Strasser and Schlunegger, 2005;Wörner et al, 2002;Mather et al, 2014;Crosta et al, 2015). In contrast, because of the potential seismotectonic trigger (Keefer, 1984(Keefer, , 2002McPhillips et al, 2014), landslide triggering along subduction active margins has been studied for a number of years, but most previous studies focused on humid climatic settings (Taiwan, New Zealand, Papua New Guinea, Japan; Meunier et al, 2008;Hovius et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Tectonic and climatic controls on the Chuquibamba landslide (western Andes, southern Peru)

et al. 2015

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Abstract. The contribution of landslides to the Quaternary evolution of relief is poorly documented in arid contexts. In southern Peru and northern Chile, several massive landslides disrupt the arid western Andean front. The Chuquibamba landslide, located in southern Peru, belongs to this set of large landslides. In this area, the Incapuquio fault system captures the intermittent drainage network and localizes rotational landslides. Seismic activity is significant in this region with recurrent M w 9 subduction earthquakes; however, none of the latest seismic events have triggered a major landslide. New terrestrial cosmogenic dating of the Chuquibamba landslide provides evidence that the last major gravitational mobilization of these rotational landslide deposits occurred at ∼ 102 ka, during the Ouki wet climatic event identified on the Altiplano between 120 and 98 ka. Our results suggest that wet events in the arid and fractured context of the Andean forearc induced these giant debris flows. Finally, our study highlights the role of tectonics and climate on (i) the localization of large Andean landslides in the Western Cordillera and on (ii) the long-term mass transfer to the trench along the arid Andean front.

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Evolution of the West Andean Escarpment at 18°S (N. Chile) during the last 25 Ma: uplift, erosion and collapse through time

Cited by 105 publications

References 43 publications

Slow Long‐Term Exhumation of the West Central Andean Plate Boundary, Chile

Slow Long‐Term Exhumation of the West Central Andean Plate Boundary, Chile

Efectos de la tectónica y el clima en la configuración morfológica del relieve costero del norte de Chile

Tectonic and climatic controls on the Chuquibamba landslide (western Andes, southern Peru)

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