DOCSLIB.ORG

Coupled Tectonic Evolution of Andean Orogeny and Global Climate

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Coupled Tectonic Evolution of Andean Orogeny and Global Climate Earth-Science Reviews 143 (2015) 1–35 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Coupled tectonic evolution of Andean orogeny and global climate Rolando Armijo a,c,⁎, Robin Lacassin a,c, Aurélie Coudurier-Curveur a,c,DanielCarrizob,c a Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Univ Paris Diderot, UMR 7154 CNRS, F-75005 Paris, France b Advanced Mining Technology Center, Universidad de Chile, Tupper 2007, Santiago, Chile c Laboratoire International Associé Montessus de Ballore (LIA MdB) CNRS (France)-CONICYT Chile article info abstract Article history: The largest tectonic relief breaking the Earth's surface (13 km vertically) is at the subduction margin of the Andes, Received 28 March 2014 which generates routinely megathrust earthquakes (Mw N 8.5) and drives the paradigmatic Andean orogen. Here Accepted 19 January 2015 we present key geologic evidence to reassess first-order features of geomorphology and tectonics across the Available online 29 January 2015 Central Andes, where the orogen includes the Altiplano Plateau and attains its maximum integrated height and width. The Andean subduction margin has a stepped morphology dominated by the low-relief Atacama Keywords: Bench, which is similar to a giant uplifted terrace, slopes gently over a width of 60–100 km from the Andes to Orogeny fi fi Climate the Paci c, and runs over more than 1000 km of coastal length. We nd that the genesis of stepped morphology Andes at the Andean seaboard is due to concomitant development of large west-vergent thrusts parallel to the subduc- Subduction tion interface and increasing aridity in the Atacama Desert, which keeps an unprecedented large-scale record of Tectonics interplaying tectonics and Cenozoic climate change. Incorporating our results with published geological knowl- Geomorphology edge demonstrates that Andean orogeny is characterized by trench-perpendicular (bivergent) and trench- parallel (bilateral) growth over the past 50 Myr, associated with positive trench velocity toward the continent (trench advance) and subduction of a wide slab under South America. We hypothesize that a global plate tectonic reorganization involving long-lasting viscous mantle flow has probably forced both, Andean orogeny and global climate cooling since ~50 Ma. In contrast, two important stepwise pulses of increasing aridity and trench- perpendicular Andean growth appear to be results of changes in erosion rates due to global Late Eocene and Middle Miocene cooling events. © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Contents 1. Introduction............................................................... 2 2. TheAtacamaBench........................................................... 3 2.1. TopographyandmorphologyoftheAndeanmargin:AtacamaBenchandmajorstructuraldiscontinuities................. 3 2.2. LateCenozoicevolutionoftheAtacamaBench:centraldepressionbasinbetweentwopediplains..................... 5 2.3. ClimaticchangeindicatedbyChojaPediplain,atthebaseoftheCDB.................................. 10 3. Hidden structure of Western Cordillera: “Incaic” backboneunderChojaPediplain............................... 10 3.1. Structure at west flankoftheAndes:Pre-Andean,EarlyAndeanandLateAndeantectonics........................ 10 3.2. AccretionofAndeanstructuralbasementduringassemblyofGondwana................................ 10 3.3. AndeanstructuralcycleduringdispersalofGondwana:fromspreadingtocontractionofAndeansubductionmargin............ 12 3.3.1. Earlyperiod....................................................... 14 3.3.2. Transitionalperiod.................................................... 15 3.3.3. Lateperiod:overviewofAndeanorogenyatsubductionmargin................................ 16 3.4. UncoveredstructuresinCordilleraDomeyko:theWestAndeanThrust(WAT)............................. 16 4. WestofAtacamaBench:structurescontrollingcoastlineandseismiccoupling................................. 17 5. Discussion:evolutionoftheAndeanorogen................................................ 17 5.1. IncorporatingtectonicfeaturesofthesubductionmarginwithmainfeaturesoftheAndeanorogen.................... 17 5.2. Approachforreconstructinga2Devolution............................................. 19 ⁎ Corresponding author. Tel.: +33 1 83957607. E-mail address: [email protected] (R. Armijo). http://dx.doi.org/10.1016/j.earscirev.2015.01.005 0012-8252/© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 2 R. Armijo et al. / Earth-Science Reviews 143 (2015) 1–35 5.3. Initialstatus............................................................22 5.4. Snapshotat40Ma:deformationlocalizedinWesternCordillera....................................22 5.5. Snapshotat30Ma.........................................................23 5.5.1. CompletionofChojaPediplainoverWesternCordillera:tectonicvs.climaticforcing.......................23 5.5.2. Late Eocene–EarlyOligoceneAndeangrowthbywidening...................................23 5.6. Snapshotat20Ma:continuingdeformationbetweenWesternCordilleraandInterandeanbelt......................23 5.7. Snapshotat10Ma:preparationforsubductionoftheBrazilianShield..................................23 5.8. Present-daystatus:LateMioceneAndeangrowthbywidening.....................................24 5.9. Comparisonofourinterpretedsectionwithearliermodels.......................................24 6. AndeanorogenyinconcertwithplatetectonicsandCenozoicclimatechange.................................26 6.1. Platetectonicsaspossiblelong-periodforcingofAndeanorogenyandglobalcooling...........................28 6.1.1. Climate,platetectonicsandAndeantectonics........................................28 6.1.2. Effectsofplatetectonicevolutionandpossibleboundaryconditionssince50Ma........................28 6.2. PossibleclimaticfeedbacksonAndeangrowthprocess........................................28 7. Conclusions...............................................................30 Acknowledgements..............................................................31 References..................................................................31 1. Introduction 2005; McQuarrie et al., 2005; Barnes and Ehlers, 2009; Whipple and Gasparini, 2014)(Figs. 1 and 2). The surface geology shows also that The Himalayas–Tibet and the Andes–Altiplano – the largest active crustal shortening started at ~50–30 Ma close to the subduction zone mountain belts creating relief in our planet – have been caused by rad- associated with west-directed thrusting in the Western Cordillera, ical changes in plate-boundary conditions. In both cases, subduction of then propagated progressively away from the subduction zone, first oceanic lithosphere beneath an initially flat continental margin, close by a jump (at ~40 Ma) to the Eastern Cordillera, then since ~10 Ma to to sea-level, evolved to critical tectonic conditions triggering substantial the easternmost Subandes Belt (Sempere et al., 1990; Allmendinger shortening and thickening of marginal continental lithosphere, either et al., 1997; Gregory-Wodzicki, 2000; McQuarrie et al., 2005; Oncken by continental collision or by an equivalent process producing similar et al., 2006; Arriagada et al., 2008; Barnes and Ehlers, 2009; Carrapa effects. Therefore, deformation should be similarly partitioned between et al., 2011; Charrier et al., 2013). Shortening of the Altiplano Plateau elastic deformation generating routinely megathrust earthquakes and occurred later (since ~30 Ma: Sempere et al., 1990; Elger et al., 2005; distributed deformation accumulating over millions of years in the Oncken et al., 2006) – and is less (as shown by crustal thickness of marginal continent. Mechanical coupling and structure of the plate in- ~70 km) – than in the two flanking Western Cordillera and Eastern terface in the two cases should be comparable as well. However, while Cordillera belts, which are both sustained by deeper crustal roots the India–Asia continental collision zone appears to be a structurally (~74–80 km thickness) (Yuan et al., 2000; Wölbern et al., 2009). The complex interface between subducting continental lithosphere and most accepted view of Andes crustal thickening describes the orogen a deforming continental region (e.g. Molnar and Lyon-Caen, 1988; as a large back-arc thrust wedge transported upon the adjacent conti- Avouac, 2003; Grandin et al., 2012), the subduction margin of South nent (South America), with subsidiary tectonic activity – accretionary America is generally assumed to be a simple subduction interface be- or non-accretionary – in the fore-arc (e.g. Stern, 2002; Lamb and Davis, tween a plunging oceanic slab and a non-deforming continental forearc 2003; McQuarrie et al., 2005). That view is readily comparable to the par- (e.g. Uyeda and Kanamori, 1979; Isacks, 1988). adigmatic description of the Cordilleran Belt of North America. However, Here we present results from a study of the Andean subduction mar- it has been recently argued that much like the Himalaya–Tibet Plateau gin and its evolution to conditions sustaining the Andean orogeny, over (core of the Himalayan orogen), the structure of the Central Andes is a range of scales in space and time. Our approach integrates key geo- symmetrically bivergent (Armijo et al., 2010a), as suggested earlier by morphological
Load more

Recommended publications
  • Field Excursion Report 2010
    Presented at “Short Course on Geothermal Drilling, Resource Development and Power Plants”, organized by UNU-GTP and LaGeo, in Santa Tecla, El Salvador, January 16-22, 2011. GEOTHERMAL TRAINING PROGRAMME LaGeo S.A. de C.V. GEOTHERMAL ACTIVITY AND DEVELOPMENT IN SOUTH AMERICA: SHORT OVERVIEW OF THE STATUS IN BOLIVIA, CHILE, ECUADOR AND PERU Ingimar G. Haraldsson United Nations University Geothermal Training Programme Orkustofnun, Grensasvegi 9, 108 Reykjavik ICELAND [email protected] ABSTRACT South America holds vast stores of geothermal energy that are largely unexploited. These resources are largely the product of the convergence of the South American tectonic plate and the Nazca plate that has given rise to the Andes mountain chain, with its countless volcanoes. High-temperature geothermal resources in Bolivia, Chile, Ecuador and Peru are mainly associated with the volcanically active regions, although low temperature resources are also found outside them. All of these countries have a history of geothermal exploration, which has been reinvigorated with recent changes in global energy prices and the increased emphasis on renewables to combat global warming. The paper gives an overview of their main regions of geothermal activity and the latest developments in the geothermal sector are reviewed. 1. INTRODUCTION South America has abundant geothermal energy resources. In 1999, the Geothermal Energy Association estimated the continent’s potential for electricity generation from geothermal resources to be in the range of 3,970-8,610 MW, based on available information and assuming the use of technology available at that time (Gawell et al., 1999). Subsequent studies have put the potential much higher, as a preliminary analysis of Chile alone assumes a generation potential of 16,000 MW for at least 50 years from geothermal fluids with temperatures exceeding 150°C, extracted from within a depth of 3,000 m (Lahsen et al., 2010).
    [Show full text]
  • Plateau-Style Accumulation of Deformation: Southern Altiplano
    TECTONICS, VOL. 24, TC4020, doi:10.1029/2004TC001675, 2005 Plateau-style accumulation of deformation: Southern Altiplano Kirsten Elger, Onno Oncken, and Johannes Glodny GeoForschungsZentrum Potsdam, Potsdam, Germany Received 5 May 2004; revised 17 December 2004; accepted 23 March 2005; published 31 August 2005. [1] Employing surface mapping of syntectonic during the Paleogene, initially reactivating crustal sediments, interpretation of industry reflection- weak zones and by thermal weakening of the crust seismic profiles, gravity data, and isotopic age dating, with active magmatism mainly in the Neogene stage. we reconstruct the tectonic evolution of the southern Citation: Elger, K., O. Oncken, and J. Glodny (2005), Plateau- Altiplano (20–22°S) between the cordilleras style accumulation of deformation: Southern Altiplano, Tectonics, defining its margins. The southern Altiplano crust 24, TC4020, doi:10.1029/2004TC001675. was deformed between the late Oligocene and the late Miocene with two main shortening stages in the Oligocene (33–27 Ma) and middle/late Miocene 1. Introduction (19–8 Ma) that succeeded Eocene onset of shortening at the protoplateau margins. Shortening [2] Although considerable advance has been made in recent years in understanding the processes involved in rates in the southern Altiplano ranged between 1 and the formation of orogenic plateaus, the precise temporal 4.7 mm/yr with maximum rates in the late Miocene. and spatial patterns of uplift and lateral progradation of Summing rates for the southern Altiplano and the
    [Show full text]
  • Lithium Extraction in Argentina: a Case Study on the Social and Environmental Impacts
    Lithium extraction in Argentina: a case study on the social and environmental impacts Pía Marchegiani, Jasmin Höglund Hellgren and Leandro Gómez. Executive summary The global demand for lithium has grown significantly over recent years and is expected to grow further due to its use in batteries for different products. Lithium is used in smaller electronic devices such as mobile phones and laptops but also for larger batteries found in electric vehicles and mobility vehicles. This growing demand has generated a series of policy responses in different countries in the southern cone triangle (Argentina, Bolivia and Chile), which together hold around 80 per cent of the world’s lithium salt brine reserves in their salt flats in the Puna area. Although Argentina has been extracting lithium since 1997, for a long time there was only one lithium-producing project in the country. In recent years, Argentina has experienced increased interest in lithium mining activities. In 2016, it was the most dynamic lithium producing country in the world, increasing production from 11 per cent to 16 per cent of the global market (Telam, 2017). There are now around 46 different projects of lithium extraction at different stages. However, little consideration has been given to the local impacts of lithium extraction considering human rights and the social and environmental sustainability of the projects. With this in mind, the current study seeks to contribute to an increased understanding of the potential and actual impacts of lithium extraction on local communities, providing insights from local perspectives to be considered in the wider discussion of sustainability, green technology and climate change.
    [Show full text]
  • Unraveling the Peruvian Phase of the Central Andes: Stratigraphy, Sedimentology and Geochronology of the Salar De Atacama Basin (22°30-23°S), Northern Chile
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/271538622 Unraveling the Peruvian Phase of the Central Andes: Stratigraphy, sedimentology and geochronology of the Salar de Atacama Basin (22°30-23°S), northern Chile Article in Basin Research · March 2015 DOI: 10.1111/bre.12114 CITATIONS READS 5 127 4 authors: Sebastián Bascuñán Cesar Arriagada University of Chile University of Chile 4 PUBLICATIONS 5 CITATIONS 90 PUBLICATIONS 664 CITATIONS SEE PROFILE SEE PROFILE Jacobus Philippus Le Roux Katja Deckart University of Chile University of Chile 141 PUBLICATIONS 1,668 CITATIONS 28 PUBLICATIONS 610 CITATIONS SEE PROFILE SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Jacobus Philippus Le Roux letting you access and read them immediately. Retrieved on: 09 August 2016 EAGE Basin Research (2015) 1–28, doi: 10.1111/bre.12114 Unraveling the Peruvian Phase of the Central Andes: stratigraphy, sedimentology and geochronology of the Salar de Atacama Basin (22°30–23°S), northern Chile Sebastia´ n Bascun˜ a´ n,* Ce´ sar Arriagada,* Jacobus Le Roux*,† and Katja Deckart* *Departamento de Geologıa, Universidad de Chile, Santiago, Chile †Centro de Excelencia en Geotermia de los Andes (CEGA), Universidad de Chile, Santiago, Chile ABSTRACT The Salar de Atacama Basin holds important information regarding the tectonic activity, sedimen- tary environments and their variations in northern Chile during Cretaceous times. About 4000 m of high-resolution stratigraphic columns of the Tonel, Purilactis and Barros Arana Formations reveal braided fluvial and alluvial facies, typical of arid to semi-arid environments, interrupted by scarce intervals with evaporitic, aeolian and lacustrine sedimentation, displaying an overall coarsening- upward trend.
    [Show full text]
  • Late Mesozoic to Paleogene Stratigraphy of the Salar De Atacama Basin, Antofagasta, Northern Chile: Implications for the Tectonic Evolution of the Central Andes
    Late Mesozoic to Paleogene stratigraphy of the Salar de Atacama Basin, Antofagasta, Northern Chile: Implications for the tectonic evolution of the Central Andes Constantino Mpodozisa,T,Ce´sar Arriagadab, Matilde Bassoc, Pierrick Roperchd, Peter Cobbolde, Martin Reichf aServicio Nacional de Geologı´a y Minerı´a, now at Sipetrol. SA, Santiago, Chile bDepartamento de Geologı´a, Universidad de Chile, Santiago, Chile cServicio Nacional de Geologı´a y Minerı´a, Santiago, Chile dIRD/Dep. de Geologı´a, Universidad de Chile, Santiago, Chile eGe´osciences-Rennes (UMR6118 du CNRS), France fDepartment of Geological Sciences University of Michigan, United States Abstract The Salar de Atacama basin, the largest bpre-AndeanQ basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic–Early Cretaceous Tarapaca´ back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation).
    [Show full text]
  • A Structural and Geochronological Study of Tromen Volcano
    Volcanism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuqu`enprovince, Argentina) Olivier Galland, Erwan Hallot, Peter Cobbold, Gilles Ruffet, Jean De Bremond d'Ars To cite this version: Olivier Galland, Erwan Hallot, Peter Cobbold, Gilles Ruffet, Jean De Bremond d'Ars. Vol- canism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuqu`enprovince, Argentina). Tectonics, American Geophysical Union (AGU), 2007, 26 (4), pp.TC4010. <10.1029/2006TC002011>. <insu-00180007> HAL Id: insu-00180007 https://hal-insu.archives-ouvertes.fr/insu-00180007 Submitted on 29 Jun 2016 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. TECTONICS, VOL. 26, TC4010, doi:10.1029/2006TC002011, 2007 Volcanism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuque´n province, Argentina) Olivier Galland,1,2 Erwan Hallot,1 Peter R. Cobbold,1 Gilles Ruffet,1 and Jean de Bremond d’Ars1 Received 28 June 2006; revised 6 February 2007; accepted 16 March 2007; published 2 August 2007. [1] We document evidence for growth of an active [3] In contrast, a context of crustal thickening, where the volcano in a compressional Andean setting.
    [Show full text]
  • Vegetation and Climate Change on the Bolivian Altiplano Between 108,000 and 18,000 Years Ago
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by DigitalCommons@University of Nebraska University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Earth and Atmospheric Sciences, Department Papers in the Earth and Atmospheric Sciences of 1-1-2005 Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago Alex Chepstow-Lusty Florida Institute of Technology, [email protected] Mark B. Bush Florida Institute of Technology Michael R. Frogley Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL Paul A. Baker Duke University, [email protected] Sherilyn C. Fritz University of Nebraska-Lincoln, [email protected] See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences Commons Chepstow-Lusty, Alex; Bush, Mark B.; Frogley, Michael R.; Baker, Paul A.; Fritz, Sherilyn C.; and Aronson, James, "Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago" (2005). Papers in the Earth and Atmospheric Sciences. 30. https://digitalcommons.unl.edu/geosciencefacpub/30 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Alex Chepstow-Lusty, Mark B. Bush, Michael R. Frogley, Paul A. Baker, Sherilyn C. Fritz, and James Aronson This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ geosciencefacpub/30 Published in Quaternary Research 63:1 (January 2005), pp.
    [Show full text]
  • Sr–Pb Isotopes Signature of Lascar Volcano (Chile): Insight Into Contamination of Arc Magmas Ascending Through a Thick Continental Crust N
    Sr–Pb isotopes signature of Lascar volcano (Chile): Insight into contamination of arc magmas ascending through a thick continental crust N. Sainlot, I. Vlastélic, F. Nauret, S. Moune, F. Aguilera To cite this version: N. Sainlot, I. Vlastélic, F. Nauret, S. Moune, F. Aguilera. Sr–Pb isotopes signature of Lascar volcano (Chile): Insight into contamination of arc magmas ascending through a thick continental crust. Journal of South American Earth Sciences, Elsevier, 2020, 101, pp.102599. 10.1016/j.jsames.2020.102599. hal-03004128 HAL Id: hal-03004128 https://hal.uca.fr/hal-03004128 Submitted on 13 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Copyright Manuscript File Sr-Pb isotopes signature of Lascar volcano (Chile): Insight into contamination of arc magmas ascending through a thick continental crust 1N. Sainlot, 1I. Vlastélic, 1F. Nauret, 1,2 S. Moune, 3,4,5 F. Aguilera 1 Université Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, F-63000 Clermont-Ferrand, France 2 Observatoire volcanologique et sismologique de la Guadeloupe, Institut de Physique du Globe, Sorbonne Paris-Cité, CNRS UMR 7154, Université Paris Diderot, Paris, France 3 Núcleo de Investigación en Riesgo Volcánico - Ckelar Volcanes, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta, Chile 4 Departamento de Ciencias Geológicas, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta, Chile 5 Centro de Investigación para la Gestión Integrada del Riesgo de Desastres (CIGIDEN), Av.
    [Show full text]
  • Geodynamics of Andean Basins : an Example from the Salar De Atacama
    Second ISAG, Oxford (UK),21-231911993 295 GEODYNAMICS OF ANDEANBASINS: AN EXAMPLEFROM THE SALAR DE ATACAMA,BASIN, NORTHERN CHILE Stephen FLINT1, Adrian HARTLEY2, Peter TURNER3, Liz JOLLEY3 Guillermo CHONG4 1. Department of Earth Sciences, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, U.K. 2. Department of Geology & Petroleum Geology, University of Aberdeen, Aberdeen AB9 2UE, U.K. 3. School of Earth Sciences, University of Birmingham, P.O. Box 363, Birmingham BI5 2TT, U.K. 4. Departamento de Geociencias, UinversidadCatolica del Norte, Antofagasta, Chile KEY WORDS: Chronostratigraphy, Central Andes, Extensional tectonics, Basin analysis INTRODUCTION We describe the historyof the Salar de Atacama, long-liveda (Permo-Triassic - Recent) nonmarine basin which, owing to the geodynamic developrnentof the Central Andes, has evolved from a non-arc-related rift basin, through cornplex "arc-related" stages,to a Miocene-Recent forearc basin. We atternpt to demonstrate that sedimentary basinsat convergent plate margins preserve the most cornpleterecord of the local geodynamic historyof the orogen and their analysis is an essential component in studies of crustal evolution. Our database includes over one hundred logged sections (some20 km of stratigraphy), field maps, and the interpretations of aerial photographs/satelliteimages and several regional seismic lines acrossthe basin. GEOLOGICAL SETTlNG The Salarde Atacama has along geological history,from Permo-Triassic to Recent,al1 of it non-marine. The composite, approximately10 km of stratigraphy can be divided into five unconforrnity-boundedmegasequences (Fig. 1). These are the Permo-Triassic Peine Formation and equivalents, the latest Cretaceous-Eocene Purilactis Group(Hartley et al., 1992), the Oligocene-earliest Miocene Paciencia Group (Flint, 1985),the early Miocene-Plio-PleistoceneSan Bartolo GroupNilama Formation (Jolleyet al., 1990) and the Holocenealluvial fans and saliferous deposits.
    [Show full text]
  • Crustal Faults in the Chilean Andes: Geological Constraints and Seismic Potential
    Andean Geology 46 (1): 32-65. January, 2019 Andean Geology doi: 10.5027/andgeoV46n1-3067 www.andeangeology.cl Crustal faults in the Chilean Andes: geological constraints and seismic potential *Isabel Santibáñez1, José Cembrano2, Tiaren García-Pérez1, Carlos Costa3, Gonzalo Yáñez2, Carlos Marquardt4, Gloria Arancibia2, Gabriel González5 1 Programa de Doctorado en Ciencias de la Ingeniería, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Macul, Santiago, Chile. [email protected]; [email protected] 2 Departamento de Ingeniería Estructural y Geotécnica, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Macul, Santiago, Chile. [email protected]; [email protected]; [email protected] 3 Departamento de Geología, Universidad de San Luis, Ejercito de Los Andes 950, D5700HHW San Luis, Argentina. [email protected] 4 Departamento de Ingeniería Estructural y Geotécnica y Departamento de Ingeniería de Minería, Pontificia Universidad Católica de Chile. Avda. Vicuña Mackenna 4860, Macul, Santiago, Chile. [email protected] 5 Departamento de Ciencias Geológicas, Universidad Católica del Norte, Angamos 0610, Antofagasta, Chile. [email protected] * Corresponding author: [email protected] ABSTRACT. The Chilean Andes, as a characteristic tectonic and geomorphological region, is a perfect location to unravel the geologic nature of seismic hazards. The Chilean segment of the Nazca-South American subduction zone has experienced mega-earthquakes with Moment Magnitudes (Mw) >8.5 (e.g., Mw 9.5 Valdivia, 1960; Mw 8.8 Maule, 2010) and many large earthquakes with Mw >7.5, both with recurrence times of tens to hundreds of years. By contrast, crustal faults within the overriding South American plate commonly have longer recurrence times (thousands of years) and are known to produce earthquakes with maximum Mw of 7.0 to 7.5.
    [Show full text]
  • Redalyc.Paleogene Calcareous Nannofossil Biostratigraphy for Two
    Andean Geology ISSN: 0718-7092 [email protected] Servicio Nacional de Geología y Minería Chile Pérez Panera, Juan Pablo Paleogene calcareous nannofossil biostratigraphy for two boreholes in the eastern Austral Basin, Patagonia, Argentina Andean Geology, vol. 40, núm. 1, enero, 2013, pp. 117-140 Servicio Nacional de Geología y Minería Santiago, Chile Available in: http://www.redalyc.org/articulo.oa?id=173925397001 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Andean Geology 40 (1): 117-140. January, 2013 Andean Geology doi: 10.5027/andgeoV40n1-a06 formerly Revista Geológica de Chile www.andeangeology.cl Paleogene calcareous nannofossil biostratigraphy for two boreholes in the eastern Austral Basin, Patagonia, Argentina Juan Pablo Pérez Panera CONICET- División Paleozoología Invertebrados, Museo de La Plata, Paseo del Bosque s/n, B1900FWA, La Plata, Argentina. [email protected] ABSTRACT. Calcareous nannofossils from two boreholes (Campo Bola and Sur Río Chico) in the subsurface of eastern Austral Basin, Santa Cruz Province, Argentina, allowed the identification of Early to Middle Paleocene, Early to Middle Eocene and Late Eocene to Early Oligocene assemblages. These assemblages match the formations logged in the boreholes Campo Bola, Man Aike and Río Leona respectively, and represent three paleogene sedimentary cycles within the basin. These results permitted the reinterpretation of previous data from an adjacent borehole (Cerro Redondo). The southern boreholes (Cerro Redondo and Sur Río Chico) yield an Early to Middle Paleocene calcareous nannofossil assemblage and an almost continuous record of nannofossils from Early Eocene to Early Oligocene.
    [Show full text]
  • Genesis and Kinematic of the Northern Bolivian Altiplano
    Third ISAG, Sr Malo (France), 17-19/9/1996 GENESIS AND KINEMATIC OF THE NORTHERN BOLIVIAN ALTIPLANO Philippe ROCHAT (l), Patrice BABY (2), Gtrard HERAIL (3), Georges MASCLE (l), Oscar ARANIF3AR (4), Bernard COLLETTA (5) (l) UPRES-A. 5025, Instut Dolomieu, 15 rue M. Gignoux, 38031 Grenoble - France (2) ORSTOM Ecuador, cc 17 1 1 6596, Quito - Ecuador (3) ORSTOM Chile, cc 53390, Santiago 1 - Chile (4) YPFB. cc 1659 Santa Cruz - Bolivia (5) IFP. 1 avenue de Bois-Prtau, BP 3 1 1,92506 Rueil Malmaison cedex - France KEY WORDS: Altiplano, thrusts, inversion, syntectonic sedimentation, erosion. INTRODUCTION The Altiplano is an enigmatic high plateau of the Central Andes, characterized by a thick crust about 70 Km (Wigger et al., 1994, Beck et al. 1996). Recent seismologic data show that magmatic accretion did not cause this crustal thickening (Dorbath et al., 1992), and numerous authors have emphasized the importance of horizontal shortening in the Altiplano structuration (Roeder 1988; Baby et al., 1992; Htrail et al., 1993). New seismic data available in YPFB as well as recent field works allow us to present a new geometrical model of the northern Altiplano, and to discuss its sedimentary evolution characterized by thick accumulations of Tertiary continental sediments (10.000 m). STRUCTURAL SE'ITJNG Recent field's works and analyses of seismic perfiles reflexions available in YPFB permit us to propose a new tectonic setting. The northern Bolivian Altiplano can be divided in three structural domains (fig. 1 5 2) - domain 1: At the eastern edge, the La Joya-Toledo plain forms the northern extremity of the Poopo basin, where late Tertairy and Quaternary deposits overlay the SW verging thrusts system of the Cordillera Oriental (Coniri Fault system).
    [Show full text]