Coupled tectonic evolution of Andean orogeny and global climate Rolando Armijo, Robin Lacassin, Aurélie Coudurier-Curveur, Daniel Carrizo To cite this version: Rolando Armijo, Robin Lacassin, Aurélie Coudurier-Curveur, Daniel Carrizo. Coupled tectonic evo- lution of Andean orogeny and global climate. Earth-Science Reviews, Elsevier, 2015, 143, pp.1-35. 10.1016/j.earscirev.2015.01.005. insu-01138548 HAL Id: insu-01138548 https://hal-insu.archives-ouvertes.fr/insu-01138548 Submitted on 14 Oct 2015 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. Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives| 4.0 International License 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