The ‘Rodados Patagónicos’ (Patagonian shingleformation) of eastern Patagonia environmentalconditions of gravel sedimentation“巨石”挂牌的巴塔哥尼亚（巴塔哥尼亚 背景：环境of Eastern Patagonia） 砾石沉积条件

《The ‘Rodados Patagónicos’ (Patagonian shingleformation) of eastern Patagonia environmentalconditions of gravel sedimentation“巨石”挂牌的巴塔哥尼亚（巴塔哥尼亚 背景：环境of Eastern Patagonia） 砾石沉积条件》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、BiologicalJournaloftheLinneanSociety,2011,103,336345.With5figuresThe‘RodadosPatagónicos’(Patagonianshingleformation)ofeasternPatagonia:environmentalconditionsofgravelsedimentationOSCARALFREDOMARTÍNEZ*andADRIANAKUTSCHKERFacultaddeCienciasNaturales,UniversidadNacionaldelaPa

2、tagoniaSanJuanBosco,SedeEsquel,Chubut,ArgentinaReceived17February2011;acceptedforpublication18February2011bij_1651336..345ThegravelmantelsknownasRodadosPatagónicosofEasternPatagoniaareoneofthemostdistinctivefeaturesoftheregionallandscape.Theirsignificantroundness,alongwit

3、hadditionalsedimentaryandgeomorphologicalevidence,indicatestheiroriginislinkedtofluvialaction.Currently,nonaturalprocessesexistonEarthpotentiallygeneratingequivalentdeposits,eitherinPatagoniaorelsewherearoundtheworld.Thehydrologicalconditionsresponsibleforthegravelformati

4、onwerethuslikelyverydifferentfromthosecurrentlyprevailinginArgentinePatagonia,suggestingthegravelmantelsformedduringtheLateCenozoic,whensurfacedrainagenetworksofrelativelyhighenergyexistedintheregion.Suchhighenergywasinducedbypowerfulflowratesand/orstrongwatergradients,at

5、tributabletotectonism,epirogenesisand/orloweringofsealevel.Periodswithwaterflowregimessignificantlyhigherthanatpresentcharacterizedthefullglacialphaseslastingseveralthousandsofyears,correspondingtoeachofthemanyglaciationsofthePlioceneandPleistocene.Thecapacityforerosionand

6、watertransportwouldhavebeenincreasedbythesealeveldropcharacteristicofeachfullglacialphase.Therewerealsomuchshorterperiods,knownasterminations,representingtheabruptendingofthemainglacialeventsduringwhichlargeamountsofwaterwerereleasedasaresultoftheintensivemeltingoftheCor

7、dilleranicesheet.Duringinterglacialperiods,intheabsenceoflargemassesoficeinthemountainsandwithaveragetemperaturessimilartoorhigherthanatpresent,layersofgravelweredepositedasaresultoftectonicorepirogenicmovementorbyreactivationofdrainagenetworksproducedbysealevellowering(

8、glacio-eustatism).Theseendogenouslandscapereactivationswerealsoindependentofandlongerthantheclimaticfluc