EarlyCretaceousPaleoclimateCharacteristicsofChina:CluesfromContinentalClimate-indicativeSediments

TheCretaceouswasoneofthemostremarkable‘greenhouse’climateperiodsingeologicalhistory.MostofthereportedstudiesoftheCretaceouspaleoclimatearebaseduponmarinesedimentaryrecords.Largespatialscalepaleoclimaticreconstruction,whichhasahighertimeresolutionbaseduponcontinentalsedimentsinChina,israrelyfound.ThisstudypresentspaleoclimatereconstructionforthesixtimeperiodsoftheEarlyCretaceousinChinabyemployingcontinentalclimate-indicativesediments,includingcalcareousdeposits,coal,oilshale,gypsum,halite,desertsedimentarysystems,ferruginousdepositsandlaterite,copper-bearingdeposits,limestoneanddolomite.Basedonthedistributionoftheassociationofclimate-indicativesedimentsandtheinfluencesofpaleotopographyandorogenicbelts(orimportantstructuralbelts)onclimate,sevenclimaticzoneshavebeenidentified:1)awarmandhumidzone;2)awarmandhumid-warmandaridzone;3)awarmandaridzone;4)anaridandhotzone;5)theTibethotandhumidzone;6)ahotandarid-semiaridzone;and7)ahotandhumid-hotandaridone.ItisfoundthattheEarlyCretaceousclimaticzonesofChinawerenearlylatitudinallydistributedfromnorthwesttosoutheast.Thearid-hotclimaticzoneexpandedintheAptian,suggestingthatahotteranddrierclimateprevailedinlaterperiodoftheEarlyCretaceous.Conversely,thehumidclimaticzoneexpandedintheAlbian,indicatingthatawetterclimateappearedattheendoftheEarlyCretaceous.Theoveralldistributionpatternofthesevenclimaticzonesindicatesthatahot-warmandaridclimatewaspredominantinChina;thiscoincideswithaglobal‘greenhouseclimate’background.However,palaeogeographicfeaturesandspecificgeologicevents,suchastheexistenceanddisappearanceoftheeasternhighplateau,andtheupliftanddenudationofYinshan,Yanshan,Tianshan,QinlingandDabieMountains,ledtodistinctiveregionalclimaticfeaturesoftheCretaceousinChina.