渭河流域典型黄土剖面的环境磁学特征及其古气候意义

:100020240(2010)0120091207:2009207211;:2009209227:(40871080;40972116;90502008):(1985),,,2007,,.E2mail:[e-mail]3:,E2mail:[e-mail]1,2,13,1,2,1,1(1.,730000;2.,730000):.:,;,.,.,:,;,,.,,fd%ARM/;,lf.:;;:P534.63:A02080,Heller[1],,.,,[2],[3-6].,[7-9],[10].,[9-12].:,;,.,..11.1(1)200km,,13,554mm.(3453N,10845E),.,23m,4m[13-14].:(1)060cm:,.(2)6090cm:S0S1,,,,.(3)90137cm:S0L1,,,.32120102JOURNALOFGLACIOLOGYANDGEOCRYOLOGYVol.32No.1Feb.2010(4)137210cm:S0S2,,,,.(5)210260cm:S0L2,,,,.(6)260320cm:S0S3,,,,.(7)320400cm:L1,,,(),12mm,.1Fig.1MapshowingtheLoessPlateauandthepositionoftheprofilesmentionedinthispaper1.2,515g,.(lf)(hf)(ARM)(IRM)(SIRM).lfhfBartingtonMS2,fd%=(lf-hf)/lf100.ARM(AFdemagnetizer)MolspinMinispin,(ARM).IRMSIRMMMPM5MolspinMinispin,VFTB..2,,[3,9,15],.,,[16-18].,,,.[16-18].,2,,S1,.DingZhongli[19-20],,,.(3).,.4,100mT,75%,80%,.2S02S1[20]Fig.2Themagneticsusceptibilityprofilesoftypicalpaleosol2loessfromS0toS1ofLoessPlateau(reference20)29323[21-23]Fig.3ThemagneticsusceptibilityprofilesoftypicalHolocenepaleosol2loessofWeihedrainageareas(references[21-23])IRM100300mT/SIRMIRM3001000mT/SIRM,,,.,,.,,,,.Liu[16-18]:,;,,,.1,,,4IRMSIRMFig.4ThestratigraphicsubdivisionsandthecurvesofIRMandSIRMinYaoxianprofile1Table1MagneticparametersoftypicalsamplesinYaoxianprofile/cmlf/(10-8m3kg-1)fd/(10-8m3kg-1)ARM/(10-8m3kg-1)fd%/%ARM/Ms/(10-5Am2kg-1)Mrs/(10-5Am2kg-1)Hc/mTHcr/mT21122.7310.82537.788.814.389757.59878.937.5433.6241120.0911.36523.959.464.369884.04832.067.1536.10167259.4528.361354.1710.935.2214360.731307.836.4927.49207227.3625.361142.6111.165.0313139.901188.016.6127.87215259.1828.181425.4910.875.5013943.101334.136.1527.42285260.7328.361248.9410.884.7914258.881316.366.3527.87321135.0913.82630.0310.234.6610312.01804.316.8934.6235184.917.91348.729.314.117469.2575.767.1539.2038966.365.09244.057.673.68516.9442.41391:,7mT30mT,,,.[24].167cm207cm285cm321cm(5).167cm207cm,;207cm321cm,.5,100mT,,,.1T,,100mT5Fig.5MagneichysteresisloopsoftypicalsamplesintheYaoxianprofile,.,,;,..,,.3lf,;fdARMSP/SDSD[9,24-26],fd%ARM/SP/SDSD.6:lffdARM,.lffd%ARM/,lf,fd%ARM/.,fd%ARM/,.fdARM,fd%ARM/,.,fd%ARM/lf.lf,fd%ARM/;lf,fd%ARM/.,fd%ARM/,fd%ARM/.6Fig.6ChangesofthemagneticparametersintheYaoxianprofile49327Fig.7ScatterplotsofthemagneticparametersinYaoxianprofile7(a)(c),,,.,,7(a)SP/SD,7(c)SD.,,,;fd%10%12%,SP/SD.12%,.ARM/20010-8m3kg-1,30010-8m3kg-1SD.,SP/SDSD,fd%ARM/.(Ms),,(2141167207215285319321351cm).fdARM(7bd),:,,;,.:,;,.,[12,27-28].,fd%ARM/,SP/SD591:fd%10%12%,,.:,;,.,,fd%ARM/,,lf.(References):[1]HellerF,LiuTS.Magnetostratigraphicaldatingofloessde2positsinChina[J].Nature,1982,300:431-433.[2]HellerF,LiuTS.MagnetismofChineseloessdeposits[J].GeophysicalJournaloftheRoyalAstronomicalSociety,1984,77:125-141.[3]ZhouLP,OldfieldF,WintleAG,etal.PartlypedogenicoriginofmagneticvariationsinChineseloess[J].Nature,1990,346:737-739.[4]KuklaG,HellerF,LiuXM,etal.PleistoceneclimatesinChinadatedbymagneticsusceptibility[J].Geology,1988,16:811-814.[5]HellerF,LiuTS.MagnetismofChineseloessdeposits[J].GeophysicalJournalofRoyalAstronomicalSociety,1984,77:125-141.[6]MengXM,DerbyshireE,KempRA.OriginofthemagneticsusceptibilitysignalinChineseloess[J].QuaternaryScienceReviews,1997,16(8):833-839.[7]MaherBA,ThompsonR.MineralmagneticrecordoftheChineseloessandpalaeosols[J].Geology,1991,19:3-6.[8]DengCL,VidicNJ,VerosubKL,etal.MineralmagneticvariationoftheJiaodaoChineseloess/paleosolsequenceanditsbearingonlong2termclimaticvariability[J].JournalofGe2ophysicalResearch,2005,110:B03103,doi:10.1029/2004JB003451.[9]LiuQingsong,DengChenglong,PanYongxin.Temperature2dependencyandfrequency2dependencyofmagneticsusceptibil2ityofmagnetiteandmaghemiteandtheirsignificanceforenvi2ronmentalmagnetism[J].QuaternarySciences,2007,27(6):955-962.[,,.[J].,2007,27(6):955-962.][10]LiuXiuming,LiuTungsheng,HellerF,etal.Frequency2de2pendentsusceptibilityofloessanditsrecordedthepaleocli2mateevolvment[J].QuaternarySciences,1990(1):42-50.[,,HellerF,.[J].,1990(1):42-50.][11]WangXisheng,YangZhengyu,LovlieR,etal.Environmen2talmagnetismandpaleoclimateinterpretationoftheloess/pal2eosolsequenceinthesoutheasternextremityoftheChineseLoessPlateau[J].ChineseScienceBulletin,2006,51(13):1575-1582.[,,LovlieR,.[J].,2006,51(13):1575-1582.][12]XiaDunsheng,ChenFahu,MaJianying,etal.Environmen2talmagneticinvestigationsofsurfacesoilsalongaNWSEtransectfromtheChineseLoessPlateautotheAlxaPlateau[J].QuaternarySciences,2007,27(6):1001-1008.[,,,.[J].,2007,27(6):1001-1008.][13]ZhaoH,ChenFH,LiSH,etal.ArecordofHolocenecli2matechangeintheGuanzhongBasin,China,basedonopticaldatingofaloess2palaeosolsequence[J].TheHolocene,200717:1015-1022.[14]LiXiaoqiang,AnZhisheng,ZhouJie,etal.CharacteristicsofvegetationintheLoessPlateauareasinceHolocene[J].MarineGeology&QuaternaryGeology,2003,23(3):109-114.[,,,.[J].,2003,23(3):109-114.][15]LiuXiuming,LiuTungsheng,HellerF,etal.TheanalysisofmagneticgrainofChineseLoessanditssignificationofpa2leoclimate[J].ScienceinChina(SeriesB),1991(6):639-644.[,,HellerF,.[J].(B),1991(6):639-644.][16]LiuXiuming,XiaDunsheng,LiuTungsheng,et