简介：TheEmeishanlargeigneousprovince(hereafternamedbyitsacronymELIP)isthefirstacceptedlargeigneousregioninChina.Thecurrentstudytriestoreconstructthedensitystructureofthecrustinthisregion.Forthispurpose,weconductedthegravitysurveyalongan800-km-longprofile,whichstretchedlaterallyalongthelatitude27°NfromLijiang(Yunnanprovince)toGuiyang(Guizhouprovince).Thefieldworkincluded338gravitymeasurementsdistributedfromtheinnerzonetotheouterzoneofthemantleplumehead.Afteraseriesofgravityreductions,wecalculatedtheBouguergravityanomalyandthenconstructedthedensitymodelforELIPbyiterativeforwardmodelingfromaninitialdensitymodeltightlyconstrainedbywide-angleseismicreflectiondata.ThetopographyoftheMoho,herephysicallyinterpretedasadensitydiscontinuityof~0.4g·cm–3,graduallyrisesfromtheinnerzone(~50kmdeep)totheouterzone(~40km),describesathickercrustintheinnerzonethaninanyothersegmentoftheprofileandlargelyreproducestheshapeoftheBouguergravityanomalycurve.BoththeBouguergravityandthedensitystructureshowsignificantdifferenceswithrespecttotheinnerzoneandtheothertwozonesofELIPaccordingtothecommonlyacceptedpartitionoftheEmeishanarea.Athickeranddensermiddle-lowercrustseemstobethemainfeatureofthewesternsectionoftheprofile,whichislikelyrelatedtoitsmaficmagmaticcompositionduetomagmaticunderplatingofthePermianmantleplume.