简介:By"concealedexplosionofmagma",wemeantheexplosiveproessofmagmaundersubterraneanconcealedconditionswhichisessen-tiallysimilartovolcaniceruptionseenatthesurface;theonlydiffer-"nceisthatthelattertakesplaceinanopenenvironmentatthesurface’`vhiletheformertinasemi-openenvironmentbelowathincovernearlhesurfac
简介:Thecharacterofthemagmaticrocksandoredeposits,formed-in’theregionsoftectonicmagmaticactivity(TMA)or"Diwa"dcpendsincertaindegreeonthebasementstructuretypes,andpartiallyonproportionsbetwccn"basalt~andgranitc-sedimentarylaycrthickncsses.Magma-andore-formationinTMA-structurcswcreconncctcdwithpowcrfulhcat
简介:TheEastTianshanisaremoteGobiarealocatedineasternXinjiang,northwesternChina.Inthepastseveralyears,anumberofgold,porphyrycopper,andFe(-Cu)andCu-Ag-Pb-Znskarndepositshavebeendiscoveredthereandareattractingexplorationinterest.TheEastTianshanislocatedbetweentheJunggarblocktothenorthandearlyPaleozoicterranesoftheMiddleTianshantothesouth.ItispartofaHercynianorogenwiththreedistinctE-W-trendingtectonicbelts:theDevonian-EarlyCarboniferousTousuquan-DananhuislandarconthenorthandtheCarboniferousAqishan-Yamansuriftbasintothesouth,whichareseparatedbyrocksoftheKanggurtagshearzone.Theporphyrydeposits,datedat322Ma,arerelatedtothelateevolutionarystagesofasubduction-relatedoceanicorcontinentalmarginarc.Incontrast,theskarn,gold,andmagmaticNi-Cudepositsareassociatedwithpost-colli-sionaltectonicsatca.290-270Ma.TheseLateCarboniferous-EarlyPermiandepositsareassociatedwithlarge-scaleemplacementanderuptionofmagmaspossiblycausedbylithospheredelaminationandriftingwithintheEastTianshan.