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区域成矿学与矿产资源调查评价——从概念到野外工作方法第一部分从蚀变到区域成矿方面的概念与描述第二部分有关成矿地质特征方面的概念与野外描述第三部分有关矿床类型方面的概念与描述第四部分矿床发现的途径第五部分蒙古人民共和国OyuTolgoi斑岩型铜矿简介第一部分从蚀变到区域成矿方面的概念与描述一、蚀变、热液蚀变、蚀变带、蚀变矿化带二、异常、矿化点、矿点、矿体、矿床、矿区、矿田、矿化集中区（矿集区、矿化密集区）、成矿区、成矿带、成矿系列、成矿省（成矿域）三、远景区、靶区三、小型、中型、大型、超大型矿床四、成矿作用以下重点介绍热液蚀变和蚀变带方面的知识：蚀变（Alteration）Rockalterationsimplymeanschangingthemineralogyoftherock.Theoldmineralsgrowarereplacedbynewonesbecausetherehasbeenachangeintheconditions.Thesechangescouldbechangesintemperature,pressure,orchemicalconditionsoranycombinationofhese.热液蚀变（HydrothermalAlteration）Hydrothermalalterationisachangeinthemineralogyasaresultofinteractionoftherockwithhotwaterfluids,called“hydrothermalfluids”.Thefluidscarrymetalsinsolution,eitherfromanearbyigneoussource,orfromleachingoutofsomenearbyrocks.Hydrothermalalterationisacommonphenomenainawidevarietyofgeologicenvironments,includingfaultzonesandexplosivevolcanicfeatures.蚀变带（AlterationZoning）Althoughmineralzoningpatternsarenotuncommonlydevelopedaroundoredeposits,theyarenotalwayspresentorobvious.Thepatternscanbecausedbychangesintemperature,fluidchemistryorgascontent.Thechangeinparametersovertime,suchasdecreasingtemperatureofthefluids,cancauseoverprintingoflowertemperaturemineralsbyhighertemperatureminerals.Structuraldeformation,suchaswhenarockshatteringorfaultingeventaffectsthehostrocks,cancausemorecomplexity.Alterationzoningcanoccurinmanydifferentgeometricforms,rangingfromconcentricshells,tolinearforms,toirregularandcomplex.Porphyrycopperdepositsarecharacterizedbyconcentricshell-shapedzonesofalteration,whichoverlaptosomeextentFigure8–1A.Thecoreareacontains“potassic”alterationintheformofpotassiumfeldsparandbiotite.Furtheroutwardisazoneof“phyllic”alterationconsistingoftheassemblagequartz-sericite-pyrite.Theoutermostzone,called“propylitic”,ischaracterizedbytheassemblagequartz-chlorite-carbonateandlocallycontainingepidote,albiteoradularia.Epithermaldepositsassociatedwithmajorstructures(faultsorfractures)havelinearzoneswhichparallelthestructure.Themineralogyishighlyvariable,asisthegeometry.OneexampleofalterationzoningassociatedwithavolcanicventisshowninFigure8–1B.Thisexampleindicatesaninnerzoneofsilicificationformswithinacentralbrecciaformation,andanouterzoneofpropyliticalterationliesadjacent.Sericiteisacommonalterationmineralformedinzonesalongfaultstructuresorfaultzonesinlowtomoderatetemperaturesettings.Exampleofproximalanddistalzoningofbasemetalveindepositofthetypeassociatedwithporphyrycopper/molybdenumdeposits.蚀变填图（AlterationMapping）Alterationcanbemappedgraphicallyusingpatternsorcolorsinmuchthesamewaythatlithologicunitsaremapped.Theprimarycharacteristicstonotearethealterationmineralogy,styleandintensity.Themineralassemblagescanbecodedusingpatternsorcolors.Thestyleofalterationreferstotheform,whichcouldbedisseminatedormassiveoranythinginbetween.Anotherformofalterationis“veinlet-controlled”,whichindicatesthatalterationisrestrictedtonarrowzonesadjacenttoveinlets.Theintensityofalterationreferstohowwell-developedthealterationis.Itcouldbeincipientmineralgrowthduetoweakdevelopment,oritmaybepervasivethroughouttherock,indicatingstrongdevelopment.Mappingalterationcanbeusedtopredictmineralization.Intheory,thisisdonebycomparingtheresultsofalterationmappingwithknownalterationzoningpatternsforknownmineraldeposits.Inpracticehowever,theprocessisseldomsosimplebecauseeverymineraldeposithassomeuniquenesstoitsalterationzoning.蚀变类型（AlterationTypes）•青磐岩化Propylitic:(Chlorite,Epidote,Actinolite)绿泥石、绿帘石、阳起石Propyliticalterationturnsrocksgreen,becausethenewmineralsformedaregreen.Thesemineralsincludechlorite,actinoliteandepidote.TheyusuallyformfromthedecompositionofFe-Mg-bearingminerals,suchasbiotite,amphiboleorpyroxene,althoughtheycanalsoreplacefeldspar.Propyliticalterationoccursatrelativelylowtemperatures.Propyliticalterationwillgenerallyforminadistalsettingrelativetootheralterationtypes.•矽卡岩化SkarnizationSkarnizationsarereplacementalteration.Theyformbythereplacementoflimestone,calcareousrocks(marlorcalc-schist),ordolomite.Awidevarietyofmineralscanforminskarn,butthemostcommonincludeoxidemineralssuchasmagnetite,sulfidemineralssuchaschalcopyrite,silicatemineralssuchasepidote,orthetungstatemineralScheelite.•绢云母化Sericitic:(Sericite)Sericiticalterationalterstherocktothemineralsericite,whichisaveryfine-grainedwhitemica.Ittypicallyformsbythedecompositionoffeldspars,soitreplacesfeldspar.Inthefield,itspresenceinarockcanbedetectedbythesoftnessoftherock,asitiseasilyscratchable.Italsohasarathergreasyfeel(whenpresentinabundance),anditscoloriswhite,yellowish,goldenbrownorgreenish.SericiticalterationimplieslowpH(acidic)conditions.Alterationconsistingofsericite+quartziscalled“phyllic”（绢英岩化）alteration.Phyllicalterationassociatedwithporphyrycopperdepositsmaycontainappreciablequantitiesoffine-grained,disseminatedpyritewhichisdirectlyassociatedwiththealterationevent.•钾化Potassic:(Biotite,K-feldspar,Adularia)黑云母、钾长石、冰长石Potassicalterationisarelativelyhightemperaturetypeofalterationwhichresultsfrompotassiumenrichment.Thisstyleofalterationcanformbeforecom