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1、中国地质大学长城学院地质英语论文系别地球科学与资源系专业资源勘查工程学生姓名学号指导教师2012年12月16日Title:OrthomagmaticoredepositsOne.OrthomagmaticoredepositsThemagmacontainsacertainnumberofmetalandvolatilecomponentsofthesilicatemelt.Allkindsofmagmaaftercrystallizationanddifferentiation,makethef
2、ormingmaterialsdispersedinthemagmagatheredandformeddeposits.Andthisdepositsiscalledmagmaticdeposits.Magmaticdepositsformedinthemagmaticstage,thesourceofthematerialofthedepositisthemainore-bearingmagma.Magmaticdepositsistheproductofthemagmabycrystalliz
3、ationanddifferentiation,andgenerallyhavethefollowingproperties:1、Depositshavethemainlyrelationshipwiththemaficandultramaficrocks.Andasmallnumberofmagmaticdepositswithalkalinerocksormagmaticcarbonatite-related.Mineralizationanddiagenesisoftenbeginatthe
4、sametime.Andthisistypicalofsyngeneticoredeposits.Fewmineralizationofthemagmaticdepositsmaybecontinuedtoalatertime,butgenerallydoesnotexceedatotalperiodofmagmaticactivity.2、Themagmaticdepositsorebodymajoritypresentstratiform,stratiform,lenticularandpod
5、iformandsoon.Andtheyproducedinthemagmabody,andthewallrockofcontainingoreisthemotherrock.Fewcases,orebodypresentingveinandstockworkenterthewallrockwhichoutsideofthemotherrock.Betweentheorebodyandthewallrockgenerallyisgradualchangeorrapidgradualchangere
6、lationship,.Onlypenetrationmagmaticdepositshavetheclearboundarieswiththewallrock.3、Excepttherareandrareearthelementsdepositsofthemagmaticcarbonatiteduetospecialcauseshavesomealterationaboutthewallrock,thevastmajorityofmagmaticdepositssurroundingrockdo
7、esnothaveasignificantalterationphenomenon.4、Theoreandthewallrockbasicallyhavethesamemineralcomposition,whentheusefulmineralsoftherockbodyaggregateandreachacertainsize,theybecometheorebody.5、Theoreofmagmaticdepositsoftenhave,disseminated,thebanded,eyep
8、orphyritic,densemassive,brecciatedandsoon,orestructure.Theoresstructurecanbebroadlydividedintothefollowingcategories:I.Structuresub-thedifferentmagmaticcondensatecrystallineorstackinginteractions;II.Reflectthestructureoftheimmisciblefluidcryst
