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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,maketheformingmaterialsd
2、ispersedinthemagmagatheredandformeddeposits.Andthisdepositsiscalledmagmaticdeposits.Magmaticdepositsformedinthemagmaticstage,thesourceofthematerialofthedepositisthemainore-bearingmagma.Magmaticdepositsistheproductofthemagmabycrystallizationanddifferentiation,andgener
3、allyhavethefollowingproperties:1、Depositshavethemainlyrelationshipwiththemaficandultramaficrocks.Andasmallnumberofmagmaticdepositswithalkalinerocksormagmaticcarbonatite-related.Mineralizationanddiagenesisoftenbeginatthesametime.Andthisistypicalofsyngeneticoredeposits
4、.Fewmineralizationofthemagmaticdepositsmaybecontinuedtoalatertime,butgenerallydoesnotexceedatotalperiodofmagmaticactivity.2、Themagmaticdepositsorebodymajoritypresentstratiform,stratiform,lenticularandpodiformandsoon.Andtheyproducedinthemagmabody,andthewallrockofconta
5、iningoreisthemotherrock.Fewcases,orebodypresentingveinandstockworkenterthewallrockwhichoutsideofthemotherrock.Betweentheorebodyandthewallrockgenerallyisgradualchangeorrapidgradualchangerelationship,.Onlypenetrationmagmaticdepositshavetheclearboundarieswiththewallrock
6、.3、Excepttherareandrareearthelementsdepositsofthemagmaticcarbonatiteduetospecialcauseshavesomealterationaboutthewallrock,thevastmajorityofmagmaticdepositssurroundingrockdoesnothaveasignificantalterationphenomenon.4、Theoreandthewallrockbasicallyhavethesamemineralcompo
7、sition,whentheusefulmineralsoftherockbodyaggregateandreachacertainsize,theybecometheorebody.5、Theoreofmagmaticdepositsoftenhave,disseminated,thebanded,eyeporphyritic,densemassive,brecciatedandsoon,orestructure.Theoresstructurecanbebroadlydividedintothefollowingcatego
8、ries:I.Structuresub-thedifferentmagmaticcondensatecrystallineorstackinginteractions;II.Reflectthestructureoftheimmisciblefluidcryst