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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,maketheformingmaterialsdispersedinthemagmagatheredan
2、dformeddeposits.Andthisdepositsiscalledmagmaticdeposits.Magmaticdepositsformedinthemagmaticstage,thesourceofthematerialofthedepositisthemainore-bearingmagma.Magmaticdepositsistheproductofthemagmabycrystallizationanddifferentiation,andgenerallyhavethefollowingproperties:1、Depositshavethemainlyre
3、lationshipwiththemaficandultramaficrocks.Andasmallnumberofmagmaticdepositswithalkalinerocksormagmaticcarbonatite-related.Mineralizationanddiagenesisoftenbeginatthesametime.Andthisistypicalofsyngeneticoredeposits.Fewmineralizationofthemagmaticdepositsmaybecontinuedtoalatertime,butgenerallydoesno
4、texceedatotalperiodofmagmaticactivity.2、Themagmaticdepositsorebodymajoritypresentstratiform,stratiform,lenticularandpodiformandsoon.Andtheyproducedinthemagmabody,andthewallrockofcontainingoreisthemotherrock.Fewcases,orebodypresentingveinandstockworkenterthewallrockwhichoutsideofthemotherrock.Be
5、tweentheorebodyandthewallrockgenerallyisgradualchangeorrapidgradualchangerelationship,.Onlypenetrationmagmaticdepositshavetheclearboundarieswiththewallrock.3、Excepttherareandrareearthelementsdepositsofthemagmaticcarbonatiteduetospecialcauseshavesomealterationaboutthewallrock,thevastmajorityofma
6、gmaticdepositssurroundingrockdoesnothaveasignificantalterationphenomenon.4、Theoreandthewallrockbasicallyhavethesamemineralcomposition,whentheusefulmineralsoftherockbodyaggregateandreachacertainsize,theybecometheorebody.5、Theoreofmagmaticdepositsoftenhave,disseminated,thebanded,eyeporphyritic,de
7、nsemassive,brecciatedandsoon,orestructure.Theoresstructurecanbebroadlydividedintothefollowingcategories:I.Structuresub-thedifferentmagmaticcondensatecrystallineorstackinginteractions;II.Reflectthestructureoftheimmisciblefluidcryst