印度洋carlsberg洋脊玄武岩的分析

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1、万方数据印度洋Carlsberg洋脊玄武岩的研究值和较低Fe8值，表明具有较冷的源区地幔、较低的部分熔融程度及较小熔融深度，熔融程度约为lOwt％。(5)Carlsberg洋脊与中印度洋脊(CIR)其它脊段(CR、NC瓜及SCIR)玄武岩化学组成相近，主要为大洋拉斑玄武岩，结晶矿物相均以橄榄石+斜长石为主。从CR、NC瓜到SCIR，地幔熔融程度及深度相近，具有全球平均水平，比快速扩张的东太平洋海隆(EPR)和中速扩张的大西洋中脊(MAR)低，比慢速／超慢速扩张的印度洋中脊(IoR)高；各脊段源区地幔富集程度相近，仅SCIR及CR区域部分脊段具有较高的源区地

2、幔富集程度。关键词：印度洋Carlsberg洋脊；玄武岩；矿物学与岩石化学；岩浆源区地幔；结晶演化；区域差异万方数据印度洋Carlsberg洋脊玄武岩的研究TheResearchofBasaltsfromCarlsbergRidgeinIndianOceanAbstractThemineralcomponent，majorelements，traceelementsandelectronprobeanalysishavebeenmadeof19basaltsdredgedfrom17locationsofCarlsbergRidgeinIndianOcea

3、n．Thepurposeofthisstudywastorevealthematerialsource，evolutionprocessofthebasaltsandthemeltingfeatureofmantleSOurCebeneaththeCarlsbergRidgethroughpetrological，mineralogicalandgeochemicalcharacteristicsanalysis．Themainconclusionsincludethefollowing：(1)Thestructuresofbasaltsaremainly

4、intersertaltextureandhyalopilitictexture，themineralphenocrystsaremainlyplagioclase，belongingtolabradoriteandbytowniteandthetypeofplagioclasemicrocrystalaremainlylabradorite；lessolivinephenocrysts，mainlybelongtochrysolite．．Clinopyroxeneisrarely，pyroxenearemainlydiopsideandaugite，fe

5、wofpigeonite．ThereexsitalotofinclusionsinplagioclasewhichM够ishigherthangroundmassindicatethemagmacompositionismoreclosetoprimitivemagmawheninclusionsformed．TheAncontentofplagioclaserecordsthepositivezoning，negativezoningandoscillatoryzoningfeatures．TheplagioclaseatIVsegmenthavethe

6、positivezoningandoscillatoryzoningwhichindicatebasaltsexperiencedthecrystallizationprocessandmixing—crystallizationprocessofmagma．TheplagioclaseatVsegmentandIIsegmenthavethenegativezoningindicatebasaltsexperiencedmoreprimitivemagmasupplyprocess．ThevariationofFocontentofolivineisno

7、tobviousandnoobviouszoningfeatureinolivine．(2)ThebasaltsofCarlsbergridgecanbeclassifiedintoolivinetholeiiticbasalt．ThecompositionofbasaltsvariouslittleandverysimilartothecompositionofN-MORB．PanofbasaltshavehighLOIreflectsrock／seawaterinteraction．Thecorrelationbetweenmajorelementsi

8、snotgoodwhichindicatebasaltsexper