学科分类
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1 个结果
  • 简介:Oxygenisotopefractionationbetweencoexistingmineralsinslowlycooledrocksconveysinformationabouttheircoolinghistory.Byusingthefastgrainboundary(FGB)modeltosimulateclosed-systemdiffusiveexchangeofoxygenisotopesbetweencoexistingminerals,Ishowthattheapparentequilibriumtemperatures(Tae)bythemineralpairwiththelargestisotopicfractionation(PLIF)alwaysliesbetweentheclosuretemperatures(Tc)ofthosetwominerals.Therefore,whentherateofoxygendiffusionandhenceTcforthePLIFchancetobecomparable(suchasinthecaseofquartzandmagnetite),TaewillserveasagoodapproximationofTcregardlessofvariationinmineralproportions.ThespecialtyofthePLIFinconstrainingTaewithintheirTcrangecanbegeneralizedtootherstableisotopesystemsandelementpartitioning.ByapproximatingTcwithTaeandinvertingDodson'sequation,thecoolingrateofplutonicormetamorphicrockscanbeinferred.

  • 标签: 氧同位素分馏 封闭温度 平衡温度 表观 共生矿物 冷却速率