Silicate-salt(sulfate)liquid mmiscibility:a study of melt inclusions in minerals of the Mushugai-Khuduk carbonatite-bearing complex(southern Mongolia)

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• 出版年：2007
• 作者：Irina A.Andreeva；Vyacheslav I.；Kovalenko；Vladimir B.Naumov
• 单位1：Institute of Geology of Ore eposit,Petrography,Mineralogy,and Geochemistry,Russian Academy of Sciences,Siaromonetnyi per.35
• 语种：英文
• 作者关键词：Alkaline rocks；Carbonatites；Silicate and salt melt inclusions；Crystal fractionation；Liquid immiscibility
• 起始页：73
• 总页数：10
• 刊名：岩石学报
• 是否内版：否
• 刊频：月刊
• 创刊时间：1985
• 主办单位：中国矿物岩石地球化学学会；中国科学院地质与地球物理研究所
• 电子信箱：Ihzd@ public.tpt.tj.cn
• 卷：23
• 期：1
• 期刊索取号：P350.66357

摘要

Crystalline and melt inclusions were studied in gamet, diopside, potassium feldspar, and sphene from the gamet syeniteporphyry of the carbonatite-bearing complex Mushugai-Khuduk, southern Mongolia. Phlogopite, clinopyroxene, albite, potassiumfeldspar, sphene, wollastonite, magnetite, Ca and Sr sulfates, fluorite, and apatite were identified among the crystalline inclusions.The melt inclusions were homogenized at 1010～1080℃ and analyzed on an electron microprobe. Silicate, salt, and combined silicate-salt melt inclusions were found. Silicate melts show considerable variations in SiO₂ concentration (56to 66wt% ),high Na₂O+K₂O( up to 17wt% ),and elevated Zr, F, and Cl contents. In terms of bulk rock chemistry, the silicate melts are alkali syenites.Duringthermometric experiments, salt melt inclusions quenched into homogeneous glasses of predominantly sulfate compositions containing nomore than 1.3wt% SiO₂. These melts are enriched in alkalis,Ba,Sr,P,F,and Cl. The investigation of the silicate and salt meltinclusions in minerals of the garnet syenite porphyries indicate that these rocks were formed under influence of the processes ofcrystallization differentiation and magma separation into immiscible silicate and salt (sulfate)liquids.