Coexisting silicate melt inclusions and H₂O-bearing, CO₂-rich fluid inclusions in mantle peridotite xenoliths from the Carpathian–Pannonian region (central Hungary)

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• 作者：K&#xe1 ; roly Hidas ; Tibor Guzmics ; Csaba Szabó ; Istv&#xe1 ; n Kov&#xe1 ; cs ; Robert J. Bodnar ; Zolt&#xe1 ; n Zajacz ; Zsuzsanna N&#xe9 ; dli ; Lisa Vaccari ; Andrea Perucchi
• 关键词：Carpathian– ; Pannonian region ; Hungary ; C– ; O– ; H– ; S fluid inclusions ; Peridotite xenoliths ; Silicate melt inclusions ; Volatile (fluid)– ; silicate melt immiscibility
• 刊名：Chemical Geology
• 出版年：2010
• 出版时间：15 June 2010
• 年：2010
• 卷：274
• 期：1-2
• 页码：1-18
• 全文大小：1647 K

文摘

Coexisting fluid inclusions and silicate melt inclusions, trapped as primary inclusions in clinopyroxene rims and as secondary inclusions along healed fractures in orthopyroxene, were studied in two amphibole-bearing spinel lherzolite peridotite xenoliths from the Bakony–Balaton Highland Volcanic Field (western Hungary). The composition of both Cpx-hosted and Opx-hosted inclusions suggests that they were entrapped from the same silicate melt, which was saturated in volatiles at mantle P–T conditions. Raman spectroscopy, combined with microthermometry and FTIR analyses, proved the existence of CO₂, H₂O and H₂S in the fluid inclusions. Trace element compositions of silicate melt and fluid inclusions were determined by LA–ICP–MS, although the results of fluid inclusions are only semi-quantitative. Trace element distributions revealed significant similarities in the compositions of silicate melt and fluid inclusions, especially with respect to K, Rb, Sr, Pb, Nb, Th and U content. This confirms the same parental melt for both silicate melt and fluid inclusions and suggests that the trace element content of the CO₂-rich end-member (containing some dissolved melt) resulted from high P–T immiscibility in deep lithospheric environments and is controlled by the trace element content of the parent silicate melt.