CO_2,carbonate-rich melts,and brines in the mantle  

作　　者：Maria-Luce Frezzotti Jacques L.R.Touret 

机构地区：[1]Department of Earth and Environmental Sciences,University Milano Bicocca.P.za Della Scienza 4.20126 Milano.Italy [2]Mineralogy,Universite Pierre et Marie Curie,4 Place Jussieu 75272 Paris Cedex 05,France

出　　处：《Geoscience Frontiers》2014年第5期697-710,共14页地学前缘（英文版）

基　　金：supported by the Italian PRIN grant 2010PMKZX7

摘　　要：This paper reviews the origin and evolution of fluid inclusions in ultramaflc xenoliths, providing a framework for interpreting the chemistry of mantle fluids in the different geodynamic settings. Fluid inclusion data show that in the shallow mantle, at depths below about 100 km, the dominant fluid phase is CO2 ± brines, changing to alkali-, carbonate-rich （silicate） melts at higher pressures. Major solutes in aqueous fluids are chlorides, silica and alkalis （saline brines; 5-50 wt.% NaCl eq.）. Fluid inclusions in peridotites record CO2 fluxing from reacting metasomatic carbonate-rich melts at high pressures, and suggest significant upper-mantle carbon outgassing over time. Mantle-derived CO2 （±brines） may eventually reach upper-crustal levels, including the atmosphere, independently from, and additionally to magma degassing in active volcanoes.This paper reviews the origin and evolution of fluid inclusions in ultramaflc xenoliths, providing a framework for interpreting the chemistry of mantle fluids in the different geodynamic settings. Fluid inclusion data show that in the shallow mantle, at depths below about 100 km, the dominant fluid phase is CO2 ± brines, changing to alkali-, carbonate-rich （silicate） melts at higher pressures. Major solutes in aqueous fluids are chlorides, silica and alkalis （saline brines; 5-50 wt.% NaCl eq.）. Fluid inclusions in peridotites record CO2 fluxing from reacting metasomatic carbonate-rich melts at high pressures, and suggest significant upper-mantle carbon outgassing over time. Mantle-derived CO2 （±brines） may eventually reach upper-crustal levels, including the atmosphere, independently from, and additionally to magma degassing in active volcanoes.

关 键 词：Fluid inclusionPeridotiteMantle metasomatismCarbonate-rich meltCO2Saline brine 

分 类 号：P588.1[天文地球—岩石学] P592[天文地球—地质学]