On the origin of CO2-rich fluid inclusions in migmatites |
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| Authors: | LS HOLLISTER |
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| Institution: | Department of Geological and Geophysical Sciences, Princeton University, Princeton, NJ 08544, USA |
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| Abstract: | Abstract Nearly pure CO2 fluid inclusions are abundant in migmatites although H2O-rich fluids are predicted from the phase equilibria. Processes which may play a role in this observation include (1) the effects of decompression on melt, (2) generation of a CO2-bearing volatile phase by the reaction graphite + quartz + biotite + plagioclase = melt + orthopyroxene + CO2-rich vapour, (3) selective leakage of H2O from CO2+ H2O inclusions when the pressure in the inclusion exceeds the confining pressure during decompression, and (4) enrichment of grain-boundary vapour in CO2 by subsolidus retrograde hydration reactions. |
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| Keywords: | fluid inclusion migmatites |
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