Assimilation processes can have a pronounced effect on lava fO 2 and should always be accounted for when constraining mantle redox. The Réunion mantle plume likely has fO 2 similar to that of MORB, despite isotopic evidence for the plume sampling an early-formed isolated mantle reservoir. The variable fO 2 of Réunion lavas results from assimilation processes within the volcanic edifice, and not source heterogeneity.
Vanadium abundances in olivine were used to constrain the lava fO 2 to between +0.2 and +1.5 ΔFMQ, intermediate between that of mid-ocean ridge basalts (MORBs) and other OIBs. La Réunion lavas are useful for examining post-melting modification due to their limited range in isotopic signatures, indicating a largely homogenous mantle source. To investigate these issues in situ trace element data of olivine in lavas from the island of La Réunion are reported. This is partly due to complications from secondary processes acting on fO 2 in OIB parental magmas. Oxygen fugacity ( fO 2) is poorly constrained in mantle reservoirs, especially those sampled by ocean island basalts (OIBs). Assimilation processes can have a pronounced effect on lava fO2 and should always be accounted for when constraining mantle redox. The Réunion mantle plume likely has fO2 similar to that of MORB, despite isotopic evidence for the plume sampling an early-formed isolated mantle reservoir. The variable fO2 of Réunion lavas results from assimilation processes within the volcanic edifice, and not source heterogeneity. Vanadium abundances in olivine were used to constrain the lava fO2 to between +0.2 and +1.5 ΔFMQ, intermediate between that of mid-ocean ridge basalts (MORBs) and other OIBs.
This is partly due to complications from secondary processes acting on fO2 in OIB parental magmas. DayDO - ĪB - Oxygen fugacity (fO2) is poorly constrained in mantle reservoirs, especially those sampled by ocean island basalts (OIBs). T1 - Oxidation of La Réunion lavas with MORB-like fO2 by assimilationĪU - R.W.
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