The Crystal/Melt Partitioning of V during Mantle Melting as a Function of Oxygen Fugacity Compared with some other Elements (Al, P, Ca, Sc, Ti, Cr, Fe, Ga, Y, Zr and Nb)

Abstract

The distribution of heterovalent elements between minerals and melts may be used to obtain information on the redox conditions of high-temperature planetary processes

Stable vanadium isotopes as a redox proxy in magmatic systems?

“…Vanadium is a moderately incompatible, refractory multivalent (2+, 3+, 4+, 5+) element and the strong dependence of its partitioning behaviour on fO 2 is wellestablished (e.g., Canil, 1997;Toplis and Corgne, 2002;Mallmann and O'Neill, 2009). In all major mantle phases, vanadium becomes more incompatible with…”

“…Letter Letter Geochemical Perspectives Letters increasing fO 2 , leading to the application of V as a redox proxy (e.g., Shervais, 1982;Canil, 1997;Lee et al, 2005;Mallmann and O'Neill, 2009). However, using concentrations alone results in fO 2 uncertainties on the order of 1-2 log units due to variations in degree of melting, original source concentration, and fractionating mineral assemblages (Lee et al, 2003).…”

“…Despite this hypothesis, there is a consensus that basaltic melts found in arcs are more oxidised than their MORB counterparts, given, for example, their elevated Fe 3+ /∑Fe ratios measured in melt inclusions (e.g., Kelley and Cottrell, 2009). In order to explain how oxidised arc basalts and more reduced MORBs can be derived from sources with similar fO 2, processes subsequent to magma generation such as degassing and crystal fractionation have been invoked (e.g., Mallmann and O'Neill, 2009;Lee et al, 2010). Evidence gleaned from both experimental and natural suites is conflicting, with cases of Fe 3+ /∑Fe increasing, decreasing and remaining invariant during magmatic degassing and crystallisation (e.g., Brounce et al, 2014;Waters and Lange, 2016).…”

Redox state of early magmas

“…1). However, it is known that terrestrial magmas do not necessarily have a high oxidation state, even if volatiles are abundant 10,11 , and that the Moon's reduced lavas contain a substantial amount of volatiles 12 . Taken together, these facts argue against the existence of an unequivocal relationship between high fO2 and the abundance of volatiles.…”

Early Cretaceous high-Ti and low-Ti mafic magmatism in Southeastern Tibet: Insights into magmatic evolution of the Comei Large Igneous Province

“…25 incompatible in mafic phases O'Neill, 2009 &. The anomalous dramatically increasing behavior of V in Group 3 (Figs.…”