Fluid-melt trace-element partitioning behaviour between evolved melts and aqueous fluids: Experimental constraints on the magmatic-hydrothermal transport of metals

Melt and fluid evolution in an upper-crustal magma reservoir, preserved by inclusions in juvenile clasts from the Kos Plateau Tuff, Aegean Arc, Greece

“…In contrast, the partition coefficients from this study are mostly at the higher end of the experimentally-determined values of Iveson et al (2019), and only those for K and Rb compare well. Experimental partitioning studies have some advantages in comparison to analyzing natural inclusions, including: (1) the relatively precisely known formation (equilibration) conditions and the possibility to vary these conditions independently to explore their effects on partitioning, and (2) the accessibility of analytes without the limitation of inclusion entrapment, whereas natural fluid inclusions are very rare, e.g., in magmatic phenocrysts.…”

“…The most extensive quantitative element distribution data between melt and fluid have been presented by Zajacz et al (2008) based on natural inclusion assemblages and by Iveson et al (2019) using an experimental approach. Many other publications focus on specific elements (e.g., Audétat and Li, 2017;Candela and Holland, 1984;Iveson et al, 2017;Tattitch and Blundy, 2017; and many more).…”

Tracing fluid saturation during pegmatite differentiation by studying the fluid inclusion evolution and multiphase cassiterite mineralisation of the Gatumba pegmatite dyke system (NW Rwanda)

“…Fig.3;London, 2008), it can be expected that the bulk distribution of Li is incompatible during mineral fractionation from the wall zone towards the core zone. In L1 fluids with a chloride molality of ~4.0 mol kg -1 , Li can be expected to be weakly soluble with a bulk fluid/melt distribution coefficient around 1.3(Iveson et al, 2019). As such, combined crystal/melt incompatible and fluid/melt soluble partitioning behaviour of Li during fractional crystallisation in a coexisting crystals-melt-fluid system produces an overall increase of the bulk Li content in the melt and fluid phase with advancing fractionation.…”

The physical and chemical evolution of magmatic fluids in near-solidus silicic magma reservoirs: Implications for the formation of pegmatites

“…First, S-and A-type magmas appear enriched in key flux elements (such as Li, B, F, P) in comparison to I-type magmas (Whalen et al, 1987;Taylor and Fallick, 1997;Trumbull et al, 2008). As recognized in models favoring pegmatite formation from single-phase hydrous silicate liquid (section 2.3), these flux elements generally partition into the fluid phase (Webster et al, 1989;Zajacz et al, 2008;Iveson et al, 2019), increase the ionic potential of the fluid, and can thus lead to the progressive dissolution of other, typically less soluble, cations (e.g., Si, Al, Na, K, Zr, and REE). In I-type magmatic systems, silicate melt and MVP may therefore be less prone to reaching miscibility, and melt and MVP remain more dissimilar to one another compared to A-and S-type granitic systems.…”