Comment on “Parameterizations of Clinopyroxene—Melt Trace Element Partition Coefficients” by Bédard, J. H. (2014)

Abstract

Abstract A better understanding of how trace element partition coefficients vary with melt and mineral composition, temperature, pressure, oxygen fugacity and fluid composition is essential to geochemical modeling of magmatic rocks. The Nernst partition coefficient D is the ratio of the concentration (by weight) of a trace element in a solid phase divided by the concentration of the same element in the equilibrium melt ( D = C s / C m ). Bédard (2014, https://doi.org/10.1002/2013gc005112 ) compiled partitioning data between clinopyroxene and silicate melt, and modeled these data to develop a set of predictive equations allowing clinopyroxene/melt partition coefficients to be predicted for most of the trace elements used in igneous petrology. A typographic error has been found in Table 2 of Bédard (2014, https://doi.org/10.1002/2013gc005112 ), where the value of the “ d ” coefficient of the equation needed to calculate the value of r 0 for the M2 site was reported as being 0.0020599. The correct value is 0.00020599. I thank Carrie Soderman of Cambridge University for spotting this. I apologize to any who attempted to implement the lattice strain model from Bédard (2014, https://doi.org/10.1002/2013gc005112 ) using this incorrect coefficient, as it would have yielded erroneous results.