Trace element partitioning in plagioclase feldspar

Compilation and interpretation of experimental and natural Nernst partition coefficient ((Plagioclase/melt) D) data show that, with a few exceptions, increases in (plagioclase/melt) D correlate with decreasing anorthite-content of plagioclase. In contrast, increases (plagioclase/melt) D for Ga. Sc. Cu, Zn.. Zr, Hf and Ti, are better correlated against decreasing melt MgO or increasing melt SiO2 contents. (Plagioclase/melt) D for Ti and the rare earth elements (REE) show little dependence on temperature, but increase as the melt water content increases. (plagioclase/melt) D for K and Sr are sensitive to pressure. Variations of Do (the strain compensated partition coefficient), r(0) (the size of the site into which REE substitute), and E (Young's Modulus of this site) were parameterized against variations Of Melt SiO2, the An-content of plagioclase. and other combinations of variables, allowing (plagioclase/melt) DREE-Y to be calculated from a variety of input parameters. The interrelations of temperature, melt MgO and SiO2 content, and plagioclase anorthite-content for wet and dry systems were also parameterized to facilitate interpolation where such data are lacking. When combined, these semi-empirical parameterizations yield (plagioclase/melt) D results comparable to available experimental and natural data. Her Majesty the Queen in right of Canada (c) 2006 Published by Elsevier Inc.