A REVIEW AND ANALYSIS OF SILICATE MINERAL DISSOLUTION EXPERIMENTS IN NATURAL SILICATE MELTS

Abstract

We present a database and a graphical analysis of published experimental results for dissolution rates of olivine, quartz, plagioclase, clinopyroxene, orthopyroxene, spinel, and garnet in basaltic and andesitic melts covering a range of experimental temperatures (1100-1500oC) and pressures (105 Pa-3.0 GPa). The published datasets of Donaldson (1985, 1990) and Brearley and Scarfe (1986) are the most complete. Experimental dissolution rates from all datasets are recalculated and normalized to a constant oxygen basis to allow for direct comparison of dissolution rates between different minerals. Dissolution rates (ν) range from 5 . 10-10 oxygen equivalent moles (o.e.m.) cm-2 s-1 for olivine in a basaltic melt to 1.3 . 10-5 o.e.m. cm-2 s-1 for garnet in a basaltic melt. Values of ln ν are Arrhenian for the experiments examined and activation energies range from 118 to 1800 kJ/o.e.m. for quartz and clinopyroxene, respectively.The relationship between calculated A/RT for the dissolution reactions, where A is the thermodynamic potential affinity, and values of ν is linear for olivine, plagioclase, and quartz. We interpret this as strong evidence in support of using calculated A as a predictor of ν for, at least, superliquidus melt conditions.