BEHAVIOUR OF BORON, BERYLLIUM, AND LITHIUM DURING MELTING AND CRYSTALLIZATION: CONSTRAINTS FROM MINERAL-MELT PARTITIONING EXPERIMENTS

Abstract

In order to provide a more substantial foundation for interpreting the behaviour of B, Be, and Li during the production and early crystallization of primitive igneous rocks, we have measured olivine-, clinopyroxene-, orthopyroxene-, and amphibole-melt partition coefficients for these elements involving broadly basaltic-andesitic melt compositions. Experiments were conducted at both one atmosphere and 1.0–1.5 GPa and employed a time-temperature history that yielded large crystals with minimal compositional zoning. Experiment temperatures ranged from 1000 to 1350°C and were selected to minimize the total crystal fraction in a given experiment. Partition coefficients for olivine and clinopyroxene were found to be independent of run duration or total concentration of B, Be, or Li suggesting that crystal-liquid equilibrium was closely approached.