A consistent partition coefficient set for clinopyroxéne, amphibole and garnet from laser ablation microprobe analysis of garnet pyroxenites from Kakanui, New Zealand

The abundances of 24 trace elements in clinopyroxene, amphibole and garnet from 4 garnet pyroxenites from Kakanui, New Zealand, were obtained by laser ablation microprobe (LAM). Since equilibrium conditions can be proven, the data are evaluated for their use of calculating reliable and consistent partition coefficients between minerals and melt. Using the experimentally determined DCPX/L values of HART & DUNN (1993) as a reference set, r>M>lp/L and DGRT/L were calculated using the measured DAMP/CPX and DGRT/CPX data from Kakanui. The overall DAMP/L pattern calculated from the Kakanui data is consistent with published experimental data. We recommend the calculated DAMP/L values for multi-element modelling in mafic and ultramafic systems since they represent an extensive data set for D1 and include reliable DAMP/L for Sc (0.74) and V (3.0). The DGRT/L values from this study differ from experimentally derived DGRT/L since values for highly incompatible elements are significantly higher in the experimental data sets. This difference is interpreted in terms of a strong structurally-controlled temperature effect on partitioning behaviour. The 920 °C Kakanui data set may be more applicable to many natural crystallization conditions than experimental data sets at 1400 °C.