Minor elements in olivine from spinel lherzolite xenoliths: Implications for thermobarometry

Abstract

The proton microprobe has been used to determine contents of Ca, Ti, Ni, Mn and Zn in the olivine of 54 spinel lherzolite xenoliths from Australian and Chinese basalts. These data are compared with proton-probe data for Ni, Mn and Zn in the olivine of 180 garnet peridotite xenoliths from African and Siberian kimberlites. Fe, Mn. Ni and Zn contents are well-correlated; because the spinel Iherzolite olivines have higher mean Fe contents than garnet peridotite olivines (average Fo89.6 vs. Fo90-92) they also have lower Ni and higher Mn contents. Zn and Fe are well-correlated in garnet peridotite olivine. but in spinel peridotites this relationship is perturbed by partitioning of Zn into spinel. ..