Journal article

VARIATIONS IN TRAPPING TEMPERATURES AND TRACE-ELEMENTS IN PERIDOTITE-SUITE INCLUSIONS FROM AFRICAN DIAMONDS - EVIDENCE FOR 2 INCLUSION SUITES, AND IMPLICATIONS FOR LITHOSPHERE STRATIGRAPHY

WL GRIFFIN, JJ GURNEY, CG RYAN

CONTRIBUTIONS TO MINERALOGY AND PETROLOGY | SPRINGER VERLAG | Published : 1992

Abstract

The proton microprobe has been used to measure the trace element contents of Cr-pyrope, olivine and orthopyroxene inclusion (DI) in>60 diamonds from southern Africa, and in concentrate garnets from the host kimberlites. Olivine inclusions show a negative correlation of Ca with Fo content, but olivines coexisting with very subcalcic garnets are anomously depleted in Ca relative to Fo. The maximum and median values of Ti, Zn, Ga, Zr and Y in DI garnets decrease as Ca decreases relative to Cr, consistent with increasing depletion by removal of silicate melts. However, the most subcalcic garnets are anomously enriched in Sr (and LREE). The contrasting depletion in Zr, Y, Ti etc. and enrichment i..

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University of Melbourne Researchers