Textural and chemical zoning in garnets related to mantle metasomatism and deformation processes

A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley, South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination technique reveal the existencal of marked elemental and oxygen isotopic zonation in these garnets, corresponding to the textural zonation. The rims are normally enriched in Ca, Ti, Cr, LREE, Sr, Nb, and depleted in Mg, Al and18O. It is demonstrated that these garnets were infiltrated by melts/fluids, probably representing the disequilibrated products of fluid-assisted mantle deformation.