FIEST FIND OF ACCESSORY DIAMONDS IN DRUSITIC ECLOGITES OF SOME OPHIOLITE COMPLEXES IN TRANSBAIKALIA

Abstract

Most banded ophiolite complexes contain rocks with eclogite or eclogite-like parageneses. These include various mineralogical varieties of eclogite and eclogite-like rocks, glaucophane and eclogite-glaucophane schists, as well as pyrope peridotites and their serpentinized analogs. Empirical data show that the thermodynamic conditions of the formation of some of them were largely similar to the conditions of natural synthesis of diamonds. This is confirmed by numerous finds of diamonds in deep-seated xenoliths with the above mineralogical composition and chemistry in kimberlite pipes in South Africa, Australia and Yakutia, as well as in similar rocks of some eclogite-gneiss, eclogite-schist and banded complexes. Even though there exists voluminous information on the diamond potential of various crystalline rocks, the authors report here on the first find of drusitic eclogite with accessory diamonds.