INCLUSIONS OF NATIVE METALS AND OTHER MINERAL PHASES INTO CARBONADO FROM THE UBANGI REGION (CENTRAL-AFRICA)

Native metals [iron, chromium, nickel, taenite gamma-(Fe, Ni), and sep arate particles of Ag] were first detected in cryptocrystalline diamon ds (carbonade) from the Ubangi region. It has been noted that taenite particles at the edges were frequently substituted by pentlandite (Ni5 Fe4S8). In addition, florencite-containing REEs, magnetite, anatase, r utile, ilmenite, hematite, goethite, and kaolinite were fixed. Based o n the experimental results obtained and taking into account the refere nce data, it has been concluded that different inclusions in carbonade from the Ubangi region (Central Africa) reflect various stages of its geological history. Native metals alpha-Fe, Cr, Ni, gamma-(Fe, Ni), a nd Ag are syngenetic inclusions and reflect the highly reducing condit ions of carbonado crystallization. Inclusions of rutile, ilmenite, and magnetite are syngenetic also and indicate the high temperatures and pressures of this process. Rare earth florencite reveals the hydrother mal metasomatic alteration of carbonade at lower physicochemical param eters, while kaolinite, hematite, and goethite reveal the late postmag matic stage of their formation in carbonade pores.