Mineralogical and geochemical features of graphitized rocks in the Chernorudka-Barakchin Tectonic Zone

Abstract

The morphological and structural characteristics of graphite from the deep Chernorudka-Barakchin Fault Zone, Western Baikal region, are described. A complex of mineralogical investigations shows that graphite varieties of the Baikal region are characterized by a perfect structure. The most crystallographically regular samples are composed only of sp 2 -carbon, whereas the virtually amorphous varieties are formed by sp 2 -and sp 3 -carbons as well. The characteristic features of the graphite varieties distinguish them from carbonaceous matter of metamorphic rocks. High concentrations of Co, Ni, Cr, Cu, Ti, Zn, Sc, V, S, Nb, Zr, Sr, Ba, Y, Nd, and La were detected while analyzing the microcomponent composition of the graphitized rocks. The majority of these elements are contained in microinclusions hosted in graphite. The elevated noble metal contents were established in graphitized metasomatic rocks, granitoids, and particularly, in graphite concentrates extracted from these rocks. Sulfides, native metals, and intermetallic compounds were detected in microinclusions. It is suggested that the inflow of reduced high-carbonaceous fluids was responsible for the transfer of chemical elements.

Geochemical studies of natural graphites by INAA determined trace element concentrations

“…Recently also its different form known as graphene is of much interest. In the case of pure science, among others, the geochemistry of different types of rocks hosting natural graphite uses TE as markers [ 5 – 7 ]. In this paper only the natural variety of graphite is concerned mainly for the geochemical meaning of its TE content.…”