Geological and physicochemical characterization of Kobe Sorsa graphite deposit, Ethiopia.

Abstract

The Kobe Sorsa graphite deposit is situated within the Adola Belt of southern Ethiopia. It composed of Graphitic phyllites and graphite schist with considerable economic potential. This study aims to characterize the Kobe Sorsa graphite for potential industrial applications through an integrated approach such as geochemical, mineralogical, petrography, sieve and carbon content analysis. Graphitic carbon content ranges from 5.37% to 22.08%, with an average concentration of 14.96%. According Petrographic and X-ray diffraction (XRD) investigation, graphite consists of medium- to coarse-grained, well-ordered flakes with an average size of ~ 300 μm, which reflect a high-quality crystalline structure. The REE and multi-element patterns of the Kobe Sorsa graphite-bearing rocks suggest a metasedimentary protolith formed from felsic upper continental crust, characterized by slight HREE enrichment, negligible Eu anomalies, and negative Nb-Ta-Ti anomalies consistent with passive-margin sedimentary sources. The enrichment of HREE's reflects partitioning into garnet and staurolite-bearing assemblages during metamorphism, whereas the smooth, unfractionated patterns imply closed-system behaviour for REEs during metamorphic recrystallization. The AKF ternary diagram indicates stable mineral assemblages: muscovite-phengite, chlorite, K-feldspar, and pyrophyllite + quartz, suggesting metamorphic conditions within greenschist facies metamorphism. A binary plot of crystallite size (Lc₍₀₀₂₎) versus interplanar spacing (d₍₀₀₂₎) shows that the Kobe Sorsa graphite samples fall within the well-crystallized graphite field with Lc₍₀₀₂₎ values range from 530 Å to 600.2 Å, while the degree of graphitization (DG) values vary between 265.7% and 279.1%, confirming a highly ordered graphitic structure. The combination of larger flake size and high crystallinity make highlight the Kobe Sorsa graphite as a strategically significant and economically promising resource for high-value industrial uses, including batteries, refractories, and advanced technologies.