Transmission Electron Microscopy of Carbonaceous Matter in Precambrian Shungite from Karelia

Abstract

Precambrian shungite (a solid bitumen from a regionally metamorphosed area of Karelia, Russia) had a structural arrangement comparable to that with Precambrian kerogens and was not typical of bitumens. The shungite was a porous carbon comparable with carbonaceous materials derived from higher vegetation and was oxidized prior to the petroleum-generating stage. From microscopic observations, a high degree of evolution for shungite was deduced; particles of higher structural arrangement can be compared to structures from kerogens heated at >2000 Deg. Such structural inhomogeneities were typical of shungite. Particles with a higher structural arrangement were obsd. in high-ash shungite, although typical tubular or spherical particles present in catalytic carbons were not obsd.