Abstract:
The genesis of carbon-rich rocks (shungite rocks) and accompanying phtanites (lydites) from the Early Proterozoic (2,1-2,0 Ga) of the Transonega Formation in Karelia (Eastern Fennoscandian Shield) is discussed. Some features of composition, structure and texture of these rocks as well as the structure of the deposits is described. Microtextures of lydites were studied by means of scanning electronic microscopy. The organogenic origin of primary sedimentary organic matter as well as the originally colloidal nature of silica could be confirmed.