Evidence of Soil-Forming Processes in Early Proterozoic as Exemplified on the Basis of the Livvian Deposits (Karelia)

The paper deals with the fossil cyanobacterial films from the Lower Proterozoic shungites (Livvian) of the Republic Karelia, Russian Federation. The films were previously described as a formal species Cyathotes nigoserica Makarikhin. These films were formed by bacteria and possibly by fungi, which existed in condition of littoral or supralittoral (zone of stochastic wave drops reaching, or splash zone, spray zone). The adaptation of these organisms for existence in temporally (possibly, long-temp) dry conditions is evidenced by development of their outer dense covers predicting against dehydration of the organism body. This basically bacterial community intensively influenced onto the mineral substrate and had changed its structure enriching the soil by biogenic chemicals/constituents and thus forming an archaic paleosole microprofile. The signs of ancient soil formation found in the course of research can be considered the transformation of the surface texture of the mineral substrate by the vital activity of terrestrial organisms (bacteria, fungi) with the formation of a specific cellular relief, a change in the internal structure of this substrate with the appearance of casts of wedge-shaped cracks in the underlying matrix, the redistribution of inorganic compounds during the formation of a paleosurface microprofile (an increase in the content of silicon oxide in the upper part profile with simultaneous reduction of the amount of iron oxides).