Microfossils in Stromatolites of the Byuk Formation of the Upper Vendian of the Berezovsky Trough in the Siberian Platform (Western Yakutia)

Numerous remains of various coccoid, rod-shaped, and filamentous microfossils were found in stromatolites of the Byuk Formation of the Upper Vendian. All of these are practically covered by a single bacterial film, however, every morphotype is isolated from the other ones by specific zones, which have several specific characteristics (density, absence of microbial relics, and a separate small hollow space out of the entire bacterial film). Such hydraulic forces within the bacterial films can preserve the community from water balance disturbance for long terms, providing an airbag in cases of mechanical impact. At the same time, they also differentiate isolated colonies of different morphotypes of microbial remains present within the community. This arrangement is not common to most previously studied microbial colonies of stromatolites. The paper discusses the reasons behind the formation of stromatolites of contrasting textural and structural features, which occurred in small embay-ment rather than in a large part of the Vendian basin floor.