Microbial Mats As a Source of Carbonate Sediments in the Late Precambrian: Evidence from the Linok Formation, the Middle Riphean of the Turukhansk Uplift, Siberia

摘要: The Linok Formation is made up of clayey and carbonate strata, 180–300 m thick, formed at the terminal Middle Riphean on northwestern margin Siberian Platform. In modern structure, it exposed in lower part Turukhansk Uplift section. sediments accumulated distal epiplatformal basin as a symmetrical transgressive–regressive cycle. Its represents deep-water environment with mixed carbonate–clayey sedimentation, whereas upper reflects origination evolution platform. Microstructures discussed this work suggest not only ancient existence benthic microbial assemblages (mats) but their active influence upon facies pattern well. was determined by ability mat-forming communities to produce under certain environmental conditions. analysis succession suggested absence an appreciable influx material from other sources. Based generation ability, one can distinguish three (carbonate-free, low-productive, high-productive) groups communities. Groups 1 2 represent mats, group 3 relatively shallow-water platformal microbial–mineral systems. productivity inversely proportional depth dwelling relative rate sedimentation. morphological reconstruction microbiolite structures showed that basins platforms greatly differed terms size elements. generate could be realized within large ecosystems.