Microbial mat structures and role of microbes in Precambrian siliciclastic sedimentation: Evidence from Indian proterozoic basins

Abstract

Microbes had been the sole occupant of the early biosphere and they strongly controlled the evolution of lithosphere, hydrosphere, biosphere and atmosphere. Many Microbes could form mat like structure on sea floor. During the Precambrian these microbial mats had a strong influence on sedimentation, and they facilitated the formation of a variety of mat-induced sedimentary structures (MRS/MISS) in siliciclastic and carbonate rocks. In last two decades many of these structures have been identified from the Indian Proterozoic rocks. Observation from modern environments indicates the formation of mat related structures in preferred segments of the shallow marine domain. We also investigate the cause and effect relationship between the mat-growth and the sequence building pattern during the Precambrian. The commonly present HSTs compared to those of corresponding TSTs possibly indicates that microbial mat-infested sea floor impedes erosion, while concomitant sediment supply facilitated formation and preservation of regressive packages during the Precambrian.