Paleocurrent Analysis of Kolhan Basin: Implications to Paleogeographic Reconstructions

The paleocurrent investigation of a basin is one of the preliminary task for understanding paleogeographic reconstructions and fluvial paleo-channels. Correct paleo channel analysis helps in supporting paleotectonic conclusions from petrology and geochemistry. In this paper paleocurrent of Proterozoic Kolhan basin has been calculated from various methods. It reveals the pattern of transport towards the north-west or north-east in the central region of the area. In the southern region it shows prominent north or northeasterly paleocurrent patterns especially in its lower part. The presence of NNE and NNW paleocurrents, in addition to an important current parallel to the NW has also been indicated. The vector means calculated from grain orientation and cross-bedding indicate at least two distinct flow systems, approximately north-westerly and northeasterly directions during the deposition of the siliciclastics. However the overall polymodal nature of the current rose diagrams suggests interaction of factors during the deposition. The mean directions are almost uniform although magnitude of the vector resultants exhibit frequent variation in the different facies.