Michael Geoffray

Famous for its controversial origin, the Precambrian Scarp Sandstone Member in the studied hillock sections is 20-25 m thick. The rock successions are made up of 3-6 m thick channelized, vertically stacked and laterally shifting sand bodies. Based on primary sedimentary structures such as small to large scale trough-and-herringbone cross -beddings, wave, current and interference ripples, tidal bundles with mud drapes, four major lithofacies and at least two of them, divisible into subfacies are identified and ascribed to above the wave base shallow marine origin. However, channelized nature of the sand bodies and their hundreds of meter wide lateral extent made up of shoaling cycles, and north-west directed polymodal palaeocurrent pattern, imply deposition in sub-tidal to inter-tidal domains of estuarine setting. Nevertheless, the overall coarsening upward trend in the grain-size in the measured sections indicates tendency of deposition in a transgressive system. Sandstones show bot...

In labalpur area the Lameta Beds are well exposed at Lameta Ghat and Chui Hill sections having thickness of abou t 20m and 50m respectively. Lameta Beds are stratigraphically divisible into five lithounits namely, Green Sandstone, Lower Limestone, Mottled Nodular Marl, Upper Limestone and Upper Sandstone and are world famous for dinosaurian remains. Among these five litho-units, Mottled Nodular Marl and the Lower Limestone are inten-sively burrowed and fossils of dinosaurian remains and their egg nests along with lizard eggs are also reported from these two horizons. Lower Limestone unit shows a characteristic variation in lithology from greenish yellow coloured limestone to sandy and pebbly limestone in the upper part. On the other hand Mottled Nodular Marl is characterized by red, green, violet coloured mottled hard sandy and soft clayey marls with apparently abundant concretions, which up~n weathering produce coarse rubble. Ichnogenera including Arenicolites, Beaconites, Fucusops...