**8. Conclusions**

In light of paleo-dimensions and flow dynamics of Early Permian Barakar river of Rajmahal Gondwana sub-basin of eastern India it concluded that:

1.About 2270 km long Early Permian Barakar river of Rajmahal sub-basin of eastern India drained an area of 107,000 to 86,500 sq. km and flowed northward on a steeper slope of 6.5 to 16.2 � <sup>10</sup>�<sup>4</sup> with a variable flow velocity (157–135 cm/ sec) from Fox Ridge; the channel sinuosity was 1.361. The rivers sub-channels

were at least 817 m–700 m wide and 13 m deep. Bed load was moderately high and about 17.74–15.60 of the total load of this river, whose mean annual discharge was 12,800–22,000 m<sup>3</sup> /sec during normal period and rose to 112,200– 170,000 m<sup>3</sup> /sec. These parameters suggest that the stream pattern was multithread (braided) in Brahmini and Pachwara sub-basins in the south. It indicates that the depositing bed load river became mixed- and suspended load within 2260 km in the downstream direction

2.Further northward in Chuperbhita and Hurra sub basins, the river record a decline in paleo-dimensions and flow dynamics such as channel width, channel depth, channel slope, sediment load, discharge and increase in channel sinuosity. Although only 8 to 10 percent of the total river load was bed load; the flow velocity of 92 and 152 cm/sec in the upper part of the lower flow regime caused the fine to medium grained sand to be in dune bed configuration. In the Chuperbhita and Hurra sub basins, it was about 500 km long, drained 42,000 to 62,000 km<sup>2</sup> area to the north and northeast. The gentle slope and abundance of fine clastics suggest slow deposition by single thread river. These paleo dimensions and flow dynamics estimates, indeed, correlate well with the corresponding differences in the lithic- fill of the northern and southern sub basins.

To sum up, the results are merely reasonable approximations that fit the stratigraphic and geologic context in which fluvial facies of the Barakar sandstone deposited in Rajmahal Gondwana sub basin of eastern India.
