Grain Size Analysis and Depositional Environment for Brahmaputra River Sand of Kurigram District, Bangladesh

M. Sahiduzzaman

Abstract: The work analyzed the grain size spectrum and texture parameters, namely mean, sorting, skewness and kurtosis etc. of Brahmaputra River Sand from Kurigram District, Bangladesh. ASTM sieves was used for grain size determination. Twenty samples were analyzed for this purpose. The results of the sieve analysis revealed that the samples from the study area ranged from fine to medium grained sand with lower sized particles. The statistical analyses were made by moment computation and graphical method which reveal that the sediments are fine to medium sand which are moderately sorted and platykurtic to leptokurtic in nature. Abundance of the fine sand to medium sand shows the prevalence of comparatively moderate to high energy conditions in the study area. The river bank and river channel deposits have been taken place in fluvial process with gradual suspension transportation system.

Keywords: Grain-size, Sand, Environment, Fluvial