Studies on textural characteristics of sediments in Lower Gadilam River, Cuddalore District, Tamilnadu, India.

The present study was carried out in order to study the textural characteristics of sediments. The graphic mean distribution for these sediments ranging from 0.50 to 2.57 ϕ, indicative of fine to coarse grained sand. The standard deviation (sorting) shows a spread of 0.46 to 1.02 ϕ and a mean value of 0.70. Most of the samples are moderate to moderately well sorted with only a few being poorly sorted. The skewness values of the samples ranged from -0.11 to 0. 61, thus indicating the presence of symmetrical to very fine skewed and coarse fraction in the particle population. The kurtosis is between 0.58 and 1.63, Thus indicates kurtosis of the river estuary sediments are platykurtic to leptokurtic in nature (0.62 to 1.63 ϕ). The sample location 2, 4 and 7 bottom cores show very platykurtic with medium to coarse sand, moderately to poorly sorted nature. The kurtosis of the midstream sediments are platykurtic to mesokurtic in nature (0.59 to 1.37 ϕ). Based on the CM pattern the river estuary sediment falls in bottom suspension and rolling while midstream sediments show bottom suspension and rolling whereas channel bar sediments show depositions by rolling mechanism.