Laminae and grain-size measures in beach sediments, east coast beaches, India

Abstract

The studies of size parameters in 1.8 mm slices in 36 4-cm long cores from different physiographic units of 4 beaches along the east coast of India, having beach states from "reflective" to "dissipative", suggest significant variations in these parameters. Individual layers have wider ranges of mean sizes, variable sorting, skewness and kurtosis values. These variations are pronounced and are observed in fine grained dark laminae as well as interlaminae space. These results suggest variations in micro-layer structure of beach sediments at berm/backshore, foreshore and offshore regions. The sediments from the 0.5, 1.0, 1.5 and 2.0-cm layers as well as from the full core show effects of mixing of the individual micro-layers. The degree of correlation, relative to the 1.8 mm layer, decreases with increase in the depth of sampling. Amongst all the measures, statistical correlation was found to be poorest for sorting index and skewness measures