A study on textural characteristics, heavy mineral distribution and grain-microtextures of recent sediment in the coastal area between the Sarada and Gosthani rivers, east coast of India

摘要

The current study aimed to describe textural characteristics,heavy mineral composition,and grain microtextures of the sediment from three micro-environments(foreshore,berm,and dune).A total of forty-one(41)representative surficial sediment samples have been collected from fifteen(15)locations along the beach area between the Sarada and Gosthani rivers on the east coast of India,where the length of the stretch is more than 100 km.The study reveals that most of the coastal sediment is medium to fine sand with relatively high ratios of coarse sand at Yarada beach,and the nature of the sediment is moderately to well sorted.These characteristics indicate a high energy environment.The heavy mineral analysis of the sediment in the current study was done for coarse(t60#)and fine(t230#)size fractions.Studying the weight percentage(WT%)reveals that a high percentage of heavy minerals is associated with fine fractions.Ilmenite,sillimanite,garnet,zircon,and rutile are the major heavy minerals identified in the current investigation.The concentrations of these heavy minerals show great variations from south to north of the study area.From an economic point of view,a considerable amount of heavy minerals(average 48.41%)are present on both sides(north and south)of the Gosthani River mouth.In the Sarada Estuary,the concentration of the economic heavy minerals was found under the minimum economic range.The grain microtextures of the major heavy minerals from the different locations along the study area demonstrate the variation in grain microtextures,which is controlled by the chemical and mechanical processes.These microtextures reflect moderate to high wave energy on the beach area,in addition to high mechanical impact on the grains from the estuary point.