Malaysian Journal of Geosciences (MJG)

The present study is an attempt to understand sediment charterstics and distribution of organic carbon and calcium carbonate in four cores viz. Turumella, Inturu, Ponnapalli and Nizampatnam of the Krishna River delta. Grain size data indicates that the sediments in the study area are dominantly composed of sandy clay and silty clay. The average organic carbon in Turumella (1.69%), Ponnapalli (1.55%), Nizmpatnam (1.18%) and Inturu (1.14%). Organic matter controlled by vegetative roots and quick sedimentation and CaCO3 persentage related to institu authegenic shell fragments. Semi arid environmental conditions and pedogenic processes for long time exposure of mud flats and flood plains before deposition of other sediments on it. Organic carbon in plants and soil undergo the primary degradation process driven by bacterial and fungal action, which alters their molecular composition before their input into riverine environment. The organic carbon (OC) is often a good index for deciphering depositional environment. It plays a major role in controlling the redox potential of the sediments constituting the source material for petroleum. The first time in the Krishna River delta, where in shallow drilling was carried out upto the 160m depth undisturbed samples have been used for the purpose.