Last Glacial Cycle has left various types of impressions on the continental shelf and along the onshore rocky promontories of east coast of India. Bathymetric and shallow seismic surveys carried out, along two shore orthogonal transects T1 and T2, 9 km apart, across almost the entire width of the continental shelf off Rattikonda in the east coast of India, on board GSI's coastal research vessel Samudra Kaustubh (cruise ST-135) have picked up four calcareous to snady ridges I, II, III and IV almost paallel to the present shorline at 122m, 76m, 63m, and 30m water depths respectively. From 30m isobath to 70m teh sediment is silty sand in the shallow area to clayey sand in the deeper region in the eastern part of the area. Silty clay to clayey sand is seen on the western part. The surface sediments in the intervening swales are silty clay to clayey silt and sometimes sand silt clay which are associated with low energy depositional environment. From 70m to about 95m depth the sendiment is sand-silty-clay and grades into sandy material near the ridges. The sendiment on ridge I is seen to contain 58.32% to 89.7% of +230 fraction. The presence of coarse sand and buried coral colonies, shell fragments point to a high energy environment and their formation can be attributed to at 100m depth as a linear zone, is a consistent feature. The sedimentary structure indicates a transgressive phase associated with the formation of the ridge II, III and IV. The radiocarbon dating of three samples from Ridges I, II and III have put thesee at 13820 yrs, 8690 yrs and 8820 yrs BP respectively.
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