Holocene and Late Pleistocene relative sea level fluctuations along the east coast of India

Hermatypic coral colonies and intertidal fossil bearing grainstone, packsto ne and sandstone beds of Holocene and of a Late Pleistocene highstand are e xposed above the present High Tide Level (HTL) at a number of locations alo ng the east coast of India from Cape Comorin to Rameswaram. Being a passive margin boundary, free from indications of Late Quaternary seismogenic move ments, this sector provides a benchmark for defining minor relative sea lev el perturbations during the Late Pleistocene and Holocene highstands along a tropical coast lying between latitudes 5 degrees N and 10 degrees N. A series of marine terraces, carved on and locally blanketted by Late Pleis tocene biotic and terrigenous accumulations, occur at different elevations (up to 4.4 m) above LTL at Manappad Point, possibly signifying discrete sti llstand episodes followed by abrupt intervals of rising/falling sea level. Sea level indicators of the Holocene highstand occur in this sector, as wel l as along the fringes of the Godavari delta further north. The Holocene hi ghstand reached nearly 3 m above LTL at 7.3 ka, remained stable for approxi mately 1.7 kyr and was followed by a relative sea level fall. Between 5.2 a nd 4.2 ka, there was a second pulse of relative sea level rise of a few met res leading to a fresh spurt in coral growth along the northern coast of Ma ndapam and Rameswaram. This was nearly contemporaneous with fresh melting o f ice sheets of Antarctica. The Little Ice Age (LIA) witnessed a minor (>1 m) relative sea level fall along this coast, resulting in rapid diagenetic hardening and infiltration of goethite into the emerged foreshore sand at K arikovil and its neighbourhood. This was followed by a rise of the sea leve l during the last few centuries. (C) 2000 Elsevier Science B.V. All rights reserved.