Evolution of the coastal wetland systems of SW India during the Holocene: Evidence from marine and terrestrial archives of Kollam coast, Kerala

Authors and Affiliation : D. Padmalal, K.P.N. Kumaran, K.M. Nair, B. Baijulal, Ruta B. Limaye, S. Vishnu Mohan, Centre for Earth Science Studies, Thuruvaikkal P.O., Thiruvananthapuram 695031, Kerala, India

Journal: Quaternary International, Volume 237, Issues 1-2, 15 May 2011, Pages 123-139

Abstract: Kerala coast in southwest India is endowed with an interlacing network of wetlands evolved during the Late Quaternary. The wetlands in the southern part of Kerala, especially around Kollam district, show antecedent characteristics and are incised on the Neogene sediments. These wetlands include 20.0–35.0 m thick deposits of Holocene sediments containing good archives of landform evolution and climate changes. Holocene sedimentation was initiated at about 8920 ± 110 BP and is represented mainly by sub-fossil wood/peat or carbonaceous clays. Subsequent deposition of brackish water to marine sediments occurred in the Middle Holocene. The proposed evolutionary model reveals that many wetland bodies including Sasthamkotta Lake, Chelupola Lake, Chittumalachira Lake and Kotta Lake were evolved from the proto-estuarine basins. The upper arms of the pre-Holocene Ashtamudi and Paravur estuaries were cut off due to progradation of alluvial sediments during the Holocene Climatic Optimum.