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Late Holocene palaeovegetational and environmental changes inferred from organic geochemical proxies in sediments from Pookot Lake, southern India

Kizhur, Sandeep and Shankar, R and Warrier, Anish Kumar and Yadava, M G and Ramesh, Rengaswamy and Jani, Rashmikant A (2019) Late Holocene palaeovegetational and environmental changes inferred from organic geochemical proxies in sediments from Pookot Lake, southern India. Arabian Journal of Geosciences, 12 (21). ISSN 1866-7511

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Abstract

The sediments from Pookot Lake situated in the Sahyadri (Western Ghats) of southern India provided a record of palaeovegetation and palaeomonsoon variations during the Late Holocene. The palaeovegetation was reconstructed using the carbon isotopic composition of bulk organic matter (δ13Corg) and organic geochemical proxies (C/N ratio, Corg %, N % and CaCO3). The vegetation composition (C3 and C4 plants) in the Pookot Lake catchment has changed in response to monsoonal variations. Around 2500 cal. years B.P., the lake had a high water level, increased aquatic plankton activity and abundant C3 vegetation in its catchment, indicating strong monsoonal conditions. From 2500 to 1000 cal. years B.P., the lake had a lower waterlevel,decreasedaquaticplanktonactivityandincreasedcontributionfromC4 landplants,indicatinglowrainfallconditions. During1500to1000cal.yearsB.P.,thecontributionsfromC3 landplantsandaquaticplanktonincreased,suggestingamoderate rainfall. From 1000cal. years B.P. tothe Present,the abundancesof C3 and C4 vegetationfluctuated, indicating variations in the monsoonal strength. During the Medieval Warm Period (1000 to 600 cal. years B.P.), the monsoon was strong, but it was weak duringtheLittleIceAge(600to350cal.yearsB.P.).From350cal.yearsB.P.tothePresent,ithasbeensteady.Asimilarclimatic trend is documented in other palaeovegetation records from geographically different parts of India although spatial variability exists. Archaeological lines of evidence suggest a possible climate–culture link in the region

Item Type: Article
Uncontrolled Keywords: Indiansummermonsoon .Palaeovegetation .Productivity .Carbonisotopes .Lakesediments .SouthernIndia
Subjects: Engineering > MIT Manipal > Civil Engineering
Depositing User: MIT Library
Date Deposited: 12 Feb 2020 10:51
Last Modified: 12 Feb 2020 10:51
URI: http://eprints.manipal.edu/id/eprint/154909

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