TY - JOUR A1 - Menzel, Philip A1 - Gaye, Birgit A1 - Mishra, Praveen Kumar A1 - Anoop, Ambili A1 - Basavaiah, Nathani A1 - Marwan, Norbert A1 - Plessen, Birgit A1 - Prasad, Sushma A1 - Riedel, Nils A1 - Stebich, Martina A1 - Wiesner, Martin G. T1 - Linking Holocene drying trends from Lonar Lake in monsoonal central India to North Atlantic cooling events JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - We present the results of biogeochemical and mineralogical analyses on a sediment core that covers the Holocene sedimentation history of the climatically sensitive, closed, saline, and alkaline Lonar Lake in the core monsoon zone in central India. We compare our results of C/N ratios, stable carbon and nitrogen isotopes, grain-size, as well as amino acid derived degradation proxies with climatically sensitive proxies of other records from South Asia and the North Atlantic region. The comparison reveals some more or less contemporaneous climate shifts. At Lonar Lake, a general long term climate transition from wet conditions during the early Holocene to drier conditions during the late Holocene, delineating the insolation curve, can be reconstructed. In addition to the previously identified periods of prolonged drought during 4.6-3.9 and 2.0-0.6 cal ka that have been attributed to temperature changes in the Indo Pacific Warm Pool, several additional phases of shorter term climate alteration superimposed upon the general climate trend can be identified. These correlate with cold phases in the North Atlantic region. The most pronounced climate deteriorations indicated by our data occurred during 62-5.2,4.6-3.9, and 2.0-0.6 cal ka BP. The strong dry phase between 4.6 and 3.9 cal ka BP at Lonar Lake corroborates the hypothesis that severe climate deterioration contributed to the decline of the Indus Civilisation about 3.9 ka BP. (C) 2014 Elsevier B.V. All rights reserved. KW - Lake sediment KW - Indian monsoon KW - Holocene KW - Climate reconstruction KW - Stable carbon isotope KW - Amino acid Y1 - 2014 U6 - https://doi.org/10.1016/j.palaeo.2014.05.044 SN - 0031-0182 SN - 1872-616X VL - 410 SP - 164 EP - 178 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sarkar, Saswati A1 - Wilkes, Heinz A1 - Prasad, Sushma A1 - Brauer, Achim A1 - Riedel, Nils A1 - Stebich, Martina A1 - Basavaiah, Nathani A1 - Sachse, Dirk T1 - Spatial heterogeneity in lipid biomarker distributions in the catchment and sediments of a crater lake in central India JF - Organic geochemistry : the international journal for rapid publication of current research in organic geochemistry and biochemistry N2 - The basin-scale spatial variability in lipid biomarker proxies in lacustrine sediments, which are established tools for studying continental environmental change, has rarely been examined. It is often implicitly assumed that a lake sediment core provides an average integral of catchment sources. Here we evaluated the distribution of lipid biomarkers in a modern ecosystem and compared it with the sedimentary record. We analyzed lipid biomarkers in terrestrial and aquatic organisms and in lake surface sediments from 17 locations within the saline-alkaline Lonar crater lake in central India. Terrestrial vegetation and lake surface sediments were characterized by relatively high average chain length (ACL) index values (29.6-32.8) of leaf wax n-alkanes, consistent with suggestions that plants in drier and warmer climates produce longer chain alkyl lipids than plants in cooler and humid areas. A heterogeneous spatial distribution of ACL values in lake surface sediments was found: at locations away from the shore, the values were highest (31 or more), possibly indicating different sources and/or transport of terrestrial biomarkers. In floating, benthic microbial mats and surface sediment, n-heptadecane, carotenoids, diploptene, phytol and tetrahymanol occurred in large amounts. Interestingly, these biomarkers of a unique bacterial community were found in substantially higher concentrations in nearshore sediment samples. We suggest that human influence and subsequent nutrient supply resulted in increased primary productivity, leading to an unusually high concentration of tetrahymanol in the nearshore sediments. In summary, the data showed that substantial heterogeneity existed within the lake, but leaf wax n-alkanes in a core from the center of the lake represented an integral of catchment conditions. However, lake level fluctuation may potentially affect aquatic lipid biomarker distributions in lacustrine sediments, in addition to source changes. Y1 - 2014 U6 - https://doi.org/10.1016/j.orggeochem.2013.11.009 SN - 0146-6380 VL - 66 SP - 125 EP - 136 PB - Elsevier CY - Oxford ER -