Abstract Lacustrine sediments in a poorly documented region regarding to lake sedimentation and paleo-environments (Bangladesh) were investigated using a multiproxy approach. Pukurpara Lake is located in eastern Bangladesh at an elevation of 360 m above sea level with a maximum water depth of 28 m. An age-depth model allowed us to investigate the changes in sedimentation that occurred since 850 CE. The high resolution multielement analyses by micro-X fluorescence scanning (μXRF) showed multiple variations over short increments. Variation in the abundance of elements with depth as well the ratios of the abundance of some elements (Fe/Ti and Zr/Rb) suggested both rapid and long-term changes in the origin of the material deposited, which, in turn, suggested changes in weather conditions. Principal Components Analysis (PCAs) mixing μXRF and Magnetic Susceptibility data allow identifying changes in geochemical redox processes between the Medieval Warm Period (MWP) and Little Ice Age (LIA). The drastic changes in the different proxies (magnetic susceptibility, diatom assemblages, fresh water/marine water diatom ratios, abundance of Fe and S, and the Fe/Ti ratio) were interpreted to be the result of climate change before and after the MWP-LIA transition period, the Little Ice Age period being relatively wet.

中文翻译：

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来自湖泊沉积物的孟加拉国东部全新世晚期古环境记录：多代理方法

摘要 使用多代理方法研究了与湖泊沉积和古环境（孟加拉国）相关的文献记载不足的地区的湖泊沉积物。普库帕拉湖位于孟加拉国东部，海拔360 m，最大水深28 m。年龄深度模型使我们能够研究自公元 850 年以来发生的沉积变化。通过 micro-X 荧光扫描 (μXRF) 进行的高分辨率多元素分析显示出短增量内的多种变化。元素丰度随深度的变化以及某些元素（Fe/Ti 和 Zr/Rb）的丰度比表明沉积材料的来源发生了快速和长期的变化，这反过来又表明了变化在天气条件下。混合 μXRF 和磁化率数据的主成分分析 (PCA) 可以识别中世纪暖期 (MWP) 和小冰河时代 (LIA) 之间地球化学氧化还原过程的变化。不同指标（磁化率、硅藻组合、淡水/海水硅藻比、Fe 和 S 丰度以及 Fe/Ti 比）的剧烈变化被解释为 MWP 前后气候变化的结果。 LIA过渡期，小冰河期相对湿润。