Linkage between Lake Xingkai sediment geochemistry and Asian summer monsoon since the last interglacial period
2018
Sun, Weiwei | Zhang, Enlou | Liu, Enfeng | Chang, Jie | Shen, Ji
In this study, we present the element geochemical data of Core XK08-A2 drilled from Lake Xingkai (Khanka), northeast China. The study aims to examine the changes of sediment provenance and geochemical composition in response to Asian summer monsoon variability since the last interglacial period. Major elemental analyses on lacustrine samples and sand samples from Lake Xingkai and the surrounding sandy ridges in northeast China indicate that their abundance varied in relatively narrow ranges. The samples had only undergone the primary stage of chemical weathering. Similar Ti/Al and K/Al ratios between the lacustrine samples from Lake Xingkai and the loess-paleosol samples in north China were observed, which suggests that they come from broadly similar desert sources. Due to the significant dependence on grain-size and influence of sediments recycling, Chemical Index of Alteration of the lacustrine sediments could not be regarded as sensitive indicators of source regions' weathering on the glacial-interglacial timescale. Alternatively, the geochemical proxies of the lacustrine sediments could be linked to the Asian summer monsoon through the development of runoff and physical erosion in the catchment. Weakened Asian summer monsoon caused more fine particles transported to the lake basin by reduced runoff in the last glacial period. In contrast, coarser and less-weathered detritus are transported into the lake accompanying strengthened Asian summer monsoon during the warm periods.
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