Environmental evolution of Xingkai (Khanka) Lake since 200 ka by OSL dating of sand hills  

作　　者：ZHU Yun SHEN Ji LEI GuoLiang WANG Yong 

机构地区：[1]Key Laboratory of Lake Science and Environmentl Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China [2]College of Geographical Sciences, Fujian Normal University, Fujian Key Laboratory of Subtropical Resources and Environment, Fuzhou 350007, China

出　　处：《Chinese Science Bulletin》2011年第24期2604-2612,共9页

基　　金：supported by the National Natural Science Founda-tion of China (40872117)

摘　　要：Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine trans gression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while shortterm fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine transgression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions （during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka） and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctua- tions in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while short-term fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.

关 键 词：光释光测年 兴凯湖 环境演变 乌苏里江流域 气候变冷 回归分析 东北亚地区 多指标分析 

分 类 号：P343.3[天文地球—水文科学]