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青海湖地区的黄土是独立于湖相沉积的重要古气候记录。对青海南山夏拉水库和橡皮山黄土剖面进行了沉积学、地貌学和光释光年代学的研究,重建了全新世以来青海湖地区的环境变化。结果表明,1)青海南山地区至少在10.4 ka之前由河流沉积转换为风成堆积,指示气候转型期;2)10.4~5.0 ka间以黄土堆积为主,偶尔夹杂风成砂,指示气候整体比较温暖适宜,有个别的降温事件;3)3.4~1.0 ka古土壤发育为主,指示气温—降水组合较好,气候最适宜;4)0.6 ka以来发育现代土壤。研究数据基本与青藏高原东北缘的古气候/环境变化记录相一致,但在时间上存在一定的相位差,可能与海拔较高,区域对气候反应滞后有关。
Loess in Qinghai Lake area is an important paleoclimate record independent of lacustrine sediments. The study of sedimentology, geomorphology and photoluminescence chronology of the Shala Reservoir in South Mountain of Qinghai Province and the Loess Hill loess section in Qinghai Province have reconstructed the environmental changes in Qinghai Lake since the Holocene. The results show that: 1) the Nanshan area of Qinghai was transformed from fluvial deposition into fluvial accumulation at least before 10.4 ka; 2) Loess accumulation mainly occurred between 10.4 and 5.0 ka, with occasional aeolian sand compaction, indicating the overall climate comparison Warmth is suitable and there are some cooling events; 3) The paleosol development is mainly from 3.4 to 1.0 ka, indicating that the combination of temperature and precipitation is better and the climate is the most suitable. 4) The modern soil is developed since 0.6 ka. The research data are basically consistent with the records of paleoclimate / environment changes on the northeastern margin of the Qinghai-Tibet Plateau. However, there is a certain phase difference in time, which may be related to the higher altitude and the lag of regional climate response.