德令哈盆地尕海湖DG03孔岩芯年龄模式与古气候变化

Age Model and Palaeoclimatic Changes of DG03 Core of Gahai Lake in Delingha Basin

通过对德令哈盆地尕海DG03孔岩芯的岩性、年代数据分析以及与可鲁可湖HL05-2孔岩芯多个气候代用指标的综合对比,确定了DG03孔岩芯的底部年龄约为11ka BP(AMS1-4C)。根据岩性变化,整个岩芯可划分为3个阶段:晚冰期晚期(11—10 ka BP),全新世早中期(10—4 ka BP)和全新世晚期(4—0 ka BP)。岩芯记录了晚冰期晚期和整个全新世的古气候和古环境变化信息,从晚冰期晚期以来,尕海湖经历了冷干—暖干—暖湿—冷干(现代)的气候变化过程,而湖泊水位则相应为低(盐湖或高盐度湖泊)—较高(盐湖—咸水湖)—高(咸水湖—半咸水湖/淡水湖)—较低(咸水湖—盐湖)。

By analyzing the lithologies and dating data of DG03 core of Gahai Lake in Delingha Basin, comprehensively comparing with the climatic proxies of HL05-2 core in Hurleg Lake, the age on the bottom of DG03 core is defined to about llka BP （AMS-^14C）. According to the lithologies, the whole core is divided three parts： the late stage of Late Glacial （11--10 ka BP） ,the Early and Middle Holocene （10--4 ka BP） ,and the Late Holocene （4ka BP--0）. The core recorded the palaeoclimatic and palaeoenvironmental information from the late stage of Late ＇Glacial period and Holocene to present. Gahai Lake experienced a process of cold and dry--warm and dry--warm and wet--cold and dry since the last stage of Late Glacial. Co.rrespondingly, the water level of the lake exhibited the changes of low （ saline lake or high salinity lake period ）hhigher （ saline lake to salty water lake period ） --high （salty water lake to brackish or fresh water lake period ） --lower （salty water lake to saline lake）.