全新世以来巴里坤湖面积变化及气候环境记录

通过新疆北天山东段巴里坤山北麓巴里坤湖及周缘地区7个剖面的沉积相带划分、OSL测年、粒度分析、磁化率测试，研究了全新世以来巴里坤湖区湖面积变化:14 000 a B.P.末次冰盛期晚期，东天山地区冰川发育，由于水体封存于巴里坤山冰川，导致巴里坤湖萎缩至1#剖面以北。8 000～4 000 a B.P.巴里坤山冰川融化，巴里坤湖扩张进入全新世以来最大湖期，湖泊扩张至1#剖面以南，面积达到600 km2。东天山地区温暖湿润的全新世适宜期为8 000～4 000 a B.P.。其后湖泊逐渐萎缩，4 000～2 000 a B.P.湖泊面积大约470 km2。2 000～1 000 a B.P.面积萎缩至380 km2。在1 500 a B.P.左右湖泊曾经基本干涸，在目前湖心地带出现泥坪沉积。其后巴里坤湖进入小湖期，湖泊面积在100 km2范围波动，时有扩张或干涸。全新世巴里坤湖水位变化主要受北半球夏季太阳辐射变化控制，具体表现在北半球冰盖由扩张转为融化背景下，全新世早期巴里坤山冰川发育和全新世中期的巴里坤湖冰川融水的注入扩张；巴里坤地区受东亚夏季风影响甚弱，西风环流带给的水量补充有限，全新世中晚期巴里坤地区向干旱环境发展。

Changing of the Lake Area and Records of Climate and Environment of Barkol Lake During Holocene

The authors have studied 7 profiles in Barkol Lake and surrounding areas at northern foothills of Barkol Mount in the eastern Tianshan. By means of sedimentary facies analysis, OSL dating, grain size analysis and magnetic susceptibility measurement, the Holocene environmental evolution of Barkol Lakes were reconstructed. The glaciers of the East Tianshan area expanded during Last Glacial Maximum (LGM) at 14 000 a B.P. Water sealed in the glaciers of Barkol Mount, resulting in Barkol Lake shrink to the north to the #1 profile. The glaciers of Barkol Mount were shrank during 8 000~4 000 a B.P. Barkol Lake attained to the largest lake of the expansion since the beginning of the Holocene. The lake expanded to the south of the # 1 section, the  area amounted to  600 km2. East Tianshan area was warm and humid during Holocene Optimum at 8 000~4 000 a B.P. subsequently the lake was gradually shrinking. The lakes area was  470 km2 at 4 000~2 000 a B.P. and shrank to 380 km2 at 2 000~1 000 a B.P.The lakes dried up at around 1 500 a B.P.  Appeared mud flat deposits in the current lake zone, subsequently Barkol Lake came into the small lake with the area changing at about 100km2  when expansion or dry. The changing of lake level of the Barkol was mainly controlled by the summer solar radiation of Northern Hemisphere, which was manifested in the expansion and shrank of the Northern Hemisphere ice sheets. the expansion of the Barkol Mount glaciers in the early Holocene and water injected into Barkol Lake by glaciers shrank in middle Holocene) . The Barkol influenced little by the East Asian summer monsoon, westerly circulation bring limited water to supple the area, which drive the Barkol to the arid environment during middle to late Holocene.