疏勒河下游安西古沼泽全新世沉积物粒度特征及其古气候环境意义

Grain-size Characteristics of the Sediments at Palaeoswamp in Anxi County in Downstream of Shulehe River during Holocene and Its Paleoclimatic Significance

通过对安西古沼泽沉积物沉积特征分析，粒度特征分析，孢粉分析并结合年代学资料，研究了安西古沼泽全新世古沼泽进退演化过程、疏勒河中下游河川径流量的变化及河西走廊西部地区古气候环境变化特征。研究结果表明：晚更新世末至全新世河西走廊西部地区气候总体趋于暖湿，但气候冷干-暖湿波动频繁交替。安西古沼泽全新世沉积物4个粒度旋回：①366～328cm，328～294cm；②294～240cm，240～206cm；③206～196cm，196～148cm；④148～54cm，54～0cm，可能代表河西走廊西部地区晚更新世末至全新世以来4个气候冷干-暖湿波动周期。

By analyzing the characteristics of the sediments, its grain-size characteristics , data of sporopollen and chronology at palaeoswamp in Anxi County, the authors have researched the process of advancing and retreating evolution of palaeoswamp in Anxi County, the change of stream flow in mid-downstream of Shulehe river, and the characteristics of palaeoclimatic changes in western Hexi Corridor during Holocene. The results indicate that the climate changes tend to be warm and humid as a whole in the western Hexi Corridor from the end of late Pleistocene to Holocene, whereas its changes of cold-arid and warm-moist alternate frequently. The 4 grain-size cycle of the sediments at palaeoswamp in Anxi County during Holocene ： ①366 ～ 328cm ,328 ～ 294cm;②294 ～ 240cm ,240 ～ 206cm ;③206 ～ 196cm, 196 ～ 148cm; ④148 ～ 54cm, 54 ～ 0cm, can represent 4 cycle of cold-arid and warm-moist in western Hexi Corridor from the end of late Pleistocene to Holocene.