作　　者： ; ; ; ; ;

机构地区： 兰州大学资源环境学院

出　　处： 《中国沙漠》 2014年第6期1480-1485,共6页

摘　　要： 花海地区位于河西走廊的西段,在全新世早期和中期亚洲季风增强时,该区域降水是否很好地响应亚洲季风的变化,以及季风的水汽输送是否会影响到该区域是仍需继续探讨的问题。本文通过对花海古湖泊沉积物样品的矿物测定,分析了花海古湖泊早、中全新世湖相沉积阶段中外源碎屑矿物含量的变化,并以此重建了该区域早全新世(10.47~8.87cal ka BP)和中全新世(8.87~5.5cal ka BP)的降水变化。结果显示,早全新世时期花海湖泊外源碎屑矿物含量高于中全新世时期,表明了该区域早全新世时期的降水高于中全新世时期,反映了该区域早、中全新世千年尺度的降水变化响应了印度季风的强弱变化,降水量受到了印度季风强度的影响。在全新世中期,由于西风环流的增强,花海地区水汽输送可能受到了印度季风和西风环流的双重影响。但全新世最湿润期出现在中全新世,与早全新世降水强度高于中全新世的结果并不一致。这种差异可能主要是由于中全新世时期较低的湖面蒸发所造成的。 Huahai Lake,located in the western part of Hexi Corridor,NW China,is a key research area for Holocene environmental changes on millennial timescales in a monsoon-westerly transition area.Based on exogenetic detrital mineral,we reconstructed precipitation changes in Huahai Lake area,Hexi Corridor of NW China during the early Holocene(10.47-8.87 cal ka BP)and the middle Holocene(8.87-5.5 cal ka BP).Results show that during early Holocene the amount of exogenetic detrital mineral was higher than that in the middle Holocene,and then it indicated that precipitation during the early Holocene was higher than that in the middle Holocene.Moreover,higher precipitation in the early Holocene was mainly controlled by strong Indian Monsoon,precipitation changes could have been affected by westerly winds that could have contributed to the water vapor supply to this region during the middle Holocene.The most humid conditions that occurred in the study area during the middle Holocene may have been caused by strong westerlies and low levels of evaporation.

关 键 词： 河西走廊 花海 全新世 季风 降水

领　　域： [天文地球] [天文地球]