盐池晚冰期以来气候及环境变化——来自中国西北的湖泊沉积物证据(英文)

编号 zgly0001585331

文献类型 期刊论文

文献题名 盐池晚冰期以来气候及环境变化——来自中国西北的湖泊沉积物证据(英文)

作者 李育  王乃昂  李卓仑  周雪花  张成琦 

作者单位 CollegeofEarthandEnvironmentalSciences  CenterforHydrologicCycleandWaterResourcesinAridRegion  LanzhouUniversity 

母体文献 Journal of Geographical Sciences 

年卷期 2013年05期

年份 2013 

分类号 P343.3 

关键词 YanchiLake  Asiansummermonsoon  Holocene  theLateGlacial  lakesediments  monsoonmarginalzones 

文摘内容 Modern climate research has shown that the Asian summer monsoon water vapor transport is limited to the eastern part of the Qilian Mountains.On the Holocene millennial-scale, whether the northwest boundary of the summer monsoon varies according to climate change is a key scientific issue.Yanchi Lake is located in the northern Qilian Mountains and the middle of the Hexi Corridor, where the modern climate is less affected by the Asian summer monsoon.It is a key research area for examining the long-term variations of the Asian summer monsoon.Paleoclimatic data, including AMS 14C dates of pollen concentrates and bulk organic carbon, lithology, grain-size, mineral composition and geochemical proxies were acquired from sediments of Yanchi Lake.The chronological results show that the lower part of the lacustrine section is formed mainly in the Late Glacial and early Holocene period, while the proxies’ data indicate the lake expansion is associated with high content of mineral salts.The middle part of this section is formed during the transitional period of the early and middle Holocene.Affected by the reworking effect, the pollen concentrates AMS 14C dates from the middle part of the section are generally older than those from the lower part.Since the mid-Holocene, Yanchi Lake retreated significantly and the deposition rate dropped obviously.The Yanchi Lake record is consistent with the Late Glacial and Holocene lake records in the Qinghai-Tibet Plateau and the climatic records in typical monsoon domain, which indicate the lake expansion and the strong Asian summer monsoon during the Late Glacial and early Holocene.The long-term monsoonal pattern is different from the lake evolution in Central Asia on the Holocene millennial-scale.This study proves the monsoon impacts on the northwestern margin of the summer monsoon, and also proves the fact that the northern boundary of the summer monsoon moves according to millennial-scale climate change.