青藏高原东北部风成沉积微量元素揭示的全新世千年尺度气候变化  

Millennial scale climate change in the Holocene revealed by trace elements of aeolian deposits in northeastern Qinghai-Tibet Plateau

作　　者：刘冰[1] 靳鹤龄[1] 孙忠[1] 苏志珠[2] 张彩霞[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,甘肃兰州730000 [2]山西大学历史文化学院,山西太原030006

出　　处：《古地理学报》2013年第3期423-433,共11页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:40971005;41271215)资助

摘　　要：通过对青藏高原东北部共和盆地典型古土壤—风成砂剖面的释光(OSL)年代测定和沉积物中微量元素的分析,重建了区域全新世千年尺度的气候变化过程。研究表明,除Co、Rb、Sr和Ba以外的12种微量元素所反映的气候变化规律较显著,其含量变化曲线上的峰值段对应于古土壤层而谷值段对应于风成砂层,这一现象可作为气候暖湿、冷干波动的标志;区域全新世气候变化可分为以下阶段:11.8～10.0ka气候寒冷干燥,10.0～9.2ka气候逐渐趋于暖湿,9.2～4.6ka气候相对冷干,4.6～0.7ka气候相对暖湿,0.7ka以来气候明显寒冷干燥;区域全新世气候变化中存在8次寒冷事件,与青藏高原和北大西洋揭示的寒冷期具有明显的对应关系,表明共和盆地千年尺度的气候变化与全球气候变化具有一致性。This paper attempts to reconstruct the millennial scale climate changes in the Holocene by the characteristics of trace elements from the typical palaeosol-aeolian sand section with OSL ages in Gong- he Basin, northeastern Qinghai-Tibet Plateau. Trace elements, except for the Co, Rb, Sr and Ba, re- flect the similar climatic change with their peaks （ high values） in palaeosols layers while the valleys （low values） in aeolian sand layers. This phenomenon thus can be regarded as the symbol of the regionalwarm-wet and cold-dry changes. The regional climate was dominated by the cold and dry in 11.8- 10.0 ka while warm and wet from 10.0 -9.2 ka. In 9.2 ~4.6 ka, the climate was relatively cold-dry and relatively warm-wet between 4.6 ka and 0.7 ka. Thereafter, it gradually tended to be cold and dry a- gain. 8 cold events were recorded in Gonghe Basin during the Holocene, which are very well correspond- ing to the cold phases in Qinghai-Tibet Plateau and Northern Atlantic Ocean, marking the higher consis- tency in millennial scale climatic change between Gonghe Basin and global change.

关 键 词：共和盆地 风成沉积 微量元素 气候变化 寒冷事件 

分 类 号：P595[天文地球—地球化学]