新疆伊犁河谷晚全新世以来的风砂沉积与环境演化

HOLOCENE AEOLIAN DEPOSITS AND ENVIRONMENTAL EVOLUTION IN YILI VALLEY, XINJIANG

摘要: 通过对新疆伊犁塔克尔莫乎尔沙漠可克达拉剖面(TKP)有机碳(TOC)、氧化铁(Fe₂O₃)及频率磁化率(X_fd)的分析,探讨了新疆伊犁河谷晚全新世以来的气候演变。结果显示:3.71~1.50 kaBP期间该区气候总体上比较干旱,气候干湿变化复杂,并经历了凉湿(3.71~3.06 kaBP)、极端干旱(3.06~2.63 kaBP)和相对湿润(2.63~1.50 kaBP)的演变过程。1.50~0.50 kaBP期间TOC、Fe₂O₃和X_fd的平均含量均达到全剖面的最高值,可能代表着这段时期区域降水比较丰沛,为伊犁河谷地区近4 ka以来气候最为适宜的时期。0.5 kaBP以来,伊犁河谷气候迅速地向干旱化发展。

Abstract: This paper discusses the Late Holocene climate evolution in the Yili Valley of Xinjinag, based on the TOC, Fe₂O₃ and X_fd from the Keledala profile in Takermohur Desert. The result shows that, in the stage of 3.71~1.50 kaBP, the climate in this area, as a whole, was relatively dry and experienced complicated changes. It was cold and humid during the period of 3.70~3.06 kaBP; extremely dry during the period of 3.06~2.63 kaBP, and relatively humid during the period of 2.63~1.50 kaBP. The average contents of TOC, Fe₂O₃ and X_fd reached the peak in 1.50~0.5 kaBP. It indicates that precipitation in this area was relatively high then, and the climate reached the best since 4 kaBP. Since 0.5 kaBP, the Yili valley has remained in drought.