地理科学 ›› 1997, Vol. 17 ›› Issue (1): 18-23.doi: 10.13249/j.cnki.sgs.1997.01.18

• 论文 • 上一篇    下一篇

青藏高原RM孔自生碳酸盐稳定同位素组成及其古气候

吴敬禄   

  1. 中国科学院南京地理与湖泊研究所, 南京210008
  • 收稿日期:1995-10-01 修回日期:1996-09-01 出版日期:1997-01-20 发布日期:1997-01-20
  • 基金资助:
    国家攀登项目(85-029-02-01)

COMPOSITIONS OF 18O AND 13C IN VARIOUS CARBONATES AND THE SIGNIFICANCE OF CORE RM IN THE ZOIE BASIN

Wu Jinglu   

  1. Nanjing Institute of Geography and Limnology, Chinese Academy of Science, Nanjing 210008
  • Received:1995-10-01 Revised:1996-09-01 Online:1997-01-20 Published:1997-01-20

摘要: 对RM孔不同成因碳酸盐(腹足类、介形类,化学成因碳酸盐)同位素进行比较研究,并利用自生碳酸盐碳、氧同位素代用指标,对该区近0.14Ma来的古气候演化进行初步讨论。研究表明:不同成因的湖泊碳酸盐其氧同位素值基本接近,碳同位素差值较大,但相关性较好;该区近0.14Ma来自生碳酸盐碳、氧同位素呈反相关关系,表明氧同位素值波动主要受温度控制,即氧同位素高值段对应气候暖期,并据此重建了该区0.14Ma来气候演化过程。

Abstract: The hole RM, the deepest one fully obtained from the core in the Tibetan Plateau, is situated in the depocenter of the Zoie Basin(33°57′N; 102°21′E)in northeastern Tibetan Plateau with a depth of 310.46 m. From 14 C dating and paleomagnetic stratigraphic study, the core RM dated back to 900 ka B.P.. In this paper we analyzed the compositions of 18O and 13C in various carbonates(snail, obstrode, chemical carbonate)in core RM and discussed preferably the paleoclimatic record by the proxies of δ 18O and δ 13C of chemical carbonate(authicarbonate)from core RM in the past 140 ka.. The results show that the values of δ 18O in various carbonates are generally identical, and the values of δ 13C in it are inconsistent while there exists a better relativity. The studies also demonstrate that there is a negative correlation between δ 18O and δ 13C of authicarbonate in core RM in the past 140 ka, showing that the changes of δ 18O values is mainly relative to the water temperature. According to the above, the climatic evolutionary sequence in the past 140 ka in the region is rebuilt.