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中国沙漠 ›› 2004, Vol. 24 ›› Issue (2): 144-148.

• 研究论文 • 上一篇    下一篇

青海湖南岸全新世黄土地球化学特征及气候环境意义

周笃珺1, 马海州1,2, 高东林1, 马万栋1, 谭红兵1, 徐黎明1   

  1. 1. 中国科学院 青海盐湖研究所, 青海 西宁 810008;
    2. 青海师范大学, 青海 西宁 810008
  • 收稿日期:2003-06-19 修回日期:2003-08-18 出版日期:2004-04-20 发布日期:2004-04-20
  • 作者简介:周笃珺(1966-),男(汉族),甘肃省玉门市人,副研究员,从事盐湖资源与湖泊演化方面的研究工作。E-mail:chowtj2000@yahoo.com.cn

Geochemical Characteristics and Climatic Environmental Significance of Holocene Loess on South Qinghai Lake Shore

ZHOU Du-jun1, MA Hai-zhou1,2, GAO Dong-lin1, MA Wan-dong1, TAN Hong-bing1, XU Li-ming1   

  1. 1. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China;
    2. Qinghai Normal University, Xining 810008, China
  • Received:2003-06-19 Revised:2003-08-18 Online:2004-04-20 Published:2004-04-20

摘要: 位于青藏高原东北部的青海湖是我国最大的内陆湖泊, 通过湖相沉积进行湖区全新世环境演变研究已取得诸多成果。作者选择青海湖南岸黑马河有绝对年代控制的全新世黄土剖面, 利用CaCO3、CaO、MgO和Sr元素组分以及氧、碳同位素等较为可靠的地球化学指标, 尝试进行了湖区全新世黄土的分层, 探讨了黄土堆积过程中的气候环境演变。结果表明, 青海湖南岸的黄土按成土作用强度的不同可分为两层: 上部为成土化较弱的黄土层; 下部为成土化较高的古土壤层, 其仍可进一步分为两个亚层。全新世湖区气候环境的波动在地球化学分布特征中有较强表现。

关键词: 黄土, 地球化学特征, 环境意义, 全新世, 青海湖

Abstract: Qinghai Lake, located in Northeast Qinghai-Tibet Plateau, is the biggest inland lake in China. Many research results with regard to Holocene environmental evolution in Qinghaie lake area have been achieved by analyzing the lacustrine sediments. The Holocene loess section at Heimahe on south Qinghai lake shore was found to contain an ashes layer of ancient human activity at about 2 m thick and it was dated to be 11 200 a BP. From the section 21 samples have been taken to test the chemical contents of CaCO3, CaO, MgO and Sr element, and the oxygen and carbon stable isotopes of carbonate. The CaCO3, CaO, MgO and Sr components contained in acid-solution fraction have been proven to be the reliable geochemical indicators for distinguishing the paleaosol from loess, and oxygen and carbon stable isotopes could reveal the climatic and environmental change in the process of loess aggradation. The distributing curves of chemical components of CaCO3, CaO, MgO and Sr in the section all exhibited two peaks and three valleys, according to which we divided Heimahe loess section into two strata, the upper one is loess and the lower one is paleosol, the paleosol is made up of two sub-layers. The distribution curves of δ18O and δ13C in the section also have remarkably shown the cold climate event at about 8 400 a BP and the climatic change from warm-humid to cold-dry since New Glaciation period. The results are similar to the research results in East Kunlun Mountains and Loess Plateau.

Key words: loess, geochemical characteristics, environmental significance, Holocene, Qinghai Lake

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