Major and Trace Element Characters of the Sediments and Paleoclimatic Evolvement during about 23.1~5.0 Ma in Xunhua Basin, Qinghai

• 责任者：Ye He (Key Laboratory of Biogeology and Environmental Geology ; Ministry of Education ; China University of Geosciences ; Wuhan 430074 ; China) ; Zhang Kexin
• 刊名：Earth Science
• 出版年：2010
• 卷期：35(5)
• 关键词：新近纪 ; Neogene Period ; 微量元素 ; minor elements ; 古气候 ; paleoclimate ; 青海 ; Qinghai Province
• 页码：p.811-820
• 图表：4 illus., 35 refs.
• 分类号：1200
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

The measured Yangjuangongbai-Xigoushangzhuang Section, Xunhua Section, lies in the southern margin of the Xunhua Basin. According to the detail research of the section and sedimentary facies, major and trace elements were analyzed to reveal paleoclimatic information from the deposits during 23.1~5.0 Ma. SiO₂, Al₂O₃, CaO and TFeO (Fe₂O₃+FeO) are the main chemical components with a sum of 80% at the average level. The element ratios between the deposits and the upper continental crust (UCC) indicate that the paleoclimate of the studied area is characterized as cold and dry during 23.1~5.0 Ma. According to variations of CIA (chemical index of alteration), Rb/Sr, TiO₂/Sr and CaO/Sr, the paleoclimate can be divided into four stages. The authors conclude that both uplift of the Qinghai-Tibetan Plateau and global climatic changes had effect on the paleoclimatic evolvement during about 23.1~5.0 Ma in Xunhua Basin.