Geochemical Characteristics and Tectonic Environmental Analysis of Volcanic Rocks from Late Triassic in Southeastern Margin of the Qaidam Basin

详细信息   

• 责任者：Zhang Hongmei (Shandong University of Science and Technology ; College of Geological Science and Engineering ; Qingdao 266510 ; China) ; Li Haiping
• 刊名：Northwestern Geology
• 出版年：2011
• 卷期：44(4)
• 关键词：火山岩 ; volcanic rocks ; 柴达木盆地 ; Qaidam Basin
• 页码：p.15-22
• 图表：7 illus., 1 table, 13 refs.
• 分类号：0801
• issnNo：ISSN1009-6248
• isbnNo：CN61-1149/P

摘要

 
    

Elashan volcanic rocks from late Triassic Elashan Group in southeastern margin of the Qaidam Basin are mainly consisted of a set of medium and acid volcanics combination, including rhyolite and dacite primarily, followed by andesites. The results of the analyses on principal elements, rare-earth elements and trace elements show that Rittman index(δ) of the samples are all below 4, and belongs to calc-alkaline volcanic rocks; the average of SiO₂ is 71.95%, most of the samples have a characteristic of low aluminum, alkali content is higher, and that belongs to the sub-alkaline volcanic rocks.