Enrichment Feature of Thorium Element in Tuff Interlayers of Upper Triassic Yanchang Formation in Ordos Basin, China

• 责任者：Qiu Xinwei (State Key Laboratory of Continental Dynamics ; Institute of Petroliferous Basin ; Northwest University ; Xi’an 710069 ; China) ; Liu Chiyang
• 刊名：Geological Bulletin of China
• 出版年：2010
• 卷期：29(8)
• 关键词：钍 ; thorium ; 凝灰岩 ; tuff ; 鄂尔多斯盆地 ; Ordos Basin
• 页码：p.1185-1191
• 图表：9 illus., 29 refs.
• 分类号：1001
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

Tuff interlayers distribute widely in Yanchang Formation of Ordos Basin. The data of natural gamma spectrometry logging shows that the thorium content is 25×10^-6～35×10^-6 in tuff layer. The results of element geochemical test indicate that the content of thorium is from 15×10^-6 to 80×10^-6, and average is 36.6×10^-6, which is obviously higher than the average of any other lithospheres and the upper and lower layers of tuff interlayers.