• 责任者：Pan Xiaoping (Xi’an Institute of Geology and Mineral Resources ; China Geological Survey ; Xi’an 710054 ; China) ; Li Rongshe
• 刊名：Geological Bulletin of China
• 出版年：2012
• 卷期：31(1)
• 关键词：火山岩 ; volcanic rocks ; 铀—铅计时 ; U-Pb dating ; 冈底斯山 ; Gangdise Range
• 页码：p.63-74
• 图表：4 illus., 4 tables, 44 refs.
• 分类号：0801
• 出版序号：20130128
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

Geologists show much concern over the problem whether there exist Cambrian strata in the southern Tibetan Plateau. The “Nyainqentanglha Rock Group” originally classified as pre-Sinian strata consists of epimetamorphic tholeiitic series bimodal volcanic rocks in Banglecun area, Nyima County, on the northern margin of Gangdise. The ²⁰⁶Pb/²³⁸U weighted average age of (536.4±3.6) Ma was obtained by in-situ LA-ICP-MS zircon dating of the meta-rhyolite, which proves that this volcanic rock was formed in Early Cambrian. The results of geochemical analysis show that the meta-basalt is enriched in LREE, LILE and some HFSE and depleted in Nb, Ta, Zr, Hf, and yields low Zr/Nb ratios (2.53~3.61). However, the meta-rhyolite is obviously enriched in LREE, LILE, Th, HFSE, and depleted in Eu, Sr, Nb, Ta and Ti.