LA-ICP-MS Zircon U-Pb Dating of Ordovician Mengmao Monzogranite in Longling Area of Western Yunnan Province and Its Tectonic Setting

详细信息   

• 责任者：Xiong Changli (Sichuan Institute of Geological Survey ; Chengdu 610081 ; China) ; Jia Xiaochuan
• 刊名：Geological Bulletin of China
• 出版年：2012
• 卷期：31(2)
• 关键词：花岗岩 ; granite ; 铀—铅计时 ; U-Pb dating ; 怒江 ; Nujiang River ; 云南 ; Yunnan Province
• 页码：p.277-286
• 图表：4 illus., 4 tables, 15 refs.
• 分类号：0801
• 出版序号：20130142
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

摘要

Mengmao monzogranite,exposed in Longling area of western Yunnan Province, was geochemically analyzed and discussed to probe into its genesis, ore-forming material source and tectonic setting. The results show that Magmatic source was typical of crustal genesis and was probably formed by rising and emplacement of granitic magma, which had been partially melted by greywacke. LA-ICP-MS U-Pb dating of zircons indicates that Mengmao granite was emplaced during the Middle Ordovician（454.7±1.5）Ma, with post-collisional magmatic activity features. Mengmao granite, as post-collisional granite and a product of magmatism by late Gondwana land orogenic movement, was formed in the tectonic transition stage from syn-collision (extrusion environment) to post-collision (stretching environment). The result of the researches on Mengmao monzogranite has significance in revealing tectonic attributes of Nujiang fault belt in western Yunnan Province.