Zircon LA-ICP-MS U-Pb Dating of Basic Volcanics from Erlangping Group of the North Qinling, Eastern Qinling Mountains and Its Geological Implications
详细信息
- 责任者：Zhao Jiao (State Key Laboratory of Continental Dynamics ; Department of Geology ; Northwest University ; Xi’an 710069 ; China) ; Chen Danling
- 刊名：Earth Science Frontiers
- 出版年：2012
- 卷期：19(4)
- 关键词：火山岩 ; volcanic rocks ; 铀—铅计时 ; U-Pb dating ; 秦岭 ; Qinling Mountains
- 页码：p.118-125
- 图表：5 illus., 1 table, 32 refs.
- 分类号：0801
- issnNo：ISSN1005-2321
- isbnNo：CN11-3370/P
摘要
///Cathodoluminescence and LA-ICP-MS analysis were conducted on zircon grains from three basic volcanic rock localities of the Erlangping Group, namely, in Junmahe, Wantan and Tuanhe-Tuanyuan regions, eastern Qinling Mountains. CL investigations show that the zircon grains from the three areas have the same behavior of euhedral to subhedral prismatic shape with weak, broad oscillatory zoning internal structure. Trace element analyses revealed a typical magmatic zircon origin. LA-ICP-MS zircon dating yield crystallization ages of (463±1.8) Ma,(475±1.5) Ma and(473±1.3) Ma for basic volcanic rocks from Junmahe, Wantan and Tuanhe-Tuanyuan sections, respectively. Together with their distinct geochemical affinities, Erlangping volcanics are of back-arc basinbasalt and the protolith of the UHP eclogite is of within plate basalt. Therefore, the UHP eclogite in the North Qinling Mountains has no direct relationship with the basic volcanics in the Erlangping Group.