西秦岭天水市元龙地区新元古代花岗质片麻岩锆石LA-ICP-MSU-Pb定年及其地质意义

收稿日期: 2006-05-15

修回日期: 2006-08-07

刊出日期: 2006-11-15

LA-ICP-MS zircon U-Pb dating of the Neoproterozoic granitic gneisses in the Yuanlong area, Tianshui City, West Qinling China, and their geological significance.

Received Date: 15 May 2006

Revised Date: 07 August 2006

Publish Date: 15 November 2006

摘要: 西秦岭元龙花岗质片麻岩位于天水市伯阳—元龙之间的渭河断裂北侧。花岗质片麻岩中锆石Th/U比值较高,阴极发光图像显示锆石内部发育振荡环带,具岩浆成因特点。LA-ICP-MS的锆石U-Pb同位素206Pb/238U加权平均年龄为(924.2±2.7)Ma(MSWD=0.67),表明花岗岩岩体形成于新元古代,反映晋宁期西秦岭北缘曾存在一次俯冲碰撞事件,与Rodinia超大陆的汇聚事件一致。
- 新元古代花岗质片麻岩锆石LA—ICP-MS U—Pb定年天水市元龙地区西秦岭
- Neoproterozoic; granitic gneisses; LA-ICP-MS zircon U-Pb dating; Yuanlong area,Tianshui; West Qinling