阿尔金、柴北缘与北秦岭高压-超高压岩石年代学研究进展及其构造地质意义  

New progress on geochronology of high-pressure/ultrahigh-pressure metamorphic rocks from the South Altyn Tagh,the North Qaidam and the North Qinling orogenic,NW China and their geological significance

作　　者：刘良[1] 陈丹玲[1] 王超[1,2] 张成立[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室／地质学系,陕西西安710069 [2]中国地质调查局西安地质调查中心西安地质矿产研究所,陕西西安710054

出　　处：《西北大学学报（自然科学版）》2009年第3期472-479,共8页Journal of Northwest University（Natural Science Edition）

基　　金：西北大学大陆动力国家重点实验室科技部专项;国家973基金资助项目(2009CB825003)

摘　　要：目的分析总结中国西部南阿尔金、柴北缘与北秦岭3地高压-超高压岩石年代学研究取得的新进展，讨论这些年代学数据所蕴含的构造地质意义。方法选取高质量锆石原位微区LA—ICP—MS或SHRIMP分析结果，综合分析确定3地不同区段高压-超高压岩石的变质时代。结果分别获得南阿尔金、柴北缘与北秦岭高压-超高压岩石的变质时代为（475～509）Ma，（420—457）Ma与（485—514）Ma，柴北缘高压-超高压岩石的变质时代明显滞后于南阿尔金约20—80Ma。结论中国西部南阿尔金、柴北缘与北秦岭3地高压-超高压岩石可能不构成同一条巨型高压-超高压变质岩带，其形成可能与多陆块或弧陆之间的对接碰撞有关。Aim To review the new achievements of geochronological study on high-pressure/ ultrahigh-pressure metamorphic （HP/UHPM） rocks from the South Altyn Tagh, the North Qaidam and the North Qinling orogenic belts of NW China and discuss their geological significance. Methods Based on the high precise zircon SHRIMP and LA-ICP-MS in situ U-Pb data, discuss the metamorphic age of the three HP/UHP terrane. Results Make sure that the metamorphic age of the South Ahyn Tagh, the North Qaidam and the North Qinling terrane are 475 - 500 Ma, 420 -457 Ma and 485 -514 Ma, respectively, and the age of the North Qaidam HP/UHP terrane is 20 -80 Ma younger than that of the South Altyn. Conclusion The South Altyn Tagh, the North Qaidam and the North Qinling may not necessarily be a identical great HP/UHP metamorphic belt; they may likely be different HP/UH- PM belts related to the collisions of multiple blocks and arc-continents.

关 键 词：高压-超高压变质带 大陆深俯冲作用 锆石LA-ICP-MS与SHRIMP定年 南阿尔金 柴北缘 北秦岭 

分 类 号：P954[天文地球—自然地理学]