摘要
新疆富蕴县境内的乌恰沟片麻状黑云母二长花岗岩及沿构造线展布的片麻状细粒花岗岩脉出露在阿尔泰造山带南缘,围岩均为苏普特岩群黑云斜长片麻岩。运用LA-ICP-MS方法对乌恰沟片麻状黑云母二长花岗岩和片麻状细粒花岗岩脉进行锆石U-Pb测年分析。测年结果显示,片麻状黑云母二长花岗岩体的生成年龄为(393.5±4.5)Ma,即形成于早泥盆世,与区域地质背景对比来看,该岩体为碰撞造山阶段所形成;片麻状细粒花岗岩脉的侵入时代为(293.5±6)Ma,表示该区的构造热事件时限。构造变形特征显示片麻状花岗质侵入体与该区左行韧性剪切变形密切相关,据此推测出该地区地层变质变形时代,以及该区左行韧性剪切作用的时限。
Wuqiagou gneissic biotite adamellite and the gneissic fine-grained granite dike which spread along the tectonic lines in Wuqiagou of Fuyun County of Xingjiang, exposed on the south ern margin of Altay orogenic belt, and the wall rock is Supute group biotite plagioclase gneiss. LA- ICP - MS zircon U - Pb dating analysis on gneissic biotite adamellite and gneissic fine- grained granite dike were carried out. The dating results show that the gneissic biotite adamellite granite＇s formation age is（393.5±4.5）Ma in Lower Devonian. By comparison of regional geolog- ical settings, this rock mass was formed by the collision orogenic stage. In contrast, the intrusion age of the gneissic fine-grained granite dike is（293.5±6）Ma, which just signifies the time limit of tectonic thermal event in this area. Tectonic deformation features show the close relationship between the gneissic granitic intrusive mass and sinistral ductile shearing of deformation and metamorphism age and the time limit of sinistral ductile were presumably speculated the tectonic lines. The shearing in this region were presumably speculated.
出处
《西北地质》
CAS
CSCD
2015年第3期127-139,共13页
Northwestern Geology
基金
国家自然科学青年基金项目(41202077)
中国地质调查局项目(12120113041000
1212011220649)联合资助
关键词
阿尔泰造山带南缘
锆石U-PB定年
片麻状花岗质侵入体
构造演化
乌恰沟
the southern margin of Altay orogenic belt
zircon U- Pb dating
gneissic granitic intrusive mass
tectonic evolution
Wuqiagou
