辽西医巫闾山变质核杂岩演化的^(40)Ar/^(39)Ar年代学制约  

Evolution of Yiwulüshan metamorphic core complex in western Liaoning constrained by ^(40)Ar/^(39)Ar thermochronology

作　　者：张必龙[1] 朱光[1] 陈印[1] 谢成龙[1] 

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥230009

出　　处：《地球化学》2013年第5期481-498,共18页Geochimica

基　　金：国家自然科学基金(91214301)

摘　　要：辽西医巫闾山变质核杂岩经历了两阶段伸展活动,早期围绕核部医巫闾山岩体周缘发育了长环形韧性剪切带(称为医巫闾山剪切带),晚期在其西侧又叠加了NNE走向的瓦子峪剪切带。本次从核杂岩不同部位的糜棱岩、片岩、片麻岩中获得的单矿物40Ar/39Ar年代学结果显示年龄跨度大,介于159~116 Ma间,其中角闪石年龄为159~129 Ma,白云母年龄为139~124 Ma,黑云母年龄为139~116 Ma。核杂岩东侧获得的年龄介于159~150 Ma间,西侧年龄集中在129~116 Ma,两者代表了核杂岩两期伸展活动的时限。The Yiwultishan metamorphic core complex （MCC） in western Liaoning experienced two stages of extensional activities. In the early stage, a loop-shaped ductile shear zone, called the Yiwultishan shear zone, developed around the central Yiwultishan pluton. And then its southwestern part was truncated by the Waziyu extensional shear zone. The ^40Ar/^39Ar thermochronology results obtained from mylonites, schists and gneisses in different parts of the core complex show large age span, ranging from 159 to 116 Ma, such as hornblende ages of 159-129 Ma, muscovite ages of 139-124 Ma, biotite ages of 139-116 Ma. The ages in the east are between 159-150 Ma, and that in the west are largely 129-116 Ma. They represent times of two extension activities, respectively.

关 键 词：医巫闾山变质核杂岩 ^40AR/^39AR年代学 伸展活动 冷却曲线 

分 类 号：P597[天文地球—地球化学]