摘要
玛因鄂博断裂两侧侵入岩较为发育,岩石类型多样,形成时代跨度大,构造活动复杂。本次研究以玛因鄂博断裂北侧阿尔勒托别北辉长岩岩体为研究对象,获得LA-ICP-MS锆石U-Pb年龄为(276.4±0.95)Ma,为早二叠世岩浆活动的产物。岩石地球化学显示为钙碱-高钾钙碱性系列,为亚碱性辉长岩。微量元素表现为Rb,Nb的富集,Ta,P,Ti的亏损。稀土元素蛛网图整体呈一右倾曲线,轻稀土相对富集,重稀土相对亏损,轻重稀土分馏不明显,并出现Ce的弱负异常。对比分析认为,该岩体形成于碰撞造山后伸展阶段,其成因与下岩石圈地幔拆沉和软流圈地幔上涌、熔融作用有关系。
The intrusive rocks on both sides of the Mayinebo fault are well developed,with many types of rocks,large span of formation age and complex tectonic activities.This study takes the northern altobe gabbro rock mass on the north side of Mayinebo fault as the research object.LA-ICP-MS zircon U-Pb age of 276.4±0.95Ma is the product of early Permian Magmatism.The rock geochemistry shows that it is calc alkaline-high-k calc alkaline series,which is sub alka-line gabbro.Trace elements are enriched in Rb and Nb and depleted in Ta,P and Ti.On the whole,the spider web dia-gram of REE shows a right inclined curve,showing that LREE is relatively enriched,hree is relatively depleted,LREE fractionation is not obvious,and weak negative anomaly of CE appears.Combined with the comparative analysis,it is considered that the pluton was formed in the post collisional orogenic extension stage,and its genesis is related to the de-lamination of the lower lithospheric mantle and the upwelling and melting of the asthenosphere mantle.
作者
韩琼
赵同阳
靳刘圆
李平
杨硕
郑加行
Han Qiong;Zhao Tongyang;Jin Liuyuan;Li Ping;Yang Shuo;Zheng Jiaxing(Xinjiang Institute of Geological Survey,Urumqi,Xinjiang,830000,China)
出处
《新疆地质》
CAS
CSCD
2022年第1期98-105,共8页
Xinjiang Geology
基金
国家重点研发计划“东天山阿齐山-清白山铜铅锌矿带深部资源预测”课题(2018YFC0604005)
新疆维吾尔自治区区域地质志(DD19-23)
新疆区域地质志、矿产志研编(Y19-1-XJ001)
新疆维吾尔自治区系列地质图件数据处理与洋板块地质研究共同资助。
