摘要
为进一步丰富西昆仑地区黑石北湖—三道河子一带侵入岩数据,为盼水河锑矿的形成时代提供年代学制约,对盼水河花岗闪长斑岩进行了地质学、岩石学、地球化学及年代学研究。LA-ICP-MS锆石U-Pb测年结果显示,盼水河花岗闪长斑岩年龄为210.9±2.8 Ma,形成于晚三叠世。岩石地球化学特征显示,盼水河花岗闪长斑岩SiO 2含量为66.1%~72.03%,全碱(Na2O+K2O)含量为5.95%~8.29%,平均值为7.10%,K2O>Na2O,岩石富钾,显示为高钾(钙碱性)岩;岩石稀土元素总量较低,且强富集轻稀土元素,Eu具弱负异常(δEu=0.66~0.90),相对富集Rb、Th、Ta、Ce、Hf,贫化Ba、K、P、Ti。构造环境判别图解显示,盼水河花岗闪长斑岩形成于同碰撞的构造环境,揭示区内松潘-甘孜陆块西北缘在华力西晚期—印支期发生了同碰撞造山作用,区内黑石北湖-三道河子岩浆岩带正是该造山作用及洋陆转换的产物。
In order to further enrich the data of intrusive rocks in Heshibeihu-Sandaohezi area of West Kunlun Mountains and provide a chronologic restriction for the formation age of the Panshuihe antimony deposit,the authors studied geology,petrology,geochemistry and chronology of the granodiorite porphyry in Panshuihe.The LA-ICP-MS zircon U-Pb dating yielded the age of Panshuihe granodiorite porphyry of 210.9±2.8 Ma,suggesting Late Triassic.Rock geochemistry shows that the content of SiO 2 in Panshuihe granodiorite porphyry is 66.1%~72.03%,the content of total alkali(Na2O+K2O)is 5.95%~8.29%,and the average value is 7.10%.The feature K2O>Na2O shows that the rock is rich in potassium and belongs to a high potassium(calc-alkaline)rock.The total REE is relatively low,and it shows strong enrichment of light rare earth elements,slight loss of europium(Eu=0.66~0.90),relative enrichment of Rb,Th,Ta,Ce and Hf,and relative dilution of Ba,K,P and Ti.The tectonic environment classification diagram shows that the Panshuihe granodiorite porphyry was formed in the tectonic environment of syn-collision,and that the syn-collision orogeny occurred on the northwestern margin of the Songpan-Garze landmass in this area from the Late Variscan to the Indosinian period,and the north lake of Heshibeihu-Sandaohezi magmatic belt in the area was formed by this orogenesis and the transition from ocean to land.
作者
唐名鹰
高振华
董振昆
翟孝志
潘诗洋
TANG Mingying;GAO Zhenhua;DONG Zhenkun;ZHAI Xiaozhi;PAN Shiyang(No.8 Exploration Institute of Geology and Mineral Resources,Riz hao 276826,Shandong,China;Hubei Geological Research Laboratory,Wuhan 430034,Hubei,China)
出处
《地质通报》
CAS
CSCD
北大核心
2020年第2期206-214,共9页
Geological Bulletin of China
基金
新疆地勘基金中心项目《新疆西昆仑红山顶南一带1∶5万四幅区域地质调查》(编号:K16-1-LQ-10).
