阿尔金地区曼特里克一带花岗岩地球化学特征及构造意义  

The Geochemical Features and Tectonic Significance of Mantelike Granite on the Altun Area

作　　者：庞振甲 成欢 王瑞廷 Pang Zhenjia;Wang Ruiting;Cheng Huan(Shaanxi Northwest Nonferrous Geological Survey Co.,Ltd,Xi’an,Shaanxi,710054,China)

机构地区：[1]陕西西北有色地质调查院有限公司,陕西西安710054

出　　处：《新疆地质》2022年第3期315-323,共9页Xinjiang Geology

基　　金：新疆维吾尔自治区地质勘查基金项目新疆阿尔金山地区曼特里克一带1:5万四幅区域地质矿产调查(K15-1-LQ16)资助。

摘　　要：阿尔金地区曼特里克一带发育不同时代花岗岩类。一类为青白口纪变质变形强烈的花岗质片麻岩类,主要包括黑云二长片麻岩和花岗闪长岩质片麻岩;另一类为早—中奥陶世未变质变形花岗岩类,主要包括正长花岗岩,二长花岗岩,花岗闪长岩和闪长岩。青白口纪花岗质片麻岩具富硅、富碱、低钙、低钛、准铝-过铝质特征,具右倾型稀土特征和显著负Eu异常,明显富集Rb,Th,K等大离子亲石元素,显著亏损Ba,Sr,Nb,Ti等高场强元素,总体显示壳源特征;早—中奥陶世花岗岩类具有和青白口纪花岗质片麻岩相类似特征。结合前人研究和区域地质背景,认为阿尔金造山带在青白口纪和早—中奥陶世均发生过强烈的碰撞造山,而青白口纪花岗质片麻岩类和早—中奥陶世花岗岩类分别是对罗迪尼亚超大陆汇聚和阿中地块与柴达木地块碰撞造山的响应。Granitoids of different ages are developed in Mantelike area of Altun area.The first type is granitic gneisses with strong metamorphism and deformation which formed during the Qingbaikou period,which mainly includes biotite monzonite gneiss and granodiorite gneiss;The second type granites is without metamorphism and deformation which formed during the early-middle Ordovician,including syenite,monzonite,granodiorite and diorite.The Qingbaikou period Granitic gneiss is rich in silicon and Alkali,low CaO and Ti O2,Quasi-aluminous-peraluminous character.It′s rare earth elements has right-leaning and significant negative Eu anomaly.The Rock is obviously rich in large-ion lithophile elements such as Rb,Th and K,and deficient in high field strength elements such as Ba,Sr,Nb and Ti,shows the characteristics of crust source;The early-middle ordovician granitoids have similar characteristics to the Qingbaikou granitic gneisses.Combined with previous studies and regional geological background,it is considered that Arguin Orogenic belt had strong collision Orogenic in Qingbaikou period and early-middle ordovician period,which shows that the Arguin Orogenic belt had a strong collisional orogeny in the Qingbaikou and early-middle Ordovician period,they are the response of convergence of the Rodinia and the Collisional Orogeny of A-zhong Massif and the Qaidam Massif,The research results provide new evidence for the geological structure evolution of Altun orogenic belt.

关 键 词：花岗岩 地球化学 构造意义 曼特里克 阿尔金地区 

分 类 号：P619.222[天文地球—矿床学] P595[天文地球—地质学]