摘要
鸡冠子山二长花岗岩LA-ICP-MS单颗粒锆石U-Pb测试年龄为245±1 Ma,说明其形成于早三叠世.岩石地球化学研究表明,岩体具有高Si、富K、贫Ti、Ca、Fe、Mg的特点;A/KNC＞1.1,显示出S型花岗岩特点;固结指数（SI）为1.68 ～ 1.88,分异指数（DI）为93.94 ～94.25,说明岩体经历了较高程度的分异演化作用;稀土元素总量较低（∑×REE=80.10×10-6 ～145.06×10-6）,轻稀土明显富集,重稀土相对亏损,Eu负异常,大离子亲石元素Rb、K较富集,表明鸡冠子山二长花岗岩属于高钾钙碱性、过铝质S型花岗岩.结合前人相关的研究成果,推测鸡冠子山二长花岗岩是华北板块和西伯利亚板块碰撞作用形成的同碰撞型花岗岩.
Abstract ： The result of LA-ICP-MS zircon U-Pb is 245 ± 1 Ma, revealling that monzonitic granite in Jiguan- zi Mountain was formed in Early Triassic. The geochemistry study of the rocks indicates that the rocks are charac- terized by high Si, K and low Ti, Ca, Fe, Mg. The ratio of A/KNC 〉 1.1 shows the characteristics of S-type gran- ite. The SI is 1.68 - 1.88, DI is 93.94 - 94.25, indicating that the rocks experienced a relatively high degree of differentiation evolution. The total content of REE is low （ ∑REE =80. 10 × 10-6 ～145.06 × 10-6） , the LREE and LILE （Rb, K） are enriched, the HREE are depleted, and it is also characterized by negative Eu anomaly. In
出处
《世界地质》
CAS
2015年第2期345-353,共9页
World Geology
基金
中国地震局教师科研基金项目(20140101)
关键词
早三叠世
华北板块
S型花岗岩
同碰撞
内蒙古
Early Triassic
North China Plate
S-type granite
syn-collisional granite
Inner Mongolia
