摘要
喀英迪铁铜矿床的形成与晚泥盘世呼斯特大型复式侵入岩体相关,由二长花岗岩、花岗闪长岩及花岗闪长斑岩等组成。岩石SiO_2含量为65.88%~76.26%、K_2O+Na_2O含量为5.76%~8.20%、K_2O含量为2.28%~4.99%,属高钾钙碱性系列;稀土总量149.88~214.32,平均185.45,总体偏低,LREE/HREE=8.59~10.59,均远大于1,属轻稀土相对富集,δEu值为0.29~0.63,具有中等-较强的铕负异常。通过R_1-R_2构造判别分析,呼斯特花岗岩的形成主要经历板块碰撞前、同碰撞期及后碰撞3个阶段,与板块构造碰撞造山有着密切关系,结合Fw%-Mw%和Nb-Y构造判别进一步分析,其侵入岩构造背景应为板块汇聚阶段的岛弧造山带。
The formation of the Kayingdi Fe-Cu deposit is related to the late Devonian husite large-scale complex intrusive body, which consists of monzonitic granite, granodiorite and granodiorite porphyry. The SiO_2 content of rocks is 65.88%~76.26%, K_2O+Na_2O content is 5.76%~8.20%, K_2 O content is 2.28%~4.99%, belonging to the series of high potassium calcium alkalinity. The total amount of rare earths is 149.88~214.32, with an average of 185.45, which is generally low. LREE/HREE=8.59~10.59, which is much larger than 1. It is relatively rich in light rare earths, with δEu value of 0.29~0.63, and has medium-strong negative europium anomaly. Through R_1-R_2 structural discrimination analysis, the formation of Husite granite mainly experienced three stages of plate collision, i.e. pre-collision, co-collision and post-collision, which are closely related to plate tectonic collision and orogeny. Combined with Fw%-Mw% and Nb-Y structural discrimination, further analysis shows that its intrusive rock tectonic background should be island arc orogenic belt in plate convergence stage.
引文
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