东天山红柳河地区海西期花岗岩的岩石学、地球化学及其构造环境  

Petrology,Geochemistry of Hercynian Granites of Hongliuhe Area and Its Tectonic Setting in Eastern Tianshan Mountains, Western China

作　　者：李伍平[1] 王涛[2] 李金宝[3] 康旭[3] 于福生[3] 韩庆军[3] 马忠平[3] 

机构地区：[1]中国科学院广州地球化学研究所,510640 [2]北京大学地质学系,100871 [3]长安大学国土资源学院,西安710054

出　　处：《地质论评》2001年第4期368-376,共9页Geological Review

基　　金：国土资源部1:5万"红柳河站幅"和"芦苇井幅"区域地质调查项目(编号甘地勘地发[1996]17号)

摘　　要：东天山红柳河地区分布着大量的海西期花岗岩体。从早到晚,依次为河西站岩体、红柳河岩体、河西岩体和天湖岩体。主要岩石类型为花岗闪长岩、二长花岗岩和斜长花岗岩。河西站和红柳河花岗岩的岩相学和地球化学具有S型花岗岩的特征,而河西岩体和天湖岩体显示出Ⅰ型花岗岩特征。河西花岗岩微量元素含量最低,具Eu弱正异常,类似于adakite岩地球化学特点;其他花岗岩微量元素含量高,具Eu负异常。与洋脊花岗岩相比,该区花岗岩不同程度地富集K_2O、Rb、Ba、Th和Ce,亏损Ta、Nb、Zr、Hf、Y、Yb等。河西花岗岩、河西站和红柳河花岗岩、天湖花岗岩分别具有火山弧、同碰撞和碰撞后花岗岩特点。河西花岗岩和其他花岗岩分别起源于先前存在的大洋拉斑玄武岩残片和古老地壳岩石的部分熔融。这些花岗岩均形成于陆内造山环境,与东天山海西晚期地壳—岩石圈的挤压和伸展作用有关。There are volumes of Hercynian granitoids of Hongliuhe area in eastern Tianshan Mountains, granitoid plutons,according to intrusive order from earlier to later,are Hexi,Hongliuhe,Hexi and Tianhu in. turn. The main rock types were plagiogranite,granodiorite,monzonitic granite. The petrography and geochemistry of Hex-izhan and Hongliuhe granites have the feature of S-type,and those of Hexi and Tianhu granites have the feature of I-type. The Hexi granites have the lowest rare earth elements,Eu postive abnormity and the feature of similar adakite, the others have higher rare earth elements, Eu negative abnormity. Compared with the ocean ridge granites(ORG),these granites have the enrichment of K2O,Rb,Ba,Th and Ce,and the dilution of Ta,Nb,Zr, Hf,,Y and Yb,the granites of Hexi,Hexizhan and Hongliuhe,Tianhu have the respectively characteristics of volcanic arc,syn-collision,post-collision. Hexi granites and other granites were derived from the part melting of ancient ocean slab and ancient continent crust materials. They formed the intracontinent orogenic process, and were related with the extrusion and extension of the crust and lithosphere in eastern Tianshan Mountains in later Hercynian.

关 键 词：花岗岩 地球化学 构造环境 红柳河地区 岩石学 海西期 东天山 

分 类 号：P588.1[天文地球—岩石学]