塔里木板块北缘活动陆缘型侵入岩带的岩石学与地球化学  

Petrology and geochemistry of an active continental-margin intrusive rock belt on the northern margin of the Tarim plate

作　　者：姜常义[1] 穆艳梅[1] 赵晓宁[1] 白开寅 张虹波[1] 

机构地区：[1]西安工程学院地球科学系,陕西西安710054

出　　处：《中国区域地质》2001年第2期158-163,共6页Regional Geology of China

摘　　要：在塔里木板块北缘，断续出露一条侵入岩带，总长度800多公里。岩石组合是：橄榄辉长岩-辉长岩-辉长闪长岩-闪长岩-石英闪长岩-花岗岩。各种类型岩石的化学组成显示了清晰的钙碱性岩浆演化趋势。稀土元素配分曲线均为轻稀土富集型，而且，重稀土元素配分曲线相对平坦。Sr、K、Rb、Ba、Th等大离子亲石元素强烈富集，而Ta、Nb、Zr、Hf、Ti等高场强元素显著贫化。这些岩石学与地球化学特征均证明，该侵入岩带形成于活动大陆边缘。An intrusive rock belt is exposed intermittently for ＞800 km on the northern margin of the Tarim plate in northwestern China． Its rock association is olivine gabbro-gabbro-gabbro diorite-diorite-quartz diorite-granite． The chemical compositions of these rock types show a marked trend of alkaline magma evolution． Their REE distribution patterns are of LREE-enriched type， while the HREE patterns are relatively flat． The large-ion lithophile elements such as Sr， K， Rb， Ba and Th are strongly enriched， while the high field-strength elements such as Ta， Nb， Zr， Hf and Ti are notably depleted． All these petrological and geochemical characteristics support the view that this intrusive rock belt originated on the active continental margin．

关 键 词：侵入岩带 岩石学 地球化学 构造环境 塔里木板块 

分 类 号：P588.12[天文地球—岩石学] P59[天文地球—地质学]