木孜塔格-鲸鱼湖地区新生代火山岩地球化学特征及其构造意义  

GEOCHEMICAL CHARACTERISTICS AND TECTONIC SIGNIFICANCE OF CENOZOIC VOLCANIC ROCKS IN MUZTAG-CETACEAN LAKE AREA

作　　者：涂其军[1] 王新昆[2] 杨子江[3] 王小虎[1] 

机构地区：[1]长安大学地球科学与国土资源学院,陕西西安710054 [2]新疆维吾尔自治区国土资源厅,新疆乌鲁木齐830001 [3]新疆地质矿产勘查开发局第一区域地质调查大队,新疆乌鲁木齐830011

出　　处：《新疆地质》2007年第1期11-17,共7页Xinjiang Geology

摘　　要：木孜塔格-鲸鱼湖地区分布的新生代火山岩,主要由玄武安山岩、安山岩、安山玄武岩、白榴碱玄岩等组成.中性火山岩约占99.1%,具钙碱性/钾质中性火山岩特征.富集Ba、Rb、K、Sr等大离子亲石元素,亏损Zr、Hf、Nb等高场强元素,并呈现相似的轻稀土元素富集的分布模式.火山岩沿区域深大断裂分布,深大断裂起到岩浆通道的作用.岩石地球化学环境判别表明它们都源自EMⅡ型地幔,属于轻稀土元素富集的一种壳-幔物质的混合地幔,形成于板内拉张构造环境.There occur Cenozoic volcanic rocks in Muztag-Cetacean lake area. They are composed mainly of bassltic-andesite, andesite, andesite-basalt and leucite-alkale-basalt. The areas of neutral volcanic rocks are about 99.1 percent. They have the characteristics of calc-alkaline/kali-neutral volcanic rocks. These volcanic rocks are generally rich in LILES （Ba, Rb, K, Sr） and depleted in HFSES （Zr, Hf, Nb）. REE distribution patterns are characterized by an enrichment of LREE. The volcanic activities occurred along the giant sinistral strike-slip fault, the deep-cut faults here acted as a magma channel. Isotopic characteristics suggested that these rocks were originated from EM Ⅱ type of mantle, a kind of REE enriched mantle with the crustal material. New evidence shows that Cenozoic volcanic rocks were formed in a continental extension setting.

关 键 词：新生代火山岩 地球化学 木孜塔格 鲸鱼湖 

分 类 号：P588.1[天文地球—岩石学]