新疆哈密双井子地区早石炭世火山岩及其地球化学特征

双井子地区位于星星峡－卡瓦布拉克地块、古生代岛弧东段北侧活动大陆边缘，分布着早石炭世裂陷盆地，有玄武岩、安山岩和流纹岩及其凝灰岩，与金矿成矿有密切的关系。本文在区域地质背景分析基础上，着重对火山岩、火山碎屑岩及其地球化学特征进行系统研究，结果认为，该区安山岩、流纹岩及其凝灰岩为高硅富钾或钠贫铝钙碱－钙性火山岩系列，岩浆源区来自中下地壳；玄武岩则为富钠碱性正常基性类型火山岩系列，岩浆源区来自下地壳，两者为非平衡部分熔融岩浆演化产物。前者Ａｓ、Ｂｉ、Ｗ、Ａｇ、Ａｎ、Ｐｂ、Ｓｂ、Ｓｅ、Ｃｏ、Ｍｏ、Ｂａ、Ｓｎ、Ｒｂ、Ｔｅ等元素含量较高，有重要找矿前景；后者也可为成矿提供部分物质。这些认识，对该区火山岩特征、性质、成矿关系和构造背景，以及进一步找矿，都将有重要理论和实践指导意义。

THE EARLY CARBONIFEROUS VOLCANIC ROCKS AND ITS GEOCHEMICAL FEATURES OF THE SHUANG JINGZI REGION IN HAMI, XINGJIANG PROVINCE

The Shuang Jingzi region is located at the active continental margin on the northern floor of eastern sector of paleozoic island arc of the Xingxingxa-Kawabulake block scattered with ear ly canboniferious faulted basin and covered with basalt,andesite. rhyolite and tuff, having good relationship with gold resources. Based on the background of regional geology, we put emphasis on systematic research on the volcanies, pyroclastics and its geochemical feature. We conclude that andesite,rhyolite and tuff belong to high silico-kalium or sodium and low aluminium- calcalkaline and cafe volcanic rock series originated from middle and low crust. The basalt belongs to the normal type of basic rocks riched in sodium and its magma derived from the lower crust. Most of them are producted by nonequilbrium partial melting. The former have high contents of As, Bi, W,Ag,Au, Pb,Sb,Se,Co,Mo,Ba,Sn,Rb,Te etc, with important prospect of ore exploration. The latter may also provide source for the metallogenesis. All these conclusions will have important theoretical and practical significance for studing the volcanic feature, metallogenic relationship, tectonic background and further ore exploration.