勒巴泉—公婆泉陆缘弧主要特征及动力学背景

文中着重讨论了勒巴泉—公婆泉陆缘弧的基本特征及形成的动力学背景。认为 ,加里东晚期弧后扩张、俯冲形成勒巴泉—公婆泉陆缘弧 ,红柳河弧后盆地的扩张与俯冲是形成勒巴泉—公婆泉陆缘弧的关键 ;陆缘弧区地层主要由公婆泉群 (SG)组成 ,由一系列链状火山岛屿和其间的火山洼地构成 ,属海潮间—潮下高能地带 ,生物发育 ,火山活动异常强烈时期形成窑洞努如和公婆泉两个火山穹隆构造 ;主要岩石类型为爆发相、钙碱性系列的中酸性火山岩。该陆缘弧不仅发育火山作用 ,同时也形成浸染状硫化物型铜成矿系统

THE MAIN CHARACTERISTICS OF LEBAQUAN-GONGPOQUAN EPICONTINENTAL ARC AND THE DYNAMIC BACKGROUND FOR ITS FORMING IN THE CONTIGUOUS AREA ACROSS GANSU, XINJIANG AND INNER MONGOLIA

This paper focus on the basic characteristics of Lebaquan-Gongpoquan epicontinental arc and the dynamic background for its formation in the contiguous area across Gansu, Xinjiang and Inner Mongolia. The late Caledonian back-arc spread and thrust led to the formation of Lebaquan-Gongpoquan epicontinental arc. The spread and thrust of Hongliuhe back-arc is the key step forming formation of Lebaquan-Gongpoquan epicontinental arc. The epicontinental arc consists of a series of chained volcanic islands and depressions.The dominant strata in the epicontinental arc area are mainly Gongpoquan Group (S G ) which formed in intertidal-lower tidal environment with abundant organisms. Both Yaodongluru and Gongpoquan volcanic domes were formed by extremely strong volcanic activity. Dominant rock type is volcanic eruption facis and calc-alkaline medium-acid volcanic rocks. Disseminated sulfide copper metallogenic system exists in the arc.