中天山南缘乌瓦门地区发现蛇绿混杂岩

Discovery of ophiolitic mélange in the Wuwamen area on the southern margin of the Central Tianshan Mountains

新发现的乌瓦门蛇绿混杂岩出露于中天山南缘断裂带中,主要表现为以变质粉砂岩为主的基质中混杂着大小不一、性质各异的块体。基质主要为泥盆纪绢云石英片岩、绢云绿泥石英片岩、二云石英片岩、千枚岩和变质粉砂岩,块体有肢解的蛇绿岩岩块、片麻岩岩块和大理岩岩块。肢解蛇绿岩岩块主要有含辉纯橄岩岩块、辉长岩岩块、基性火山岩岩块和硅质岩岩块。

The Wuwamen ophiolitic mélange found recently by the authors is exposed in the southern Central Tianshan marginal fault belt.It is chiefly marked by mixing of blocks of varying size and nature in matrix dominated by metasiltstone.The matrix consists dominantly of Devonian sericite -quartz schist,sericite-chlorite schist,two -mica-quartz schist,phyllite,and metasiltstone,and the blocks include dis-membered ophiolite blocks,gneiss blocks,and marble blocks.The dismembered ophiolite blocks mainly include pyroxene-bearing dunite blocks,gabbro blocks,basic volcanic blocks,and siliceous blocks.The discovery of the Wuwamen ophiolitic mélange has great significance for the establishment of the Paleozoic tectonic framework in the Tianshan Mountains.