西昆仑山库地蛇绿岩的特征及其构造意义  

THE CHARACTERISTICS OF KUDI OPHIOLITE SUITE AND ITS TECTONIC SETTING

作　　者：杨树锋[1] 陈汉林[1] 董传万[1] 沈晓华[1] 齐德文[1] 赵冬冬 贾承造 魏国齐 李继亮[3] 

机构地区：[1]浙江大学地球科学系,杭州310027 [2]塔里木石油勘探指挥部,库尔勒841000 [3]中国科学院地质研究所,100029

出　　处：《地质科学》1999年第3期281-288,共8页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家"九五"科技攻关项目;浙江大学曹光彪高科技发展基金;南京大学内生金属矿床成矿机理国家重点实验室基金

摘　　要：库地蛇绿岩套由下部超镁铁质岩、辉长岩、幔源型花岗岩和上部基性火山岩、复理石等成分构成，形成于震旦纪—寒武纪。通过基性的辉长岩、玄武岩的矿物学、岩石学和地球化学研究得出，辉长岩表现出与典型蛇绿岩套中的堆晶辉长岩的特征相一致；而玄武岩则与大洋中脊玄武岩的特征一致，认为该蛇绿岩套是形成于洋中脊的蛇绿岩套。结合库地岛弧花岗岩的特征，提出塔里木盆地南缘在震旦纪—早古生代时期存在一个广阔的大洋，这一大洋在志留纪末期关闭。Kudi ophiolite suite is composed of ultramafic rocks, gabbro, mantle source granitoid, basic volcanic rocks and flysch. It was formed during Sinian and Cambrian. Through the research of mineralogy, petrology and geochemistry of gabbro and basalt, the authors concluded that characteristics of gabbro are similar to those of cumulate structural gabbro. The characteristics of basalt are similar to those of ocean ridge basalt. Therefore, Kudi ophiolite suite is a typical ophiolite suite formed in ocean ridge. Combining the characteristics of Kudi island arc granitoid, the authors also suggest that there had been a wide ocean lying to the south of Tarim basin during Sinian and Early Paleozoic, and this wide ocean was closed at the end of Silurian.

关 键 词：西昆仑山 蛇绿岩套 岩石地球化学特征 构造背景 

分 类 号：P588.1[天文地球—岩石学]