克拉玛依蛇绿混杂岩带的基本特征和锆石SHRIMP年龄信息  

Basic characteristics of the Karamay ophiolitic mélange,Xinjiang,and its zircon SHRIMP dating

作　　者：徐新 何国琦[2] 李华芹 丁天府 刘兴义 梅绍武 

机构地区：[1]新疆资源环境中心,新疆乌鲁木齐830011 [2]北京大学地球与空间科学学院,北京100871 [3]宜昌地矿研究所,湖北宜昌443003 [4]新疆第一区调队,新疆乌鲁木齐830011

出　　处：《中国地质》2006年第3期470-475,共6页Geology in China

基　　金：国家重点基础研究发展规划项目(2001CB09810)

摘　　要：新发现的克拉玛依蛇绿混杂岩带分布于准噶尔盆地西北缘,表现为组分齐全的蛇绿岩和增生杂岩。由盆地边缘向山区方向,大体呈依次带状分布的超镁铁质岩、镁铁质岩、枕状玄武岩和深海相硅质岩,同时发现超镁铁岩之上被一套火山磨拉石沉积不整合覆盖。在克拉玛依蛇绿岩的白碱滩段中采得蚀变辉长岩样品,锆石SHRIMP定年结果集中在(414.4+8.6)Ma和(332±14)Ma。这一发现为研究中亚洋盆形成和消亡时代提供了重要依据,也为确定准噶尔盆地基底性质提供了重要线索。The newly discovered Karamay ophiohtic mélange distributed along the NW edge of the Junggar basin has a complete sequence of ophiolite and accredonary complex. From the basin edge toward the mountains, ultramafic rocks, mafic, pillow lavas and abyssal radiolarian cherts generally show a zonal distribution. The ultramafic rocks are unconformably overlain by volcanic molasse. The ages given by zircon SHRIMP dating of altered gabbro samples taken from the Baijiantan segment of the Karamay ophiolite mtlange cluster at 414.4±8.6 and 332±14 Ma. This discovery provides important evidence for studying the ages of formation and elimination of the Central Asian ocean basin and also an important clue to the determination of the nature of the basement of the Junggar basin.

关 键 词：西准噶尔 蛇绿岩 SHRIMP年龄 克拉玛依 

分 类 号：P588.3[天文地球—岩石学]