华北克拉通北缘狼山西段太古代绿片岩发现及构造意义  

Discovery of Archean greenschist and its tectonic significance in western Langshan mountain,northern margin of north China craton

作　　者：陈世强[1,2] 戴霜[1] 王崇礼[3] 张明震[1] 张永全[1] 张文防[1] 赵杰[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室,兰州730000 [2]甘肃省地矿局第四勘查院,甘肃酒泉735000 [3]长安大学地球科学与资源学院,西安710000

出　　处：《兰州大学学报（自然科学版）》2012年第5期9-14,共6页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(40972025;40721061);中央高校基本科研业务费专项(lzujbky-2012-k44);教育部新世纪人才计划项目(NCET-07-0389)

摘　　要：通过对新发现的狼山西段赛乌素绿片岩岩石地球化学特征研究,发现该绿片岩北东东向展布,出露长约20km,厚20～274 m.岩石地球化学成分显示绿片岩w(SiO_2)为48.03%～53.93%,富集轻稀土和不相容元素.原岩恢复显示绿片岩为岛弧玄武岩变质而成,指示当时狼山西段为一活动大陆边缘环境.从绿片岩空间分布与厚度变化推测岛弧活动时间较短,规模有限,这对认识华北克拉通构造组成与属性具有重要意义.A study was made of the geochemical characteristics of the greenschist unit discovered first by us in the Saiwusu, in western Langshan mountain, north China craton. It was found that the greenschist is NEE trending, its outcrop being about 20 kin, and with a thickness of 20～274 m. The geochemistrical measurement showed that its SiO2 content is 48.03%～53.93~0, and that it is rich in light REE and incompatible elements. The protolith recovery showed that the greenschist originated from the metamorphism of arc-island basalt, suggesting that the western Langshan was occupied by an active continental margin at that time, with a special distribution and thickness variation of the greenschist, indicating that the arc-island took place in a short period and in a limited area. This discovery is important for deciphering the formation and attributes of the north China craton.

关 键 词：绿片岩 岩石地球化学 构造环境 狼山西段 

分 类 号：P618[天文地球—矿床学]