甘肃北山地区变形岩石X光组构特征及其构造意义  

XRAY ANALYSIS OF DEFORMED ROCKS FROM BEISHAN AREA, GANSU PROVINCE

作　　者：陈柏林[1] 舒斌[2] 吴淦国[1] 叶得金[1] 刘晓春[2] 杨农[2] 

机构地区：[1]中国地质大学地球科学学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《吉林大学学报（地球科学版）》2003年第4期424-429,442,共7页Journal of Jilin University：Earth Science Edition

基　　金：原地质矿产部定向研究基金(地科定96-21)资助

摘　　要：通过对甘肃北山地区变形岩石的X光岩组分析,得知该区岩石变形比较强烈。石英变形机制是以中低温底面型或近底面型滑移为主,部分为中高温柱面Ⅰ型和柱面Ⅱ型滑移系。从岩石组构特点结合宏观构造分析,可以推测榴辉岩是在其形成之后经过比较长时间的结晶恢复后才被抬升出露地表的。该区属于中浅—中等层次(10～20km,T=300～450℃,p=0.25～0.50GPa)的韧脆性-韧性变形。变形运动学和动力学特征是伴有右行剪切的压扁变形。最大主压应力(σ1)为南北向,这与该区处于塔里木板块与哈萨克斯坦板块聚合边界的构造部位和构造变形带的演化历史相吻合。Based on the Xray petrofabrics analysis of deformed rocks from Beishan area, Gansu, the authors draw the conclusion as follows. There happens a strong deformation in the rocks from the area. Quartz is mainly deformed along its basal or basalnear glide system and partly along its prismatic Ⅰ and Ⅱ glide system. There is a long time for stable crystallization before the Gubaoquan eclogite was uplift to the earth surface from the deep site. The deformations of the rocks happen under a medium and mediumdeep depth of 10～15 km, a low-middle and middle temperature of 300～450℃ and a low-middle pressure of 0.25～0.40 GPa. The characteristics of deformation is a compression with a partly righthanded shearing, and the main compressive stress (σ1) is SN oriented.Clearly, all features above are accountable by their specific tectonic site at the convergent plate margin of Tarim plate and Hasakatan plate and are in accord to their evolution history.

关 键 词：X光衍射 组构分析 变形岩石 甘肃北山地区 

分 类 号：P313[天文地球—固体地球物理学]