大别山双河超高压硬玉石英岩显微组构特征及其流变学意义  

Microfabric Characteristics of Ultrahigh Pressure Jadeite-Quartzite and Its Rheology Significances in Shuanghe, Dabie Mountains

作　　者：王璐[1] 金振民[1] 刘祥文[2] 金淑燕[1] 

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074 [2]中国地质大学纳米科技中心,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2004年第3期293-302,共10页Earth Science-Journal of China University of Geosciences

基　　金：国家重点基础研究发展规划项目 (G19990 75 5 0 1)

摘　　要：硬玉石英岩是大别—苏鲁超高压 (UHP)变质带内重要超高压岩石类型之一 ,其变形机制和动力学背景参数 (应变、应力、应变速率 )对于全面了解超高压造山带的形成和演化有非常重要的意义 .对大别山双河地区超高压硬玉石英岩 3个样品中的主要组成矿物硬玉和石英进行显微组构和透射电镜 (TEM)的初步研究 .晶格优选方位 (LPO)测量成果表明 :硬玉组构类型与绿辉石相近 ,为L ,LS型 ;石英组构类型主要为单斜对称 .TEM研究表明硬玉滑移系以 (1 0 0 ) [0 0 1 ]、(1 1 0 ) [0 0 1 ]及 (1 - 1 0 ) 1 / 2 [1 1 0 ]为主 .石英中位错发育 ,滑移系以 (0 0 0 1 ) [1 1 2 - 0 ]底面滑移为主 。Jadeite-quartzite of Dabie Mountains is one of the important rock types occurring in ultrahigh-pressure (UHP) metamorphic belts. It is significant to study the jadeite-quartzite's deformation mechanisms and geodynamical parameters (such as stress, strain, strain rate) for the knowledge on the formation and evolution of the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belts. Three representative samples of the Shuanghe jadeite-quartzite from Dabie UHP belt were undertook by the microfabric and TEM for lattice preferred orientation (LPO). The results show that the LPOs of jadeite are similar to those of omphacite. Their LPOs are L- and LS-type. However, the LPOs of quartze are monoclinic symmetry type. The slip systems of jadeite are mainly (100), (110) and (1-10)1/2. Abundant dislocations develop in quartz, which is of dominant slip system of (0001)-derived from basal glide. The slip system represented regional shearing durin g the exhumation of the UHP belt.

关 键 词：硬玉 绿辉石 组构 变形 流变学 双河 TEM 

分 类 号：P585[天文地球—岩石学]