地震地质 ›› 1998, Vol. 20 ›› Issue (4): 332-342.

• 科研简报 • 上一篇    下一篇

郯庐断裂带南段韧性剪切带糜棱岩化过程中长石成分和结构状态变化特征的研究

杨晓勇1, 杨学明1, 刘德良1, 董树文2, 戴金星3   

  1. 1. 中国科学技术大学地球和空间科学系, 第二世界科学院中国科学技术大学地球科学和天文学高级研究中心, 合肥 230026;
    2. 地质矿产部南京地质矿产研究所, 南京 210016;
    3. 中国石油与天然气总公司勘探开发科学研究院, 北京 100083
  • 收稿日期:1997-11-30 修回日期:1998-04-30 出版日期:1998-12-09 发布日期:2009-11-25
  • 基金资助:
    国家“九五”重点科技攻关项目(961100107);国家自然科学基金资助(48970172)。

VARIATIONS OF THE COMPOSITIONS AND STRUCTURAL STATE OF FELDSPARS DURING MYLONITIZATION IN THE DUCTILE SHEAR ZONES OF THE SOUTHERN TANCHENG LUJIANG FAULT

Yang Xiaoyong1, Yang Xueming1, Liu Deliang1, Dong Shuwen2, Dai Jinxing3   

  1. 1. Department of Earth and Space Sciences, University of Science & Technology of China, Advanced Center for Earth Sciences & Astronomy, University of Science & Technology of China, the Third World Academy of Sciences, Hefei 230026;
    2. Nanjing Geological Institute of the Aaministry of Geology & Mineral Resources, Nanjing 210016;
    3. Academy of Peroluem & Gases for Research and Exploraion, CNPC, Beijing 100083
  • Received:1997-11-30 Revised:1998-04-30 Online:1998-12-09 Published:2009-11-25

摘要: 在对郯庐断裂带南段3条韧性剪切带中糜棱岩及围岩进行矿物组合、结构构造观察研究的基础上,对长石矿物进行了多项分析测试,发现长石成分及其结构状态参数的变化与构造应力场的构造作用存在明显的对应关系:随剪切变形作用的加强,长石矿物的结构状态参数呈增大趋势,矿物单位晶胞的体积和斜长石中Si/Al比值随之减小;长石的变形指数(Iss)和斜长石中的钙长石分子(An)与岩石的变形强度呈明显的正相关关系。这些研究结果为探讨构造变形场中矿物岩石的变形 变质作用提供了一种简捷有效的手段。

关键词: 郯(城)-庐(江)断裂带, 剪切带, 糜棱岩, 显微构造, 构造应力场, 长石

Abstract: On the basis of observations of the mineral assemblages and microstructures in the tectonic rocks from the ductile shear zones in the southern part of the Tancheng Lujiang fault,the feldspar was analyzed by means of EPMA,XRD and infrared spectrometry. It has been found that there are close correlations between the intensity of the rock deformation and the composition and structural state of the feldspars in the rocks. The relations are as follows: the positive correlation between the intensity of shearing deformation and the parameters of the feldspar structural state,the deformed index of feldspar(Iss) and An values of plagioclase,and the negative correlation between intensity of shearing deformation and the unit cell volume of the feldspars and Si/Al value of the plagioclase. These results provide simple and effective methods for studies of the deformation metamorphism in structural strain field.

Key words: Tancheng Lujiang fault zone, shear zone, Mylonite, Microstructure, Tectonic stress field, feldspar