| 韧性剪切带的剪切作用类型和韧性减薄量 |
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| 引用本文： | 李建波1,王 涛2,郭 磊2,童 英2,欧阳志侠3,曾 涛2,史兴俊2,张建军2. 韧性剪切带的剪切作用类型和韧性减薄量[J]. 地质通报, 2012, 31(01): 26-37. |
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| 作者姓名： | 李建波1 王 涛2 郭 磊2 童 英2 欧阳志侠3 曾 涛2 史兴俊2 张建军2 |
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| 作者单位： | 1. 东华理工大学地球科学学院, 江西 抚州 344000; 2. 中国地质科学院地质研究所, 北京 100037;3. 广东省有色金属地质勘查局地质勘查研究院,广东 广州 510080 |
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| 摘 要： | 韧性剪切带组构的演化和剪切作用类型受到许多研究者的关注。运用极莫尔圆法、有限应变法、刚性颗粒法、石英光轴组构结合有限应变测量法、拖尾形态法、剪切带内变形脉体（岩墙）法、碎斑法等方法可以估算剪切带变形过程中的运动学涡度，进而判别剪切带中单剪切组分与纯剪切组分的相对含量。自然界的剪切带一般介于单剪与纯剪之间，运动学涡度Wk介于0~1之间，表明韧性剪切带在变形过程中发生了垂直于剪切带边界（Z轴）方向的韧性减薄。剪切带变形过程中的韧性减薄量可依据有限应变测量与运动学涡度估算求得，也可依据剪切带内的石香肠（布丁）构造求解，还可依据构建极莫尔圆求解。以华北克拉通北缘的楼子店变质核杂岩及其韧性剪切带，以及希腊西奈山的Chelmos剪切带为例，介绍估算韧性剪切带韧性减薄的方法，这种韧性减薄是对大规模岩石圈减薄的有益补充和完善。研究结果表明，定量估算与变质核杂岩相关的韧性剪切带的剪切作用类型是分析变质核杂岩形成机制的有效途径和方法。
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| 关 键 词： | 韧性剪切带 有限应变 运动学涡度 韧性减薄量 |
The shear types and the ductile thinning of the ductile shear zone |
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| LI Jian-bo1, WANG Tao2, GUO Lei2, TONG Ying2, OUYANG ZHi-xia3,ZENG Tao2, SHI Xing-jun2, ZHANG Jian-jun2. The shear types and the ductile thinning of the ductile shear zone[J]. Geological Bulletin of China, 2012, 31(01): 26-37. |
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| Authors: | LI Jian-bo1 WANG Tao2 GUO Lei2 TONG Ying2 OUYANG ZHi-xia3 ZENG Tao2 SHI Xing-jun2 ZHANG Jian-jun2 |
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| Affiliation: | 1. East China Institute of Technology, Fuzhou 344000, Jiangxi, China;2. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;3. Geological Survey Institute,Guangdong Nonferrous metals Geological Survey Bureau, Guangzhou 510080, Guangdong, China |
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| Abstract: | Many researchers have focused their attention on the evolution of the fabric and the shear type of the shear zone. The kinematic vorticity can be estimated by using the polar Mohr method, the finite strain, the rigid grain net, the finite strain and the quartz C-fabric, and the components of simple shear and pure shear during the evolution of the ductile shear zone can also be calculated. Many facts have confirmed that the natural shear zones are always general shear zones which combines different components of simple shear and pure shear and whose values of kinematic vorticity range from 0 to 1, suggesting that the ductile thinning perpendicular to the band of the shear zone occurred. The rate of the ductile thinning during the evolution of the ductile shear zone can be estimated by the methods of the finite strain measurement and kinematic vorticity, the budding of the shear zone and the polar Mohr. Using the Louzidian ductile shear zone and Greece Hellenides Chelmos shear zone, this paper indicates that the ductile thinning really occurred in the ductile shear zone. The ductile thinning is the supplement and perfection of lithosphere thinning; at the same time, the shear types of the ductile shear zone related to the metamorphic core complex constitute an effective method to analyze the mechanism of the metamorphic core complex. |
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| Keywords: | ductile shear zone finite strain measurement Kinematic vorticity quantities of ductile thinning |
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