超高压—高压剪切带  

ON THE ULTRAHIGH PRESSURE AND HIGH PRESSURE SHEAR ZONES

作　　者：索书田[1] 游振东[1] 钟增球[1] 张泽明[1] 韦必则[1] 桑隆康[1] 

机构地区：[1]中国地质大学地球科学学院

出　　处：《地质科技情报》1997年第2期1-6,共6页Geological Science and Technology Information

基　　金：国家自然科学基金;地质矿产部"九五"重大科技项目

摘　　要：超高压—高压剪切带是在大陆碰撞造山过程中变质—变形分解作用形成的一类特殊的剪切带。剪切带内的构造岩以含柯石英、金刚石等超高压—高压矿物的榴辉岩、面理化超基性—基性岩、片麻岩、大理岩为特征，具有复杂的变形组构和变形历史。最终形成布丁—基质或残斑—基质结构。深入研究超高压—高压剪切带的几何学、运动学和流变学特征，对分析超高压—高压变质岩石的形成—折返过程及碰撞造山动力学。Field detailed geological observations and mapping indicate that ultrahigh pressure(UHP)and high pressure(HP)shear zones are formed by metamorphic and deformation partitioning in the ultradeep crust during continental collision orogenic processes,which commonly results in a regional scale boudin matrix or clast matrix rheology.Rocks within these shear zones contain coesite and diamond bearing UHP and HP metamorphic mineral assemblages with complex deformation fabrics and structural geometry.The UHP and HP shear zones are very susceptible to remodification during late or post collision orogenic exhumation and retrogressive metamorphism.The deformation partitioning for eclogite blocks is examined by progressive bulk inhomogeneous shortening and simple shear regimes.The geodynamic implication of the UHP and HP shear zones in the continental collision orogens is briefly discussed.It is emphasized that the study of the UHP and HP shear zones has great significance both in orogenic theory and practice,since the UHP and HP shear zones preserve different stage information of the evolution for continental collsion orogens from pre ,syn to post UHP and HP deformation and metamorphism.

关 键 词：剪切带 碰撞造山带 构造几何学 大别山 

分 类 号：P542.2[天文地球—构造地质学]