辽南万福变质核杂岩韧性剪切带的应变与剪切作用类型  

Strain and Shear Types of Liaonan Wanfu Metamorphic Core Complex Ductile Shear Zone

作　　者：李建波[1] 鲁勇花[1] 蒋振频[1] 

机构地区：[1]东华理工大学,江西抚州344000

出　　处：《东华理工大学学报（自然科学版）》2012年第3期238-245,共8页Journal of East China University of Technology(Natural Science)

基　　金：国家自然科学基金项目"医巫闾山变质核杂岩韧性剪切带的应变;剪切作用类型与韧性减薄量的分布特征及构造意义"(41102129)

摘　　要：辽南万福变质核杂岩韧性剪切带为一走向近SN,倾向NE的低角度韧性剪切带,带内的主要岩石类型为花岗质糜棱岩。以长石为应变标志体的Rf/φ应变测量显示应变类型为压扁应变;以极莫尔圆与长短轴法的运动学涡度估算表面,剪切带的剪切作用类型为以简单剪切为主的一般剪切。结合区域构造演化与年代学资料,认为辽南万福变质核杂岩韧性剪切带形成于加厚地壳造山后垮塌,且在早白垩纪华北克拉通大规模地壳伸展的联合作用下由地壳的中、深层次被抬升至地表,并与各时代的岩石在同一露头上并置而成。The Liaonan Wanfu metamorphic core complex ductile shear zone is a SN-striked and SE-dipped ductile shear zone. Finite strain measurement of feldspar strain markers using the Ri/φ method shows the strain types of the mylonitics are flattening strain. The kinematic vorticity values （ Wk ） estimated by the Polar Mohr diagram and the finite strain method suggest the shear type is simple dominated general shearing. All these, together with iso- tope geochronology and regional tectonic background, suggest that the Wanfu metamorphic core complex ductile shear zone uplifted from the middle-lower crust resulted from thickened crust collapsing and a large scale crust extension during the Cretaceous Period.

关 键 词：万福变质核杂岩 韧性剪切带 应变 剪切作用类型 

分 类 号：P542[天文地球—构造地质学]