辽西医巫闾山地区中生代两期韧性变形的研究  

Study of two period ductile deformations in Yiwulushan area of western Liaoning in Mesozioc

作　　者：张宏[1] 王五力[2] 李之彤[2] 杨芳林[2] 张立君[2] 郑少林[2] 

机构地区：[1]西北大学地质系,陕西西安710069 [2]沈阳地质矿产研究所,辽宁沈阳110032

出　　处：《世界地质》2004年第3期213-220,共8页World Geology

基　　金：科技部2000年度科技基础性工作第35专项;国土资源部专项(9501122-3);中国地质调查局(200113000052-2)项目资助

摘　　要：医巫闾山地区的韧性剪切构造是中生代两期韧性变形作用的产物。早期韧性变形中a线理发育,线理走向和糜棱面理走向基本一致,线理在xy面上的侧伏角绝大多数<30°;该期韧性变形是以左行走滑运动为主。晚期韧性变形中a线理发育,线理倾伏向和糜棱岩中糜棱面理倾向相近,线理在xy面上侧伏角主要在45°～90°之间;该期韧性变形是伸展作用的产物。医巫闾山中生代两期韧性剪切变形作用表明,在侏罗纪至早白垩世期间辽西地区不仅发生了强烈挤压推覆作用和伸展作用,也发生了大规模左行走滑作用。该韧性变形作用的发现对进一步研究辽西中生代的构造演化序列、期次和构造格架转换等问题有重要意义。The ductile shear tectonics in Yiwulushan Mountain region are formed in two periods in Mesozioc. In early-period ductile shear structure,the strike a-lineations(on xy plane)are very developed,the most pitches of a-lineation are lower than 30°,and the movement of early ductile shear is sinistral displacement. In late-period ductile shear structure,the dip a-lineations(on xy plane)are developed and the most pitches of a-lineation are between 45°～90°. The movement of late ductile shear is extensional displacement. The characteristics of two period ductile tectonics in Yiwulushan Mountains demonstrate that not only the over-thrust and extension tectonic system was formed,also sinistral displacement tectonics was one of the specified tectonics in Jurrasic to Early Cretacous,which is very important for studying the tectonic evolution history of western Liaoning in Mesozoic.

关 键 词：医巫闾山 两期 韧性剪切变形 伸展 左行走滑 

分 类 号：P534.5[天文地球—古生物学与地层学] P553[天文地球—地质学]