摘要
东天山区域韧性剪切带是近年来中国西部发现的大型剪切带之一，称秋格明塔什－黄山韧性剪切带，东西长逾６００ｋｍ，宽５～２０ｋｍ，位于两大板块碰撞接合地带。变形组构较发育，分四期变形，序列演化明显，应变测量属平面单剪，剪切位移量达７５ｋｍ以上。存在逆冲剪切和韧－脆性剪切变形转换。变形时代为海西中晚期，介于３１０～２５０Ｍａ间，高峰期为２９０～２６５Ｍａ，变形机制属地壳中深层次塑性流变和韧性剪切，其与两大板块间的俯冲－碰撞构造演化密切相关，并经历了多期多阶段演变。它的厘定和研究对再造该区构造演化和金铜矿产勘查预测有重要意义。
Regional ductile shear zone of Eastern Tianshan is one of the large shear belts discovered in recent years in the west part of China.It is called Qiugamintashi Huangshan ductile shear zone with about 600 km long and 5～20 km wide,where it located in the collision junction belt of two great plates.There developed different scale deformation petrofabrics,which can be divided into four deformation stages.Sequence of evolution is obvious by strain measurement,the second and third stages are belong to the simple shear of plane strain.The distance of shear displacement is 75 km at least .There should have a transition from compressional thrusted ductile shear to ductile brittle deformation during its late evolution.Deformation time is the Mid Late Hercyian(310～250 Ma),with the peak stage in 290～265 Ma on the base of isotopic dating and geological comparative analysis.Deformation mechanism is plastic flow and ductile shear at the mid deep tectonic level of crust.The deformation is most closely related to the subduction collision tectonic evolution between the two great plates,which have undergone multi stages and multi periods of evolution.Defining and studying on this region have an important significance for the research of tectonic evolution and ore discovering gold (copper)mineral resouces finded in this region.
出处
《新疆地质》
CAS
CSCD
1999年第1期56-65,共10页
Xinjiang Geology
基金
国家"305"项目
关键词
东天山
秋格明塔什-黄山
韧性剪切带
变形特征
构造演化
Eastern Tianshan\ Qiugamintashi Huangshan\ ductile shear zone\ deformation feature\ tectonic evolution
