摘要
西藏洛扎地区发育的拆离断层叠加在先期逆冲推覆构造之上,并被以脆性变形为特征的高角度北倾正断层改造,各阶段变形结构面交切关系清楚。拆离活动表现为韧性-韧脆性层间剪切,拆离体依次向北西(北北西)近水平左行滑断。与韧性拆离断层具有成生关系的淡色花岗岩产状特征及年代学研究表明,拆离断层变形时代为中新世中晚期。本文着重阐述拆离断层几何学及运动学特征,并根据地球物理场资料所反映的青藏高原深部结构特征讨论其成因。
Detachment fault in Luozha area, Tibet, was superposed on the early tectonic of thrust plate, and reformed by the high angle normal fault, which dips to north and underwent brittle deformation. Deformation stages are clear on the intersects of texture surface. Detachment activities show the layer-to-layer shear of ductile-ductile and brittle, and detachment bodies being slipped to NW (NNW) in proper order. The occurrence feature and chronological study of the granite, which is related to the origin of ductile detachment fault, imply that the deformation age of the detachment fault is middle Miocene-late middle Miocene. The paper expatiates on the geometry and kinematic features of the detachment fault, and discusses the origin of the fault based on the data which refect the Tibetan plateau deep-seated structure.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2005年第2期189-197,共9页
Geotectonica et Metallogenia
基金
中国地质调查局地调项目(编号H46C004001)资助.
关键词
拆离断层
洛扎地区
构造变形
detachment fault
Luozha area
tectonic deformation
