摘要
云南省西部沿澜沧江分布的临沧花岗岩，呈ＳＮ向延伸，长达５００ｋｍ，但平均宽度只有２５ｋｍ，系逆冲与推覆叠置变形缩短的结果。岩片冲断和推覆的方向普遍为自西向东，临沧花岗岩带向东推覆的距离为３０—８０ｋｍ，最大距离１２０ｋｍ，冲断叠瓦构造和推覆构造形成的时代主要为中、新生代。糜棱岩的同位素年龄为１５．４３Ｍａ、２５．５５Ｍａ和１７９Ｍａ。新生代沿冲断层发生了近ＳＮ向水平走滑运动和沿ＮＥ、ＮＷ向断层的剪切运动。
Granite across the thrust fold zone of the Lancang River in western Yunnan Province is generally termed as Lincang granite, it extends 500km near SN with an average width of 25km only, being extensively compressed by orogenic movement. Licang granite has obvious thrust fault, well developed thrust-imbricate structure and large-scale nappe. The thrust fault of east edge of the leading imbricate fan is the biggest in the Lancang River Thrust Fold Zone. Granite divided into two massive rock sheets by the middle thrust fault formed imbricate structure. There are many klippen and thrust rock sheets in the north of Fenqing county and Changning county. The direction of rock sheets thrusts and klippen transported are generally from west to east. Granite of the thrust fault roof of east edge slipping 30 to 80km towards east. Cataclasitic rock and mylonite grew along the thrust fault. Iochroits which were pulled into pieces often can be found in mylonite among the thrust rock sheets. The thrust-imbricate structure and the nappe structure were mainly formed is from end of Paleozoic to Cenozoic, more than 200 Ma. Isotopic ages of the mylonite are 179 Ma, 149Ma, 15.4Ma and 25.6Ma. During later period of the thrust and nappe along the thrust fault near SN strike-slip fault and the NE or NW shear fault occurred.
出处
《地质科学》
CAS
CSCD
北大核心
1996年第2期130-139,共10页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金
关键词
花岗岩
冲断叠瓦构造
推覆构造
Lincang granite, beading imbricate fan, Thrust-imbricate structure,Nappe structure, Lancang River
