滇西北独龙江岩浆弧和丙中洛地块的划分与特征

为查明滇西北贡山地区大地构造单元的划分与特征,系统收集整理了不同比例尺的区域地质调查资料,得出4方面新认识:1该区大地构造单元划分为独龙江岩浆弧和丙中洛地块,二者分界为向东倾斜的高黎贡山逆冲推覆断裂;2独龙江岩浆弧属腾冲造山带,丙中洛地块属三江造山带,其间被中特提斯洋所分隔;3中特提斯洋于中侏罗世打开,晚侏罗世—早白垩世早期向西俯冲消减,早白垩世晚期—晚白垩世闭合;4班公错—东巧缝合带在该区已被向西逆冲推覆的高黎贡山岩群(Pt_1G.)所压覆。

Division and characteristics of Dulongjiang magmatic arc

To clarify the division and characteristics of Gongshan tectonic units in northwestern Yunnan，the authors collected and collated different scaled regional geological survey data，and then obtained four new under- standings: ① tectonic units are divided into Dulongjiang magmatic arc and Bingzhongluo block，and the demarca- tion between them is the inclined eastward Gaoligong Mountain thrusting nappe fault; ②Dulongjiang magmatic arc belongs to Tengchong orogenic belt，while Bingzhongluo block belongs to the Three Ｒiver orogenic belt，which are separated by Meso-Tethys; ③ the Meso-Tethys opened in Middle Jurassic，westward subducted in Late Jurassic- early Early Cretaceous，and closed in later Early Cretaceous and Late Cretaceous; ④ Bangongcuo-Dongqiao suture zone in the district has been covering by the Gaoligong Mountain rock group which westward thrust nappe．