缅甸大地构造单元的划分与特征

为合作开发周边国家矿产资源,在实地调研的基础上,结合前人资料的收集与整理,将缅甸的大地构造单元自西向东划分为5个Ⅰ级构造单元、10个Ⅱ级构造单元.具体是:①西克钦邦-若开邦结合带(E-N_1)(Ⅰ),进一步划分为钦邦-若开邦结合带(E-N_1)(Ⅰ_1)、西克钦邦结合带(E-N_1)(Ⅰ_2);②西缅甸-苏门答腊弧盆系(E-N_1)(Ⅱ),进一步划分为蒙育瓦-勃生岛弧带(E-N_1)(Ⅱ_1)、瑞保-仰光弧后盆地(E-N_1)(Ⅱ_2)、密支那岛弧带(E-N_1)(Ⅱ_3);③腾冲-马来半岛造山带(T_3-K)(Ⅲ),进一步划分为八莫陆缘弧(T_3-K)(Ⅲ_1)、毛淡棉陆缘弧(T_3-K)(Ⅲ_2)、德林依达地块(P_z_2)(Ⅲ_3);④保山-掸邦陆块(■-T_2)(Ⅳ);⑤昌宁-孟连-清莱结合带(C-T_2)(Ⅴ).这10个构造单元以9条断裂为边界.自西向东为:那加山-若开山逆冲断裂(F_1)、平梨铺-卑谬伸展断裂(F_2)、实皆-勃固右行平移断裂(F_3)、葡萄-格杜逆冲断裂(F_4)、英昆-八莫伸展断裂(F_5)、南坎-抹谷右行平移断裂(F_6)、曼德勒-垒固左行平移断裂(F_7)、锡当-三塔左行平移断裂(F_8)、孟宾-清迈逆冲断裂(F_9).

DIVISION AND CHARACTERISTICS OF THE GEOTECTONIC UNITS OF MYANMAR

On the basis of field survey,with collected previous data,the authors divide the geotectonics of Myanmar into 5 first-ordered tectonic units,including 10 second-ordered tectonic units. They are,from west to east,1)West Kachin-Pakhine suture zone(E-N1)(Ⅰ),with Chin-Pakhine suture zone(E-N1)(Ⅰ1)and West Kachin suture zone (E-N1)(Ⅰ2);2)West Myanmar-Pulau Sumatera arc basin system(E-N1)(Ⅱ),with Monywa-Pathein island arc belt (E-N1) (Ⅱ1),Shwebo-Yangon back-arc basin (E-N1) (Ⅱ2)and Myitkyina back-arc basin (E-N1) (Ⅱ3);3) Tengshong-Kra Peninsula orogenic belt(T3-K)(Ⅲ),with Bhamo continental marginal arc(T3-K)(Ⅲ1),Mawiamyine continental marginal arc(T3-K)(Ⅲ2)and Tanintharyi block(Pz2)(Ⅲ3);4)Baoshan-Shanbang landmass( -T2) (Ⅳ);and 5)Changning-Menglian-Chiang Let suture zone (C-T2) (V). The tectonic units are bounded by 9 faults, which,from west to east,are:Naga Yoma-Rakhine Yoma thrust fault (F1),Pinlebu-Pye extensional faults (F2), Sagaing-Bago dextral strike-slip fault (F3),Putao-Kadu thrust fault (F4),Ringhkung-Phamo extensional faults(F5), Namhkam-Mogok dextral strike-slip fracture (F6),Mandalay-Bago sinistral strike-slip fracture (F7),Xidang-santa sinistral strike-slip fracture(F8)and Mong Ping-Chiang Mai thrust fault(F9).