楚雄复式盆地演化及形成的动力学机制

楚雄盆地处于中国云南省中部，位于扬子板块西南缘，南西界以红河断裂为界与哀牢山造山带相连，北西界为程海断裂，东边为绿汁江断裂。盆地基底包括结晶基底和褶皱基底双重结构。盆地内发育了中三叠世以后的沉积盖层，西部中三叠世和晚三叠世早、中期为海相沉积，晚期为海陆交互相和陆相沉积；盆地东部为陆相沉积。侏罗—白垩纪整个盆地为巨厚的陆相沉积。楚雄盆地的构造格架分为４个带：（１）哀牢山造山带；（２）褶皱逆冲带；（３）中部沉降带；（４）东部隆起带。盆地形成与演化分为六个阶段：（１）被动大陆边缘沉降阶段；（２）拉张热隆起边缘——裂谷盆地阶段；（３）沟－弧－盆系阶段；（４）残洋－周缘前陆盆地阶段；（５）走滑－拉张盆地阶段；（６）走滑－挤压－改造阶段。楚雄盆地的形成与演化体现了盆地动力学性质转化和复合，在多种动力系统作用下或经过多旋回构造阶段产生了复式盆地

THE DYNAMIC MECHANISM FOR THE FORMATION AND EVOLUTION OF THE CHUXIONG COMPOSITE BASIN IN YUNNAN

The Chuxiong Basin located in central Yunnan on the southern margin of the Yangtze plate is bounded on the southwest by the Honghe fault,on the northwest by the Chenghai fault,and on the east by the Liizhijiang fault.The basement of the basin consists of the two-storied architecture of crystalline and folded basement,upon which there exist a se-quence of sediments as the sedimentary cover ranging in age from the Middle Triassic to Recent:the marine sediments during the Middle Triassic and early and middle Late Trias-sic 5 the alternating terrestral-marine sediments during the late Late Triassic in the western part of the basin;the terrestrial sediments in the eastern part of the basin,and the thick terrestrial sediments throughout the basin during the Jurassic to Cretaceous. Tectonically,four zones may be distinguished for the Basin.They are the Ailaoshan orogenic zone,fold-thrust zone,central subsidence zone and eastern uplifted zone.The basin has experienced six stages of evolution,i.e.the passive continental margin subsidence phase,extensional thermal uplift margin-rift basin phase,trench-arc-basin system phase, remnant oceanic-peripheral foreland basin phase,strike-slip and extensional basin phase and strike-slip-compression-reworking phase.The formation and evolution have reflected the transformation and combination of the dynamic regimes of the basin.The composite basin was just formed through multiple processes of dynamic systems and polycyclic tec-tonic stages.