准南前陆冲断带构造特征及其对油气成藏的影响

自晚古生代以来,准噶尔盆地先后经历了海西、印支、燕山和喜马拉雅多期构造运动,伸展、挤压、剪切等构造作用交替进行,多旋回构造发展造成多期活动、类型多样的构造组合,形成了众多不同级次的断裂,发育了许多不同类型的褶皱构造,特别是准噶尔盆地南缘,受天山造山带及邻区构造演化控制,多期不同类型盆地和构造变形叠加,使得准南前陆冲断带断裂发育、构造复杂。指出受新近系以来的强烈冲断构造变形作用,准南前陆冲断带具有自南向北扩展的复杂多变的新生代逆冲挤压构造和埋藏式的冲断楔前缘,发育台阶状逆断层及各类断层相关褶皱,具有“东西分段、南北分排”的特征;造山带隆升时产生的力源在释放过程中克服的阻挡对象不同,导致冲断带东段、中段、西段不同的构造具有相似的构造变形特征的同时又表现出一定的差异。

THE TECTONIC CHARACTERISTICS ON THE FORELAND THRUST BELT AND ITS INFLUENCE ON RESERVOIRING OF OIL AND NATURAL GAS IN SOUTHERN JUNGGAR BASIN

The Junggar basin suffered multiple stage-times tectonic movements successively in Hercynian epoch,Indo-chinese epoch,Yanshan epoch and Himalayan epoch since late Paleozic era,stretching,pressing and cutting etc,tectonic actions happened by turns,multiple gyre tecnotic evolution resulted in the structure assemblages with various patterns and be activated for long time,which caused numerous faults with different scale and folds with various styles to be formed.In particular,Under the control of the evolutions of Tianshan orogenic zone and its adjacent area,various basin-styles and structure distortion in multiple stage-times were piled up,abundance of faults and complex structure were produced accordingly in the Forland thrust belt in southern Junggar basin.Here are complexities of structure features of the Foreland thrust belt in southern Junggar basin be pointed out.Because of the effect of compression deformation and thrusting intensely in late Tertiary era,there were provided with complex and changeable Cenozoic thrusting and pressing structures and buried preceding thrust-wedge,step reverse thrust and all kinds of folds related to fault in turn from south to north,these characteritics displays "classified some segments from west to east,classified some rows form south to north".The power from the rise of orogenic belt needs to conquer different obstructs while it be released,which leads to these structure put up similar deformation feature but quite a few difference between the eastern segment,middle segment and western segment in the thrust fault zone.