吐哈盆地HYS反转构造及其平衡演化

吐哈盆地HYS构造从晚中生代至新生代经历了拉张伸展期、挤压抬升期、伸展拗陷期和强烈挤压褶皱期等演化阶段。拉张伸展期盆地引张伸展，断层为正断层，形成半地堑式构造单元；挤压抬升期，盆地受挤压抬升，断层活化为逆断层，伴随产生弱压缩褶皱；伸展拗陷期盆地再次引张伸展，断层转化为正断层，盆地呈拗陷沉降；强烈挤压褶皱期，受挤压应力场的作用，断层又活化为逆断层，并伴随断层产生相关的褶皱，形成了正反转构造和复杂的地层构造关系。后期的强烈挤压褶皱反转虽然形成了油气的聚集场所，但同时又破坏了构造圈闭的完整性及其保存条件，不利于构造油气藏的形成。

HYS inversion structure in Tuha basin and its balance evolution

During late Mesozoic-Cenozoic, HYS inversion structure in Tuha basin underwent the following main tectonic evolution phases: tensile stretch, compressed uplifting, extensional depression and severely compressed folding. In tensile stretchphase, the basin stretched, and normal fault caused tectonic element of half grabenlike basin. In compressed uplifting phase, basin uplifted beacuse of compression,and norrnal fault became overthrust one, with weak folding. In the extensional depression phase, the basin stretched again, and overthrust fault turned into normalone, with depressive sediments in the basin. In the severely compressed foldingphase, normal fault changed to overthrust one again because of terrible compression, and folding happened near fault, resulting in positive inversion structure andcomplicated stratum relations. The late terrible folding and inversion createdfavourable geological structure for hydrocarbon accumulation; but they also damaged some whole structural trap and corresponding reserve conditions, which is unfavourable to the formation of structural hydrocarbon accumulation.