关键词: 库车再生前陆逆冲带, 生长褶皱, 生长地层, 倾斜剪切恢复, 膝折带迁移, 翼旋转

Abstract: The Kuqa rejuvenation foreland thrust belt is one of the most important regions in the north flank of Tarim Basin for hydrocarbon exploration.The exploration results show that almost all hydrocarbon traps are anticlinal ones.Therefore,it becomes more important for researching on the evolution of folds in the Kuqa rejuvenation foreland thrust belt.Unfolding of inclined-shear restoration of growth folds is the anti-process of folding.Syntectonic sediments record clearly the detailed processes of folding and faulting.Therefore,the geometry of fold of every stage can be restored by analyzing the geometry of syntectonic growth strata.Then analyses on the changes of limb length,limb dip and axial surface dip can conclude the mechanics of the fold.Inclined-shear restoration techniques can be used to check the interpretations of seismic profiles,well data and surface geology.During inclined-shear restoration of growth fold,the restored profiles ought to be geologically reasonable.The inclined-shear restoration technique to process the growth folds that are interpreted on the seismic profiles was applied to restore the growth folds in the Kuqa rejuvenation foreland thrust belt systematically and carefully.The inclined-shear restoration results show that the Misibulake anticline was formed through limb rotation with limb increasing after starting before 24.5 million years.The Yiqikelike anticline through kink band migration with constant dip of limb and increasing limb length started before 16.9 million years.The Dawanqi anticline through limb rotation with constant limb length and increasing limb dip started before 3.1 million years.The Kuqa rejuvenation foreland thrust belt,including mechanics of fault-bend folding,fault-propagation folding and detachment folding,grows and propagates forward and southward by limb rotation and kink band migration in the Kuqa structure.The fold growth age is in accordance with timing of hydrocarbon generation and migration in Kuqa.The folds are ideal natural gas trap structures.

Key words: Kuqa rejuvenation foreland thrust belt, inclined-shear restoration of growth fold, growth strata, kink band migration, limb rotation