塔里木盆地圈闭形成的主控因素及展布特征

Dominant Factors of Trap Formation and Their Distribution Charateristics in Tarim Basin

塔里木盆地圈闭类型十分丰富。塔里木盆地不同方向的几组构造带或构造圈闭区，分别受加里东期、早海西期、晚海西—印支期、燕山—喜马拉雅期构造运动的影响而形成。非构造圈闭如地层削截、地层超覆尖灭、岩性、相变带、盐体边缘下陷充填等圈闭，是在特定的区域构造背景条件下，受沉积作用、成岩作用、不整合等因素控制的产物。在漫长的演化过程中，经历了多期构造活动，形成了大型的古隆起、古斜坡及坳陷带，并使这些隆起、斜坡及坳陷带发生横向上与纵向上的构造迁移、叠加和改造，为形成多种类型的非构造圈闭提供了优越的地质背景条件。复合型圈闭是构造活动与沉积作用共同控制的产物，随着隆起在横向上的不断迁移，沉积实体随之改变，在隆起的高部位地层遭受强烈剥蚀，堆积和充填在隆起的侧翼及相对较低的位置，形成构造、不整合、地层尖灭和岩性圈闭。

： The types of traps in Tarim Basin are abundant． Several groups of structural belts or structural trap zones in Tarim basin are formed under the influence of Caledonian， early Hercynian， late Hercynian－ Indo－China， Yanshan－Himalayan orogeny respectively． Non－structural traps such as formation truncation， formation overlapping pinchout，lithology， factes－changing belt， salt－body marginal depression and infilling etc． are the result of sedimentation， diagenesis， unconformity under the specific regional tectonic settings． During the prolonged time of evolution， through multistage structural activities， large palaeohighs， palaeoslopes and geotectogene were formed， which underwent horizontal and vertical structural migration， superposition and reconstruction， providing favorable geological settings for formation of multi－type non－structural traps． Combination traps are the result of joint control of tectonic activities and sedimentation． As the uplifts migrated constantly in horizontal direction， the depositional body varied with them， and the upper formations suffered from intense corrosion， while accumulating and packing in the flanks and lower parts of the uplifts，forming structural， unconformity， stratigraphic pinchout and lithological traps．