准噶尔盆地车排子-莫索湾古隆起的形成演化与成因机制

Development and genetic mechanism of Chepaizi-Mosuowan uplift in Junggar basin

准噶尔地块是在前寒武纪"微"地块与环绕它的早古生代陆缘增生褶皱带的基础上经历石炭—二叠纪过渡阶段的构造演化之后固结形成的新克拉通地块。准噶尔盆地是在这一"新克拉通"之上发展起来的克拉通内坳陷盆地(T—E)与前陆盆地(N—Q)相叠加而成的叠合沉积盆地。周缘边界断裂带的多期活动与基底的非均一性使该"新克拉通地块"在后期活动强烈,集中表现在准噶尔盆地腹部于中—晚侏罗世形成了一个大型的SWW-NEE向的车排子-莫索湾隆起。该隆起经历了燕山早期(J1s)初始发育、燕山中期(J2x,J2t)强烈发育并定型、燕山晚期埋藏隐伏和喜马拉雅期掀斜消亡的完整过程。它是在中—晚侏罗世区域压扭背景之下,受周缘边界断裂带活动的控制,侏罗—白垩系构造层和石炭—三叠系构造层上下拆耦,发生镜像旋转而形成的压扭性构造带,为一形态不规则的复合性质隆起。车排子-莫索湾隆起对沉积与油气成藏有明显的制约作用,其两翼发育了一系列岩性、地层圈闭,目前发现了石南21、石南31、莫北、莫西庄和永丰等多个大中型油气田。车排子-莫索湾隆起将是准噶尔盆地腹部下一步岩性、地层油气藏勘探的重要领域。

The Junggar continental block is a neo-cratonic block that developed on the basis of the pre-Cambrian ＂micro-＂ continental block and its surrounding Early Paleozolc continental marginal accretion fold belts, and experienced the tectonic transitional development in the Carboniferous-Permian period. The Junggar basin is a superimposed depositional basin developed on the ＂neo-craton＂, which resulted from the superposition of the intracratonic depression of the Triassic to the Paleogene （T-E） and the foreland basin of the Neogene to the Quaternary （N-Q）. The multi-stage activities of surrounding fault belts and the heterogeneity of basement had led to strong activities of the ＂neo-cratonic block＂ in the later stages, resulting in the development of a large- scale SWW-NEE-trending Chepaizi-Mosuowan uplift in the interior of the Junggar basin in the Middle and Late Jurassic. This uplift has experienced a complete process--the initial development in the early Yanshanian period （Jts）, rapid growing and shaping in the middle Yanshanian period （Jzx, Jzt）, buried in the late Yanshanian period, and tilting and destructed in the Himalayan period. Controlled by the activities of the surrounding fault belts under the regional transpression of the Middle and Late Jurassic, it has been an image-like rotated transpressional structural belt, a composite uplift with an irregular shape, owing to the decoupling of the overlying Jurassic-Cretaceous structural layer and the underlying Carboniferous-Triassic structural layer. The Chepaizi-Mosuowan uplift had a marked influence upon the deposition and oil and gas accumulations. A series of lithologic and stratigraphic traps have developed on the two slopes of the uplift. Currently, a number of large and medium-sized oil and gas fields have been found in the area, such as Shinan-21, Shinan-31, MobeL Mox izhuang, and Yongfeng. The Chepaizi-Mosuowan uplift will be an important area for oil and gas exploration of the lithologic and stratigraphic plays in the interior of the Junggar basin at the next stage.