鄂尔多斯盆地西缘北段沉降史与沉积响应

通过对鄂尔多斯盆地西缘北段沉降史的分析可知,晚三叠世-白垩纪,由于中三叠世巴颜喀拉地体、晚三叠世羌塘地体、中-晚侏罗世拉萨地块、白垩纪冈底斯地体连续向北增生、碰撞以及燕山期伊佐奈岐板块的俯冲,盆地西缘北段的响应显示为陆内前陆盆地的特征.受地体碰撞的影响,盆地西缘造山带发生幕式构造运动,从而导致盆地沉降也发生幕式变化.造山带每次挤压逆冲均导致相应的前陆盆地沉降和沉积物充填,并直接控制前陆盆地的沉积充填特征.

Subsidence History and Sedimentary Response in the North of Western Ordos Basin

Through the analysis of subsidence history in the north of western Ordos basin, as a result of the terranes northward accretion and the successive collision of the Baykala block in the Middle Triassic, the Qiangtang block in the Late Triassic, the Lhasa block in the Middle Jurassic, the Gangdese block in the Cretaceous and the subduction of Izanagi plate in Yanshanian period, the studied region became a intracontinental foreland basin from Late Triassic to Cretaceous. Because of the collision of the terranes, the episodic tectonic activity occurred in the orogenic belt, resulting in the episodic subsidence of the basin. Each compression and thrusting of orogenic belt led to the subsidence of the foreland basin and the sediment filling, directly controlling the filling sequences and sedimentary characteristics of the foreland basin.