关键词: 鄂尔多斯盆地, 点碰撞, 中央古隆起, 数值模拟, 微板块

Abstract:

To reveal the formation mechanism of the Carboniferous slender-waist-shaped central paleouplift in Ordos Basin, a series of stress-strain simulations were carried out，in which the basin was simplified into an isopachic, isotropic and elastic shell model and loaded with the NS trending extrusion.The positive strain along Z axis (εz) corresponded to the uplift, and the shape of positive εz isoline represented that of the uplift. Repeated simulations showed that the outline of positive εz isoline always appeared slender-waist shape along the maximum stress axis，which approved that the central uplift resulted from stress transfer in the Ordos Basin under the NS trending extrusion.Moreover, the shape of the positive εz isoline caused by the point force was narrow, while that by the  linear pressure was relatively wide in the simulations.Since the shapes of εz isoline induced by the linear pressure was less analogical to the geological uplift in the Ordos Basin, the linear pressure was less reasonable than the point force, which may represented the point collision between microplates or arc-continent collision during Carboniferous.

Key words: Ordos Basin, point collision, central paleouplift, numerical simulation, microplate