鄂尔多斯盆地早古生代波状构造及其古地理意义

Wave Structre in Paleozoic Era of Ordos Basin and Its Significance in Paleogeography

波动是地质作用的基本形式之一 ,地壳的波状运动和变形是客观存在的。用波动论对鄂尔多斯盆地早古生代构造、沉积与古地理进行了探讨 ,将鄂尔多斯及邻区早古生代波状构造单元划分为 :阴山波谷带、伊盟波峰带、中部波谷带、渭北波峰带、北秦岭波谷带、阿拉善波峰带、贺兰波谷带、中央隆起波峰带、东部波谷带、苛兰波峰带。东部波谷带与中部波谷带的复合形成了东部波谷复合区。早奥陶世马家沟期东部盐洼区就是该波谷复合区的产物。在该复合区还形成鄂尔多斯盆地最为重要的下古生界烃源中心。中央古隆起波峰带与中部波谷带相复合形成定边波峰波谷复合区 ,使得中央古隆起在定边一带呈现出鞍状形态 ,从而合理解释了中央古隆起向北延伸至定边一带“断掉了”这一现象。

Undulation is one of the fundamental models of the geological effect ,the undulation motion and variation in shape of earth crust is an geologic facts. In this paper,the undulation theory is applied to discuss the structure,deposit and paleogeography pattern of Paleozoic of Ordos Basin.The units of wave structure of Ordos and its neigbhouring areas are divided as:Yinshan wave trough,Yimeng wave crest,Central wave trough,Weibei wave crest,Qingling wave crest,Alashan wave crest,Helan wave trough,Central doming wave crest,Eastern wave trough and Kelan wave crest structure belt.The compound of Central wave trough and Eastern wave trough formed eastern salt depression.This area has also formed the big center of hydrocabon source that are the most important in under Paleozoic group of Ordos Basin.Central doming wave crest structure belt and Central wave trough structure belt were formed Dinbian compound areas,which make the central doming appear saddle in Dinbian.It also reasonably explains the phenomenon that Central doming is suspended in Dinbian area.