一、引言湖北省云梦、应城、京山、安陆诸县,广泛出露大片红色地层。它们具有共同的发育史。其形成,受着相同地质因素的控制。此红层分布区位于江汉中-新生代拗陷区东北部,是一个具备一定独立性的次级凹陷单元,称为云应凹陷。云应凹陷北接淮阳地盾,南跨南大巴山-大洪山台褶带。就在这两个刚柔悬殊的地质体衔接之处,经过燕山运动的强烈改造之后,从早白垩世开始,形成了这个陆相红色沉积盆地。云应凹陷的红层露头并不连续,较大面积分布的红色地层见于(京山县)宋河地区、(安陆县)雷公店地区及有玄武岩与红层互层产出的安陆县城附近地区。而其中又尤以宋河地区出露最为完整与连续。总观云应凹陷的红色沉积,其分布具有明显的规律性。即自西北及沿前白垩系老山 I. INTRODUCTION Yunmeng, Yingcheng, Jingshan and Anlu counties in Hubei province have exposed a large amount of red stratums. They share a common developmental history. Its formation, subject to the same geological factors control. This red layer is located in the Jianghan - Cenozoic depression northeast, is a certain independence of secondary depression units, known as Yun Ying depression. Cloud should be hollow north of Huaiyang shield, south of South Daba Mountain - Dahongshan platform fold belt. Just after the convergence of the two gentle and soft geologic bodies, after the strong transformation of the Yanshan movement, the continental red sedimentary basin was formed from the Early Cretaceous. The red layer outcrops in the Yunying depression are not continuous. The red beds distributed over a large area are found in the Songhe area (Jingshan County), the Lei Gongdian area (Anlu County), and the Anlu county where there is an interbedded layer of basalts and red beds area. Among them, Songhe area is the most complete and continuous. The total cloud should be recessed red sediments, the distribution has obvious regularity. That is, from the northwest and along the former Cretaceous Laoshan