一、地貌及地质概况本区从地貌上看,为一近于东北一西南向的狭长形盆地。地势南高而陡,北低而缓,中乃是平坦的洼地。盆地南缘有一条大凌河,自西南流向东北,经过朝阳、义县和锦县而注入渤海。盆地南缘由震且纪石灰岩构成,北、西北及东北则由白垩纪页岩、砂岩、砂质页岩及侏罗白垩纪的火山岩系组成,盆地中部则沉积了厚而广的第四纪粘 First, the geomorphological and geological overview The area from the topography, as a nearly northeast-southwest of the narrow basin. The terrain is high and steep south, north and slow, but in the flat depression. There is a Daling River in the southern margin of the basin, which flows to the northeast from the southwest and flows into the Bohai Sea through Chaoyang, Yixian and Jinxian. The southern margin of the basin is composed of epithermal and limestone, Cretaceous shale, sandstone, sandy shale and Jurassic Cretaceous volcanic rocks are formed in the north, northwest and northeast. Thick and broad Quaternary viscous