【摘要】 大安古河道位于中新生代松辽沉降带上的中央凹陷区 ,第四纪壳运动以大面积继承性缓慢沉积为主。盖层包括白垩纪浅海相砂岩 ,第三系砂岩、泥岩及厚达 14 3m的第四系碎屑沉积。全新世粘土及粉细砂出露地表 ,对实施水利工程有利。区域地貌属松嫩冲积低平原 ,阶地海拔高度 14 0m左右 ,呈台状高地。古河道的主体嫩江河漫滩一般低于 132m ,平坦开阔 ,自然坡降 1 5 0 0 0～ 1 10 0 0 0 ,便于布置水利工程。古河道邻近嫩江和月亮泡 ,引水十分方便。排水可直泄查干湖 ,然后回归嫩江河谷 ;或者从三家子古河道出口排入嫩江河谷 ,均为可行。更多还原

【Abstract】 Da′an paleochannel is located in the central fallen area of Song-Liao subsiding belt which formed in the Mesozoic and Cenozoic, where the earth’s crust motion in the Quaternary period was mainly slow and successively extensive sedimentation. The cover layers consist of cretaceous sandstone forming in shallow sea, Tertiary system sandstone and mud stone and Quaternary system fragmental deposit stone, of which thickness is 143 m. That clay and mealy sand of Holocene were exposed to ground is in favor of constructing irrigation works. The area landform belongs to Songnen alluvial low plain. The altitude of terrace, which presented highland, is about 140m. The main body of paleochannels, namely Nenjiang flood land, is generally below 132m above sea level, which is even and widen. Natural grade from 1/5000 to 1/1000 is in favor of disposing constructing irrigation works. That the paleochannel nears to Nenjiang River and Moon Lake is convenient for using water, and the drainage can be discharged into Chagan Lake, then into the Nenjiang River,or discharged into the Nenjiang River at the Sanjiazi paleochannel pass.更多还原