辽西地区中生代盆地构造演化

Tectonic evolution of Mesozoic basins in western Liaoning

辽西地区为华北地台北缘阴山 燕山造山带的东延部分 ,中生代发育火山 碎屑岩沉积盆地。盆地地质分析表明 ,该区在早白垩世早期之前发育的沉积盆地为挤压型盆地 ,早白垩世中期以后属伸展断陷盆地。根据沉积 构造分析 ,该区中生代盆地构造演化可划分为 5个构造演化阶段 :(1 )早三叠世—早侏罗世 ;(2 )早侏罗世—中侏罗世 ;(3 )中侏罗世—晚侏罗世 ;(4 )早白垩世早期 ;(5 )早白垩世中期—晚白垩世。

The western Liaoning is the eastern extension o f Yinshan-Yanshan orogenic belt,the northern margin of North China platform.Dur ing the Mesozoic period volcanic-sedimentary clastic basins were developed in t he region.The geologic analysis on basins indicates that basins developed prior to the early stage of Early cretaceous are of compressional type,while those dev eloped after the middle stage of Early cretaceous belong to extensional down-fa ulted ones.Based on the tectonic depositional analysis,the tectonic evolution of Mesozoic basins in the region can be divided into 5 stages:(1)Early Triassic-E arly Jurassic;(2)Early Jurassic-Middle Jurassic;(3)Middle Jurassic-Late Jurass ic;(4)Early stage of Early Cretaceous;(5)Middle stage of Early Cretaceous-Late Cretaceous.