试述北京西山古裂谷构造演化程式

On the Evolution Model of Structure of Palaeorift in Beijing West Hill

北京西山是中生代的一个大陆裂谷盆地，盆地中堆积了厚达８０００余米的火山熔岩、火山碎屑岩和含煤碎屑岩，具有穹窿—火山型裂谷的特点，经历了早侏罗世至中侏罗的伸展期、晚侏罗世至早白垩世早期的膨胀期和早白垩世晚期至晚白垩的萎缩期三个不同的演化阶段．西山古裂谷的形成既受到西伯利亚板块与华北板块碰撞作用的影响，更受到库拉板块活动的控制．

Beijing West Hill was a continental rift basin having pyroclastic lava, pyroclastic rock and coal detrital rock with a total thickness of about 8000m in Mesozoic era. It experienced three different periods: extending period (J1—J2), expanding period (K1—K2), and shriveling period (K2—K3). It has characters of domevolcanic rift valley, its development was controlled by Kula plate and was bound up with collision of North China and Siberia plates.