燕山构造带凤山盆地早白垩世的沉积过程

凤山盆地是燕山构造带内的一个早白垩世伸展盆地。盆地内沉积岩相和相组合的详细分析结果显示，盆地内部发育不同的沉积相带，并显示明显的空间变化。盆地北部和西部边缘以冲积扇砾岩和扇三角洲砂岩、砾岩沉积为主，盆地中心为湖泊细粒沉积。古流向和物源恢复结果证明，盆地沉积物主体来自北部和西部变质岩基底。盆地构造沉降和沉积过程主要受北缘和西缘张性断层的控制。断层下盘基底岩石的抬升与盆地边界正断层活动相关，从而成为盆地主要的物源区。凤山盆地的演化可划分为3个阶段，即早期火山喷发阶段、中期强烈断陷阶段和晚期填平阶段。

Early Cretaceous Depositional Process of the Fengshan Basin in Yanshan Structural Belt

The Fengshan basin is a well-preserved extensional basin in the Yanshan structural belt.There exist various sedimentary lithofacies that show obvious spatial variation.Alluvial fan and fan delta sedimentation dominated proximal areas of the northern and western basin margin,while fine-grained lacustrine sediments were prevalent in the basin centre.Sediments were demonstrated to have mainly come from metamorphic basements on the north and west.Tectonic subsidence and sedimentation were primarily controlled by the northern and western basin border faults.Uplift of base rocks of the footwall was due to the tilting of border faults and became main provenance areas.Sedimentary evolution of the Fengshan Basin can be divided into three stages:the first stage is featured by vigorous volcanic eruptions,the second by extensional subsidence and the third by sediment infilling.