【摘要】 本文首次确认在北京西山晚侏罗世后城组的客观存在，并就其岩石组合、发育特征、以及与下伏髫髻山组的接触关系进行了论述。通过区域对比，探讨了北京西山后城组的建立在研究西山地区中生代火山盆地的演化及其地层学等方面的影响和意义。更多还原

【Abstract】 It is affirmet for the first times in the paper that the Mesozoic Houcheng Formation is existed in the Western Hills of Beijing. Its rock associations,development features and its contact relations with the underlying Tiaojishun Formation are discussed.Based on the regional comparisons,writers probe that the influence and significance of establishment of the Houcheng Formation in the evolution and stratigraphy of Mesozoic volcanic-sedimentary basin in the Western Hills of Beijing.更多还原