除西北區(qū)外，北京的侏羅紀(jì)含煤地層也很著名，稱為門頭溝煤系或門頭溝群，厚700～1 000m，自下而上包括杏石口組、南大嶺組、窯坡組和龍門組，其中南大嶺組為火山巖系，窯坡組為主要含煤層組。窯坡組一般厚400m左右，含可采煤4～9層，總厚可達(dá)10m。所含植物化石仍為錐葉蕨-擬刺葵組合，下部所含瓣腮類包括侏羅紀(jì)早期的分子，時代仍為早、中侏羅世。
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