京西木城涧矿区窑坡组沉积体系及相关聚煤因素

Yaopo Formation Depositional System and Related Coal-accumulating Factors in Muchengjian Mine Area, Beijing

通过实测剖面、岩矿鉴定、编制沉积断面图、砂体和煤层等厚图等资料分析,从京西木城涧矿区窑坡组中识别出湖泊沉积体系、河流沉积体系和沼泽沉积体系,并详细阐述了其成因相的岩相构成;在此基础上,指出窑坡组沉积早期为湖泊环境,主体沉积期为总体NE流向的网结河环境,其间伴随湖泊或河流周期性消亡而大面积泥炭沼泽化形成了稳定的可采煤层和含煤沉积旋回。富煤带总体呈NE50°～80°展布,与泥炭沼泽沉积期下伏不同沉积相的压实效应有关,后者通过影响地表起伏和积水深度,控制着泥炭的堆积速率和厚度。

Based on measured sections,rock and mineral examination results,sedimentary sections,sand body and coal seam thickness contour data analyses,identified lacustrine,fluvial and swamp sedimentary systems in the Yaopo Formation,Muchengjian mine area,western Beijing and expounded genetic lithofacies composition in detail.On this basis,pointed out the early depositional stage of Yaopo Formation was in a lacustrine mainly NE flow direction anastomosing river environment,attended by periodic wither away of lakes and rivers,large area peat swamping and formed stable mineable coal seams and coal-bearing sedimentary cycles.Coal rich zone mainly present NE50o～80o extending,related to the compaction effect of underlying different sedimentary facies during the stage of peat swamping,then impacted surface undulating and waterlogged depth,thus controlled peat accumulating rate and thickness.