阜新盆地王营矿区煤系沉积环境及聚煤特征

Coal Measures Sedimentary Environment and Coal Accumulation Features in Wangying Mine Area,Fuxin Basin

运用沉积学和煤地质学原理,通过对王营矿区岩石的结构、古生物化石、垂向层序和沉积断面特征等方面的综合分析,从煤系中识别出湖泊相、扇三角洲相、冲积扇相、河流相和沼泽相。认为矿区东南部阜新组高德段沉积期主要为萎缩的湖泊-扇三角洲环境;阜新组高德段主采煤层由湖泊淤浅泥炭沼泽化形成,其他各段主采煤层形成于网结河周期性衰退或消亡阶段的冲积扇前泥炭沼泽,一些不稳定的薄煤层及煤线则为湖滨或网结河湿地中局部的泥炭沼泽产物;泥炭沼泽的发育面积与同时期冲积扇的发育程度呈消长关系。

Using sedimentology and coal geology principles,through comprehensive analyses of rock structure,paleontologic fossils,vertical sequence and sedimentary sectional features in the Wangying mine area,thus the lacustrine,fan delta,alluvial fan,fluvial and swamp facies in the coal measures have been identified.The study has considered that,during the depositional stage of the Gaode Member,Fuxin Formation in the southeastern mine area was in a shrinking lacustrine-fan deltaic environment;main mineable coal seams in the member were formed in silting lake peat bog,while main mineable coal seams in other members were formed in alluvial fan front peat bogs during anastomosing stream periodically waning or extinct stage.Some unsteady thin coal seams and streaks were formed in local peat bogs in lake shore or anastomosing stream wetlands.The relation between development area of peat bogs and simultaneous fluvial fan development is reciprocal.