六盘水煤田湾田勘查区龙潭组下部可采煤层特征及沉积环境分析

Minable coal seams characteristics and sedimentary environment of Wantian exploration area in Liupanshui Coalfield in lower part of Longtan Formation

六盘水煤田湾田勘查区含煤地层龙潭组为一套早二叠世的海陆交互相沉积建造。根据勘查区钻探资料,龙潭组下部含可采煤层5层(26、27-1、29-1、29-2、32),对比可靠,岩性组合为细砂岩、粉砂岩、泥岩、煤层夹灰岩。综合分析认为该区龙潭组下部表现为三角洲—潮坪沉积体系,潮控下三角洲平原相沉积环境,沉积类型主要有分流潮汐水道、分流间湾、泥炭沼泽等。

Wantian exploration area of Liupanshui Coalfield is located in Longtan Formation,a coal-bearing formation and a set of marine-continental interactive sedimentary formation in the early Permian.According to the drilling data in the exploration area,there are 5 minable coal seams(No.26,27-1,29-1,29-2 and 32) in the lower part of Longtan Formation,and correlation of coal seams shows a good reliability.The lithologic combination includes fine sandstone,siltstone,mudstone,and limestone mixed with coal seam.Comprehensive analysis shows that the lower part of Longtan Formation in this area is characterized by delta and tidal flat sedimentary system,delta plain sedimentary environment under tide control,and sedimentary types mainly include distributary tidal channel,distributary bay,peat swamp,etc.