鸡西盆地梨树镇坳陷城子河组成煤环境及其对煤层分布的控制作用

COAL-ACCUMULATING ENVIRONMENTS AND THEIR CONTROLS ON THE COALBED DISTRIBUTION IN CHENGZIHE FORMATION OF LISHUZHEN DEPRESSION OF JIXI BASIN

鸡西盆地是黑龙江省东部重要的含煤盆地,盆地内煤和煤层气等矿产资源十分丰富.煤层是煤矿及煤层气赋存的主体,其分布受控于成煤环境.前人围绕野外露头和煤矿区开展了一些沉积相和层序方面的研究,但对成煤环境认识较为笼统.从岩心、测井等资料出发,通过对鸡西盆地南部梨树镇坳陷沉积演化、沉积体系和成煤环境以及控煤作用深入研究,揭示研究区发育有3种成煤环境,即湖沼、曲流河河漫沼泽和三角洲平原沼泽.其中：湖沼相和三角洲平原沼泽相富煤,煤层分布广、厚度较大,是最有利的成煤环境;曲流河河漫沼泽煤层发育较差,煤层较薄,分布局限,是较不利的成煤环境。

Jixi Basin is the one of the important coal-bearing basins in East Heilongjiang Province,for the mineral resources such as coal,coalbed methane and so on are pretty rich.The coalbeds are the hosts of the coal deposit and CBM reservoir,their distributions are controlled by the coal-accumulating environments.The previous researchers have carried out some researches about the sedimentary facies and sequence in the field outcrops and coal mining area,but the understandings about the coal-accumulating environments are relatively limited and incomplete.From the viewpoints of the core,well logging data and so forth,by means of the deep studies on the sedimentary systems and evolution,coal-accumulating environments and coal-controlling actions for South Lishuzhen Depression of Jixi Basin,three kinds of the well-developed coal-accumulating environments are explored：limnetic facies,meandering-river flood swamp facies and delta plain swamp facies.Among the above three,the first and last ones are rich in coal and characterized by wider coal distribution and pretty thicker coalbeds,so the coal-accumulating environments are the most favorite; the rest is featured by rather thin and less well-developed coal seams,limited distribution and rather unfavorable coal-accumulating environments.