永夏煤田可采煤层发育特征与沉积控制

Development characteristics and sedimentary control of mineable coal seams in Yongxia coalfield

为系统了解永夏煤田煤层发育特征,对永夏煤田以往地质资料进行综合统计分析,结果表明,研究区可采煤层为山西组的二2煤层、下石盒子组的三2煤层和三4煤层。其中,二2煤层是主力可采煤层,区内大部分可采,结构单一,层位稳定,平均厚度2.67m;其他可采煤层均为局部可采,结构复杂,含1层到多层夹矸,平均厚度1.08~1.46m,煤层稳定性相对较差。可采煤层形成于两大沉积体系,即二2煤层以下的潮坪-潟湖沉积体系和二2煤层以上的三角洲沉积体系,煤层厚度和煤层结构主要受研究区内泥炭沼泽持续发育时间、基底形态、碎屑物供给及河流冲刷作用等因素影响。

In order to investigate the development characteristics of mineable coal seam of the Yongxia coalfield,this paper systematically analyzes previous geological data of the study area.The results show that the mineable coal seams in study area are二_(2) coal seam of the Shanxi formation and三_(2) coal seam and三_(4) coal seam of the lower Shihezi formation.二_(2) coal seam is the main mineable coal seam.It is minable in most areas with single and stable structures and the average thickness is 2.67 m.The others are locally mineable,they are generally 1.08-1.46 m thick,poorly stable,and have complex structure with 1 layer to multi-layer gangue.The minable coal seams are formed in two major sedimentary systems,which are the tidal-lagoon sedimentary system below二_(2) seam coal and the delta sedimentary system above二_(2) coal seam.The thickness and structure of coal seams are obviously affected by persistent development time and basement morphology of peat marshes,debris supply,and river scouring.