陕西澄合矿区中深部4号煤层厚度变化原因

陕西渭北石炭-二叠纪煤田澄合矿区4号煤层是区内主要可采煤层之一。通过对区内煤层厚度与其上覆煤系厚度、煤中灰分、硫分及煤层顶板岩性-岩相等因素的相关性分析,结合4号煤层成煤期与聚煤期后环境分析,探讨了研究区及其周缘地区4号煤层厚度变化原因。结果显示:4号煤层厚度与上覆煤系厚度、煤中灰分及硫分均呈正相关关系,相关系数分别为0.810 1、0.430 9、0.813 6;该煤层发育于浅水型三角洲沉积体系的三角洲平原地带;煤层厚度变化受控于聚煤期同沉积构造和聚煤期后河流冲蚀作用的双重影响,前者使煤层厚度变化较小,后者对煤层厚度影响较大,甚至出现无煤带。 

The reasons for thickness changes of seam No.4 at medium depth in Chenghe mining area

Coal seam No.4 is one of the main mined seams in the study area. The research on the distribution of coal seam and its thickness change regularities as well as reasons provides the basis for coal resources exploration in next step and mine construction in the future. With the correlation analysis between coal seam thickness and other factors such as its overlying coal seam thickness, coal ash, sulfur and roof lithology, lithofacies etc., the paper investigated the reasons for the thickness change of coal seam in the study area and the surrounding area in combination with environmental analysis of coal seam No.4 during coal- forming period and coal-accumulating period. The results show that there is positive correlation between thickness of coal seam No.4 and its overlying coal measure thickness, coal ash and sulfur. The correlation coefficient is 0.810 1, 0.430 9 and 0.813 6. The coal seam No.4 was developed in the delta plain of shallow water delta, the thickness of coal seam was affected by syndepositional structures during the coal-accumulating period and river erosion after the formation of coal seam. Small changes of coal seam thickness is caused by the former factor, large changes of coal seam thickness caused by the latter, and even more seriously, there was non-coaliferous zone. In the process of peat accumulation, the coal seam thickness, ash and sulfur were reduced in the secondary uplift area; The coal seam becomes thicker in the secondary depressed area and coal ash, sulfur are higher.