曹家湾井田延安组成煤环境分析

Coal-forming environment of Yanan Formation in Caojiawan mine field

详细分析了宁夏曹家湾井田延安组的成煤环境及煤岩特征:岩性组合、可采煤层、厚度变化、沉积构造、物性特征、含煤系数等。井田含煤地层平均厚度440.61 m,含煤30余层,编号煤层平均总厚度18.90 m,含煤系数4.1%。延安组自下而上可分为5个岩段,其中第Ⅰ段沉积环境以河流体系的冲积平原相为主,含4层煤;第Ⅱ、第Ⅲ段和第Ⅳ段均为三角洲平原沉积体系,共含13层煤;第Ⅴ段为河流沉积体系,含5层煤。研究成果为该区煤炭资源勘探开发和综合评价提供参考。

Analyze the coal-forming environment and coal petrographic characteristics such as lithological combination ,minable coal seams, thickness variation, sedimentary structure, physical properties, and coal bearing ratio of coal bearing strata in Yanan Formation in Caojiawan mine field, Ningxia Province. The average thickness of Yanan Formation is about 440. 61 m, containing more than thirty coal-beds. The average total thickness of numbering coal seams is about 18.90 m, and the average coal bearing ratio is 4. 1 percent. Yanan Formation can be divided into five sections from bottom to top. The sedimentary environment of the first section is dominated by fluvial plain, containing five coal seams, the sections from the second one to the fourth one are delta plain sedimentary system, totally containing thirteen coal seams, the fifth section changes into fluvial facies again, containing five coal seams. The results provide references for the exploration, development, and overall evaluation of coal resources in this area.