火山活动对彝良向斜煤矿区成煤环境的影响

依据彝良向斜煤矿区钻孔资料,峨眉山玄武岩之上的宣威组底部广泛分布着数层厚薄不一的凝灰质泥岩,煤层夹矸中有火山蚀变成因矿物组成的粘土岩,这些火山活动所形成的玄武岩、凝灰质泥岩、煤层粘土岩夹矸在时空分布特征上反映了火山活动的规律,火山活动控制着区域沉积环境及成煤环境的演变。研究区自西向东受火山活动的影响逐渐减弱而使东部的含煤性优于西部,煤层的分布与火山活动痕迹呈此消彼长的关系,反映了火山活动的逐渐减弱使得宣威晚期逐渐形成了稳定的成煤环境。因此,研究区东部宣威组上段地层是煤炭资源进一步勘查的重点。

Impact from Volcanic Activities on Coal-forming Environment in Yiliang Syncline Coalmine Area

Based on drilling data in the Yiliang syncline coalmine area, some layers of tuffaceous mudstone with different thicknesses have widely distributed in the bottom part of the Xuanwei Formation above the Emeishan Basalt, and in coal seams contain claystone gangues formed by volcanic altered minerals. Distribution characteristics of basalt, tuffaceous mudstone and coal seam claystone gangue formed by volcanic activities have reflected the regular pattern of volcanic activities. While the evolution of regional depositional environment and coal-forming environment were controlled by volcanic activities. The impact from volcanic activities is decreasing from west to east in the study area, thus the coal-bearing property in the east part is superior to the west part. The growth and decline of coal seam distribution and volcanic activity imprints have reflected the gradual weakening of volcanic activities and made a steady coal-forming environment during the Late Xuanwei Age. Thus, the Upper Member of Xuanwei Formation in the east part is a prospect area for further coal resource exploration.