Analysis and regional implication of cleat and joint systems in selected coal seams, Carbon, Emery, Sanpete, Sevier, and Summit Counties, Utah (SS-74)

By: B. P. Hucka This study is intended to help Utah coal operators plan longwall and room and pillar mining operations. Cleat and joint orientations were performed in 22 active mines located in the Book Cliffs, Wasatch Plateau, Emery, and Coalville coalfields in Utah. Since joints in mine roofs very often outline slabs or blocks which may bell if not properly supported, this study should help to improve the safety of mine workings. Further, the productivity of continuous miner operations can be improved if working faces are oriented parallel to the main cleans. The frequency of cleat distribution and orientation in the seams was investigated and the results of approximately 4000 field measurements are presented both as rose diagrams and contoured stereographic projections (Schmidt). This report also includes the macroscopic and microscopic (maceral inventory and rank determination) descriptions of coal seams, and addresses the extent of healing of cleat planes, sometimes respon