2022-02-22_PERMIT FILE - C1980007 (5)

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West Elk Mine 2.04-34 Rev. 11/04- PR10, 04/06- PR10, 09/07- PR12, 10/08- PR14; 01/22- MR459 faults is found at the sandstone cliff faces along Minnesota Creek but is covered with alluvium and colluvium elsewhere. E Seam displacement is acknowledged to be 60 to 70 percent of the displacement of the B Seam along the same fault trace. Within the West Elk Mine coal lease area, the major cleat orientation within the F and B Seams trends approximately north 65 to 70 degrees east. This face cleat direction is prominent and consistent throughout the existing F and B Seam workings. Fracture sets and cleat orientations of the E Seam should generally be the same. Further to the north and west, the major cleat direction in the nearby Bear and Somerset mines is from north 70 to 75 degrees east. This direction is representative of the face cleat direction in the Jumbo Mountain area. Geologic Surface Features Prominent Fault and Fracture Zones In-mine geologic mapping, seismic surveys, low altitude air-borne magnetic surveys, and exploration drilling have been used to delineate the main fault and fracture systems within the West Elk Mine coal lease area. The effect of faults and fractures in roof rock is most serious when it is coincident with other geologic factors contributing to bad mining conditions. Prominent faulting, when coincident with weak roof shales, large damage zones, and roof and floor water, are important factors to consider in mine design and planning. These parameters were taken into consideration in the longwall panel designs for the B and E Seams in the West Elk Mine. Several fault and fracture studies have been conducted within the coal lease area at West Elk Mine. Aerial photography, LandSat imagery, and photogrammetric mapping have proven to be of limited success in revealing the major fault systems present in the coal bearing strata. The use of aerial photo mapping of drainages and topographic lineaments, and the common assumption that these features directly relate to the distribution and orientation of joints and fractures on the surface and in the subsurface, may not be true in this area. While it is true that most photo lineaments correspond to drainages and erosional features, the assumption that the drainages and erosion features are controlled by joint and fracture patterns, may or may not be true. Most major drainages in Western Colorado were established several million years ago in the Pliocene or Miocene in beds many hundreds, and possibly, thousands of feet stratigraphically higher and younger than the Mesaverde beds that are now exposed. Stress patterns and lithology at that time were significantly different than current conditions. As the younger beds were eroded, most drainages maintained established patterns. Several published fracture research papers (Lorenz, et al 1991; Lorenz and Finley, 1991; Grout and Verbeek, 1985; Diamond, McCulloch and Bench, 1975) indicate the problems of using photo-linears for fracture identification and in projecting that information into the subsurface. Of even greater significance to potential hydrologic consequences and the concerns of water moving vertically through the alternating sandstones, shales, mudstones and coals of the Mesaverde at the West Elk Mine are their conclusions concerning the vertical discontinuity of observed fractures in surface outcrops and sub-surface cores.