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Subsidence Over Limited Extraction Room and Pillar Mining Page 2 <br />Survey line One over the room and pillar section, with no retreat, shows significant <br />measurable surface movement. noting especially monuments 1-10 to 1-12. <br />Map B is the same area with a different scale. <br />Map C shows a typical section along the state highway, the depth from the surface <br />to the coal in this section is about 300 ft. According to Mr Snow there was <br />significant subsidence in these sections which effected the surface. there is a section <br />of the mine about 2000 ft east that is clearly marked " Do not pull pillars." <br />I am sorry that the Fax technology that I have avalable, does not lend itself to <br />sending these full size maps, but they do exist and they are available for review. <br />I realize that some of these facts are contrary to your observations and experience, <br />however earth science is not precise, if it were, earthquakes would be more <br />predictable. Faulting, lineaments, changes in the water table, and other aspects <br />may all effect the model as it apparently does in this coal area. <br />My conclusion is that measurable, significant, surface movements have occurred in <br />this region, over room and pillar mines with limited extraction, that is, mining <br />widths of 20 ft. ± and pillars that have widths of 60 to 80 ft and lengths commonly <br />over 100 ft. <br />For your information the sump pump situation has been thoroughly investigated by <br />the Geotechnical engineer, W. Attwooll, and his conclusion that it was not a factor. <br />