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SPRING 2007 Subsidence and Geologic Field Observations <br />Box Canyon, and South of Divide Mining Areas <br />whereas comparative photographs taken in previous years are included as figures in Appendix C <br />and referred to in the report text with a preceding letter "C" before the figure number. <br />5.1 Traverse A-A' <br />Traverse A-A' begins at well site E-Seam Methane Exploration Well No. I over mined longwall <br />panel 13 and ends at the fork in the drill roads (at B of Traverse B-B') above the southern edge <br />of mined longwall panel 14. <br />Traverse A-A' winds its way above mined longwall panels 13, 13A, 17, 16, 15 and 14. Light <br />gray to brown soil, colluvium, and local outcrops of siltstone and sandstone of the Barren <br />Member of the Mesaverde Formation occur in the road cuts. Overburden depth to the B-Seam <br />varies from 1,000 to 1,650 feet. <br />One small soil/colluvial failure in the road cutbank was noted at Location 1. <br />5.1.1 Location 1 <br />At Location 1, the upgradient (cutbank) side of the road has failed on a relatively steep slope of <br />what appears to be an old landslide deposit along several hundred feet of road both to the east <br />and west (Figure 5). The failure occurred in an area above the unmined coal barrier pillar near <br />the southeast corner of mined longwall panel 13 in the uppermost portion of Sylvester Gulch. <br />Overburden depth above the B-Seam at this location is approximately 1,200 feet. A second <br />location, approximately 150 feet east of Location 1, shows some evidence of landslide <br />reactivation (i.e., some observed cracking and bulging) in the road cutbank. Given the period of <br />time that has elapsed since mining last occurred in this area (i.e., about 6 years), it is believed <br />that this failure is the result of springtime gravitational stresses on an over-steepened slope cut <br />by a drill road. <br />831-032.780 Wright Water Engineers, Inc. Page 11 <br />July 2007 <br />