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' Subsidence and Geologic Field Observations <br />Apache Rocks and Box Canyon Mining Areas <br />July 12-15, 2004 <br />' 4.3 Subsidence Observation and Evaluations for July 14, 2004 <br />4.3.1 Traverse M-M' <br />Foot traverse begins at a fork in drill road (L-L' traverse) above the eastern edge of mined <br />longwall panel 22 and ends at a point on the ridge between a south fork of Raven Gulch to the <br />north and Deep Creek to the south (Map 1). <br />• Traversed above the eastern edge of mined longwall panel 22, a stock pond (Pond P23-4, <br />Location 11), thence eastwazd above un-mined coal to an observation point for both the <br />eastern part of the Box Canyon mining area and the southeastern part of the West Flatiron <br />Lease. <br />• Traversed primarily in weathered bedrock of the Wasatch Formation clays and in local areas <br />of colluvium and soil. <br />• The overburden thickness to the B Seam ranges from 2,200 to 2,300 feet. <br />• No subsidence features were observed. Careful and extensive observations were made <br />azound Pond P23-4, because the pond and surrounding area is above the north-trending, rigid <br />pillars at the eastem edge of mined longwall panel 22 (Figure 14). <br />• Therefore, in theory, the pond area would be subjected to maximum static and permanent tilt <br />and strain (as opposed to dynamic and transient tilt and strain that occurs above a moving <br />longwall face). <br />Location 11: <br />Stock watering Pond P23-4 located above the eastem edge of mined longwall pane122. <br />• The pond is located in weathered clays and local alluvium and colluvium derived primarily <br />from the Wasatch (Figure 14). <br />831-032.640 Wright Water Engineers, Inc. Page 27 <br />September 2004 <br />