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Subsidence and Geologic Field Observations <br />Apache Rocks and Box Canyon Mining Areas <br />July 12-15, 2004 <br />4.3.5 Traverse Q-Q' <br />Foot traverse from fork in trail (P-P') to Drill Hole SOM 46. <br />• Traversed above mined longwall panel 13. Colluvium, soil, weathered bedrock were <br />exposed along the trail. <br />• Overburden thickness to the B Seam ranges from 1,200 to 1,300 feet. <br />• No subsidence features were observed, except at Location 15, described below. <br />^ <br />Location 15: <br />A number of fresh subsidence features (cracks and bulges) were present in a friable sandstone <br />outcrop at this location 5 years ago. <br />• Numerous cracks, some as much as 1.5 inches wide, were observed in 1999 (see Figures 5 <br />' and 6 of the 1999 report). All but one of these features is now sealed up by sloughing, <br />erosion, and filling. <br />' Overburden depth to the B Seam is about 1,200 feet. <br />' The only visible crack trends northward, is about 0.25 inch wide, and is 1.5 feet long <br />(Figure 19). <br />' 831-032.640 Wright Water Engineers, Inc. Page 35 <br />September 2004 <br />