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Subsidence Field Observations <br />West Elk Mine <br />July 22-24, 2003 <br />4.3.3 Traverse P-P' <br />Traverse P-P' is a vehicle traverse beginning on the main access road near Apache Rocks and <br />ends at the boundary of the map. <br />• The traverse extends northward across mined-out longwall Panel 12, thence above the east- <br />west-trending main haulage and access entries, thence southward above the western part of <br />longwall Panel 12 and the northeastern part of mined-out longwall Panel 13. <br />• The material encountered was primarily colluvium and soil, and occasional sandstone and <br />siltstone of the Barren Member of the Mesaverde Formation. <br />• Overburden thickness to the B-Seam ranges from 1,150 to 1,350 feet. <br />• No subsidence cracks or bulges were observed. <br />Location 13: <br />This is the extensive subsidence crack area at Apache rocks. <br />• The cracks in the hard sandstone outcrop look much like they did on August 29, 2002 (Figure <br />16). However, the colluvium and weathered bedrock has caved and sloughed into some of <br />the widest cracks. This sloughing exposes more of these cracks to [he west that had <br />previously been covered up (Figure 17 and 17A). <br />• The exposed crack length now ranges from a few feet to as much as 300 feet. The width of <br />the cracks ranges from a fraction of an inch to as much as 3.5 inches. <br />831-032.610 W right W afar Engineers, Inc. Page 29 <br />' September 2003 <br />