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Subsidence Field Observations <br />West Elk Mine <br />August27-29,2002 <br />• Overburden thickness ranges from 1,500 to 1,650 ft. <br />• Cracks and fractures caused by construction activity were locally abundant. <br />4.1.3 Traverse C-C' <br />This traverse begins at the same point as the beginning of Traverse B-B' and thence extends <br />along the new drill road in the first west side canyon of Deep Creek south of West Flatiron. <br />• Traverses the eastern part of mined-out longwall Panel 15 and the northern part of un-mined <br />longwall Panel 16. <br />• The overburden depth to the B-Seam along traverse ranges from 1,100 to 1,650 ft. <br />• The road cut exposes mostly thick (6-15 ft) colluvium, with a thin soil layer at the top. <br />• The cracks observed above mined-out longwall Panel 15 were mainly related to construction <br />activities, rather than related to subsidence. The estimated ratio of subsidence/construction <br />caused cracks is 30%/70%. <br />4.1.4 Traverse D-D' <br />Traverse begins at the intersection of the ATV trail down the first Deep Creek drainage south of <br />West Flatiron and the new drill road to Drill Site 17-03 (Traverse I-I'), thence down the canyon <br />bottom to Deep Creek, thence northward along the Deep Creek trail. <br />• Traverse begins above the un-mined part of longwall Panel 16, thence across the surface that <br />is within the area of mining influence of mined-out longwall Panels 14 and 15. <br />• The overburden depth along traverse ranges from 950 to 1,150 ft above the B-Seam. <br />• No cracks of any kind were observed along this traverse. The traverse is in thick colluvium <br />and soil. <br />831-032.570 Wright Water Engineers, Inc. Page 8 <br />December 2002 <br />