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Subsidence end Geologic Field Observations <br />Apache Rocks entl Boz Canyon Mining Areas <br />July t2-15.2004 <br />• Traversed above mined longwall panels 13 and 13A in colluviunt, weathered bedrock, and <br />local outcrops of sandstone of the F3arren Memtxr of the Mesavcrde Formation. <br />• Overburden depth to the B Seam ranges from about 1,200 to 1,350 feet. <br />• No subsidence features were observed, except two crocks in sandstone at location 14 <br />(Figure S). <br />Location 14: <br />Location of two subsidence cracks in sandstone of the Marren Member of the Mesaverde <br />Formation. <br />• The cracks, which look about the same as last year (compare with Figure 13 of the 2003 <br />report), arc as much as 0.75.inch wide and 3 feet long. <br />• The cracks arc located above the approximate midpoint of mined longwall panel 13 in 1,300 <br />feet of ovcrbunlcn. <br />Figure 18. Subsidence cracks located in sandstone above the center of mined longwall panel 13. The <br />cracks ara as much as one inch witle and about 2 feel long. Their appearance is similar to last July. <br />831-032.840 <br />Septembor 2004 <br />Wnght Water Engmaers, Inc. Page 34 <br />