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2005 Subsidence and Gootogrc Field Observations <br />Box Canyon, West Flatiron. Apache Rocks, <br />end Souln of Divide Mlning Areas <br />Fj' "R <br />i~ <br />r <br />.d ;, ~ <br />Figure 11. Westward view of a subsidence crack In <br />the road cut of the main dell road to West Flatiron. <br />Note that the crack width decreases downward Irom a <br />to 6 inches in the soil above the bedrock to a closact <br />fracture at the base of the sandstone outcrop. <br />4.11 Traverse J-J' <br />Traverse 1-J' is a tout tra~crse hegintnne at stark Ixmd P2±-~l (h>L.ated ahuvc the eas[ern solid <br />coal huundarv of mined lungwall panel ?2). The traverse continues nonhrtstward along a ridge <br />underlain by weathered Clays and local culluvtum of the 1b'asatch Formation, and massisr <br />sandstones ut Cho Ohio Crcck ~lcmtxr u( the Mesavcrdc Formation. to an ohscrvatiun point <br />u~erlouking thr western pan of the West Flatiron mining ana (Ltwatiun 111. <br />l,a•ul cracks. similar to thosx observed alxwe un•mined coal un the. nartow ridges of ',`,'cst <br />Flatiron, wen hxally observed on this traverse. In addition, hxal irregular, hranching and <br />converging desiccation cracks, as much as I inch weir, were also observed. <br />837.032.710 Wnghl Water Engmeors, Inc. Page 2s <br />November 2005 <br />