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II West Slil=nains and Panel AA: <br />• Mined Length: 1200 feet of sutmain advance development west of South III <br />SUtroains and thrax~ first 4 crosscuts of Panel AA. 850 feet of <br />full pillar extraction retreat mining. <br />Overkxaden 'Ihic~aiess: Varying frcm approximately 1000 to 1350 feet. <br />MinirxJ Height: 9-il feet on advance; 15-18 feet on retreat. <br />Roof: Comprised of mudstones and sandstones with a hick concentration of pots <br />aryl slickensides. 'Ibp coal of 2-3 feet in tltiakness was left on the roof <br />to provide enhanced stability when possible. Mesh utilized in localized <br />areas where top coal not available. <br />Ribs: Rib slwc~~age was m; n;mal with ribs stardvg well. <br />Floor: The lower "D" seam was used as floor which provided conq~etent conditions. <br />Anat~alous Conditions: Upper "D" coal seam thickened as southern margin of west <br />thick coal pod encow~tered. Upper "D" thinned as west <br />thick coal pod was exited in vicinity of neck of Panel) <br />AA. Several significant roof falls encwntered <br />particularly in intersections. Typical seeps fmn both <br />roof aryl floor. <br />• Panel z: <br />Mined am~rth: 2800 feet of panel advance development in crosscuts 2 through <br />21. <br />Overburden 'Thic]mess: Varying from approximately 1000 to 1500 feet. <br />Mining Height: 9-11 feet on advance. <br />Roof: Comg~rised of mudstones and sandstones with intermittent sandstone <br />channels. Zbp coal of 2-3 feet in thickness was left on the roof. Mesh <br />used in localized areas to maintain intersections, repair fall areas. <br />Pillar widths increased at crosscut 12 to enhance roof and rib stability <br />as Dover increased. <br />Ribs: Rib sloughage was moderate and increasing with increasing depth. <br />Floor: 'The la.+er "D" seam was used as floor which provided ccmg~etent conditions. <br />Anomalous Conditions: Increaser) rib instability associated with increasing <br />Dover depths. 'Typical intermittent seeps fran both roof <br />and floor associated with sarrLstone channels encountered <br />at various locations. <br />Panel Y- <br />• Mined Length: 7000 feet of panel advance development in ca.-os_scuts 3 throuc~ <br />54. <br />2 <br />