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1988 PRODUCTION AND GEOLOGIC CONDITIONS Page -2- <br />• <br />Mining height: 9-11 ft. <br />U <br />Roof: Comprised of mud stones with a high concentration of pots and slick- <br />enslides through 28 X-cut. A sandstone channel was encountered approximately 10 <br />feet above the coal seam throughout the remainder of the section. Top coal of <br />4-5 feet in thickness was left to prevent roof problems that would normally be <br />encountered with this strata type. <br />Ribs: Moderate to heavy rib sloughage occurred in local areas. 4 tt. and <br />5 ft. rib bolts were installed in areas of weak cleated coal and high mining <br />heights. <br />Floor: The lower "D" coal seam was used as floor which provided competent <br />conditions. <br />Anomalous conditions: Shear zones were prevalent in the areas from 4120 to <br />4125 X-cut, Small seeps from the roof were encountered, the interburden thick- <br />ened as the panel was driven north with the interburden contributing to a high <br />ash content which halted mining at 4134 crosscut. Attempts were made to mine the <br />lower "D" using interburden as roof material with limited results. <br />• <br />