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4-15 <br />• resistivity log. The interpretation depends on the type of medium used for drilling. If <br />water was used for drilling, the interpretation of electric resistivity logs could not <br />distinguish the difference in the level of ground water or drilling fluid; therefore, it is <br />necessary to usee not only geophysical logs for the interpretation, but also driller's logs. <br />Because most of the bore holes were drilled with air and with the occasional use of <br />foam, the electric logs indicate, in most cases, the depth to water table. <br />Using data from resistivity logs measured in the exploration bore holes, made it possible <br />to develop a map (Figure 4.4-1) approximating the unsaturated and saturated zones of <br />the Cameo coal seam. <br />• For the Munger Canyon mine permit area, the results of the interpretations of <br />geophysical logs were confirmed in two exploration bore holes. Borehole 7.21.3, <br />located in the northeast quarter of Section 21 just north of the permit area, was dry to <br />the depth of 200 feet from the surface. This indicates that saturated sandstone strata <br />are about 210 feet below the Cameo Coal seam at that point; therefore, it is reasonably <br />• <br />Mu Volume 1 12/18/95 <br />