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2.04.6 <br />A shown on Map 7 there are numerous faults in the permit and adjacent <br />area. The faults in the central portion of the permit area trend N40 ° W and <br />dip 70 to 80 degrees to the northeast. These high angle normal faults have <br />an apparent strike slip component. The throw of the fault ranges from 7 to <br />30 feet. The down side is the north side of the fault. The faults that have <br />been mined through are slip faults. <br />0 <br />• <br />PR -12 <br />�9 �PRovED <br />Fault zones encountered within the Bowie No. 1 Mine workings range in <br />displacement from a maximum of 50 feet to less than 1 foot (shear zones). <br />They are typically high angle normal faults which contain minor amounts of <br />gouge (1 to 4 feet) and produce minimal mine inflows. Drag folding <br />commonly accompanies the fault planes. Based upon underground <br />observations, two separate episodes of faulting occurred within the area. The <br />earliest fault system trends approximately N65 0 E and dips 70 to 80 degrees <br />to the down thrown side. Two faults have been exposed which are <br />subparallel and result in a graben structure. Displacements are 2 to 6 ft. and <br />locally bifurcate into shear zones. The younger fault system trends <br />approximately N35 and dip 70 to 80 degrees to the northeast. These high <br />angle normal faults have an apparent strike slip component and offset the <br />earlier faults in a left lateral direction. <br />Although present drill hole spacing is adequate for detection of large scale <br />faults (approximately 50 ft. displacement), uncertainty exists in predicting <br />faulting with less displacement, and the probability of encountering "blind ", <br />unexpected faults within the mine workings is moderate. <br />The geologic structure of the permit area may be modified by the nearby <br />location of igneous intrusive bodies. Coal seams in this area have been <br />coked and devolitized by suspected sills, undoubtedly related to the Miocene <br />Iron Point Pluton (Junge, 1976). The combined effect of extension type <br />structural features, nearby igneous activity, and frequency of inferred <br />structures may indicate the presence of an igneous complex at depth <br />beneath the area. Regional geophysical studies or deep drilling would be <br />required to confirm this idea. <br />0 <br />2.04-17- 06/10 <br />