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GEOLOGIC SETTING OF COAL BASIN MINE AND ADJACENT AREA <br /> *ram Geology of Coal Basin Mine Vicinity provides an overall <br /> • view of the Coal Basin geology (Full , 1972 ; Tweto, 1978) . As <br /> discussed briefly earlier in this report , Coal Basin consists <br /> of an eliptical anticline resulting from an igneous intrusion <br /> superimposed on the Grand Hogback (Collins, 1977) . Dips in the <br /> bedrock units of the anticline vary from about 100 to 300. <br /> The direction of dip of the Grand Hogback is to the west; <br /> directions of dip in the Coal Basin anticline vary from north <br /> to west to south in a counter clockwise direction (Full, 1972) . <br /> Numerous small faults break the Mesaverde and upper Mancos <br /> shale in the west and south west portions of the anticline, <br /> (Full , 1972) . These faults are believed to be associated with <br /> the folding of the bedrock units and are related -to the <br /> formation of the anticline (Collins , 1977) . <br /> The intrusive body does not outcrop at the ground surface, <br /> although there are a number of related features .including a <br /> zone of baked shale near the center of the anticline and a <br /> number of porphyry dikes cutting through the bedrock units . <br /> It is believed that the intrusive body is laccolithic and <br /> related to the other laccoiiths in the West Elk area . The <br /> estimated depth to the intrusive body varies ; some estimates put <br /> it at the Morrison formation and others put it deeper (Collins , <br /> 1977) . <br /> 4 <br />