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• <br />and dips down into the exposed cut face between 5 and 10 degrees. There <br />are several near - vertical major joint sets that strike almost perpen- <br />dicular to the highwall face. Minor joints dip down out of the cut face <br />from about 75 degrees to 90 degress as measured from horizontal and are <br />slightly off parallel to the cut. It appears that the dip of the minor <br />joints as well as weathering and slaking, control the angles at which <br />the face of the various rock layers presently exist. Figure 5 presents <br />a summary of structural geology observed during our field investigation. <br />Spoil Conditions <br />Exploratory test pits were excavated at 13 'locations to observe con- <br />ditions near the toe and crest of the existing spoil face. Seven of the <br />• test pits were excavated near the toe of the spoil with the remaining <br />6 excavated near the crest. The approximate locations of the test pits <br />are presented on Fig. 3 with logs of the soils encountered shown on <br />Fi g. 4. <br />Conditions observed in the test pits excavated along the slope crest <br />were relatively consistent. The spoil encountered predominantly included <br />cobble, gravel, and sand -size sandstone and shale. Less than 10 percent <br />of the material appeared to be larger than 12 inches in diameter. We were <br />present periodically during mining of the hillside. We estimate that <br />70 percent of the overall spoil was greater than 6 inches in diameter, <br />but smaller than 24 inches with 15 percent larger than 24 inches. The <br />remaining fraction was estimated to be soil sizes. With the dragline method <br />�J <br />