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- 15 - <br />encountered were silty sands and gravels containing some cobbles. The <br />• granular soil particles were ann~~lar and appeared to be the upper <br />weathered and fractured surfaces: of the bedrock. <br />Based on the penetration resistance values and the laboratory <br />test results, the soils appear to be dense to very dense. They are <br />generally dry and light brown in color. <br />The bedrock in the south hillside was generally explored by [~D( <br />core drilling. The NX core drilling was undertaken because our drill <br />rigs were not capable of angering through the sedimentary rocks in <br />this area and because our field reconnaissance indicated that the <br />bedding in this area dipped north towards the valley bottom, creating <br />a potential for instability of the structures on the hillside. <br />Abbreviated logs of the wre holes on the hillside are shown on <br />Figs. A-1 and A-6. Detailed logs of the core holes are presented in <br />• Figs. A-7 through A-16. Generally, the core logs indicate the <br />presence of two major coal seams in the hillside. The upper seam <br />varies in thickness from 4 to 6 feet. Overclay was encountered above <br />the coal seam in Test Holes 16 and 18 and beneath this seam in Test <br />Holes 16, 18 and 19. The underclay and overclay materials are weak, <br />moist to very moist, carbonaceous to very carbonaceous clay <br />materials. <br />A deeper opal seam approximately 12 feet thick was also <br />encountered. An underclay was encountered beneath this seam in Test <br />Hole 19, but no obvious zone of underclay or overclay was encountered <br />in the remaining holes adjacent to this seam. The coal encountered in <br />both seams was fractured and b1~.jcy. <br />• <br />