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-3- <br /> <br />Generally, the shales are dark gray in color. Coal seams occur in thicknesses of I <br />To about 12 feet. The sedimentary bedrock dips north-northwest at about 5 <br />degrees. <br />The soils which mantle the surface are probably the result of in-place <br />weathering of the formational materials. The thickness of surficial soils ranges <br />from nearly 0 to as much as 10 feet on the higher portions of the site. In the <br />valley areas near the toe of the proposed spoil, our borings encountered up to <br />30 feet of sandy clays. These clays contained fragments of sandstone and <br />claystone and we believe they are colluvial in origin. <br />The bedrock formation exposed in the mine appeared relatively impervious. <br />Where water percolates down Through the near surface soils, we believe it will <br />tend To perch on the surface of the relatively unweathered formation rock. <br />Groundwater may also occur within some of the fractured coal senms lower in the <br />formation. <br />FIELD INVESTIGATION <br />Our field investigation included field reconnaissance of the proposed spoil <br />disposal ores and drilling of I I exploratory borings at the approximate locations <br />shown on Sheet I and Fig. I. The borings were drilled with a 4-inch diameter, <br />continuous-flight auger powered by atruck-mounted, C.ME-55 drill rig. Samples <br />were obtained at approximately 5 foot intervals. To determine the relative <br />stiffness of materials encountered, penetration resistance tests were performed <br />during sampling. The samplers used included a 2.5-inch (O.D.) California-type <br />barrel and a 2.0-inch (O. D.) split spoon. These sampling devices were driven using <br />a 140-pound hammer falling 30 inches. Our geologist was on site To direct <br />