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-5- <br />• test drilling, requested following the draft of this report, w(11 be <br />presented in subsequent addenda. The graph(cal Logs of Exploratory <br />Holes are presented on Ftgs. 3 through 5, and Figs. 7 through 9 show <br />detailed logs of the test holes which were cored. Cross-sections <br />depicting proposed excavation levels and corresponding subsurface <br />material types and free water conditions are shown on Figs. 10 through 12. <br />Processing Facll(ties: Test Holes 1 through 17 show the subsoils encoun- <br />tered along the proposed processing system alignment and structures. <br />Near-surface and subsoils generally consist of relatively shallow, stiff. <br />sandy to silty clay with Interbedded clayey sand and gravel immediately <br />overlying claystone bedrock at depth 6 to 13 feet. On the slope north <br />_ of the truck dump along the haul road alignment, overburden soils are <br />. relatively thin, but downslope to the southeast they become deeper. <br />Truck Dump Hopper: Overburden clay soils at the truck dump hopper <br />are approximately 6 to 7 feet Tn depth and will essentially be removed <br />to achieve a fl.nal surface elevation of 6412.0 feet. Excavation of the <br />• hopper to the proposed depth of 28 feet below the final surface grade <br />will be In medium hard to hard claystone bedrock. Previously, a lower <br />level of 6372 feet was considered. Unconfined compressive strength <br />tests In the claystone indicate that it has a high supportive capacity. <br />Cora recovered from Test Hole 2 shows moderate RQD values and indicates <br />moderately low to fair competency of the bedrock together with a highly <br />Jointed network of fractures filled with gypsum. Typical with claystones, <br />they are competent in a confined. unexposed wndition but wJ.i'1 slake or <br />• weather rapidly upon exposure. <br />...~. <br />swell-consotidatlon tests indicate the <br /> <br />i <br />