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5 <br />batter being poured into a pan." Both operators quickly drove their equipment to the <br />eastern highwall and had intended to drive up the haul road out of the pit, but the haul <br />road was buried under the toe of the slide mass. <br />Mr. John Bertrand observed the slide from his residence near the quarry where he has a <br />view of the upper half of the west pit slope. He initially observed movement of the <br />upper pit slope just below the natural topographic spur referred to as the "middle <br />peak." This upper portion moved downward for about 6 seconds, then stopped for <br />several seconds; the motion resumed for several seconds, then stopped again. The third <br />and final motion included the opening of the large rift extending southward from <br />where the motion was first observed, and the iovement was observed over the entire <br />mass below this rift. From his vantage point, Mr. Bertrand did not hear any noise from <br />the first two movements, but heard noise from the slide only when the final movement <br />occurred. No airborne dust was noticed during or after the slide. <br />Mine Site Geology <br />We gathered available geologic information and mapping from the CGS and internet <br />sources, including a geologic map of the 71h minute Cascade Quadrangle, published in <br />2003. The company mines a localized outcrop of the Ordovician-aged Manitou <br />Limestone and overlying Peerless Dolomite which is exposed within a fault bounded <br />wedge formed by the Rampart Range Fault, a high angle thrust fault, and a near- <br />vertical "splay" fault to the west, as shown in Figures 2 and 3. Folding occurred prior <br />to, or in conjunction with, the faulting. The geologic map indicates that the limestone <br />bedding dips from 24 to 45 degrees from horizontal and have a dip direction at <br />azimuths ranging from 70 degrees to 110 degrees. In the area of the slope failure, the pit <br />slope faces an azimuth of about 80 degrees. Thus, the bedding discontinuities beneath <br />the east-facing pit slope are approximately parallel to the slope, which is an unfavorable <br />orientation from a stability standpoint. <br />The geologic data also indicates that the Manitou limestone is underlain by the locally <br />thin and discontinuous Sawatch sandstone, which is in turn underlain by the Pikes Peak <br />Granite. This granite is exposed at the surface on the up thrown side of the splay fault <br />which forms the western edge of the limestone outcrop. The Pikes Peak Granite is <br />subject to deep weathering and near the surface is typically comprised of decomposed <br />granite that is able to be excavated with earth moving equipment, particularly on the <br />wetter north and east facing slopes. Therefore, there may also be an unfavorably <br />oriented, weak discontinuity at the contact between the granite and the limestone under <br />the pit slope. <br />The high angle thrust faulting in the site vicinity is not believed to be historically active. <br />The faults are believed to dip steeply to the west and are not oriented so they would <br />directly contribute to the instability of the slope. However, zones of "gouge" (broken