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' observed in temporary slopes and these conditions will continue to be observed during fur[her development in this area. Rock mass properties significantly improve with depth, due to higher strength parent rock, less weathered and more massive than the rock mass above, ' which is composed of low strength rock material with weathered and slick joint surfaces. The overall slope on the west side appears stable. Localized instabilities are infrequent and ' consist of relatively small loose blocks and wedges, generally less than 10 feet in length. These instabilities are as expected for the highwall and only cause localized operational inconveniences. The overall slope on the north end appears stable. Localized instabilities are infrequent and consist of relatively small loose blocks and wedges, generally less than 10 feet in length. ' These instabilities are as expected for the highwall and only cause localized operational inconveniences. ' 5.03 North Quarry The highwalls and benches are aligned curvilinear bearing approximately 000 to 080a ' azimuth as the pit emends to the east.--Tlie rock type is primarily granite gneiss with mafic and felsic intrusions (felsite dikes and pegmatites). The primary joint set coincides with foliation of the rock mass. In general, the foliation dips ' in a west/southwest direction with minor trends northwest. Foliation orientation has local variations due to several sets of localized anticline/syncline structural features in the rock mass. The primary joint set is perpendicular to sub-perpendicular on the northern side ' dipping into the mining face. Dip angle varies from approximately 25~ to 40~. This foliation joint set is shown in Table I. Spacing of joints in the primary joint set typically ranges from ' 0.5 ft to 2 ft. Joint surfaces are typically tight and appear slightly to moderately weathered. Joints are very continuous in certain locations and discontinuous in other locations . , ' Three dominant secondary joint sets are present. These joint sets are orthogonal to each other, striking in the north, northeast, and southeast directions. The secondary joint sets are shown in Tabie I. Spacing of joints in the secondary joint set typically range from 1 to 5 feet. Joint surfaces are typically tight and appear slightly weathered. Joints are both continuous and discontinuous. The overall slope appears stable. Localized instabilities are limited to single benches and are evidenced by relatively small block and wedge shaped slip surfaces, generally less than 10 feet in length. These slip surfaces are as expected for the highwall and cause only localized operational inconveniences. The overall condition of the slope on Benches 3 and 2 is "competent'. An isolated shear zones exists in conjunction with a mafic dike at Location C on Figure 1. G:\PROIECTS\20200 Morrison Quarry\008\2002\2002 geomchnical adder~dum.doc