2010-02-02_REPORT - M1973021 (2)

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5.3 South Ouarry Mining in the South Quarry in 2009 appeared to adhere to the mine plan and extended the quarry depth to an approximate elevation of 6700. Rock observed in the highwalls consisted primarily of granitic gneiss with localized areas of biotite gneiss. Rock exposed at elevation 6820 and portions of the rock exposed at elevation 6760 appeared fresh to slightly weathered. Rock exposed above elevation 6820, portions of rock exposed at elevation 6760, and rock exposed at elevation 6700 appeared slightly to moderately weathered. Highwall orientations are both north to south (east facing) and east to west (north and south facing) and foliation and joint orientations are favorable with respect to this highwall development plan. Current mine slopes are being excavated steeper than the default slope configuration utilizing 11/2:1 highwall height to bench width (60 foot highwalls to 40 foot benches). Rock observed in the highwalls was predominantly competent with the following exceptions: • Bench 6880 stations 4+00 to 4+75 consisted of granitic gneiss with a jointset dipping out of the highwall face creating minor potential for plane failure. • Bench 6760 stations 8+75 to 13+60 consisted of a granitic gneiss with a jointset dipping out of the highwall face creating minor potential for plane failure. Based on our observations the overall slope conditions for the steeper slope configuration are considered stable and warrant primarily operational considerations. -9- Morrison Quarry Annual Report 2009 February 2010 P:\23514\133-23514-10003\Deliverables\Deliv-0l-Annual Report\Annual_Report_2009_Geotech, 1-25-10.doc