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3.2 Central Oua <br />No mining occurred in the Central Quarry in 2008 and thus no new orientation data related to <br />mining activity was collected. Observations of the existing highwalls and benches were <br />conducted and compared with previous observations. Localized instabilities were observed <br />and local raveling of the rock faces has occurred. This raveling is likely due to adverse <br />jointing, rock weakened by alteration, and/or weathering actions such as freeze thaw cycles. <br />Blocks loosened in this fashion are generally small (less than approximately 1 '/2 feet in <br />diameter) and collect on the benches. <br />Observation of the highwall adjacent to the haul road constructed in 2008 indicated only minor <br />raveling of the rock face has occurred. The rockfall mesh above the haul road was observed to <br />have captured rocks up to 8 inches in diameter. No other highwall disturbance was observed at <br />this location. <br />Observations of the stabilized slope area indicate no visible movement or large erosional <br />features. Aggregate Industries provides survey support to monitor movement of this slope as <br />well. However, survey data is collected as conditions change and no survey was completed in <br />2008. <br />3.3 South Quarry <br />Geotechnical data was collected for the areas mined in 2008. These areas include three <br />highwall and bench combinations at elevations 6880, 6820, and 6760 as shown on Figure 3. <br />Bench development is on-going at all three of these elevations. The highwall faces are referred <br />to by elevation for reference in this report. The benches represent an increased depth of <br />mining in the South Quarry from last year and include expanded mining areas to the west (east <br />facing). <br />The type of rock encountered in the highwalls is consistent with rock types described in <br />previous geotechnical addenda and primarily consists of fine to medium grained granitic gneiss <br />or biotite gneiss. Occasional pegmatitic intrusions, biotite schist zones and shear zones are <br />also present in the area. <br />Gneiss observed in the highwalls is slightly to moderately weathered and generally displays <br />two prominent joint sets and a foliation surface. Joint spacing ranges from approximately 2 <br />inches up to 7 feet. Joint surfaces generally are slightly rough to rough and are usually closed. <br />When joint surfaces are open or exposed, the joint faces are typically slightly to moderately <br />weathered with iron staining. The joints generally do not contain infill material. <br />Foliation plane spacing ranges from less than one inch up to 6 feet. Foliation surfaces <br />generally are smooth to rough and are usually closed. When foliation surfaces are open or <br />exposed, the aperture is up to one tenth of an inch and the foliation faces are typically slightly <br />weathered with iron staining. The foliation generally does not contain any infill material. The <br />highwalls observed were dry and seepage through the rock at the upper elevations is not <br />anticipated. Average RMR values calculated for the rock exposed in the highwalls of the <br />South Quarry range from 45 to 77 indicating fair to good rock. Joint orientation field data and <br />-3- <br />Morrison Quarry Annual Report 2008 February 2009 <br />F:\39 19_038\Annual_Report_2008\Geotech_Report _2008\Annual_Report_2008_Geotech. doc