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area. Dip measurements rarely portrayed less than 85 degrees and reflected near vertical <br />attitude at a number of highwall bench outcrop locations. <br />Joint Measurements, Faulting, and Intrusive Considerations <br />A primary joint system is notable across the entire face of the granite gneiss highwall <br />with a strike measurement of consistently N10W + or - 10 degrees. This joint pattern is <br />most evident in the feldspar -rich massive pink granite zones exposed at many locations <br />across the highwall exposures. Dip varies from 65 -85 degrees to the East. <br />Secondary jointing systems were noted at much less frequency than the primary joint <br />system, displaying strike direction of N25E + or - 10 degrees with dips measured at lower <br />angles (45 -50 degree) dipping southeast. This secondary joint pattern is limited in <br />occurrence but notable along the mid - section benches of the existing highwall benches. <br />At least two sets of intrusive dykes intersect the exposed highwall area composed of fine <br />grained feldspar and quartz. The largest intrusive dyke was measured 10 -12" thick, <br />striking N5E and dipping 60 degrees West. A 7" fine - grained felsic dyke crosses the mid- <br />level of the bench system at the south end of existing highwall, striking N39E and <br />dipping 52 degrees West. Slickensides were noted along the contact of the intrusive dyke <br />with granite gneiss bedrock, although evidence of significant offset was not apparent. <br />Other small (felsic) intrusive dykes can be viewed along reaches of the lower highwall <br />benches striking N by W and nearly vertical in attitude. Due to the lack of evidence of <br />offset due to faulting along intrusive contacts and the predominantly western direction of <br />dip of the intrusive members, the disturbance of the dykes by mining appears to have <br />little to no effect regarding the conformation of the mining face; i.e., the dyke material <br />displays fracture and parting characteristics similar to the surrounding gneiss materials. <br />Little to no differentiation was noted regarding rock habit, weathering, or texture of the <br />dykes vs. the surrounding rock. All of these factors appear to result in minimal effect <br />regarding long -term highwall stability. Nevertheless, secondary joint system dip angles <br />of approximately 60 degrees from horizontal were included in projected failure planes in <br />the Galena parameters input to align potential failure surfaces with the joint dip angle for <br />factor of safety calculation. <br />Current Mine Bench Alignment <br />By far the most predominant rock characteristic viewed at the disturbed (mined) face has <br />to do with foliation. At the southern end of the highwall feature, as throughout most of <br />the exposed rock, foliation strikes N20W, but is subject to considerable variability at <br />certain locations. At several locations along the mid -level of the northern reach of the <br />present highwall feature, the strike of gneiss foliation and the predominant joint pattern <br />strike align at close to N12W + o r- 3 degrees. The dip angle ranges from 75 -85 degrees, <br />resulting in a relatively clean, monolithic mining face remaining (with a slightly warped <br />surface appearance). At the time of the last highwall investigation (1997), the mine <br />bench configuration was aligned N40E along the strike of the bench face after mining. <br />Due to the attentiveness of mining personnel to natural fracture habit of mined material as <br />14 <br />