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Intrusions <br /> A total of five (5) mafic dikes were mapped within the South and West Quarry areas and are <br /> shown in Figure 4. Three mafic dikes are also clearly visible in both the east-facing and <br /> west-facing highwalls of the Central Quarry. The dikes are approximately 3 to 5 feet wide in <br /> most locations and are vertical or steeply dipping to the south. Although competent in many <br /> locations at the site, the unit can be highly weathered in some locations and may result in <br /> block failures where the dikes cut through foliations and fractures. <br /> Foliations <br /> The bedrock structure at the South Quarry and West Quarry is dominated by an undulating, <br /> sub horizontal foliation with a predominant southwest dip ranging from about 10' to 30°. <br /> The foliations are observed as j oints in many locations, where the j oints have formed at the <br /> foliation surface. Foliation joints within the gneiss are the most dominant, consistent, and <br /> easily observed discontinuity at the project site. Foliation joints are generally moderately <br /> spaced (SP4: 0.3 to 1 ft)to very widely spaced (SP2: 3 to 10 ft) although there are localized <br /> areas with tighter joint spacing. Foliation surfaces and foliation joints are generally planar to <br /> undulating and rough (R2) and in some places are stepped (R1). They are slightly continuous <br /> (C2: 3 to 10 ft) moderately to continuous (C3: 10 to 30 ft lengths). They are typically clean <br /> but may contain iron staining, and infill material is generally not present. Photo 2-3 shows <br /> foliations in the granitic gneiss. <br /> . _,�� „•,�.'_ ,� 'fir <br /> .. of <br /> r <br /> Photo 2-3. Granitic gneiss as observed in a boulder at ground surface in <br /> West Quarry, showing gneissic banding and a foliation joint. <br /> Discontinuities <br /> In addition to the foliations and foliation j oints, there are two other j oint sets that are <br /> prominent and visible throughout the South Quarry. They are orthogonal and are steeply <br /> dipping (near vertical), with one set striking approximately east-west and the other striking <br /> Aggregate Industries—Morrison Quarry GEI Consultants, Inc. <br /> AM-07 Geotechnical Stability Exhibit November 2020 <br />