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Martin Marietta Materials <br />Spec -Agg Project <br />Within the main pit of the quarry an approximately east -west trending fault was exposed a few years ago <br />(Figure 3). This fault is exposed in the east and west to northwest walls of the main pit and appears to range <br />between 20 and 50 feet wide (Figure 3). Exposures of this fault were visible in the northwest corner of the <br />main pit along the margin of the recently excavated sump during previous field investigations (2008- 2009), <br />the fault has an average dip of 84° south. This fault was also mapped by Gable as striking 260 -270° and <br />dipping 80 -85° to the south and will continue to be exposed across the main pit floor and on the east and <br />north walls as the pit deepens (Figure 3). A previously identified fault mapped in Jackson Gulch has been <br />informally named the Jackson Gulch fault and is not shown on the map due to the difficulty to map the <br />surficial trace. The area has been extensively modified and fresh exposures have been covered up by <br />backfill material before measurements could be made. <br />In the expansion area, Gable (1968) mapped a third fault that also trends roughly east -west (Figure 3). This <br />fault was initially exposed during the 2006 investigation, and was noted by a distinct pegmatite vein that is <br />surrounded by decomposed weak biotite rich gneiss. The fault was exposed in a north south trending <br />temporary wall along the western margin of the expansion area, and has been exposed again during the <br />current investigation (Figure 3; Photo 2). GPS measurements taken along the margin of the fault exposure <br />were registered in Google Earth to the existing fault map yielding a good match with the previously mapped <br />trace (Photo 3). At this location it is noted that the material to the south of the fault is more gneissic and is <br />more difficult to blast (Photo 4). Measurements were taken along the fault exposure with resulting strikes <br />ranging from N75 -80 °W and dipping 75 -90 °S. <br />The granitic gneiss found in the quarry is generally hard and relatively competent. The gneiss varies in color <br />from grayish orange to dark gray, with occasional banding visible along the foliation of the rock. The term <br />foliation refers to the realignment of minerals into a parallel orientation as a result of the intense heat and /or <br />pressure of metamorphism. The rock mass tends to be weakest along the foliation planes, which ultimately <br />results in a discontinuity set parallel to the orientation of the foliation. The foliation orientation is the most <br />prominent discontinuity set identified in the quarry and is readily visible in the east and west walls. The rock <br />foliations undulate in a synclinal and anticlinal fashion, with noticeable variation in dip angles across each <br />wall. <br />February 13, 2012 <br />Project 11361017 00 <br />Page 3 <br />Lachel & Associates, Inc. <br />©2012 All Rights Reserved <br />