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Martin Marietta Materials Spec-Agg 2016 Annual Report 5.0 FIELD OBSERVATIONS Field observations for the 2016 Annual Report consisted of rock structure mapping and collecting of information regarding areas of visible, large-scale instability, seepage, and mining activity. Observations for the current annual report were made during two site visits, which took place in July and December 2015. During our visits, we performed rock structure mapping to collect representative discontinuity measurements from recently mined rock exposures in the Southern Expansion Areas (Figure 2; Photos 1 through 3). Orientation measurements (i.e., dip/dip direction) of joints, foliation, and faults were taken from the faces of advancing benches. A geological compass was used to obtain discontinuity measurements both indirectly by sighting along the discontinuity surfaces and, where deemed safe, by direct measurement on the discontinuity surfaces. A handheld GPS was used to record the location of data collection points (Figure 2). A total of 79 discontinuity measurements were collected in 2015 at six data collection points, and were added to the measurements from previous years. When combined with data collected from previous annual reports (1997-2002, 2004-2015) and with borehole geophysical data collected during the 2003 geotechnical investigation, a total of 3,359 discontinuity orientation measurements have been obtained over the past 19 years. Figure 5 shows the 79 discontinuity orientation measurements collected for this annual report overlain on a contour stereonet plot of the entire Spec-Agg structural dataset. During our July and December 2015 site visits, we observed two new fault exposures (probably of the same fault) along the temporary excavation wall in the Southern Expansion Area at stations 16-01 and 16-05 (Figure 3 and Photo 3). The fault is oriented approximately east-west, with apparent dip/dip direction of 75-80/145-175 and was exposed in the north to north-east facing temporary wall of the expansion area. The fault zone consists of weathered, broken and blocky rock, with parallel fracturing, and iron-stained slickenside surfaces with local clayey gouge. The location of this fault is, in general, a good match with the previously mapped trace. The apparent width of the fault zone varies from 15 to 30 feet. The fault orientation measurements for this annual report are presented with previous fault measurements and differentiated by the fault feature they represent in Figure 4. Minor raveling conditions resulting from rock fragmentation during blasting and subsequent freeze/thaw conditions exist along each wall in the quarry, but appear more prevalent along the south wall possibly due to the north facing exposure. The quarry walls observed during the 2015 site visits appeared to be relatively dry; with the exception of minor seepage visible in the southwest corner of the main pit, which has been documented in the past. Other than minor seepage observed along the temporary access road to the Southern Expansion Areas, no major seepage was observed. Additionally, we observed impounding water in the Main Pit floor (Photo 4); apparently, the sump pump was not operating during our visits. Reportedly, during the September 12-13, 2013 historic rainfall event in Colorado, water flowing from highwalls caused some minor damage to temporary rock barriers along the temporary quarry access road. The northern faces of the Main Pit were modified after planar failure along foliation planes in 1998 and 1999. Based on visual inspection from the access road and bottom of the pit, these slopes did not appear February 8, 2016 Page 4 Lachel 8r Associates, Inc. Project 15364004.00 02016 All Rights Reserved