2016-04-14_REPORT - M19741004

• Permit No: M1974004
• IBM Index Class Name: Report
• Doc Date: 4/14/2016
• Doc Name: Annual Fee, Report & Map
• From: Specification Aggregates Quarry
• To: DRMS
• Annual Report Year: 2016
• Email Name: MAC
• Media Type: D
• Archive: No

Martin Marietta Materials
Spec-Agg 2016 Annual Report
A mapped reverse fault trending roughly north-south is located within the quarry property and constitutes
the boundary between the metamorphosed Precambrian bedrock to the west and the Pennsylvanian
sedimentary rocks to the east(Smith, 1964; Scott, 1972). The quarry property straddles this boundary,
with the majority of the processing plant and the entire asphalt plant located east of the fault(Figure 3).
The bedrock material east of the fault is dominantly composed of upturned sandstones and shales of the
Fountain Formation (Scott, 1972). West of this fault, the material is mapped as migmatitic quartzo-
felspathic gneiss with intrusions of granitic pegmatite veins (Scott, 1972).
Two other approximately north-south trending faults have been exposed in the northern quarry walls, as
shown on Figure 3 and discussed in the previous 2013 report (Lachel, 2013). They roughly parallel the
Golden Fault, which is a major fault that forms the north-northwest trending hogback immediately east of
the quarry property.
4.0 MINING PLAN AND PROGRESS
Mining activities have typically been focused in two distinct areas: the Main Pit and the Southern
Expansion Area (Figure 2). Minimal mining activity except groundwater pumping appears to have
occurred in the Main Pit since the last report. During our 2015 site visits, we observed that the sump
pump was off and standing water had formed a small lake in the main pit. Plant operation records indicate
that the daily pumping durations from the Main Pit are usually three to four hours under normal weather
conditions with increases durations during rainfall events. Under normal weather conditions
approximately 80,000 to 100,000 gallons of water are discharged per day (mainly from groundwater).
Significant mining activity has taken place in the Southern Expansion Area since our last annual report
and between our July and December 2015 site visits (Photos 1 to 3). The current temporary benches are
being advanced to approximately the 6,685-ft elevation (Figure 2, Station 16-06) with reclamation
occurring in stages following excavation along permanent benches. Three temporary benches were
actively being mined during our site visits, including an upper bench near the western margin of the
Southern Expansion Area (see stations 16-01 and 16-04 in Figure 2). The next lower bench is being
mined starting from the eastern side approximately 35 feet lower than the upper bench and working to the
west(see stations 16-02 and 16-05 in Figure 2). An additional area of recent mining was observed in the
southeastern portion of the Southern Expansion Area (see stations 16-03 and 16-06 in Figure 2). This
area may represent the start of a new lower bench of the Southern Expansion Area.
Based on the current mine plan developed by Martin Marietta (formerly Lafarge West, Inc.) in December,
2003, and the current Colorado Division of Minerals and Geology mine plan, we understand that the mine
will eventually be excavated to the topographic configuration shown in Figure 2, with an approximate final
mine floor elevation of 6,200 feet. The orientations of the final planned highwalls are the basis for our
rock structural discontinuity assessment, as discussed in Section 6.0.
February 8, 2016 Page 3 Lachel & Associates, Inc.
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