2009-05-29_REVISION - M1977211 (6)

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0 SITE GEOLOGY Our and others' interpretation of site geology is presented on Fig. 4. The geology of the site was evaluated by reviewing readily available published geologic maps, reports and aerial photographs, conversations with quarry personnel, and observing field conditions. A list of references is included at the end of this report. The quarry is excavated primarily into limestone and dolomite beds that are fault- bounded on the east and west sides of the quarry. The faults are part of the Rampart Range Fault Zone, which locally is about 1,500 feet wide. If the folded beds and minor faulting on the east side of the fault zone are included, the zone is up to 6,000 feet wide. The bedrock to the east of the east fault is Pierre Shale, and the bedrock on the west side of the west fault is Pikes Peak Granite. The units exposed within and below the quarry from top to bottom are the Manitou Limestone, Saguache Sandstone, and Pikes Peak Granite. To the north and south of the quarry, within the permit boundaries, the hilltops are covered by the Verdos Alluvium, • which is a glacial outwash gravel. Other surficial units are present in the eastern part of the map area on the slopes and small terraces above the drainage. The native conditions have been disturbed due to various mining activities across the site. The various map units are described in more detail in the following sections and are followed by a brief description of the structural geology of the quarry. Landslide, Recent (Qlsr) The area labeled Qlsr is our estimated extent of the recent slide mass. This slide mass consists of the material that moved down the highwall and across the bottom of the "Hole" portion of the pit. This mass consists largely of gravel to boulder-size pieces of limestone, with some areas of soil which were placed on benches as part of the reclamation of the southern portion of the high wall. The scarp is mapped separately, as are other fractures that opened up at about the same time that the slide occurred. Previous slides that occurred within the quarry were removed by later excavation of the slide material during mining. TRANSIT MIX AGGREGATES 6 PIKEVIEW QUARRY SLOPE CTLIT PROJECT NO. CS17341-125 S:1CS17000-174991CS17341.000112512. Reports1CS17341-125-R1-Final.doc