2009-02-17_REPORT - M1974004 (2)

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STRUCTURAL GEOLOGY EVALUATION SPECIFICATION AGGREGATES QUARRY 1.0 Introduction LACHEL FELICE & Associates, Inc. (LF&A), Golden, Colorado has prepared this independent annual structural geology evaluation for the Specification Aggregates (Spec-Agg) Quarry located in Golden, Colorado (Figure 1) for the 2009 year. This study was conducted at the request of Lafarge West, Inc., the owner of the quarry, as a requirement for State of Colorado, Permit Number M-74-004. The structural geology evaluation presented herein includes observations and measurements from the quarry that have been obtained annually by LF&A staff over the past twelve years (1997-2008) as well as results of the detailed geotechnical investigation conducted by LF&A in 2003. The main purpose of the annual evaluation is to monitor the impact the bedrock ' structural geology has on pit wall stability as mining progresses. The data collected for this report were performed on a quarterly basis to ensure adequate exposures were measured. Observations and structural analyses of data were conducted by LF&A geologists and engineers, and are applicable to the quarry at the time the data were obtained (August 2008 through January 2009). More specifically, the goals of this study are as follows: Inspect the recent exposures at the quarry for stability and variation in fractures and foliations. Document geologic discontinuities by mapping and taking photographs along ' recently exposed quarry walls to utilize the data in validating and updating the existing structural geology database; ' • Analyze the new data relative to the existing data in order to verify and/or modify existing conclusions and to investigate possible emerging trends; Review and characterize the existing stability conditions at the quarry relative to the current long-term mine plan; Locate and document changes in groundwater conditions; ' 0 Locate and document any obvious slope instabilities.