2008-04-15_REVISION - M1980244 (309)

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• other lineations are at a N40-50E structural orientation delineated by discontinuous phonolite dikes that increase in frequency to the north, and a N45W trend of discontinuous, narrow faults observed only in the northern portion of the site. There appears to be minimal displacement (less than 10-30 feet) along the observed faults. Four rock types compose the general bedrock geology of the Phase 5 VLF area. The predominant bedrock unit is Granodiorite, which is a massive to foliated, medium to coarse grained, hornblende biotite ganodiorite. The second most common unit is the Cripple Creek Lapilli breccia, which is generally massive, structureless, matrix-supported breccia that is poorly sorted, typical, diatremal crater-fill breccia. Clasts are sub-angular to sub-rounded and primarily composed of various phonolite units with occasional Precambrian fragments. The breccia commonly shows varying degrees of weak argillic to potassic alteration. The third and fourth rock types are the Biotite Phonolite and Phonolite, respectively. The Biotite Phonolite is generally a gray, fine-grained porphyry with euhedral biotite and alkali feldspar phenocrysts. The phonolite is light- to medium- gray, porphyry with subhedral to euhedral, medium- to coarse-grained phenocrysts of alkali feldspar with minor amounts of feldspathoids, glassy apatite and pyroxenes. • 4.5 Geochemistry In 1998, for Amendment No. 7, Shepherd Miller Inc. ("SMI") and Adrian Brown Consultants conducted extensive investigations of the ground water hydrology and geochemistry of the District. These studies were reviewed and updated as a part of the investigations for the Amendment No. 8. Additional studies were conducted in 2008 by Adrian Brown Consultants as part of this MLE. A copy of the most recent study is included as Appendix 1 in Volume II of this document. The results of this study are summarized below. The 2008 study reached two conclusions: ¦ The proposed MLE will not increase the average regional ground water flow rate; and Any potential acid generation that might occur at the surface or in historical underground mines will be neutralized along the subsurface flow paths in the diatreme to the regional ground water table as intersected by the Carlton Tunnel. The 2008 study updated the regional hydrology of the proposed MLE including the new mining areas and the overburden storage areas. It was determined that the • evapotranspirative losses from disturbed land in the project area are approximately the Cripple Creek & Victor Gold Mining Company Cresson Project Mine Life Extension 4-6