Laserfiche WebLink
~1,,~ <br />SMITH WILLIAMS CONSULTANTS, INC. <br />• <br />summarized in Table 2. These evaporation data were used to represent the Cresson Project, and <br />were used to develop a monthly evaporation loss distribution. <br />In summary, the average amount of precipitation per year is 18.9 inches, and the average amount <br />of lake evaporation per year is 44.3 inches. <br />2.3 Geology <br />A description for the regional geology of the area is .presented in reports by CC&V that have <br />been previously submitted to the DRMS in Amendment No. 5 and supporting documentation <br />(see the July 29, 1993, letter from CC&V to the DRMS titled, `Amendment S to Permit #M- <br />1980-244; Information Responding to Concerns of DRMS Staff"). This information is not <br />reproduced in this document; however, a summary is presented below. This information was <br />compiled by CC&V and presented to Smith Williams for use in this report. The information <br />provided to Smith Williams was confirmed during site reconnaissance. Drawing A110 presents <br />a map of the surficial geology in the project area. <br />Four rock types compose the general. bedrock geology of the Phase 5 VLF area. The <br />predominant bedrock unit is Granodiorite (Xgd), which is a massive to foliated, medium to <br />coarse grained, hornblende biotite granodiorite. The second most common unit is the Cripple <br />Creek Lapilli breccia (Tbxll), which is generally massive, structureless, matrix-supported <br />breccia that is poorly sorted, typical of diatremal crater fill breccia. Clasts are sub-angular to <br />sub-rounded and primarily composed of various Phonolite units with occasional pre-Cambrian <br />fragments. The breccia commonly shows varying degrees of hydrothermal alteration. The third <br />and fourth rock types are the Biotite Phonolite (Tphb) and the Phonolite (Tph), respectively. The <br />Biotite bearing plagioclase Phonolite is generally gray, fine-grained porphyry with euhedral <br />biotite and alkali feldspar phenocrysts. The Phonolite is light- to medium-gray, porphyry with <br />subhedral to euhedral, medium- to coarse-grained phenocrysts of alkali feldspar with minor <br />amounts of feldspathoids, glassy apatite, and pyroxenes. <br />2.4 Underground Workings <br />Portions of the area beneath Phase 5 VLF were previously mined by underground means. <br />Underground mine development was generally undertaken from shafts and occurred at various <br />elevations. The underground working levels generally followed veins that were typically less <br />than 12 feet wide (cross-sectional dimension of drifts and laterals). In some workings, open <br />stope mining methods were used that followed ore veins upward from the working level <br />• excavations. <br />S:\PROJECTS\1125 CC&V PHASE 5 VLF\H2 - DESIGNVIREQUA VLFIVLF PHASE 5 FINAL REPORT V2.DOC 14 <br />