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Whirlwind Mine Groundwater Characterization Report <br /> ledges. Conglomerate is pebbly but may contain cobbles to 1-ft in diameter or more <br /> consisting of quartzite, granite, felsite, gneiss and schist clasts (Doelling, 2002). <br /> Boring BM00-1, drilled by Umetco in 2000 on Beaver Mesa approximately 0.75 miles west of the <br /> Whirlwind Decline portal, was shown to intercept 105 ft of Burro Canyon Formation, 405 ft of <br /> Brushy Basin Member, and penetrated 50 ft into the Salt Wash Member. The Burro Canyon <br /> Formation was characterized by white to light buff colored calcareous sandstone that was very <br /> fine-grained. Several sequences of sandstone units were encountered in the Brushy Basin, two <br /> of which measured 11 and 49 ft thick, and 150 to 122 ft above the interpreted bottom of the <br /> Brushy Basin, respectively. The sandstones were noted as light brown and medium-to coarse- <br /> grained. The bulk of the Brushy Basin was comprised of variegated mudstone. The intercepted <br /> sandstone in the Salt Wash was noted as light reddish gray and fine-grained and dark gray, to <br /> black medium-grained with slightly argillaceous black uranium mineralization. <br /> Generally, the Salt Wash Member in the vicinity of Beaver Mesa consists of lenticular, cross- <br /> bedded sandstone interbedded with slope-forming red mudstone and shale. The lenticular <br /> cross-bedded sandstone beds are very fine-to fine-grained but other units may be fine-to <br /> medium-grained. These channel sandstones coalesce into thicker units in the upper part of the <br /> Salt Wash forming the Top Rim unit, a main uranium and vanadium ore-bearing unit in the <br /> Beaver Mesa Unit. As discussed above, thinner sandstone sequences are present in the central <br /> part of the member and are referred to as the Middle Rim sands. Like the Top Rim, a thicker <br /> sequence of sandstone occurs in the bottom portion of the member; this sequence is referred to <br /> as the Bottom Rim. The Middle Rim and Bottom Rim also host uranium/vanadium ore deposits <br /> (EFR, 2008a) <br /> 3.2 Geologic Structure <br /> The geologic structure in the vicinity of the Whirlwind Mine is relatively uncomplicated and <br /> reflects somewhat typical structure observed in other parts of the Colorado Plateau. The <br /> sedimentary rocks in the study area dip gently one to three degrees to the northeast(Eicher and <br /> others, 1957). Faulting in the area is essentially limited to the Lumsden Canyon Fault, a normal <br /> east/northeast trending (N700E) fault that has been mapped by Eicher and others (1957) along <br /> the axis of the upper part of Lumsden Canyon and extending to the west side of Beaver Mesa. <br /> According to drill hole logs, vertical displacement along this fault is indicated to be <br /> Western Water& Land, Inc. 10 <br />