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SUNDAY MINE COMPLEX-HYDROGEOLOGIC REPORT <br /> did not penetrate pre-Paradox strata. Furthermore, all surface occurrences of the Paradox <br /> member in the area are related to salt intrusions. <br /> The progressively younger strata are exposed on the ridges or cuestas north and south of Big <br /> Gypsum Valley, dipping northeast on the north ridge and southwest on the south ridge where <br /> the SMC workings are located. A few small outcrops of Permian Cutler Formation have been <br /> mapped as the lowest strata exposed at the bottom of north ridge at the mouth of Hamm <br /> Canyon, across Big Gypsum Valley from the SMC. The Triassic Chinle Formation also occurs at <br /> the base of the north ridge and is the predominant older mapped unit in the local stratigraphic <br /> sequence. The south face, top, and north face of the north ridge exposes the progressively <br /> younger rocks up through the Cretaceous Burro Canyon Formation that lies mostly on the lower <br /> northeast facing slope of the north ridge facing Dry Creek Valley. <br /> The stratigraphy of the SMC area consists mostly of the strata within the Mesozoic-age section. <br /> This area forms the southwest limb of the Big Gypsum Valley anticline, so strata generally dip <br /> 15° to 20° southwest, exposing the older rocks at the base of the cuesta ridge and progressively <br /> younger rocks upslope and to the southwest. The cuesta consists of Upper Jurassic-age <br /> Morrison Formation Salt Wash member and the overlying Brushy Basin member. The Brushy <br /> Basin unit makes up most of the north, top, and south flank of the ridge. The Salt Wash Member <br /> is exposed in smaller outcrops along the base of northeast flank of the ridge. The uranium and <br /> vanadium ore bodies are present in the Top Rim Sandstone unit within the upper 100 ft of the <br /> Salt Wash Member (CDM, 2009). The overlying Cretaceous Burro Canyon Formation forms the <br /> lower half of the ridge's southwest flank. Progressively younger strata have been mapped by <br /> Cater to the south into Disappointment Valley with the Mancos Shale making up the central part <br /> of the valley. Further to the southwest, at the Dolores River, the Dakota Sandstone, Burro <br /> Canyon Formation and Brushy Basin outcrop again, indicating the presence of the syncline as <br /> mapped by Cater. <br /> Big Gypsum Valley is mostly overlain by a veneer of Quaternary alluvium, but in the area <br /> immediately northeast of the SMC, there exists a faulted down thrown block of Mesozoic strata <br /> that includes the Burro Canyon Formation, Dakota Sandstone, Mancos Shale, and Mesa Verde <br /> Formation, exposed in that order from southwest to the northeast. This mass of rock juxtaposes <br /> the Salt Wash and Brushy Basin strata with Burro Canyon Formation on the southwest side of <br /> the valley, immediately adjacent to the mines of the SMC. <br /> Western Water& Land, Inc. 10 <br />