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SUNDAY MINE COMPLEX- HYDROGEOLOGIC REPORT <br /> formation ranges from 400 ft thick within Hamm Canyon to a very thin layer near the center of <br /> Big Gypsum Valley. <br /> The San Rafael group is comprised of the Middle and Upper Jurassic Carmel Formation and the <br /> Upper Jurassic Entrada sandstone and Summerville Formation in ascending order. The group <br /> outcrops in a narrow band along the cliffs on the northern side of Big Gypsum Valley and in <br /> wedges towards the center of the valley. Red sandstone and mudstone make up the Carmel <br /> Formation overlain by the orange, buff and white-colored fine-grained Entrada Sandstone. The <br /> Summerville Formation, comprised of thin-bedded red, gray, green and brown sandy and silty <br /> shales and mudstone, overlies the Entrada sandstone and is uniform in thickness of <br /> approximately 105 ft except near the Gypsum Valley anticline where it gets thinner. Thin beds of <br /> green and red chert are common within the formation. <br /> The contact between the Summerville Formation and the overlaying Upper Jurassic Morrison <br /> Formation is hard to distinguish because of the similarity of the shales and mudstones of the <br /> formations. The lower member of the Morrison Formation, the Salt Wash sandstone member, is <br /> the uranium/vanadium ore-bearing zone of the SMC. The Salt Wash sandstone member is <br /> characterized by thick ledges and benches of nearly white to gray, light buff and rusty red <br /> sandstone. The Salt Wash sandstone member is interspersed with lenses of red shale and <br /> mudstone and ranges from 320-380 ft thick. Unlike the underlying strata, the Salt Wash <br /> sandstone does not thin near the Gypsum Valley anticline. The upper member of the Morrison <br /> Formation, the Brushy Basin member, is comprised of white, red, blue and green bentonitic <br /> shales and mudstones with lenses of sandstone, conglomerate and thin limestone. The Brushy <br /> Basin member ranges from 350-430 ft in thickness. <br /> The Morrison Formation is overlain by the Lower Cretaceous Burro Canyon Formation <br /> consisting of white, gray and red sandstone and conglomerate interspersed with beds of green <br /> and purple shale. The Burro Canyon Formation ranges from 190-240 thick in the area. <br /> The Lower and Upper Cretaceous Dakota sandstone overlies the Burro Canyon Formation and <br /> is mostly coarse-grained crossbedded gray, yellow and buff colored sandstone. Thin seams of <br /> gray and black shales and impure coal also occur within the sandstone. The Dakota sandstone <br /> is about 200 ft thick in the area. <br /> Western Water& Land, Inc. 8 <br />