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9 <br />beds in a cycle range from several tens to several hundreds of feet in <br />thickness. During the latter part of Pennsylvanian time, about <br />2,000 feet of limestone and shale, the Limestone member of the Hermosa <br />Formation, was deposited on tap of the Paradox member. <br />Beginning in late Pennsylvanian time and extending into the early <br />Permian, strong, positive movements occurred in the bordering <br />Uncompahgre Uplift. The uplift was accompanied by faulting near the <br />basin's margins and by erosion in the highlands. At this time, a <br />thick section of arkosic sandstone and conglomerate, the Cutler <br />Formation, was deposited in the adjacent Paradox Basin. The coarse, <br />arkosic sediments are intercalated with marine deposits in the western <br />portion of the basin. <br />During the majority of Mesozoic time, about 2,400 feet of <br />continental sediments were deposited in the area as it subsided <br />slowly. These deposits consist primarily of fluvial sandstones, <br />conglomerates and mudstones with some eolian sandstones. The known <br />deposits of uranium and vanadium ores occur in the Mesozoic sections. <br />The principal host rocks for the uranium and vanadium deposits are <br />sandstone and conglomerate lenses in the Chinle Formation and Salt <br />Wash member of the Morrison Formation. <br />Continental sedimentation terminated with the deposition of the <br />Dakota sandstone and the transgression of a late Cretaceous seaway. <br />At this time, a thick deposit of marine shales, the Mamas Shale, was <br />deposited in the area. Continental sediments of the late Cretaceous <br />Mesa Verde Formation were deposited on top of the Manoos Shale. Both <br />of these late Cretaceous formations have been extensively eroded; they <br />