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<br />I <br /> <br />II <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />)1)1139 <br /> <br />The contact ranges from transitional, with the mu1tifacied Eagle Valley <br />Formati on as observed in Mi 11 er Creek and on the ri dge north of Buford, to <br />abrupt with the Eagle Valley Evaporite facies near Buford. The contact is <br />often c1 early defi ned by the presence of a hard gray 1 imestone bed about 10 <br />feet thick. This unit is harder than both the younger and older rocks and is <br />easi 1y mapped in the fi e1 d, primari 1y up E1 k Creek and south of Warner Poi nt. <br />The Maroon Formation is Pennsylvanian-Permian in age and is characterized by <br />hard mi caceous maroon-to-pi nk sandstone interbedded wi th thi nner 1 a,yers of <br />dark red siltstones and mudstones. Limestone beds rangi ng in thickness from <br />one inch to two feet occur throughout the fonnation. The Maroon is the <br />predominant formation in the upstream part of the study area, cropping out on <br />both si des of the river from above Lake Avery to the conf1 uence of Mi 11 er <br />Creek. Owing to the gentle (=.150) dip to the northwest through this area, <br />the exposures along the right side of the river are usually spectacular barren <br />red cl iffs, wi th a steep stai r-stepped appearance. caused by the di fferenti a1 <br />weathering of the thin, weak mudstone layers and the more resistant <br />sandstone. The exposures on the left of the river are generally gentle dip <br />slopes covered by thick vegetation with good outcrops visible only in <br />tributary ravines. <br /> <br />Weber Sandstone (PPW) <br />The Maroon Formati on is over1 ai n by the Weber Sandstone, a1 so of <br />Pennsylvanian-Permian age, which is a resistant unit composed of light-gray to <br />tan, fine to medium grained, well sorted, well consolidated sandstone that <br />forms the crest of hi gh ri dges and northwest-faci ng di p slopes. The uni t <br />ranges from 100 to 250 feet in thickness in the project area. Utilizing the <br />Weber Sandstone as a marker was one of the most useful tools in establishing <br />the structural geology in the eastern part of the study area. <br /> <br />State Bridge Formation (TPs) and Chinle Formation (TPc) <br />Unconformably over1yi ng the Weber are the Tri assi c-Permi an State Bri dge and <br />Chinle Formations. These formations are characterized by orange-to-red, <br />massive siltstone and pebble conglomerate deposits with occasional <br />discontinuous light buff sandstone and gray limestone lenses. One of these <br /> <br />4-2 <br />