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Geotechnical Stability Exhibit M <br /> boulders. Clasts are unweathered or only slightly weathered, <br /> subround to subangular,and consist largely of diorite <br /> porphyry,monzonite porphyry,sandstone and siltstone. <br /> Unit may contain placer gold(Eckel,1949)and may be a <br /> source of sand and gravel. <br /> Pleistocene Older Colluvium(Qco) Occurs on dissected hill slopes,ridgelines,and drainage <br /> divides as erosional remnants. Texture,bedding and clast <br /> lithology resemble those of colluviums(Qc).Unit may be <br /> subject to collapse,piping and settlement where fine grained <br /> and low in density. <br /> Upper Cretaceous Mancos Shale(Km) Argillaceous limestone and calcarenite with thin beds of <br /> limestone.Unit is rich in sulfur which can be corrosive to <br /> concrete and may affect the quality of groundwater. <br /> Upper Cretaceous/Lower Dakota Sandstone/Burro Canyon Dakota Sandstone is light-to-medium gray,light to medium <br /> Cretaceous Formation(Kdb) brown,and yellowish brown,fine to coarse-grained <br /> sandstone and minor conglomeratic sandstone and <br /> conglomerate that is interbedded with dark-to-medium-gray <br /> siltstone,carbonaceous shale and thin coal beds. The <br /> uppermost part of the Dakota includes thinly bedded,marine <br /> sandstone. The Burro Canyon Formation is a It brown-very <br /> It gray,medium-coarse-grained sandstone,chert-pebble <br /> conglomerate and grayish-green,non-carbonaceous <br /> claystone.The Dakota Sandstone and Burro Canyon <br /> Formation generally serve as good foundation material. <br /> Shear fractures commonly act as failure planes for rock falls <br /> and rock topples.The unit is prone to land sliding along <br /> shale beds within the formation The Dakota Sandstone is <br /> an oil and gas reservoir in parts of the San Juan Basin. <br /> Upper Jurassic Morrison Formation Qm) Bentonitic mudstone and claystone containing thin beds of <br /> very fine-grained sandstone and minor conglomeratic <br /> sandstone.Bentonitic beds within the formation may be <br /> prone to swelling soil problems The Brushy Basin Member <br /> may be subject to landslidmg where exposed on steep <br /> hillsides or on dip slopes.The Salt Wash Member has <br /> yielded Uranium in the region although no know radioactive <br /> occurrences have been reported in the quadrangle. <br /> Junction Creek Sandstone Qjc) Highly cross-bedded to massive,fine to coarse-grained <br /> sandstone.It may pose rock fall hazards where exposed in <br /> steep cliffs. <br /> Wanakah Formation(Jw) Very fine to fine-grained sandstone and mudstone. No <br /> recorded eolo is hazards. <br /> Entrada Sandstone Fine to coarse grained highly cross bedded sandstone. <br /> Where ex osed in cliffs,may cause rock fall hazards. <br /> Upper Triassic/Lower Dolores and Cutler Formations Both formations may be prone to rock fall hazards where <br /> Permian (TRPdc) exposed in steep cliffs. <br /> Geologic and geotechnical consideration were considered in evaluating the potential to affect the <br /> following: <br /> • May Day No. 1 Portal entry collapse and head scarp stabilization (TR-1)-construction is <br /> completed: <br /> • New Access Road- (TR-2)-construction is completed and approved by DRMS <br /> Wildcat Mining Corporation <br /> 112(d)Permit—May Day and Idaho Mine Application <br /> Revised November 14,2014 <br /> Rule 6.5 Page 2 of 7 <br />