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§2.04 APPLICATION FOR PERMIT FOR SIIRFACE OR UNDERGROUND MINING ACTIVITIES -- <br />MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOURCES. <br />• ' <br />2.04.6 <br />Geology Description. <br />(2) (a) (Cont'd.) <br />D'^^~ ~t"C~510~ seven cycles of marine-nonmarine deposition in the <br />,~,~oc ~ ("eastern Piceance Basin. The coal deposits of the area <br />~7'~''~ were deposited as the complex relationships of deltaic, <br />fluvial, and barrier island fades were intermittently <br />modified by transgressive-regressive cycles of the re- <br />ti~ treating Cretaceous shoreline. <br />ti <br />I <br />O~ <br />4 <br />I ~ti The coal bearing member of the Mesaverde Formation lo- <br />~ ~ Y 2_iv' tally contains four to six mineable coal seams in the <br /> G <br />, aoo' North Fork Valley, named in ascending alphabetical or- <br />N ~~ <br />~' I <br />~, ~p o'~ler, within the stratigraph ic interval 500 to 600 ft. <br /> ti above the Rollins Sandsto ne Member (DURrUd, 1976). <br />\pbp <br />~y ~~ ~'~ Mines recently operating in the various coal seams are <br /> as fo llows: Tomahawk Strip - A through F; Somerset - R <br />and C; Orchard Valley - D; Blue Ribbon, Hawks Nest, and <br /> <br />Bear - E; Mount Gunnison - F (Kelso, et al, 1981). Due <br />~~~\/~s~~~ to the depositional environment of the coal bearing <br />member, individual coal seams are not laterally contin- <br />uous nor do they maintain uniform thicknesses from dif- <br />fering locations throughout the area. <br />The barren member of the Mesaverde Formation is lithol- <br />ogically similar to the coal bearing member with the <br />exception of virtually no mineable coal seams. In the <br />North Fork area, the barren member is stratigraphically <br />between the F coal seam and the Ohio Creek conglomer- <br />ate, and coas estimated by Lee (1912) to be 1500 ft. <br />thick. The paucity of coal deposits within the barren <br />member probably represents progradation of terrigenous, <br />nonmarine sediments deposited in response to the re- <br />treating shoreline. Hail (1972) reports maximise thick- <br />ness of the entire Mesaverde Formation [o be about 2300 <br />ft. <br />The Paleocene Ohio Creek Formation unconformably over- <br />lies the Mesaverde Formation. The Ohio Creek Formation <br />consists of light gray, locally conglomeratic sandstone <br />which ranges in thickness from locally 0 to a maximum <br />of 200 ft. Where the conglomeratic fades is lacking <br />or obscured by surficial deposits, the Ohio Cceek For- <br />mation is mapped within the Mesaverde Formation (Hail, <br />1972). <br />Revised 08(01184 <br />Revised 10/01/87 <br />16 <br />