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compaction within co2a seams, channel sands, etc., within the formation. <br /> With regard to the regional stratigraphy, the rocks outcropping in the North <br /> Fork valley would include from youngest to oldest the Oligicene intrusives, Ohio <br /> Reek conglomerate, Mesa Verde formation and Mancos shale. In general, the Ohio <br /> Reek conglomerate and the Oligicene intrusives will be found topographically <br /> above the site toward McClure Pass. The Mancos shale outcrops downstream of the <br /> site toward Delta, Colorado. The most commonly used terminology for the Mesa <br /> Verde formation in the North Fork valley breaks the Mesa Verde into four members. <br /> The base of the Mesa Verde is a thick, massive sandstone known as the Rollins <br /> Sardstone member. Immediately above the Rollins is the Lower Coal member which <br /> commonly contains the "A", "B", and nCn seam coals. Above that unit is the Upper <br /> Coal member which CMta?iis the nEYI, "E", and "F" seams. Although coal is present <br /> no significant minable seams are considered to exist above the "F" seam. That <br /> portion of the Mesa Verde located above the "F" seam is commonly referred to as <br /> the Barren member. <br /> Prediction of subsidence effects in this study have been accomplished using <br /> the zone area method which is an influence function procedure. Although some <br /> work has been done in the last decade or so concerning the potential effects of <br /> varying overburden lithology on subsidence, the state the art is not considered <br /> to be developed to the point where it may be used reliably as a predictive tool. <br /> Therefore, for the purposes of this study we have made no attempt to account for <br /> the stratigraphic variations in the lithology of the overburden materials. <br /> 2.2 Land Use <br /> The topography in the vicinity of the mine site is rugged, mountainous <br /> terrain with steep tree and brush covered slopes. The surface contains numerous <br /> F <br /> i <br />