2014-08-13_PERMIT FILE - C1981018A (2)

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• D Seams are of sufficient thickness and areal extent to be considered economically recoverable. In Federal coal lease C-44693, only the D Seam is mineable. The B Seam is not mineable in this lease because of splits in the coal seam. The other five seams which overlie the B and D Seams are thinner and lack continuity and are therefore not mineable. These upper five seams are difficult to correlate over large areas within the Deserado Mine area. The seven seams located in the Lower Williams Fork are described in the following: B Seam The B Seam is the thickest and most laterally persistent coal seam in the Deserado Mine area. This seam varies from less than five feet thick to over twenty feet thick. Although this is the thickest seam in the area and underlies the entire Deserado Mine area it is also the most geologically complex of the seven seams. Seam complexity is the result of partings and major seam splits which tend to divide the seam into two major parts which are identified as: lower and upper B seam. Previously, (original MLR Permit Application Section II.B), the lower, upper B Seam, and upper B Seam split were referred to as the A Seam, B Seam and C Seam respectively; where the B Seam is not split, the Seam was previously referred to as the A/B/C Complex. Illustrations 36, 37 and 38 show the stratigraphic relationship of the B Seam and splits to the underlying B Horizon sandstone, the Iles Seam, and the other six seams located stratigraphically above the B Seam. Map 132 is an isopach map of the mineable B Seam. B Seam development began in 1997 and continued through 1998 with the completion of the B Seam shaft. Longwall operation is scheduled for mid-1999. • D Seam The D Seam has been a target of interest in the Rangely coal field area since the late nineteenth century and was mined at the now abandoned Staley-Gordon Mine until about 1970. Thickness of the D Seam varies from 0 (areas of non-deposition) in the western portion of the Deserado Mine area to slightly aver 10 feet in the central and eastern most portions of the area. Where presently being mined, the D Seam is of consistent quality and thickness. Map 133 is an isopach map of the mineable D Seam. Major partings to the north and east limit the mineability of the D Seam. The E Seam The E Seam occurs in relatively close proximity to the D Seam (6 inches to 20 feet). The economic significance of the E Seam is severely limited by its extreme variability in thickness and extent. The E Seam exceeds 3.5 feet of thickness in an area of about 200 acres centered in the NW1/4 Section 2, T2N R101W, achieving a maximum of about 6.5 feet. Interestingly, areas of maximum thickness of E coal coincide with minimum thickness, 3 to 6 feet, of the D to E interburden interval. Areas of thin interburden could have an adverse effect on the recoverability of portions of the reserve in the underlying D Seam as the thin interburden presents poor roof conditions. Exploration drilling in Federal lease C-51551 shows that the E Seam actually converges with the D Seam in that lease to produce a single coal bed of 11 to 13 feet in thickness. • F and G Seams The F and G Seams occur in an extremely variable stratigraphic interval positioned from 5 to 30 feet above the E Seam. Both seams approach 5 feet in thickness in isolated areas. (Permit Renewal #3 1/99) II.B-5