Laserfiche WebLink
Topographic features within the permit area include gentle southwest facing slopes; gentle <br />rolling upland hills and ridges; old terraces, benches, and mesas; and shallow drains (ephemeral) <br />and sloughs which feed Tuttle Draw (perennial). <br />Borehole and Corehole Locations. The 355 boreholes (also referred to as drill holes) and <br />coreholes, that are located within and nearby to the NHN Mine permit area, are shown on Map <br />2.04.6 -1. Boreholes (drill holes) provide stratigraphic data (top and bottom elevations, lithology, <br />and thickness), whereas, coreholes provide stratigraphic data as well as core samples for <br />laboratory analyses. Most of these holes were drilled by Peabody Coal Company. WFC drilled <br />8 holes within the permit during 1993 to verify the Peabody drilling and have drilled an <br />additional 23 holes in adjacent areas (three of which were within the permit during 2008 and <br />2009) that have further verified both structure and stratigraphy in the NHN area. To date, there <br />have been 174 holes drilled within the proposed NHN permit boundary. Fifty five (55) of these <br />holes were core drilled for sample analyses. Attachment 2.04.6 -1 of the New Horizon 2 Mining <br />and Reclamation Permit (C -81 -008) contains numerous lithologic and geophysical drill logs in <br />the general permit area which show and describe the lithologic characteristics and thickness for <br />each coal seam and associated strata. The location and elevation of these drilling sites are also <br />provided in the referenced appendices. The location of the New Horizon North drill holes for the <br />geologic cross - sections A -A' and B -B' are shown on Map 2.04.6 -1. The locations and summary <br />information on all holes located within the NHN permit area are contained in Appendix 2.04.6 -1 <br />of this permit application. <br />Structure The proposed NHN Mine permit area is located along the northeast flank of the axis <br />of the structurally simple Nucla Syncline. Structure contours in the NHN area that are drawn on <br />the top of the Lower Dakota (LDx) coal seam indicate that the coal seam strike is N. 26 degrees <br />W. and the dip is to the southwest toward the synclinal axis at about 1.9 degrees. Minor local <br />variations in the attitude of these coals occur due to spuriously trending small folds and <br />penecontemporaneous depositional features (differential compaction). These slight undulations <br />are best seen in the high wall and mine floor of the adjacent New Horizon Mine. The coal seam <br />outcrop patterns and overburden thicknesses are determined by a combination of topography and <br />geologic structure. The surface and drainages appear to have developed on the dip slope. Map <br />2.04.6 -2 is a structure contour map of the NHN area, which is drawn on the top of the LDx coal <br />seam. Minor faults (several feet) have been observed at the adjacent New Horizon Mine and one <br />persistent fault has a displacement of up to 10 feet. Suspected faulting is shown on Map 2.04.6 -2 <br />and indicates that a northeast trending fault with a displacement of about 30 ft occurs in the <br />northwest corner of the proposed permit area. <br />Map 2.04.6 -3 is an overburden map to the top of the LDx Seam. This map shows that the <br />maximum overburden thickness to the top of the LDx Seam is slightly over 90 feet and occurs in <br />the southern portion of the permit area adjacent to the old highwall of Peabody's Nucla Mine. <br />Minimum overburden thickness (ten feet or so) occurs along the drainage referred to as "Meehan <br />Draw" as well as the northeastern corner of the permit area where the structure and topography <br />result in thinner overburden. <br />Section 2.04.6 Page 2 April 2011 <br />