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section extension and the new cross section H-H' are based on coal exploration holes drilled by <br />Western Fuels-Colorado during 1993. Figure 2.04.6-1 was prepared using information obtained by <br />geologists, hydrologists, and soil scientists during the baseline studies conducted during 1986 and <br />1987. Stratigraphic correlation of individual driller's logs in Maps 2.04.6-2 through 2.04.6-5 proved <br />to be difficult, and at times, confusing because of the wide variation in driller's terminology. Only the <br />principle stratigraphic units (i.e., coal seams, sandstone, shale, etc.) were correlated in these cross <br />sections. The principal coal seam being mined is the #2 or lower Dakota coal seam. One localized <br />area of upper Dakota coal (#1 seam), which includes Drill Hole Location 871 E, may be mined in this <br />permit term. These seams lie within the "middle" Dakota lithologic unit described by Young (1973), <br />and are characterized by carbonaceous shale and impure coal with lessor amounts of interbedded <br />sandstone and siltstone. Basically, these coals are high BTU, low sulfur bituminous coals that show <br />good lateral continuity. Each seam shows awell-defined system of vertical to near vertical joints (coal <br />"cleats") at the outcrop. These joints are less evident in core samples indicating a lower porosity than <br />would be expected by outcrop examination. Fractures of this sort are highly anisotropic. <br />The upper Dakota (#1) seam generally ranges from 0.6 to 2.1 feet (partings omitted) in thickness with <br />. an average of about 1.2 feet and lies approximately 99 feet from the base of the Dakota. The lower <br />Dakota (#2) seam generally ranges from 4.2 to 6.9 feet (partings omitted) in thickness with an <br />average of about 5.5 feet and lies approximately 86 feet from the base of the Dakota. There is <br />approximately 7.5 feet of interburden separating these seams within the New Horizon 2 permit area. <br />A 0.4 foot laterally discontinuous "rider" coal seam is found about 7.2 feet above the upper Dakota <br />coal seam in some parts of the permit area. Two additional coal seams, the Nucla (#3) seam and an <br />unnamed seam, are present in the New Horizon 2 study area. The Nucla seam typically ranges from <br />1.5 to 3.6 feet (partings omitted) in thickness with an average of about 2.5 feet and lies approximately <br />56 feet from the base of the Dakota. The laterally discontinuous unnamed coal seam generally <br />ranges from 0.5 to 1.6 feet in thickness with an average of about 1.0 feet and lies approximately 24 <br />feet from the base of the Dakota. <br />Sandstone and sandy shale are the predominant lithologies in overburden material within the New <br />Horizon 2 study area. The sandstones are generally fine to medium grained, of low porosity, well <br />cemented, lenticular, discordant, and crossbedded. Most sandstones on outcrop show awell-defined <br />system of iron stained joints and fractures. Continuous horizontal gypsum lenses occur between <br />~~ Revised 9/99 2.04.6-4 <br />