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SaYiar - ?.04.6 Drillhole 1«ations are shown on the Mine Area Geology Maps, (Maps 2.04-M3)~ d dnllhole logs • and other relevant geologic information is included in Exhibit 2.04-E3,`~eologic Information. Toooeraohv The topography of the mine permit area includes a portion of the valley of the North Fork of the Gunnison River along the southern pemtit boundary, elevated river terraces along the northern margin of the valley, relatively steep mountain sideslopes and exposed r«ky cliffs rising up from the terraces; numerous steep-sided drainages along the mountain slopes with intervening ridgelines; and relatively flatter mountain park areas along and north of the northern perrrrit boundary. Elevations range from approximately 6,000 feet amyl along the North Fork Valley to over 5,500 feet ams] on the highest mountain peaks to the north. Stratieraohv Within the mine permit and adjacent areas, surface r«k exposures and mine development will «cur within the sequence of sedimentary rock units described in the following sections in descending order from the ground surface and shown on Figure 2.04.6-F1, Typical Geologic Cross-Section. In addi[ion to the primarysedimentaryunits, isolated igneous intnrsives maybe encountered az noted. Wasatch Formation (Tertiary) -The Wasatch (ako designated az the Ruby) Formation overlies the Mesa Verde Fomration along a regional low-angle unconfomuty. It consists of red and buff shales and red sandstones in the upper part of the formation, and red to gray conglomerates in the lower portion. The indicated source for these units would be weathered volcanic r«ks, with some remnant weathered volcanic rocks evident in the lower 100 to 200 feet of arkosic and conglomerate beds of this formation. The Ohio Creek Conglomerate, which is the basal conglomerate unit, is a regional • marker and commonly referenced geologic mapping datum Mesa Verde Formation (Cretaceous) -The Mesa Verde Formation u the primary coal-bearing formation in this region and confomtably overlies the Mancos Shale Formation. It consists of approximately 2,300 feet of inter-bedded coal seams, sandstones, shales, and silutones that are sub- divided into the following members: Barren Member -The upper portion of the Mesa Verde Formation, which u approximately 1,600 fee[ in thickness, contains no coal seams. It consists primarily of buff, lenticular sandstones with minor interbedded grayshale units. Paonia Member -The Paonia Member, which ranges from 300 to 500 feet thick in this area, u composed of roughly equal proportioru of shales and interbedded buff, lenticular sandstones with some coal seams. The top of the Paonia Member u a massive cliff-fomvng buff sandstone approximately 100 feet thick, or more. Due to its lenticular nature, the unit u not continuous and there may be some variation in iu l«ation and elevation within the stratigraphic sequence. The Paonia Member contains the 1«allysignificant D and E coal seams. Bowie Member -The Bowie Member, which ranges from 270 to 350 feet thick in this area, consisu primarily of gray shales with inter-bedded lenticular buff sandstones and coal searru. The top of the Bowie Member u marked by a massive buff sandstone and several l«ally significant coal seams «cur in the upper portion of this member. Similar to the Paonia Member, the capping sandstone unit is discontinuous and may «cur at shghdy different horizons in the sequence. The Bowie Member contains the A, B, and C coal seams. • Rollins Sandstone Member -The Rollins Sandstone, which ranges from 120 to 200 feet in thickness, rs a massive, cross-bedded, mediutrr to coarse-grained, buff to white sandstone unit. In other areaz, it's massive nature results in prominent cliff exposures, although in this area, it «curs near the base of or below the exposed stratigraphic sequence. The Rollins Sandstone lies confomrably on the PR04 2.04-9 Revised August 2000