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feasible. At a future time, auger mining may prove to be a viable mining method in <br />this locale. Auger mining is not proposed to be employed in this mining and <br />reclamation permit. <br />Regional hydrologic impacts to the surface and groundwater regime are not anticipated <br />from the mining and reclamation operations. The surface and groundwater resources of <br />the permit and adjacent area aze limited (based on topography and position of strata, as <br />well as size and location of the potentially impacted drainage basin). <br />2.04.6(21 Surface Mining <br />Discussion of the general stratigraphy is limited to those formations outcropping above <br />the Mesaverde Group of Upper Cretaceous Rocks (See Figure 4-1) and is illustrated on <br />the Geologic Map (Map 4-2). <br />Lewis Shale (Kl Upper Cretaceous) The Lewis Shale is a dark gray to black <br />homogeneous clay shale with scattered concretions of shaley limestone and a few thin <br />bentonite seams in the upper portion. The formation averages 1,800 feet in thickness. <br />Pictured Cliffs Sandstone (Ktx Upper Cretaceous) The Pictured Cliffs Sandstone <br />consists of two members in the Carbon Junction area. The lower member overlying the <br />• Lewis Shale consists of a sequence of interbedded clay shale and thin sandstone <br />averaging 80 feet in thickness. This lower member is informally noted on the geologic <br />cross sections as "Transition Zone" due to its lithologic transition from Lewis Shale to <br />the more massive sandstones of the upper Pictured Cliffs Sandstone. <br />The Upper Pictured Cliffs Sandstone is a white to light gray, well sorted sandstone <br />within thin interbeds or lenses of clay shale or siltstone. The sandstone is usually fine <br />to medium grained with a high percentage of quartz (8546+) and very hard. The <br />average thickness of the Upper Pictured Cliffs is 120 feet. <br />Fruitland Formation IKf Upper Cretaceous) The Fruitland Formation consists of a <br />sequence of complexly interbedded sandstone, siltstone, shale coaly shale and coal. <br />The contacts between the lithologic stratums aze arbitrarily chosen due to their <br />gradational contacts. A tongue of the under]ying Picture Cliffs Sandstone wedges <br />between the Lewis Coal Zone and the overlying Cazbonera Coal Zone in the Carbon <br />Junction Mine area. For the purpose of discussion, this tongue has been mapped as a <br />part of the Fruitland Formation. Amore detailed description of the stratum zones <br />slated for disturbance by surface mining occurs in the test borings section. The upper <br />portion of the Fruitland is gradational into the overlying Kirtland shale so the <br />formational contact is azbitrarily chosen. The average thickness for the formation is <br />700 feet. <br /> <br />Technical Revision 09 (v 1.0) 48 Revised 3/1998 <br />