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Geology - Rules 2.04.5 and 2.04,6 <br />A detailed description of the geology of the permit area and adjacent area is <br />contained under Section 2.04.6, of the Dennit document. Additional <br />information on the geology of the permit area and adjacent area is shown on <br />Map 2, Mine No. 3 Geology; Map 3, Geologic Cross-sections; Map 21 a, Detention <br />Basin cross-sections; Exhibit 1; Tables 1, 2, 3, and 4; and Figures 1 and 2. <br />The proposed Dermit area lies on the southeastern flank of the Twentymile Park <br />Structural Basin. The basin is a synclinal extension of a much larger basin <br />to the northwest, the Washakie-Sand Wash Structural Basin. The syncline <br />forming the basin `is a doubly plunging, north-south trending syncline known as <br />the Twentymile Park Syncline. <br />The only major structural feature existing on site is a 200 foot wide fault <br />zone. The zone lies to the west of the proposed mining area and trends <br />northwest - southeast. It has a normal type displacement of 60 to 100 feet. <br />Four geologic formations exist in the vic <br />No. 3. They are, in ascending order, the <br />Williams Fork Formations of the Mesaverde <br />(Fi;gures 3 and 41. These strata were all <br />Period. Generally, the strata dip to the <br />the Twentymile Park Basin. <br />inity of the proposed Energy Mine <br />Mancos Shale, the Iles and <br />Group, and the Lewis Shale Formation <br />deposited during the late Cretaceous <br />west at 8 degrees to 14 degrees into <br />Three mineable coal seams, the Lennox, Wadge, and Wolf Creek coals, are <br />located within the Williams Fork Formation. The Wadge coal seam was mined at <br />the Energy Mine No. 3 surface mine. <br />Results of chemical analyses of overburden samples from the Energy Mine No. 3 <br />are Dresented in Table 4, Overburden Chemical Data, The applicant has <br />included overburden geochemical analyses from five drill holes within the <br />proposed permit area; geographic and vertical sampling density are in <br />accordance with State guidelines for overburden geochemistry sampling and <br />analysis. No acid-forming, toxic-forming or alkalinity producing material <br />have been identified. <br />No data are available in the permit application on chemical analysis of the <br />Lennox Coal Seam. This coal seam, which is known to be somewhat high in <br />pyritic and organic sulfur content in the Twentymile Park Basin, occurred in <br />the western portion of the surface mined area, and was spoiled with the <br />overburden. Given the small quantities of the Lennox coal seam which was <br />spoiled (a rough estimate is 5X or less of the total overburden in the mined <br />areal, no reclamation problems associated with the Lennox were anticipated and <br />none have been exhibited, For these reasons, lack of site-specific data for <br />the Lennox is not considered a significant environmental concern. <br />-5- <br />