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DESCRIPTION OF THE ENVIRONMENT <br />Geology <br />The Marr Strip Mine is located in North Pazk, an intermountain valley bound to the north by <br />Independence Mountain, to the east by the Medicine Bow Range, to the south by the Rabbit Eazs <br />Range, to the southeast by the Never Summer Range, and to the west by the Pazk Range. There is a <br />complex structure of folding within the North Pazk Basin, known as the North Pazk Syncline. <br />Within this syncline there aze numerous smaller folds generally trending southeast in the permit <br />area. The permit azea occupies the western, steeper flank of the asymmetrical Johnny Moore <br />syncline, which plunges to the south. The McCallum anticline is located just to the west, and <br />pazallels the permit area. The dip of the coal within the permit area ranges from 45° to 86° to the <br />east and northeast, averaging 68°. Two faults intersect the permit area along Bush and Williams <br />Draws. These strike from southwest to northeast and have a displacement of 100 to 150 feet. <br />The Marr Strip Mine produced coal from the Sudduth seam, a seam ranging from 35 to 75 feet in <br />thickness, averaging 50 feet. This seam is the lowest coal found in the 5000-foot-thick Tertiary <br />Coalmont Formation. Shale overlies the Sudduth seam, while a 50-foot-thick, fine-to-medium <br />grained sandstone lies between the coal and the underlying Pierre Shale. Quaternary alluvium of <br />sand, gravel, clay, dune sand, and glacial till is found along the creeks and rivers in the azea. <br />Geoctremical Analysis of Overburden and Underburden <br />Kerr Coal Company drilled numerous holes within the permit area and conducted toxicity analysis <br />of the overburden and Underburden. A total of 67 samples were taken from 18 drill holes. <br />Dissimilaz lithologies were sampled at five-foot intervals and analyzed for potential toxicity. The <br />areal sampling density was a minimum of one hole every 1300 feet. Other drill hole sample <br />analyses were available from the USGS and the BLM for azeas in and azound the permit azea. Kerr <br />sampled and interpreted the results using the published guidelines of the Wyoming Department of <br />Environmental Quality and the Montana Department of State Lands, Reclamation Division. <br />Interpretation of the analysis indicated no overall overburden or Underburden toxicities. Some of <br />the analyses showed a few values that exceeded the suspect levels identified in the guidelines from <br />one or the other of the two States. Levels for nickel were mazginally in the suspect range <br />(Wyoming guidelines). The overburden was found to be alkaline, however, and nickel in the <br />concentration ranges found at the mine would, according to certain studies, not suggest plant or <br />hydrologic toxicity problems. Some sample analyses showed mazginal potential toxicities for <br />selenium. Of 54 samples taken, 12 exceeded the suspect level (Wyoming guidelines). Of these 12 <br />samples, eight came from holes drilled with mud. This was believed to suggest that some <br />contamination had occurred. The remainder of the samples that showed elevated levels represents <br />12.7 percent of the overburden volume. Studies conducted by the federal government show that up <br />to 20 percent of potentially toxic material in atruck-and-shovel operation would be diluted to <br />acceptable levels. <br />Twenty-three of the samples exceeded the Montana guidelines suspect levels for molybdenum. <br />Wyoming does not have a suspect level for molybdenum. Studies indicate that a field occurrence <br />Marr Mine Permit Renewal OS 17 March 2006 <br />-R- <br />