2011-04-08_PERMIT FILE - C1981012A (8)

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2.04.6 Geology Description gY P (1) Coal presently being mined at the New Elk Mine lies within the upper Cretaceous - Tertiary Raton Formation, a heterogeneous sequence of lenticular, argillaceous sandstones, siltstones, shales and coal. Lithologic types are highly variable both laterally and vertically with correlations being best established through the coal seams. Bedrock geology in the mine area is limited to the Tertiary Poison canyon Formation and the Raton Formation as shown by Map 5, Geology. The Poison canyon Formation intermittently tops the hills in the mine vicinity and is not affected by mining operations. The relative position and stratigraphy of the coal being mined within the Raton Formation is shown in Map 7, Geologic Cross Sections. The mine plan area lies on the west flank of the Raton Basin, an asymmetrical, north -south trending structural basin. Generally, the structure of the rocks dip towards the east - northeast at approximately 2 percent over the area to be mined. An easterly trending normal fault was encountered during the course of mining operations and was successfully mined through without adverse effects. Rocks immediately above and below the Allen seam consist of interbedded sandstone, siltstone and shale. A description of the surficial geology within the New Elk Mine area is included under Geomorphology, Page 8, Exhibit 8, Hydrology and Geology Information. In order to identify potential acid - forming, toxic - forming or alkalinity- producing materials, a sample of refuse leachate was collected and analyzed, the results of which are presented in Exhibit 8, Hydrology and Geology Information. This method provides direct analysis of leachate as opposed to an inferred approach achieved through point sampling and analyzing and extrapolating data from raw rock samples. • However, to demonstrate correlation between the chemistry of the roof and floor of the Allen and Maxwell Seams, analyses are presented side by side in Exhibit 9, Overburden and Underburden Analysis. The drill logs located in Exhibit 8 present the nature, depth, and thickness of the coal seams to be mined, any coal or rider seams above the seams to be mined, each stratum of the overburden, and the stratum immediately below the lowest coal seam to be mined. Experience on site dictates that the makeup of these materials and the analysis of the coal is not indicative of the components of that would potentially lead to acidic runoff or adversely affect groundwater quality. Based on available analytical data, low sulfur levels for the coal seams and associated strata pose minimal impact in reference to acid mine drainage. With slightly basic groundwater and low sulfur values of the strata, reclamation efforts at the New Elk Mine should be highly successful. Four coals seams are of interest for mining; from bottom to top, they are the Allen Seam, the Apache Seam, the Maxwell Seam and the Blue Seam. The thickness of the Allen Seam varies from 2 to 11 ft, with areas where the thickness considered mineable exceeds 4 ft. The Apache Seam is found from 20 to 50 ft above the Allen Seam and has a thickness ranging from 4 to 8 ft. The Maxwell Seam is located 25 to 50 ft above the Apache Seam and has a thickness ranging from 4 to 12 ft. The Blue Seam is located 150 to 250 feet above the Maxwell Seam and has a thickness of less than 2 to 7 ft. The elevation of the Maxwell Seam ranges from 6,925 ft MSL to over 7,450 ft MSL as shown on Map 6A. This translates to depths ranging from about 300 to 900 ft. TR -55 2.04 -9 • 01/20/11