Laserfiche WebLink
State Reg. <br /> (1973) , and are characterized by carbonaceous shale and impure <br /> coal with lessor amounts of interbedded sandstone and silt- <br /> stone. Basically, these coals are high BTU, low sulfur bitu- <br /> minous coals that show good lateral continuity. Each seam <br /> shows a well-defined system of vertical to near vertical joints <br /> (coal "cleats") at the outcrop. These joints are less evident <br /> in core samples indicating a lower porosity than would be ex- <br /> pected by outcrop examination. Fractures of this sort are <br /> highly anisotropic. <br /> The Upper Dakota (#1) seam averages frcm 1.6 to 3.3 feet in <br /> thickness and lies approximately 100 feet from the base of the <br /> Dakota. The Dower Dakota R2) seam averages from 5.9 to 7.9 <br /> feet in thickness and lies approximately 83 feet frccn the base <br /> of the Dakota. There is roughly 7 feet of interburden sepa- <br /> rating these seams at the mine site. A 1 foot laterally dis- <br /> continuous "rider" coal seam is found 8 feet above the Upper <br /> Dakota coal seam in sane parts of the permit. in the under- <br /> burden, two additional coal seams, the Nucla (#3) seam and <br /> an unnamed seam, are observable in the Nucla area. They occur <br /> approximately 52 feet and 23 feet, respectivel1T, above the <br /> base of the Dakota. <br /> Shale and sandy shale are the predominant lithologies in over- <br /> burden material at the Nucla Mine site. These shales are <br /> characterized by their extremely fine-grained nature, fria- <br /> bility, high carbon content, and exceedingly low vertical and <br /> horizontal permeabilities. Two thin clay (kaolinite?) beds <br /> are widely traceable in the northwest part of the permit. <br /> These clays average 1 to 2 feet in thickness and are found <br /> approximately 42 feet and 52 feet above the Upper Dakota Coal <br /> Seam. <br /> 6-15 <br />