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.~ <br />. State of Colorado <br />Department of Natural Resources <br />• December 28, 1976 <br />Page two - <br />Lessee: <br />DFC Ceramics, Inc. <br />(2-d) <br />Map of Location and Area: <br /> <br />Attached. The 9-acre mining <br />the 148-acre quarter section <br />from the State of Colorado. <br />(2-e) <br />area is entirely within <br />leased by DFC Ceramics, Inc. <br />Approximate Size of Affected Land: <br />A total of 9 acres, with actual mining to be done on <br />only a small portion of this, approximately 4 to 5 acres. <br />(2-f) <br />Type of Mininq Operations: <br />The principal operation is the extraction of about <br />250 tons per year of a siliceous clay lying about 2 <br />to 3 feet behind (west) of the steeply sloping hard <br />sandstone faces now exposed on the east side of the <br />Golden Hogback. The outer rock face is blasted and <br />pushed away, and the clay behind is then blasted to a <br />depth of 3 to 5 feet and loaded out with a front-end <br />loader. The depth o£ mining is set by the thickness <br />of the clay over a second hard sandstone layer behind it. <br />Actual operations take a few weeks each year or two and <br />the area mined is about 600 to 800 feet of face per <br />year. No new land is being stripped as the faces <br />being mined have been exposed for 30 to 40 years. <br />An additional very small operation has been carried on <br />to extract a thin (about 3 to 4 feet thick) bed of <br />plastic clay lying about 20 to 30 feet east of the <br />exposed sandstone faces, and having the same steep <br />dip of these faces. Only about 20 to 30 tons per year <br />of this clay is being mined. <br />Extraction is done by opening a short horizontal tunnel <br />about 15 to 20 feet long at a point about 100 feet <br />below the exposed sandstone faces. This tunnel <br />intersects the plastic clay vein, and a shrinkage stope <br />is then driven upward toward the surface, finally <br />reaching the surface at a point on the edge of the <br />bench in front of the old exposed sandstone faces. <br />When extraction is complete, the top of the stcpe is <br />blasted in to close it. Almost no surface change occurs <br />due to the thinness of the vein. <br />Due to the small amount of clay extracted, one of these <br />stopes will last for a period of 5 years or moz•e, so the <br />surface disturbance is negligible. <br />