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<br />The coal to be mined from the Bear No. 3 portals is located in the <br />Paonia Coal Field. The Paonia Coal Field lies east of Paonia and south <br />of Grand Mesa in Delta and Gunnison Counties, Colorado. The North Fork <br />of the Gunnison River has cut a deep canyon acro..., the northern part of <br />the field. This canyon separates the tablelands south of the river from <br />the Grand Mesa. This southern tableland, 2,000 feet or more above the <br />valley around Paonia and Somerset, is deeply dissected by tributary <br />streams of the North Fork, and is bounded on the south and east by an <br />arc of intrusions of igneous rock which forms the rugged mountains <br />inherent with the Gunnison National Forest. <br />2.04.6 Geoloov Descriotion <br />As an "old coal field", the geology of the Paonia Coal Field has been <br />thoroughly studied and many reports on the area have been published. A <br />summary report of the area of immediate interest has been published by <br />the United States Geological Survey and is entitled, "Geology of the <br />Paonia Coal Field, Delta and Gunnison Counties, Colorado", (1948), by <br />Vard H. Johnson. <br />Stratigraphy <br />C <br />The rocks exposed in the Paonia Coal Field consist of the Mancos Shale <br />and the coal-bearing Mesaverde Formation of Upper Cretaceous Age, the <br />Ohio Creek Conglomerate, and the Wasatch Formation of Early Tertiary <br />Age, and the Quartz monzonite porphyry of Tertiary Age. <br />Mancos Shale <br />The Mancos Shale, the oldest formation exposed in the Paonia area, <br />comprises a sequence of dark gray to drab, locally buff marine shale, <br />2,000 to 3,000 feet thick. The shale weathers to a drab color and is <br />characterized by rolling badlands and terraces. Only the upper part of <br />the formation is exposed in the Paonia area. <br />2.04-12 <br />