Laserfiche WebLink
• <br />2.04.6 Geology Description <br />The coal to be mined from the Coal Gulch Mine is located in the <br />northwestern flank of the San Juan Basin west of Durango, in La Plata <br />County, Colorado. Coal Gulch has cut a canyon across the coal field. <br />As an "old coal field", the geology around Durango, Colorado has been <br />thoroughly studied and many reports on the area have been published. <br />Coal mining has been conducted in the area since around the turn of the <br />century. <br />Stratigraphy <br />The rocks exposed in the Hesperus area of the San Juan Basin consist of <br />the Mancos Shale, and the Point Lookout Sandstone, the Menefee <br />Formation, and the Cliff House Sandstone of the Mesaverde Formation. <br />Several other formations occur in the area, as shown on the Regional <br />Geology Map (Map 5). <br />Mancos Shale <br />The Mancos Shale, the oldest formation exposed in the general area west <br />of Durango comprises a sequence of dark gray to drab, locally buff <br />marine shale, 2,000 to 3,000 feet thick. The shale weathers to a drab <br />color and is characterized by rolling badlands and terraces. Only the <br />upper part of the formation is exposed in the Durango area. <br />Mesaverde Formation <br />The Mesaverde Formation, which overlays the Mancos Shale, is divided <br />into three members which are, in ascending order: <br />• Point Lookout Sandstone. <br />• Menefee Formation. <br />• • Cliff House Sandstone. <br />2.04-10 <br />