2011-06-29_REVISION - C1981018 - Laserfiche WebLink

Home Browse Search

Phvsiographic Setting Geologic Setting Coal Seam Stratigraphy Township 2 North, Range 101 West of the 6 Principal Meridian Portions of Sections 1, 2, 3, 4, 10, 11, and 12 Township 3 North, Range 101 West of the 6 Principal Meridian Portions of Sections 1, 4, and 5 All of Sections 2 and 3 Township 6 North, Range 90 West Portions of Sections 21, 23, 25, 26, 27, 28, 30, 31, 34, 35, and 36 All of Sections 22, 29, 32, and 33 The elevations at the Deserado Mine site range between 5,300 ft. and 5,900 ft. The permit area and adjacent areas are characterized by gently rolling to moderately steep landforms. Slopes range from 0 to 6 percent in the valleys and level uplands and up to 50 percent on drainage side slopes. The bedrock at the ground surface in the Deserado permit area is contained within the Mesaverde Group of Upper Cretaceous age. These sedimentary beds are well exposed as a southwest facing escarpment along the flank of the Rangely anticline and along the course of Scullion Gulch and its tributaries. Throughout much of northwest Colorado, the Mesaverde Group has been divided into the basal Iles Formation and the overlaying Williams Fork Formation, with the contact lying atop the Trout Creek Sandstone Member of the Iles Formation. The strata exposed in the mine permit area have been subdivided into three zones. In ascending order the three zones are the Iles Formation, the Lower Williams Fork Formation, and the Upper Williams Fork Formation. All mining and related mining activity associated with the Deserado Mine is performed within or upon rocks of the Mesaverde Group. The carbonaceous zone containing the coal beds of interest occupies the basal 200 to 300 feet of the Lower Williams Fork Formation. The B and D coal seams are contained in a 25 to 70 -foot interval occurring 10 to 40 feet above the top of the B horizon sandstone. Although coals are prevalent throughout the rest of the carbonaceous zone, the coals are commonly too thin or of too little lateral extent to be considered mineable. Surface Water Hydrology The permit area is situated in the lower White River Basin. Snowmelt is the primary source of surface water, originating mainly on the north slopes of the White River Plateau. The permit area occupies portions of two watersheds which are tributary to the White River. The Scullion Gulch Basin, an ephemeral watershed, lies to the west and covers 7,560 acres. The larger Red Wash Basin, intermittent at higher elevations, covers approximately 78,400 acres. Channels draining the two main watershed form dendritic patterns, with Scullion Gulch flowing generally towards the southeast and Red Wash towards the south - southwest. Deserado Mine Permit Revision 07 C- 1981 -018 17 29 June 2011