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facing escarpment along the flank of the Rangely anticline and along the course of Scullion <br />Gulch and its tributaries. Throughout much of northwest Colorado, the Mesaverde Group has <br />been divided into the basal Iles Formation and the overlaying Williams Fork Formation, with the <br />contact lying atop the Trout Creek Sandstone Member of the Iles Formation. The strata exposed <br />in the mine permit area have been subdivided into three zones. In ascending order the three zones <br />are the Iles Formation, the Lower Williams Fork Formation, and the Upper Williams Fork <br />Formation. <br />Coal Seam Stratigraphy <br />All mining and related mining activity associated with the Deserado Mine is performed within or <br />upon rocks of the Mesaverde Group. The carbonaceous zone containing the coal beds of interest <br />occupies the basal 200 to 300 feet of the Lower Williams Fork Formation. The B and D coal <br />seams are contained in a 25 to 70 -foot interval occurring 10 to 40 feet above the top of the B <br />horizon sandstone. Although coals are prevalent throughout the rest of the carbonaceous zone, <br />the coals are commonly too thin or of too little lateral extent to be considered mineable. <br />Surface Water Hydrology <br />The permit area is situated in the lower White River Basin. Snowmelt is the primary source of <br />surface water, originating mainly on the north slopes of the White River Plateau. The permit area <br />occupies portions of two watersheds which are tributary to the White River. The Scullion Gulch <br />Basin, an ephemeral watershed, lies to the west and covers 7,560 acres. The larger Red Wash <br />basin, intermittent at higher elevations, covers approximately 78,400 acres. Channels draining <br />the two main watershed form dendritic patterns, with Scullion Gulch flowing generally towards <br />the southeast and Red Wash towards the south - southwest. <br />Groundwater Hydrology <br />The Williams Fork Formation is divided into three hydrologic units: the Sandstone Facies, which <br />underlines the A coal seam and is generally equivalent to the Trout Creek Sandstone and the <br />upper portion of the Iles Formation; the Siltstone and Coal Facies, which consists of the <br />interbedded coal, siltstone, and shale strata of the Lower Williams Fork Formation; and the upper <br />Sandstone Facies of the Upper Williams Fork Formation. A fourth hydrologic unit is the <br />alluvium of the White River and its tributaries. The maximum thickness of the White River <br />alluvium near the permit area was found to be 37 feet. The groundwater in the alluvium occurs in <br />an unconfined condition. The Red Wash Syncline and major fracture zones located along the <br />Red Wash, Scullion Gulch, and the White River control movement of the Mesaverde <br />groundwater. Groundwater in the northwest portion of the permit area moves down dip to the <br />Red Wash syncline. Within the central and southern portion of the permit area, groundwater <br />flows south to the White River. <br />Regional Climate <br />The climate in the Uinta Basin is controlled primarily by its continental and intermountain <br />location. Situated between various ranges of the middle and southern Rocky Mountains, the <br />20 <br />