PERMFILE72612 - Laserfiche WebLink

Home Browse Search

~ ~ • • United Companies, Inc. March 21, 1994 Page 3 dome that underlies the San Juan Mountains. Generally, the Mancos shale formation is quite thick, however due to the up thrust of the San Juan Mountains, the underlying Dakota Sandstone formation surfaces just a few miles south of the property. The Mancos Shale and Dakota Sandstone are from the Cretaceous age and are overlying sedimentary layers from the Jurassic and Triassic age followed by Permian and Precambrian age deposits. The site lies on a flat topped terrace of sand, gravel and cobblestones excavated from the San Juan Mountains by glaciers and carried here by the Uncompahgre River during the high glacial melt and runoff period. To the west of the site approximately 1/4 to 1/3 mile is the toe of the Uncompahgre Plateau and to the east beyond the Uncompahgre River is the north end of the Cimarron Ridge which extends in a south southeasterly direction. The proposed gravel pit property is located on the gently sloping valley floor about 1/4 to 1/3 mile west of the Uncompahgre River. The slope of the site is to the southeast at approximately 1 percent with 20 feet of elevation differential across the property. The site has an elevation of 6208 to 6228 feet above sea level and the general area is semi- arid. No geologic hazards such as rock falls, landslides or etc. exist at the site. The Vernal clay loam soils are largely derived from Mancos shale and Mancos shale has relatively high concentrations of sulfate and sodium salts. These salts may produce corrosion of concrete or metal objects in contact with the soil or rock. Pursuant to CRS 34-32-115(4)(d) mining operations are to remain 200 feet or more from any significant, valuable and permanent man-made structures unless it can be demonstrated the mining operation will not adversely affect the stability of those structures. The only man-made structures that are known to exist within the 200