Laserfiche WebLink
The New Horizon Mine 2 area will encompass approximately 503.3 acres with the approval of PR- <br /> 05. Approximately 653.5 acres will be disturbed due to mining or related activities at Mine 2. The <br /> majority of this findings document pertains to the Mine 2 area since the activities at Mine 1 have <br /> ceased with the exception of water monitoring. <br /> The topography is gently sloping with a few small ridges and swales. Most of the land surrounding <br /> the permit area is agricultural and is used primarily for irrigated and non-irrigated farmland which <br /> produces alfalfa and pasture grasses. <br /> Both mines are located within the southeast portion of the Colorado Plateau. The region is <br /> characterized by broad, fairly smooth surfaced plateaus and mesas with gently dipping slopes <br /> dissected by steep canyons. Surface elevations at the New Horizon Mine 2 area range from a high <br /> of 5,795 feet (MSL) in the northeast part to a low of 5.560 feet in the southeast part along Tuttle <br /> Draw for a total relief of about 235 feet. <br /> Climate <br /> The regional climate of the New Horizon area is typical of intermountain regions. It is characterized <br /> by cold winters, hot summers, low rainfall, and short growing seasons. The mine receives <br /> approximately 12 inches of precipitation in an average year. The majority of the precipitation falls <br /> between October and May. <br /> Regional Geology <br /> The New Horizon Mines are located near the axis of the Nucla Syncline (San Miguel Syncline), a <br /> shallow, broad synclinal fold running northwesterly for 65 miles. No evidence of faults has been <br /> observed in drill holes at New Horizon Mine 2 area. The Nucla Syncline is 10 to 15 miles southwest <br /> of the major regional geologic feature of the area, the Uncompahgre uplift. The region lies in the <br /> Dolores River basin. The mines are located two to four miles northeast of the San Miguel River. <br /> Gently rolling terrain traverses the area and the mine occupies a predominantly southwestern <br /> exposure. <br /> The mines are located in the Nucla-Naturita coal field. The coal is found in late Cretaceous <br /> sediments. The youngest Cretaceous rocks in the area consist of Mancos shale, a dark grey marine <br /> shale, present only on isolated hilltops south of the town of Nucla. Two hundred feet of Dakota <br /> sandstone outcrops extensively along the axis of the Nucla syncline. This formation consists of a <br /> yellowish-gray, fissile sandstone and conglomeratic sandstone interbedded with dark grey shale and <br /> coal. There are two coal seams within 100 feet of the base of the Dakota. The lower Cretaceous unit <br /> in the area, the Burro Canyon Formation, is separated from the Dakota by an unconformity. The <br /> Burro Canyon is comprised of white, grey and light brown sandstones and conglomerates <br /> interbedded with green and purplish shales, siltstones, mudstones and thin beds of limestone. This <br /> formation has a maximum thickness of 200 feet and outcrops on rims of canyons west and northwest <br /> of the mine. This formation is difficult to differentiate from the Dakota in this area and is commonly <br /> considered hydrogeologically similar. The Jurassic Morrison Formation is composed of 250 feet to <br /> 600 feet of varicolored siltstones and mudstones with beds of limestone and sandstone. <br /> 3 <br />