Laserfiche WebLink
CM0001994 <br />the upper end of Tenmile Creek valley, while the tailing impoundments are located in the <br />Tenmile Creek valley and the Eagle River Valley. A plan map of the mine site is presented in <br />Figure 1. <br />The Tenmile Creek, the East Fork of the Arkansas River, and the East Fork of the Eagle River <br />are inhabited by naturally reproducing and self-sustaining trout populations (Aquatics <br />Associates, 1994). In addition these watersheds support extensive macroinvertebrate <br />communities. Terrestrial ecosystems have been identified and are incorporated into the Climax <br />Reclamation Permit (Climax Molybdenum Co., 1977). <br />There are no users of ground water within four miles of Climax and thus the only beneficial use <br />of ground water in the vicinity of Climax Mine is for surface water recharge. <br />Site Geoloav <br />Climax Mine is located in the Mosquito-Tenmile Range of the southern Rocky Mountain <br />Cordillera. The ore bodies are hosted by two Precambrian rock formations, the Idaho Springs <br />Formation, and the Silver Plume Granite. The Idaho Springs Formation is a meta-sedimentary <br />rock, metamorphosed 1.7 billion years ago during a period of major geologic activity. Its major <br />components are biotite schist and gneiss. Silver Plume Granite occurs in stocks, dikes and sills <br />that intruded the Idaho Springs Formation approximately 1.4 billion years ago. These two <br />formations also are intruded, to a lesser degree, by early Tertiary diorite porphyry and quartz <br />monzonite approximately 60 million years old. <br />The Climax ore bodies lie just east of the Mosquito Fault, an important local structure that <br />• trends roughly north-south, and that dips approximately 60 degrees to the west. The fault, as <br />shown on Figure 1, runs north-northeastward across the Tenmile Creek valley over a distance <br />of approximately 30 miles. The Mosquito Fault presents a discontinuity between the <br />Precambrian bedrock on the east with the Paleozoic and Tertiary bedrock on the west. <br />Location and Description of classified stream seaments <br />Arkansas segment 1 b, mainstream of the East Fork of the Arkansas River from the source to a <br />point immediately above the confluence above Birds' Eye Gulch, is classified as Aquatic Life <br />Cold 1 and Recreation 2. <br />The mainstream of the Eagle River from the source to the compressor house bridge at Bolden <br />is classified as Aquatic Life Cold 1, Recreation 1, Water Supply, and Agriculture. <br />The mainstream of Tenmile Creek below the Climax Parshall Flume in segment 13 is classified <br />as Aquatic Life Cold 2, Recreation 2, and Agriculture. <br />Site HXdrogeoloay <br />• <br />Ground water in the vicinity of the Climax mine site is generally present within a thin veneer of <br />alluvium and glacial till overlaying the bedrock, and ranges from near ground surface to a few <br />tens of feet below ground surface. Ground water occurrence within the bedrock is limited to the <br />upper fractured portion of the bedrock units. A hydrogeologic study of the underground <br />workings (Titan, 1994) indicated that the bulk permeability of the bedrock is relatively low and <br />that the bedrock is not capable of transporting significant quantities of ground water.