PERMFILE114852 - Laserfiche WebLink

Home Browse Search

Western Slope Carbon, Inc. Page 8 December 15, 1981 Surface Water As discussed above, two unnamed, intermittent shallow stream channels I tributary to Cottonwood Creek drain the site area. Both of these channels were dry at the time of our site investigation. Based on the lack of a definite channel in either drainage, the low precipitation, the amount of ] vegetative cover, and the small size of the drainage basin, it is unlikely that either channel carries significant quantities of water. SEISMICITY The Pit No. 6 area is located in the eastern portion of the Colorado Plateau Seismotectonic Province. Kirkham and Rogers (Colorado Geological Survey, 1981)* characterize the Colorado Plateau Province as follows: "Except for the Uncompahgre Uplift, the Colorado Plateau Province appears to be fairly stable tectonically. A series of faults associated with collapsed salt anti- clines and evaporite flowage in Paradox and Big Gypsum Valleys show considerable Neogene movement and some late Quaternary and Holocene activity, but their non-tectonic J origin and movement due to plastic deformation indicate a low potential for even moderate sized earthquakes. The ' Uncompahgre Uplift, however, is a major tectonic feature that has been recurrently active at least since the late I Paleozoic. Some faults that flank the uplift show evidence of Quaternary activity and Cater (1966) infers considerable Quaternary Uplift of the entire structure based on abandon- , went of Unaweep Canyon. One fault on the southwest end of the uplift, the Ridgeway Fault, has microseismicity associated with it (Sullivan and others, 1980). Quaternary movement may also have occurred on one or more of the northwest-trending faults in the Piceance Basin." I *Kirkham, R.M. G W.P. Rogers, 1981, Earthquake Potential in Colorado, a preliminary evaluation, Colorado Geological Survey, Department of Natural Resources, Bulletin No. 43.