WSP02750 - Laserfiche WebLink

Home Browse Search

-. r) ..- .,,1 ' J 'j J'; 2. Topography and Drainage . The conduit roughly parallels Fountain Creek. a south flowing tributary to the Arkansas River. The Arkansas River drainage basin is separated by an east-west trending divide from the South Platte River Basin in the northern portion of the Colorado Piedmont. The rivers leave the state flowing eastward, but near the mountain front much of the drainage is north-south trending. The land surface in the project area slopes southward from an elevation of about 5800 feet along Fountain Creek near Colorado Springs to an elevation of 4750 feet in the Arkansas River Valley near Pueblo. Fountain Creek meanders in a wide flat valley typical of the Great Plains streams. The north end of the conduit follows the edge of the Fountain Creek Valley. At the south end, where the conduit leaves the Pueblo Reservoir, its course lies first across the limestone bluff area and then across the alluvium-covered bedrock surface (See Figure III-I, Limestone Bluff Area). This portion is drained by intermittent streams. 3. Geology and Economic Geology a. Geologic History The portion of the geologic history of the area which is pertinent to the conduit location begins with the time of the vast Cretaceous sea which deposited a thick sedimentary sequence of shale, limestone, siltstone, and sandstone in this part of Colorado. These sediments are the bedrock of the project area. The Laramide mountain building period then deformed these rocks. In the conduit area, significant structures formed during this period include the large north-south trending anticline of the Front Rnage, some associated faults and smaller folds, and the large Denver Basin east of the range. i., Erosion of the anticline has left a monoclinal structure in the Cretaceous formations along the mountain front and produced a hogback sequence in resistant beds which dip steeply eastward the mountain front and more gently eastward under the conduit Along the border of the anticline, echelon folds are common. Rock Canyon anticline just west of the initial segment of the conduit is such a structure. along area. The III-2 .