Geology of the Beaver Creek Watershed

The Beaver Creek Experimental Watershed (BCEW) is in the Colorado Plateau physiographic province within the Mogollon Slope. The regional dip of the Mogollon Slope is northeast; however, a major flexure north of the watershed (the Mormon Mountain anticline) reverses the regional dip in the Beaver Creek area. The drainage is situated across the Mogollon Rim, which separates the Colorado Plateau and the Verde Valley.

Volcanic parent material covers the area at depths from zero at the lower elevations to an estimated 305 m (1,000 ft) near some of the cinder cones in the area. The average thickness is believed to be approximately 152 m (500 ft ), based on the projected position of the erosion surface of the Kaibab Formation on which the volcanics were deposited.

The sedimentary rocks below the volcanic cover are porous and permeable because of their origin and the abundant fracture systems developed in them. Water that penetrates the volcanic mantle may be expected to continue through the sedimentary beds to the regional water table, estimated to be between 305 and 610 m (1,000 and 2,000 ft) below the surface.

Of the rock types exposed on Beaver Creek, the basaltic and andesitic lavas are the least porous and permeable. When unfractured, they are essentially impervious to water. The cinder deposits are highly porous even when cemented. Water falling on the cinder cones percolates downward and produces very little surface stormflow. However, because the cones are built upon a lava base, the permeability of this base determines whether the water continues downward to the regional water table or seeps out along the base of the pyroclastic materials.

The general topography of the watershed area has developed as the result of outpouring of successive lava sheets that are inclined towards the Verde Valley. The slope-controlled distribution of streams has produced a subparallel drainage system of numerous, closely spaced streams.

For information on erosion and sedimentation potential in the semi-arid Southwest, see Erosion and Sedimentation in the Central Arizona Highlands.

Selected References on Geology of the Region

Benfer, J.A.; Beus, S.S. 1968. The relationship of cinders to runoff in the Beaver Creek watersheds. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Beus, S.S. 1968. Gravity data from the Beaver Creek Watersheds, Coconino County, Arizona. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Beus, S.S.; Rush, R.W.; Smouse, D. 1966. Geologic investigation of experimental drainage basins 7-14, Beaver Creek Watershed, Coconino County, Arizona. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Emmons, P.J. 1977. Relationship between seismic velocity, degree of weathering, and seepage potential: Watershed 17, Beaver Creek watershed, Coconino County, Arizona. MS Thesis, Northern Arizona University, Flagstaff, Arizona.

Ffolliott, P.F.; Fishers, D.L.; Thorud, D.B. 1972. A physiographic survey of the ponderosa pine type on the Salt-Verde River Basin. Agricultural Experiment Station, Technical Bulletin 200, University of Arizona, Tucson.

McCabe, K.W. 1971. A geo-botanical study of Stoneman Lake, Wet Beaver Creek experimental drainage basin, Coconino County, Arizona. MS Thesis, Northern Arizona University, Flagstaff, Arizona.

McCain, R.G. 1976. Relationship between water loss from stream channels and gravity and seismic measurements: Beaver Creek watershed 7, Coconino County, Arizona. MS Thesis, Northern Arizona University, Flagstaff, Arizona.

Rush, R.W. 1965. Report of geologic investigations of six experimental drainage basins, Beaver Creek Watershed, Yavapai County, Arizona. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Rush, R.W.; Smouse, D. 1968. Geologic investigation of experimental drainage basins 15-18 and Bar M Canyon, Beaver Creek Watershed, Coconino County, Arizona. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Scholtz, J.F. 1968. Geology of the Woods Canyon drainage basin, Coconino County, Arizona. MS Thesis, Northern Arizona University, Flagstaff, Arizona.

Scholtz, J.F. 1969a. The Beaver Creek volcanics: a new formation, Coconino-Yavapai Counties, Arizona. Geological Society of America Bulletin 80:2637-2643.

Scholtz, J.F. 1969b. Evidence for revision of the name Hickey Formation east of the Verde Valley, Coconino County, Arizona. Journal of Arizona Academy of Science 5:182-183.

Scholtz, J.F. 1969c. Investigation of low-stage transmission losses in stream channels on watersheds 7, 9, 11, and 12; Beaver Creek experimental drainage basin, Coconino County, Arizona. Final Report Prepared by Northern Arizona University, Flagstaff, Arizona, Submitted to the Rocky Mountain Forest and Range Experiment Station, Flagstaff, Arizona.

Thompson, J.R., Jr. 1968. Geology of Wet Beaver Creek Canyon, Yavapai County, Arizona. MS Thesis, Northern Arizona University, Flagstaff, Arizona.

Twenter, F.R.; Metzger, D.G. 1963. Geology and ground water in Verde Valley--the Mogollon Rim Region Arizona. United States Geological Survey Bulletin 1177.

Williams, J.A.; Anderson, T.C., Jr. 1967. Soil survey of Beaver Creek area, Arizona. USDA Forest Service, Soil Conservation Service, and Arizona Agriculture Experiment Station.