Geology of National Parks, 3D and Photographic Tours
Seligman Member of Toroweap Formation
|Usage of Geologic Unit Name:
Seligman Member of Toroweap Formation (AZ*)
Seligman Limestone of Kaibab Group (UT)
Plateau sedimentary province*
Basin and Range province*
Aubrey Cliffs northwest of Seligman, Coconino Co., AZ. Reference section: from southwest corner sec. 12, T. 33 N., R. 9 W., to top of Hurricane Cliffs, Whitmore Point 7.5' quad, Mohave Co., AZ (Sorauf and Billingsley, 1991).
|Unit Name History:
Named (C.R. Keyes, 1922, Pan-Am. Geologist, v. 38, no. 3, p. 251, 338) [Geologic names lexicons, USGS Bull. 896, 1200]. Assigned to Kaibab Group (Welsh and others, 1979). Revised, designated as basal member of Toroweap Formation; Type locality stated; Reference; Areal limits (Sorauf and Billingsley, 1991).
|Description from Grand Canyon Area (from Billingsley, George H., 2000)
Seligman Member—Gray, light-purple, and yellowish-red, slope-forming, thin-bedded dolomite, sandstone, and gypsum above intertongued Coconino Sandstone, and yellowish-tan, flat-bedded, thin-bedded sandstone below the Coconino. In eastern two-thirds of map area, unit is mostly a purplish to light-red, flat-bedded calcareous sandstone interbedded with gray, thin-bedded limestone. In western third of map area, unit is gray-white gypsum and light-red to yellowish-red, thinbedded calcareous sandstone and gray dolomite. Forms slope or recess between overlying cliff-forming Brady Canyon Member and underlying cliff-forming Coconino
Sandstone (Pc) in southeastern two-thirds of map area; forms a gypsifereous slope similar to that of Woods Ranch Member in northwestern third of map area. Sharp gradational contact with the interbedded Coconino where crossbedded sand dunes of the Coconino were beveled off and sand was redistributed as flat-bedded sandstone. The Coconino intertongues with lower part of the Seligman in western third of map area (Fisher, 1961; Schleh, 1966; Rawson and Turner, 1974; and Billingsley and Workman, 2000). Thickness about 30 ft (9 m) in eastern half of map area, increasing to about 55 ft (17 m) in western half.
Fisher, W., 1961, Upper Paleozoic and lower Mesozoic stratigraphy of Parashant and Andrus Canyons, Mohave County, northwestern Arizona: Lawrence, Kans., University of Kansas Ph. D. thesis, 345 p.
Welsh, J.E., Stokes, W.L. and Wardlaw, B.R., 1979, Regional stratigraphic relationships of the Permian "Kaibab" or Black Box Dolomite of the Emery high, central Utah, IN Baars, D.L., ed., Permianland: Four Corners Geological Society Field Conference Guidebook, 9th Field Conference, Moab, UT, September 27-30, 1979, p. 143-149.
Sorauf, J.E. and Billingsley, G.H., 1991, Members of the Toroweap and
Kaibab Formations, Lower Permian, northern Arizona and southwestern Utah:
The Mountain Geologist, v. 28, no. 1, p. 9-24.
* show accepted USGS usage. Note that data on this page is modified from information available via the
National Geologic Map Database GEOLEX: