Owl Rock Member of Chinle Formation

Usage of Geologic Unit Name:
Owl Rock Member of Chinle Formation (AZ*,CO*,NM*,UT*)
Triassic, Late*
Geologic Province:
Plateau sedimentary province*
Black Mesa basin*
San Juan basin*
Paradox basin*
Areal Extent:
Type Locality:
Intent to name and type locality not stated (Stewart, 1957).
Type "locality": near base of Owl Rock, from which unit is probably named, Navajo Co., AZ. Type "section": at Owl Rock, about 7.5 mi north of Kayenta (Witkind and Thaden, 1963).
Unit Name History:
First used as a member of Chinle Formation (Stewart, 1957). Overview; Type locality"/"section" designated (Witkind and Thaden, 1963). Overview; Areal limits (Stewart and others, 1972). Revised (Green, 1974). Overview (Dubiel, 1987). Overview; iostratigraphic dating (Kirby, 1989).


Stewart, J.H., 1957, Proposed nomenclature of part of the Upper Triassic strata of southeastern Utah: American Association of Petroleum Geologists Bulletin, v. 41, no. 3, p. 441-465.

Witkind, I.J. and Thaden, R.E., 1963, Geology and uranium-vanadium deposits of the Monument Valley area, Apache and Navajo Counties, Arizona: U.S. Geological Survey Bulletin, 1103, 171 p.

Stewart, J.H., Poole, F.G. and Wilson, R.F., 1972, Stratigraphy and origin of the Chinle Formation and related Upper Triassic strata in the Colorado Plateau region: U.S. Geological Survey Professional Paper, 690, 336 p.

Green, M.W., 1974, The Iyanbito Member (a new stratigraphic unit) of the Jurassic Entrada Sandstone, Gallup-Grants area, New Mexico, IN Contributions to stratigraphy: U.S. Geological Survey Bulletin, 1395-D, p. D1-D12.

Dubiel, R.F., 1987, Sedimentology and new fossil occurrences of the Upper Triassic Chinle Formation, southeastern Utah, IN Campbell, J.A., ed., Geology of Cataract Canyon and vicinity 1987; field symposium: Four Corners Geological Society Field Conference Guidebook, 10th Field Conference, Durango, CO, May 14-17, 1987, p. 99-107.

Kirby, R.E., 1989, Late Triassic vertebrate localities of the Owl Rock Member (Chinle Formation) in the Ward Terrace area of northern Arizona, IN Lucas, S.G., and Hunt, A.P., editors, Dawn of the age of dinosaurs in the American southwest: New Mexico Museum of Natural History, p. 12-28.

Tanner, Lawrence H., 2000, Palustrine-lacustrine and alluvial facies of the (Norian) Owl Rock Formation (Chinle Group), Four Corners region, Southwestern U.S.A., implications for Late Triassic paleoclimate: Journal of Sedimentary Research, v. 70, no. 6, p. 1280-1289.

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* show accepted USGS usage.
Note that data on this page contains information that has been partly revised from bibliographic resources available via the National Geologic Map Database GEOLEX:
The URL is: https://gotbooks.miracosta.edu/gonp/coloradoplateau/lexicon/chinle_owlrock.htm
Last modified: 1/7/2011