Usage:
Sixtymile Formation of Grand Canyon Supergroup (AZ*)
Originally misspelled Sixty Mile.
Geologic age:
Cambrian*
Type section, locality, area and/or origin of name:
Type section: Sixty Mile section H, cliffs on north side of upper part of Sixtymile Canyon [approx. Lat. 36 deg. 12 min. 30 sec. N., Long. 111 deg. 50 min. 42 sec. W., Cape Solitude 7.5-min quadrangle], eastern Grand Canyon, Grand Canyon National Park, Coconino Co., northern AZ (Ford and Breed, 1973).
Alternate type section: accessibility to type section from Colorado River is not easy; formation also well exposed at top of Nankoweap Butte where it is about 120 ft (36 m) thick, [about 4.5 mi (7 km) north-northwest of type, approx. Lat. 36 deg. 15 min. 49 sec. N., Long. 111 deg. 53 min. 02 sec. W., Point Imperial 7.5-min quadrangle], eastern Grand Canyon, Grand Canyon National Park, Coconino Co., northern AZ (Ford and Breed, 1973; see also U.S. geologic names lexicon, USGS Bull. 1520).
Named from Sixty Mile [Sixtymile] Canyon, [Cape Solitude 7.5-min quadrangle], eastern Grand Canyon, Grand Canyon National Park, Coconino Co., northern AZ (Ford and Breed, 1973).
AAPG geologic province:
Plateau sedimentary province*
Southern Rocky Mountain region*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).