- Usage in publication:
-
- White Ledges formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Quartzite
- Argillite
- AAPG geologic province:
-
- Basin-and-Range province
Summary:
Sequence of older Precambrian volcanic and sedimentary rocks more than 15,000 ft thick occurs in Blackjack Mountains and White Ledges, 20 mi north of Globe, AZ. This sequence consists of (older to younger): Redmond formation (new) (acidic volcanic rocks) and Hess Canyon group (new) (clastic sedimentary rocks). Hess Canyon group is subdivided into: White Ledges formation (new), Yankee Joe formation (new) and Blackjack formation (new). White Ledges formation consists of interbedded quartzites and argillaceous rocks. Intruded by Ruin Granite.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- White Ledges Formation
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Basin-and-Range province
Summary:
Shown in geological column of Salt River Canyon as Middle Proterozoic age. Divided into lower (0 to 1800 feet thick) and upper (600 to 800 feet thick) members. Lower member is dominated by argillaceous beds with minor sandstone graywacke units; is slope former and has been subjected to metamorphism. Upper member characterized by massively bedded 30-ft-thick white quartzite, prominent cliff former; bedded purple, yellow, and pink quartzite with sericite matrix; and interbedded siltstones. Shown on geologic sketch maps of Corral Canyon, Horseshoe Bend, and Redmond Flat areas.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
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 ([ ]).