Challis Volcanics (ID*,MT?)
/Challis Volcanic Group (ID)
[A group name combines a geographic name with the term "group," and no lithic designation is included (ACSN, 1961, 1970; NACSN, 1983, 2005).]
GROUP STATUS (alphabetical) --all in ID: Cheney Volcanics, Kadletz Volcanics, [?]Kenney Formation, Yearian Volcanics.
Not designated. Named from Challis National Forest and town of Challis, Custer Co., ID (Ross, 1930).
Named from town of Challis, Custer Co., ID (Ross, 1934).
Idaho Mountains province*
Central Western Overthrust*
Snake River basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.
"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).