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National Geologic Map Database

Geologic Unit: Challis

Usage:

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).]


Subunits:

GROUP STATUS (alphabetical) --all in ID: Cheney Volcanics, Kadletz Volcanics, [†?]Kenney Formation, Yearian Volcanics.


Geologic age:

Tertiary*
Eocene*


Type section, locality, area and/or origin of name:

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).


AAPG geologic province:

Central Western Overthrust*
Idaho Mountains province*
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 ([ ]).