Usage:
Tonzona Group (AK*)
Geologic age:
Silurian* or Devonian*
Type section, locality, area and/or origin of name:
Not synopsized to date. Named from Tonzona River, Alaska Range, southwestern AK, where unit typically occurs in basin of river (Brooks, 1911).
AAPG geologic province:
Alaska East-Central region*
Alaska Southern region*
Alaska Southwestern 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 ([ ]).