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National Geologic Map Database

Geologic Unit: Yonna

Usage:

No current usage.
(Rocks of †Yonna Formation (OR) reallocated to several unnamed units.)


Geologic age:

late Tertiary (latest Miocene to early Pliocene)


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

Type locality: along west side of Yonna Valley, in T. 38 S., R. 11 1/2 E., Klamath Co., Willamette meridian and baseline, Klamath Co., southwestern OR (Newcomb, 1958).


AAPG geologic province:

Southern Oregon 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 ([ ]).