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National Geologic Map Database

Geologic Unit: Umpqua

Usage:

Umpqua Formation (CA,OR*)
Umpqua Group (OR)


Subunits:

GROUP STATUS: Roseburg, Lookingglass, and Flournoy Formations [not adopted by USGS].
FORMATION STATUS (ascending): Bushnell Rock, Tenmile, White Tail Ridge, and Camas Valley Members [not adopted by USGS].


Geologic age:

Tertiary
Eocene, middle*
Eocene, early*


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

Type section: occurs along north Umpqua River, about 17 mi northeast of Roseburg, Douglas Co., OR (Weaver and others, 1944).


AAPG geologic province:

Oregon-Washington Coast Ranges province*
Klamath Mountains province*


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 ([ ]).