Usage:
Spieden Group (WA*)
Spieden Formation (WA)
Subunits:
(alphabetical) --all in WA*: Sentinel Island Formation, Spieden Bluff Formation*.
Geologic age:
Late Jurassic to Early Cretaceous*
Type section, locality, area and/or origin of name:
Composite type section (Spieden Bluff and Sentinel Island Formations): northwest and southwest shoreline of Spieden Island, in sec. 2, T. 37 N., R. 4 W., and western shoreline of Sentinel Island, San Juan Islands, WA (Johnson, 1981).
AAPG geologic province:
Puget Sound province*
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 ([ ]).