- Usage in publication:
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- Slack Canyon unit
- Modifications:
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- [Informally named]
- AAPG geologic province:
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- Eastern Columbia basin
Summary:
Pg. 23 (fig. 1), 38 (table 2), 43. Slack Canyon unit (informal) in Grande Ronde Basalt of Columbia River Basalt Group. Consists of 3+ flows; typically fine-grained, aphyric to rarely plagioclase microphyric, and dikytaxitic. Has normal magnetic polarity (in N2 magnetostratigraphic unit). Thickness up to 90+ m. Lies below and interfingers with Sentinel Bluffs unit (informal) in Grande Ronde Basalt; lies above Field Springs [Fields Spring] unit (informal) in Grande Ronde Basalt. Age is middle Miocene.
Named from Slack Canyon, adjacent to Moses Coulee, [in secs. 2, 3, and 11, T. 23 N., R. 23 E., Alstown and Palisades 7.5-min quadrangles, Douglas Co., central WA].
Reference locality: Douglas Creek-Slack Canyon, in sec. 11, T. 23 N., R. 23 E., Palisades 7.5-min quadrangle, [Douglas Co., central WA].
[Additional locality information from USGS historical topographic map collection TopoView; accessed September 15, 2013.]
Source: Publication.
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 ( ).
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