- Usage in publication:
-
- Ashland formation
- Modifications:
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- Original reference
- Dominant lithology:
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- Shale
- Limestone
- AAPG geologic province:
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- New England province
Summary:
Pg. 170-172, 173-174; 1940 [abs.], GSA Bull., v. 51, no. 12, pt. 2, p. 1978-1979. Ashland formation. Defined to include Ashland limestone, Ashland shale, and Graptolite shale of Williams (1900). Field relations and fossils suggest that Graptolite shale and Ashland shale are parts of one stratigraphic unit, that strata designated Ashland limestone are lenses of limestone in this shale, and that Sheridan sandstone succeeds Ashland shale. Thus interpreted, section becomes (descending) Sheridan formation, Ashland formation, Aroostook formation. [Age is Silurian.]
W.S. White, P.E. Cloud, Jr., and Josiah Bridge, 1941 [abs.] GSA Bull., v. 52, no. 12, pt. 2, p. 1939-1940. Stratigraphic sequence given (descending) Ashland formation, Aroostook formation, Sheridan sandstones.
Named from exposures in Ashland village, Aroostook Co., northeastern ME.
Source: US geologic names lexicon (USGS Bull. 1200, p. 151).
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 ([ ]).