- Usage in publication:
-
- Gunn member
- Modifications:
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- Original reference
- AAPG geologic province:
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- Wisconsin arch
Summary:
Pg. 153 (fig. 2), 154 (fig. 3), 155. Gunn member of Mount Simon formation. Name applied to the relatively fine-grained unit overlying Lacey member (new). Type section extends from depths of 1,648 to 1,880 feet. Thickness 71 to 260 feet. Underlies Charter member (new). Recognized in subsurface of northern Illinois. Age is Late Cambrian.
Type well: depth-interval 1,648 to 1,880 feet, McQueen No. 1 (well 6), in SW/4 NE/4 NE/4 sec. 27, T. 42 N., R. 3 E., DeKalb Co., northeastern IL. Named for Gunn School, 2.75 mi northwest of type well.
Source: US geologic names lexicon (USGS Bull. 1200, p. 1633).
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 ([ ]).