- Usage in publication:
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- Lacey member
- Modifications:
-
- Original reference
- Dominant lithology:
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- Sandstone
- AAPG geologic province:
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- Wisconsin arch
Summary:
Pg. 153 (fig. 2), 154 (fig. 3), 155. Lacey member of Mount Simon formation. Name applied to conglomeratic sandstone overlying Mayfield member (new). Type section extends from depths of 1,880 to 2,070 feet. Thickness 176 to 230 feet. Underlies Gunn member (new). Recognized in subsurface of northern Illinois. Age is Late Cambrian.
Type section (subsurface): depth-interval 1,880 to 2,070 feet, McQueen No. 1 (well 6), in SW/4 NE/4 NE/4 sec. 27, T. 42 N., R. 3 E., DeKalb Co., northern IL. Named from Lacey School, 2.5 mi east of type well.
Source: US geologic names lexicon (USGS Bull. 1200, p. 2066).
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 ([ ]).