- Usage in publication:
-
- Boarman Member
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Limestone
- Dolomite
- AAPG geologic province:
-
- Wisconsin arch
Summary:
Figs. 3, 10, 16. Boarman Member of Mifflin formation. Limestone or dolomite about 4.5 feet thick. Shown on columnar section as underlying Establishment member (new) and overlying Brickeys member (new). Age is Middle Ordovician.
[Notable exposures in Dixon-Oregon area, northern IL.]
[GNC remark (ca. 1966, US geologic names lexicon, USGS Bull. 1200, p. 408): In copy of guidebook used by compiler [G.C. Keroher], a handwritten note states that Brickeys member overlies Boarman member. Thus, Boarman would be basal member of Mifflin formation and would overlie Oglesby member of Pecatonica formation. Since the compiler had no way to determine what changes, if any, had been made to other copies of guidebook, it was impossible to be certain of true stratigraphic relation.]
Source: US geologic names lexicon (USGS Bull. 1200, p. 408).
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 ([ ]).