Figs. 3, 15B, 15C. Elm member of Nachusa formation. Shown on columnar section as underlying Everett member (new) and overlying Eldena member (new). Thickness as much as 3 feet. Age is Middle Ordovician.
[Notable exposures in Dixon-Oregon area, northern IL.]
Source: US geologic names lexicon (USGS Bull. 1200, p. 1243).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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