Moredock Member of Dunleith Formation of Galena Group (IL)
Late Ordovician (Mohawkian; Chatfieldian)*
Type section: quarry of Columbia Quarry Company, and exposure in Mississippi River bluff, just north of crushing plant, center north line SW/4 sec. 3, T. 3 S., R. 11 W., Kimmswick quadrangle. Named from Moredock Lake at Valmeyer, Monroe Co., southwestern IL (Templeton and Willman, 1963).
Notable exposures in Dixon-Oregon area, northern IL (Templeton and Willman, 1952).
Illinois basin
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
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Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).