Usage:
Jordan Formation (IA,MN,WI)
Jordan Sandstone (IL*,IA*,MN*,MO*,WI*)
Jordan Sandstone Member of Trempealeau Formation (IA*,MI*,WI*)
Subunits:
(ascending) Norwalk (IA,WI*,MN*), Waukon (IA,WI), Van Oser (IA,WI*,MN*), Sunset Point (WI), and Coon Valley (IA,MN) Members.
Geologic age:
Cambrian, Late*
Ordovician, Early
Type section, locality, area and/or origin of name:
Named from exposures in Sand Creek at Jordan, Scott Co., MN (Winchell, 1872).
AAPG geologic province:
Wisconsin arch*
Sioux uplift*
Iowa shelf*
Michigan basin*
Lincoln anticline*
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 ([ ]).