National Geologic Map Database

Geologic Unit: Kings Lake


Kings Lake Formation of Decorah Group (IL*,MO*)
Kings Lake Formation of Galena Group (IL,MO)
Kings Lake Limestone of Galena Group (IL)
Kings Lake Member of Decorah Formation (MO)
Kings Lake Formation of /Decorah subgroup [informal] (IL)

["Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). Decorah subgroup considered informal and should not be capitalized.]


(alphabetical) --all in IL,MO: Mincke Member, Tyson Member.

Geologic age:

Late Ordovician (Mohawkian)*

Type section, locality, area and/or origin of name:

Type section: exposure in west bluff of Mississippi River Valley, 1.6 mi north of Foley, about 500 ft north of road junction at Kings Lake, in SE/4 SE/4 NE/4 sec. 26, T. 50 N., R. 2 E., Foley 7.5-min quadrangle, Lincoln Co., MO (Templeton and Willman, 1963).
Reference sections in MO: (1) roadcut on U.S. Interstate Highway I-55, mileage 182, in SW/4 NW/4 NW/4 sec. 7, T. 41 N., R. 6 E., Herculaneum 7.5-min quadrangle, Jefferson Co.; (2) roadcut on north frontage road of U.S. Interstate Highway I-44 west of Allenton-Six Flags exit, in sec. 33, T. 44 N., R. 3 E., western St. Louis Co.; (3) exposure on St. Louis County Road W., 1 mi south of Eureka, in NW/4 NW/4 NE/4 sec. 12, T. 43 N., R. 3 E., Pacific 7.5-min quad; and (4) roadcut on U.S. Highway 61, north of bridge over Spencer Creek, in SE/4 SE/4 sec. 21, T. 44 N., R. 4 E., St. Louis Co. (Thompson, 1991).

AAPG geologic province:

Illinois basin*
Lincoln anticline*
Ozark uplift*

For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).