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National Geologic Map Database

Geologic Unit: Tarkio

Usage:

Tarkio Limestone Member of Zeandale Limestone of Wabaunsee Group (IA*,KS*,MO*)
Tarkio Limestone Member of Zeandale Formation of Wabaunsee Group (IA,NE)
Tarkio Limestone Member of Zeandale Limestone of /Richardson subgroup [informal] of Wabaunsee Group (KS)
Tarkio Limestone Member of Zeandale Formation of /Richardson subgroup [informal] of Wabaunsee Group (MO)

["Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Richardson subgroup considered informal and should not be capitalized.]


Geologic age:

Late Pennsylvanian (Virgilian)*


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

In Missouri River bluffs northeast of Corning, Holt Co., MO. This location is west of Tarkio Valley in MO (Condra, 1935; 1949).
On Mill Creek southwest of Maple Hill, Wabaunsee Co., KS. This area noted by Swallow under designation of "Chocolate limestone." Calvin applied Tarkio to rocks on Tarkio Creek, north of Coin, Page Co., IA (Moore, 1936).


AAPG geologic province:

Forest City basin


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 ([ ]).