U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Arnheim

Usage:

Arnheim Formation (OH*, and TN*-local)
Arnheim Shale (OH*)
Arnheim Formation of Cincinnati group (informal) (OH)

(informal Cincinnati group is the usage of the OH Geol. Survey. The rank or lithologic term should not be capitalized.)


Subunits:

(ascending) --all in OH: Sunset Member, Oregonia Member.


Geologic age:

Late Ordovician (Cincinnatian; Maysvillian to Richmondian)*


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

Named from Arnheim, Brown Co., southwestern OH (US geologic names lexicons, USGS Bull. 896, 1200).


AAPG geologic province:

Cincinnati arch*


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 ([ ]).