Usage:
Tokio Formation (AR*,LA*,OK*)
Tokio Formation of Austin Group (LA*)
Subunits:
(alphabetical) --all in LA: Roberson Sand [Member], Trees City Sand [Member].
Geologic age:
Late Cretaceous*
Type section, locality, area and/or origin of name:
Not designated. Mapped in T. 7, 8, and 9 S., R. 24, 25, and 26 W., Hempstead and Pike Cos., AR. Named from village of Tokio, AR (Miser and Purdue, 1918, pl. 1).
AAPG geologic province:
Ouachita folded belt*
Arkla 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 ([ ]).