Pearlette family ash bed (informal) (CO*,IA*,KS*,NE*,OK*,SD*,TX*)
(Pearlette Ash Member of Sappa Formation* abandoned.)
Informal. The rank or lithologic term should not be capitalized.
late Tertiary (late Pliocene) and Quaternary (Pleistocene)*
Age determined using 1.8 Ma as Plio-Pleistocene boundary.
Named from old post office of Pearlette, Meade Co., southwestern KS (Cragin, 1896).
Central Kansas uplift*
Forest City basin*
Las Animas arch*
Palo Duro basin*
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 ([ ]).