Usage:
Graptolite Canyon Member of Post River Formation (AK*)
Geologic age:
Ordovician to early Silurian*
Type section, locality, area and/or origin of name:
Type section: part of type section of Post River Formation near center sec. 7, T. 24 N., R. 23 W., southeastern part of McGrath 1:250,000 quadrangle (measured from west to east up a steep canyon near summit of southwestern part of Terra Cotta Mountains), AK (Churkin and Carter, 1996).
AAPG geologic province:
Alaska West-Central region*
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 ([ ]).