Usage:
Sappington Member of Three Forks Formation (ID*,MT*)
Sappington Member of Three Forks Shale (MT*)
Sappington Sandstone (MT)
Sappington Formation (MT*)
Geologic age:
Late Devonian to Early Mississippian (Famennian to Kinderhookian)*
Type section, locality, area and/or origin of name:
Type locality: near village of Sappington, in NW/4 sec. 36, T. 2 N., R. 1 W., [approx. Lat. 45 deg. 53 min. 02 sec. N., Long. 111 deg. 40 min. 45 sec. W., on eastern side of Milligan Canyon, Milligan Canyon 7.5-min quadrangle], Jefferson Co., southwestern MT. Named from Sappington which is in Gallatin Co. (Berry, 1943; see Holland, 1952).
Reference section (= type section of Three Forks): on north bank of Gallatin River at Logan, in SW/4 SE/4 sec. 25, T. 2 N., R. 2 E., [Logan 7.5-min quadrangle], Gallatin Co., MT (Sandberg, 1965).
AAPG geologic province:
Snake River basin*
Montana folded belt*
Sweetgrass 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 ([ ]).