Usage:
Madson Basalt of Snake River Group (ID*)
Geologic age:
late Pleistocene*
Type section, locality, area and/or origin of name:
Named from Madson Spring(s) [local name], in NE/4 NE/4 sec. 20, T. 6 S., R. 13 E., Gooding Co., southern ID, which issues from alluvium some distance below outcrops of basalt. Crops out directly above talus and beneath basalts in east wall of Snake River Canyon near Steele Springs [local name], in SE/4 sec. 21, T. 6 S., R. 13 E., 0.5 mi downstream from mouth of Big Wood River, [Bliss 7.5-min quadrangle], Gooding Co., southern ID (; Stearns and others, 1938).
AAPG geologic province:
Snake River 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 ([ ]).