Usage:
Lennep Sandstone of Montana Group (MT*)
Lennep Sandstone Member of Sedan Formation of Livingston Group (MT*)
Geologic age:
Late Cretaceous (Campanian)*
Type section, locality, area and/or origin of name:
Named from exposures at Lennep Station, on the Chicago, Milwaukee, Saint Paul, and Pacific RR, at northern end of Crazy Mountains, Meagher Co., MT (Stone and Calvert, 1910).
Reference section: in S/2 SW/4 sec. 17, T. 4 N., R. 8 E. (Skipp and McGrew, 1977).
AAPG geologic province:
Montana folded belt*
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 ([ ]).