Usage:
Ditch Creek Siltstone Member of Hornbrook Formation (CA*,OR*)
Geologic age:
Late Cretaceous (Turonian to Coniacian)*
Type section, locality, area and/or origin of name:
Type section: roadcuts along northbound lane of U.S. Interstate Highway I-5, 3 km south of Hornbrook, in NE/4 NE/4 sec. 32, T. 47 N., R. 6 W., Hornbrook 15-min quadrangle, Siskiyou Co., CA. Named from Ditch Creek, 3 km west of Hornbrook (Nilsen, 1984).
AAPG geologic province:
Klamath Mountains province*
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 ([ ]).