Usage:
Willis Formation (LA*,TX*)
Willis Sand (LA*,TX*)
Subunits:
Hockley Mound Member (LA,TX).
Geologic age:
Pliocene* or Pleistocene, early*
Type section, locality, area and/or origin of name:
Named from town of Willis, 10 mi north of Conroe, Montgomery Co., southeastern TX, which is located on top of north end of a ridge held up by the formation (Doering, 1935).
AAPG geologic province:
Gulf Coast 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 ([ ]).