Usage:
Rio Piedras Siltstone (PR*)
Rio Piedras Formation (PR)
Geologic age:
Tertiary (late Paleocene)*
Type section, locality, area and/or origin of name:
Type section: quarry just west of Highway 181 (Puerto Rico Meter Grid System 195,360 E.; 60,940 N. to 195,150 E.; 60,360 N.), San Juan quadrangle, Puerto Rico (Pease, 1968).
AAPG geologic province:
Caribbean region*
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 ([ ]).