Usage:
Robles Formation (PR*)
Subunits:
(alphabetical): /Barranquitas Tuff Member, Canabon Lava Member*, Cayey Siltstone Member*, Collao Member*, Helechal Tuff Member, Lapa Lava Member*, Las Tetas Lava Member*, Rio Maton Limestone Member*, Varian Ranch Beds.
In Comerio quadrangle and Coamo area, PR: Rio Maton Limestone Member*, Lapa Lava Member*, Las Tetas Lava Member*.
In Cayey quadrangle, PR: Rio Maton Limestone Member*, Lapa Lava Member*, Cayey Siltstone Member*, Las Tetas Lava Member*, Collao Members*.
In Barranquitas quadrangle, PR: Rio Maton Limestone Limestone Member, Lapa Lava Member, Las Tetas Lava Member, Canabon Lava Member*.
Geologic age:
Late Cretaceous (Coniacian)*
Type section, locality, area and/or origin of name:
Type area: exposures along Highway 14 and the valley of Quebrada Honda, Barrio Robles, Municipio de Aibonito, southwestern Comerio quadrangle, Puerto Rico (Pease and Briggs, 1960).
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 ([ ]).