- Usage in publication:
-
- Rio Piedras Siltstone*
- Modifications:
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- Principal reference
- Revised
- Age modified
- AAPG geologic province:
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- Caribbean region
Summary:
The Rio Piedras Siltstone, here renamed and adopted [Formation of Soriano and Gelabert (1964)], was previously called the Fajardo Formation by Kaye (1956), but recent discovery of Late Cretaceous ammonites in the type area of the Fajardo necessitates a new name for younger rocks near Rio Piedras. Rio Piedras consists of thin-bedded to laminated siltstone interstratified with thick-bedded to massive volcanic wacke. Includes 4 informal members: basal siltstone member, tuffaceous bedded limestone member, coarse-grained wacke member, and interlayered sandstone and siltstone member. Conformably overlies the Guaracanal Andesite; underlies Quaternary terrace deposits. Age is Paleocene and probably Eocene.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Rio Piedras Siltstone*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Caribbean region
Summary:
The Rio Piedras Siltstone occurs in eastern Puerto Rico and consists of volcanic sandstone, siltstone, and a basal conglomerate. Maximum thickness is 1400 meters. The Rio Piedras is of late Paleocene age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
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 ([ ]).