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National Geologic Map Database

Geologic Unit: Blacho

Usage:

Blacho Tuff Member of Pozas Formation (PR*)


Geologic age:

Late Cretaceous (Maastrichtian)*


Type section, locality, area and/or origin of name:

Outcrops 100 m west of the mouth of Quebrado Blacho in the cliff adjacent to Rio Toro Negro, Ciales quadrangle, north-central Puerto Rico (Berryhill, 1965).


AAPG geologic province:

Caribbean region*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).