The National Geologic Map Database is migrating to a new infrastructure. We apologize for any service disruptions during this process.

U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Cuchillas Member*
  • Modifications:
    • Named
  • Dominant lithology:
    • Volcanics
    • Sandstone
    • Siltstone
  • AAPG geologic province:
    • Caribbean region
Publication:

Nelson, A.E., 1966, Cretaceous and Tertiary rocks in the Corozal quadrangle, northern Puerto Rico, IN Contributions to stratigraphy, 1966: U.S. Geological Survey Bulletin, 1244-C, p. C9-C10.


Summary:

Rio Orocovis Formation redefined as a Group and Avispa Lava Member redefined as a Formation. A lenticular unit of interbedded volcanic breccia, sandstone, and siltstone that separates lava flows in the lower and upper parts of the Avispa is named the Cuchillas Member.

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 ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 21 May 2026 05:01:02 PM MDT