- Usage in publication:
-
- Regina Member*
- Modifications:
-
- Named
- Dominant lithology:
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- Shale
- Siltstone
- Mudstone
- Sandstone
- AAPG geologic province:
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- San Juan basin
Summary:
Named as a member of San Jose Formation for exposures near town of Regina, Sandoval Co, NM in San Juan basin. Type section measured in SW1/4 sec 31, T25N, R1E and SE1/4 sec 36, T25N, R1W. Overlies and intertongues with Cuba Mesa Member (new) of San Jose, and intertongues with and underlies Llaves Member (new) of San Jose at type where Regina is 753 ft thick. Present in southern two-thirds of area. In western part of Largo Plains, member is 100-300 ft thick. Is 1,100 ft thick in well drilled in sec 2, T23N, R4W. Consists mainly of soft clay shale, siltstone, mudstone, shaly sandstone, and sandy shale. Most of the beds are gray, tan, or olive gray. Includes several resistant conglomeratic sandstone beds. Recognized in southern two-thirds of area. Is of early Eocene age. Geologic map. Cross sections. Correlation chart. Measured sections.
Source: GNU records (USGS DDS-6; Denver 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 ([ ]).