- Usage in publication:
-
- Virden formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Conglomerate
- Sandstone
- Shale
- AAPG geologic province:
-
- Pedregosa basin
- Basin-and-Range province
Summary:
Name applied to a 4,000 ft thick fanglomerate, fluvial conglomerate, tuffaceous sandstone, and gray shale. Conglomerate has boulders of Cretaceous volcanic rocks. Type locality is in sec 16, T18S, R20W, Hidalgo Co, NM, Pedregosa basin. Mapped in two outcrop areas in Hidalgo Co into adjoining Grant Co in the Basin-and-Range province where it is in contact with the Colorado shale and the Datil formation. Plant fossils tentatively date formation as Late Cretaceous.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Virden Formation
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Pedregosa basin
Summary:
Local unit in Pedregosa basin. Contains boulders of the underlying andesite. Has plant fossils tentatively dated as Late Cretaceous. Unconformably overlies Colorado Shale in northern Hidalgo Co south of Steeple Rock. Southwest of Steeple Rock, is unconformable on unnamed andesites, dacite, and rhyolite of Late Cretaceous age.
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 ([ ]).