- Usage in publication:
-
- Oronoco formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Sandstone
- Tuff
- Andesite
- AAPG geologic province:
-
- Piedmont-Blue Ridge province
Summary:
Oronoco Formation probably named for Oronoco post office, Amherst Co., central VA. Consists of a variable thickness of both metamorphosed and unmetamorphosed conglomerate sandstone, tuff, and andesite. Underlies Catoctin Formation; unconformably overlies Precambrian crystalline basement complex.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Oronoco formation
- Modifications:
-
- Not used
- AAPG geologic province:
-
- Piedmont-Blue Ridge province
Summary:
In central VA, Oronoco formation has been applied to a series of flows, tuffs, and arkose. At its type locality, Oronoco overlies injection complex, is overlain by Catoctin basalt, and is equivalent to Swift Run tuff, which had previously been named and mapped as far south as this part of VA. Oronoco formation not warranted.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Oronoco formationâ€
- Modifications:
-
- Abandoned
- AAPG geologic province:
-
- Piedmont-Blue Ridge province
Summary:
Name should be abandoned in favor of Swift Run [tuff] which is its equivalent and has priority.
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 ([ ]).