- Usage in publication:
-
- Union City Complex*
- Modifications:
-
- Named
- Dominant lithology:
-
- Granite
- Gneiss
- AAPG geologic province:
-
- Piedmont-Blue Ridge province
Summary:
The Union City Complex is here named in the Newnan-Tucker synform near Atlanta, GA. It is a complex of porphyritic muscovite-biotite granites and granite gneisses, foliated and unfoliated, intruding the Atlanta Group. The age is probably Paleozoic.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Union City Granite*
- Modifications:
-
- Revised
- Age modified
- AAPG geologic province:
-
- Piedmont-Blue Ridge province
Summary:
Recent mapping has shown that intercalated lenses of gneiss in Union City Complex granite are probably large xenoliths, roof pendants, or floor cupolas of Crider Gneiss (new) country rock. Therefore, name is revised to Union City Granite. Age is changed from Paleozoic(?) as assigned by Higgins and others (1988) to Carboniferous(?). Union City is similar to Ben Hill and Palmetto Granites, which are assigned a Carboniferous age based on preliminary U-Pb ages reported by Atkins and Higgins (1980). Age of Union City is changed based on Ben Hill and Palmetto, but with a larger margin for error.
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 ([ ]).