Usage:
Old Mill Branch Metasiltstone Member of Popes Head Formation (VA*)
Geologic age:
Cambrian*
Ordovician
Type section, locality, area and/or origin of name:
Exposures along Old Mill Branch between Clifton Road and the Occoquan Reservoir, Manassas 7.5-min quadrangle, Fairfax Co., VA (Drake and Lyttle, 1981).
AAPG geologic province:
Piedmont-Blue Ridge province*
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 ([ ]).