Usage:
Millbrook Quarry Member of Waterfall Formation (VA*)
Geologic age:
Jurassic, Early*
Sinemurian*
Pliensbachian*
Type section, locality, area and/or origin of name:
Exposures at Millbrook quarry south of VA Highway 55, 1.2 km (0.7 mi) east of Thoroughfare Gap, Thoroughfare Gap quadrangle, Prince William Co., VA (Lee and Froelich, 1989).
AAPG geologic province:
Piedmont-Blue Ridge province*
Culpeper basin*
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 ([ ]).