Dale City Quartz Monzonite named in eastern Prince William Co., VA. Unit is foliated to massive. Intrudes Quantico Slate; underlies Cretaceous and younger Coastal Plain sediments. Age is Early Cambrian based on U-Th-Pb-zircon date of 560 Ma.
Source: GNU records (USGS DDS-6; Reston GNULEX).
Dale City Quartz Monzonite is mapped in Eastern Prince William Co. Medium- to light-gray, medium-grained, massive to well-foliated quartz monzonite, quartz monzodiorite, and subordinate quartz diorite. Intrudes the Chopawamsic Formation and is unconformably overlain by the Quantico Formation. Map symbol indicates a Cambrian age.
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 ([ ]).