Quartzite and Quartz-Sericite Tectonite

Light-gray to white, fine- to medium-grained, massive; contains rounded zircons, thin lenses of graphite, and pods of paragneiss (Yp); unit is considered part of a metasedimentary suite.
State Virginia
Name Quartzite and Quartz-Sericite Tectonite
Geologic age Proterozoic Y
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Minor
Tectonite
Comments Blue Ridge Basement Complex, Middle Proterozoic (Early or Pre-Grenville-Age) Gneisses
References

Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.

Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.

NGMDB product
Counties Loudoun