Yorkshire Formation

Yorkshire Formation (Drake and Morgan, 1981). Polygenetic melange consisting of a dark quartz-plagioclase chlorite matrix that contains chips, fragments, and small blocks of quartz, ultramafic rock, metagabbro, plagiogranite, mafic volcanic rock, and other exotic blocks. Characterized by abundant light-colored feldspar grains that contrast with the dark-colored phyllosilicate component. The Yorkshire forms thin, discontinuous lenses at the base of the Piney Branch Complex.
State Virginia
Name Yorkshire Formation
Geologic age Cambrian
Lithologic constituents
Major
Tectonite > Melange
Comments Western Piedmont (Northern)
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 Fairfax