Felsic Volcanic and Volcaniclastic Rocks

Dark-gray to black, biotite- and pyrite-rich volcaniclastic rock interbedded with medium-gray, fine-grained rocks with numerous quartzfilled vesicles; upper part of the unit consists of medium dark-gray, fine-grained felsic rock with numerous clasts of fine-grained, white-weathering, vesiculated felsite interlayered with fine-grained, clast-free felsic rock. Dikes of clast-free felsic rock cut nearby Middle Proterozoic granitic gneiss (Ybp); conformably overlain by feldspathic metasandstones of the Fauquier Formation.
State Virginia
Name Felsic Volcanic and Volcaniclastic Rocks
Geologic age Proterozoic Z
Lithologic constituents
Major
Sedimentary > Clastic > Mixed-clastic
Igneous > Volcanic > Felsic-volcanic
Comments Blue Ridge Basement Complex, Late Proterozoic Igneous
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 Fauquier - Henry - Patrick