Leucocratic Granulite and Gneiss (VAYgn;0)

Leucocratic Granulite and Gneiss

Leucocratic, fine- to medium-grained layered gneiss contains predominantly alkali feldspar and blue quartz; ferromagnesian minerals including pyroxene, ilmenite, horn blende, reddish-brown biotite, or garnet constitute less than one percent of the mode. Quartz and feldspar are granoblastic; gneissic fabric is defined by discontinuous quartz-rich domains.

State	Virginia
Name	Leucocratic Granulite and Gneiss
Geologic age	Proterozoic Y
Lithologic constituents	Major Metamorphic > Gneiss Metamorphic > Granulite
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	NGMDB product page for 34878
Counties	Albemarle - Amherst - Bedford - Floyd - Montgomery - Nelson - Roanoke - Rockbridge - Salem

Leucocratic Granulite and Gneiss

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.