Melrose Granite

Light-greenish-gray to pink-banded, massive, medium- to coarse-grained biotite granite; ranges in composition from quartz monzonite to quartz diorite. Fabric shows a southeastward progression from protomylonite to mylonite to ultramylonite where the unit is cut by the Brookneal shear zone (Gates and others, 1986). Mineralogy: quartz + plagioclase + potassium feldspar + biotite + muscovite + chlorite + epidote + titanite + garnet + mag ne tite-ilmenite + calcite + zircon (Gates, 1981). Geophysical signature: positive radiometric, negative magnetic. The Melrose has been dated at 515 Ma (U-Pb zircon; Sinha and others, 1989).
State Virginia
Name Melrose Granite
Geologic age Cambrian
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granite
Minor
Igneous > Plutonic > Dioritic > Quartz-diorite
Igneous > Plutonic > Dioritic > Quartz-monzodiorite
Comments Western Piedmont (Southwest and Central)
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 Campbell - Halifax - Pittsylvania