?THE MADISON QUADRANGLE, VIRGINIA

ECONOMIC GEOLOGY:

"Currently, there are no active mineral  extraction sites in the Madison quadrangle. However, there may be economic potential for the production of crushed stone, sand and gravel, and gemstones. The most comprehensive discussion of the mineral resources of this area can be found in Rhesa Allen's Geology and Mineral Resources of Greene and Madison Counties (1963)."

page 20.:

"Titanium-bearing minerals such as ilmenite (FeTiOr), titanite (CaTiSiOr), and rutile (TiOr)

are present in the granitoid and gneissic rocks of this quadrangle. Although the titanium-bearing

minerals are primarily accessory minerals in these rocks" a concentrated occurrence of these minerals within the alkali feldspar syenite of the Robertson River Igneous Suite was observed along State Highway 231,2 miles north of Madison (1864-902). There is a zone of concentration of ilmenite

and titanite that extends from this location in the alkali feldspar syenite westward to the southeast

slope of Yager Mountain in the biotite granitoid and layered granitic gneiss (Allen, 1963)."

https://www.dmme.virginia.gov/commercedocs/PUB_157.pdf