Geology Tidbits with Tyler – May 2020

North Carolina Granite Corporation’s Mt. Airy Quarry

North Carolina Granite Corporation’s Mt. Airy quarry is the largest open-face granite quarry in the world. The Mount Airy granite is an Alleghanian pluton, approximatly 330 MA (Winchester, 2013), post-kinematic, leucocratic, hypidiomorphic inequigranular biotite granitoid. Modal analyses of the the body by DeRosset (1978) show that it is a monzogranite consisting of perthitic alkali feldspar, plagioclase, quartz, muscovite, biotite, and epidote, with accessory apatite, monazite, ilmenite, rutile, and allanite.

There are many statutes monuments, and memorials around the world made from this granite, two notable examples being the Wright Brothers Memorial in Kitty Hawk, NC and the World War II Memorial in Washington, DC.

References:

DeRosset, W.H.M and Hewitt, D.A., 1978, Emplacement and late cooling history of the Mt. Airy, North Carolina, granite: Geologic Society of America Abstracts with Programs, v. 111, p. 176.

Winchester, C.L., 2013, Alleghanian Plutonism in the Eastern Blue Ridge Province of the Southern Appalachians: Origin and Tectonic Setting, unpublished master thesis, University of North Carolina-Chapel Hill, 40 p. Link – https://cdr.lib.unc.edu/concern/dissertations/0c483j51k?locale=en