Mineralogy, petrology, petrology of massif anorthosites and related rocks, regional geology of the Virginia Piedmont Owens, B.E., and Buchwaldt, R., 2024, Further ...

It's a batholith, the Index batholith ... the black hornblendes. It's geology 101 here. This is textbook granite. But it's the walls themselves that are striking and they're visible here on ...