At 4,784 feet (1,458 meters), the summit of Brasstown Bald is Georgia's highest point, although a few other northeast Georgia peaks approach that altitude. Not far away from the Tallulah Falls Dome, Brasstown Bald has a domal structure eroded such that a stratigraphically lower layer of schist is exposed in its center. Amphibolite (meta-gabbro) and ultramafics outcrop in a ring-shaped pattern around the schist, in thrust contact with it. Apparently, this mafic layer is a slab of ocean crust pushed into place over a sedimentary layer during assembly of Pangea. Just northeast of Brasstown Bald, across Lake Chatuge in North Carolina, Garland Mountain shows a similar structural pattern.
What raised Brasstown Bald's dome? I once thought there might be a pluton under it; now, I'm not so sure. It could be a big wrinkle; it could be the surface expression of a deeply buried thrust fault; or its bulge may in fact hide a granitic pluton like those of Georgia's Piedmont. Beats me!
For further information on rocks around Brasstown Bald, consult:
Located on Georgia Geologic Map.
See list of specific sites