The kinematic and metamorphic development of the Towaliga-Goat Rock mylonites, Georgia-Alabama

The Towaliga-Goat Rock and Bartletts Ferry deformation zones are major tectonic boundaries of the southeastern Piedmont. The Towaliga zone separates the Pine Mountain Belt and the Inner Piedmont and the Goat Rock and Bartletts Ferry Zones separate the Pine Mountain and Uchee Belt. The Uchee Belt is composed of granitic gneisses and amphibolites modified by deformational phases, each represented by distinctive mesoscopic folding patterns. The earliest is a poorly developed folding of obscure compositional layering. Later leucocratic banding is folded by recumbent isoclines with subhorizontal axial plane cleavage. Intensification of cleavage to the northwest produces the southeast dipping mylonitic foliation of the Goat Rock and Bartletts Ferry Zone. Mesoscopic structural patterns is accounted for by regional compressive folding accompanied by ductile drag folding and mylonitization on the limbs of a major anticlinal structure.