Structure, stratigraphy, tectonostratigraphy, and evolution of the southernmost part of the Appalachian orogen, Georgia and Alabama

The southernmost part of the Appalachian orogen is composed of three enormous stacks of folded thrust sheets: from bottom to top the stacks are the Rome-Kingston (Valley and Ridge - 3 sheets), Georgiabama (crystalline terrane - 11 sheets), and Little River thrust stacks (crystalline terrane - 3 sheets). Together these stacks preserve rocks formed in a variety of environments that virtually spanned the Iapetus Ocean, including ocean crust and mantle. The Rome Kingston stack was assembled from top to bottom during the Caroniferous. Assembly of the Georgiabama thrust stack took place from the Iapetus Ocean toward the North American Craton, and from top to bottom, with the first-moving uppermost thrust sheets being farthest-travelled and the later-moving lowermost sheets being least-travelled. The Little River stack appears to have been assembled from bottom to top as its sheets were being thrust upon the already assembled and moving Georgiabama stack. All of the metamorphism and deformation in the southernmost Appalachians can be related to the movement of the thrust sheets and stacks. Thrusting took place continuously from Early Ordovician through Carboniferous time.