Geology of the Eastern Blue Ridge in the Napoleon 7.5' Quadrangle in East Central Alabama and West Central Georgia

The geologic history of the southern Appalachians, specifically the rock suites comprising the Wedowee-Emuckfaw units in the Eastern Blue Ridge, have been the subject of debate for decades. A growing body of evidence implies the Taconic orogeny developed in an accretionary orogenic setting in the Southern Appalachians, rather than the collisional orogenesis assigned to the Northern Appalachians. These units, as well as the Jackson’s Gap Group, are genetically related as all having formed in a back arc setting on the Laurentian Plate rather than in an exotic arc collisional environment, as interpreted by previous research and the findings of this study. The data collected for this evaluation provides additional information and high-resolution field mapping to strengthen the verification of the tectonic history of the region. Crossbedding structures were discovered for the first time in the Emuckfaw group, as well as undifferentiated diamictites in proximity to the fluvial structures. The nature of the Wedowee-Emuckfaw Groups contact was discovered to be stratigraphic in nature, with no faulted displacement found in the study area. Geothermobarometry constrained the timing of metamorphism in the field area to an average maximum temperature and pressure regime of 542 ± 44°C and 6.3 ± 2.2 kb for the Wedowee Group and 594 ± 49°C and 8.9 ± 1.9 kb for the Emuckfaw Group.