Re-interpretation of the deformation history of the Greenbrier fault, great smoky mountains: Critical assessment of previous work

The Greenbrier fault as originally defined fails to explain many aspects of Great Smoky and Snowbird group geology and introduces unnecessary complexities for the tectonic history of the Great Smoky Mountains region (e.g. multiple depositional basins). Early workers admitted to limitations in assumptions that were the basis for their interpretation that the fault is premetamorphic and accommodates at least 23 km of shortening. Although original work did not describe a specific exposure of the fault at the type locality, displacement along the Great Smoky-Snowbird contact is inferred from truncation of bedding in rocks adjacent to the contact. This truncation is the only observation consistent with premetamorphic displacement along the contact, but it is also consistent with post-metamorphic slip. Taken as a whole, the evidence permits the alternative interpretation that the Greenbrier is a faulted stratigraphic contact exhibiting mostly postmetamorphic slip between thick units of markedly different competency that does not require tens of kilometers of displacement or deposition in separate basins.