Abstract

The southern Appalachians record a complex tectonic history associated with the convergence of land masses that assembled Pangea following the breakup of Rodinia that included three main mountain building events : the Ordovician Taconic, Silurian-Devonian Acadian, and the late Paleozoic Alleghanian orogenies. The NE-SW striking dextral Acadian Burnsville fault has been documented from north of Spruce Pine, NC to Asheville, NC and reactivates the contact between Grenville basement rocks that date back to the supercontinent Rodinia and the Ashe Metamorphic Suite (AMS). This contact extends southwest into the 7.5-minute Clyde quadrangle near Waynesville, NC and transitions into what has been mapped as a part of the older NE-SW striking Taconic Hayesville thrust fault. The southward extension of shearing on the Burnsville fault has remained unclear. The Clyde quadrangle encompasses the intersection of this contact with what has been mapped as the Alleghanian Fries and Chattahoochee thrust faults, and the Taconic Hayesville fault. N-S striking, west directed thrusting associated with the Fries and Chattahoochee faults has been proposed north and south of what has been mapped as the Hayesville fault in this quadrangle, respectively. This study used detailed field mapping of the rocks and structures along with documentation of the kinematics and shear sense indicators along the faults in this quadrangle to answer the following questions: (1)What is the nature of the AMS and basement rock contact in this quadrangle, and (2) How are the Taconic Hayesville and Alleghanian Chattahoochee and Fries faults related in time to deformation Acadian deformation? Vertical NE-SW striking mylonite, shallow NE-SW trending stretching lineations, and dextral shear sense indicators suggests that dextral shearing associated with the Burnsville fault continues into this quadrangle and locally overprints a portion of the Hayesville fault. Acadian dextral shearing is not offset by the Alleghanian Fries and Chattahoochee thrusts in this quadrangle, indicating that these thrusts predate shearing on the Burnsville fault and are not Alleghanian structures.

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