PRELIMINARY PETROGRAPHIC ANALYSIS OF METAMORPHIC GRADE IN THE GREENSBORO, NORTH CAROLINA AREA

The Greensboro, North Carolina area of study is located along strike of two significant shear zones of the Southern Appalachians, situated just north of the Gold Hill shear zone (GHSZ) and south of the Hyco shear zone (HSZ). Due to limited exposure, few detailed geologic studies concentrating on this area have been performed and the lithostratigraphy and nature of the GHSZ and HSZ within this area is largely unknown.

Preliminary results of geologic mapping in the area (Pastrana, Eller, Carter 2014) found Neoproterozoic fine to coarse grained granodiorite, medium to coarse grained granite, and fine to coarse grained mafic igneous rocks of Peri-Gondwanan origin in the southern area. In the northern area, regional maps identify a medium grained granitic pluton as part of the Late Carboniferous Churchland Plutonic Suite. In addition, there was evidence of three deformation events along a northeast-southwest trending shear zone.

Current research focuses on the metamorphic grade and the lithostratigraphy of the area. Preliminary results show increasing strain and higher grades of metamorphism moving from greenschist to epidote amphibolite facies, trending northward towards the shear zone. Mineral assemblages and lithostratigraphy of these rocks will provide better understanding of the Appalachian orogenesis and the evolution of the eastern Laurentian margin.