MAPPING THE VESUVIUS MEGACRYSTIC GRANITE AND ASSOCIATED UNAKITE, BLUE RIDGE, VA

The basement complex of the Blue Ridge contains many interesting rocks that are often mapped as one unit. Within the porphyritic, “hyperthene”-bearing, granitoid gneiss (Ypg)(Willaims, 2007), approximately five km south west of Vesuvius, Virginia, is the Vesuvius Megacystic Granite (VMG)(Southworth, pers comm, 2017) formally known as the Vesuvius Megaporphyry (Batholomew and Lewis, 1984). The VMG is dark grey-blue, massive to foliated, medium to coarse grained rock, with feldspar porphyroclasts up to 10cm. The VMG is altering to unakite, seen as veins along fractures and huge boulders in Turkey Farm Hollow, although the size and complexity of this rock association was previously unknown. Mapping using GPS and GIS indicates the integrated structure of the 2 rocks types, VMG, unakite, and the hybrid. This map will be used for sample collection for thin section, SEM, whole rock analyses ,and microprobe data to further understand the metasomatic reactions from VMG to unakite.