Virgilina greenstone (Laney, 1917). Grayish-green, fine- to coarse-grained basaltic tuff, metavolcanic breccia, and porphyritic to amygdaloidal greenstone, with minor interlayered metasedimentary rocks. Hydrothermally mineralized zones occur within the greenstones; these contain bornite, chalcocite, and chalcopyrite, and have been mined for copper. Mineralogy: plagioclase + hornblende + chlorite + epidote + calcite + apatite + quartz + opaque minerals. Geophysical signature: linear positive magnetic anomaly. Watson (1911) used the term Virgilina Group for a wide belt of rocks in the vicinity of Virgilina, Virginia. Mafic metavolcanic rocks in this sequence were named Virgilina greenstone, and felsic metavolcanic rocks and associated metasedimentary rocks were named Aaron slate by Laney (1917). Kreisa (1980) refined Laney's stratigraphy in defining the Aaron Formation as containing upper and lower members equivalent to Laney's Aaron slate, and a middle member equivalent to the Virgilina greenstone. The stratigraphy was further modified by Harris and Glover (1985), who combined the middle and upper members of Kreisa's Aaron Formation to make the Virgilina Formation. Virgilina greenstone is herein used in the sense of Laney (1917), but is equivalent to the middle member of the Aaron Formation of Kreisa (1980), and the lower portion of the Virgilina Formation of Harris and Glover (1985) (Figure 2).
Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.
Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.