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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Fork Mountain formation
  • Modifications:
    • Named
  • Dominant lithology:
    • Schist
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Conley, J.F., and Henika, W.S., 1973, Geology of the Snow Creek, Martinsville East, Price, and Spray quadrangles, Virginia: Virginia Division of Mineral Resources Report of Investigations, no. 33, 71 p., (incl. geologic maps, scale 1:24,000 and 1:48,000


Summary:

Fork Mountain formation is here named in the Smith River Allochthon of south-central VA. Described as gray mica schist with thin lenses of quartzite and micaceous gneiss. Age is Precambrian.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Fork Mountain Formation
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Horton, J.W., Jr., and McConnell, K.I., 1991, The western Piedmont, IN Horton, J.W., Jr., and Zullo, V.A., eds., The geology of the Carolinas: Carolina Geological Society, 50th Anniversary Volume, p. 36-58.


Summary:

Fork Mountain Formation of Conley and Henika (1973) structurally and stratigraphically(?) overlies the Bassett Formation in southern VA. Unit is composed of a garnetiferous mica schist on the northwest side of the Smith River allochthon and a biotite gneiss on the southeast side. The garnetiferous mica schist is composed mainly of muscovite, quartz, garnet, and staurolite or sillimanite. The biotite gneiss is medium-gray, compositionally banded, and composed of interlayered quartzofeldspathic gneiss and garnetiferous muscovite-biotite gneiss. A "mica schist and gneiss unit" mapped by Lewis (1980) in NC may be equivalent to the Fork Mountain.

Source: GNU records (USGS DDS-6; Reston GNULEX).


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

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