SOUTH CAROLINA
Sassafras Mountain
       7 ½’ quadrangle: Eastatoe Gap, SC-NC
       Pickens County
       Owned by state of South Carolina
       Inner Piedmont

Metamorphic (metamorphosed igneous)
3, 560 ft (1, 085 m)
Henderson Gneiss (photo by Jack Garihan). View north from Sassafras (Jack Garihan).


Bedrock: Henderson Gneiss
Early to Middle Ordovician
Biotitic augen gneiss, with white microcline augen up to 3 cm, and coarse-grained mylonitic phases grading into more micaceous, finer-grained ultramylonite zones near ductile shear zones. The nearest ductile thrust fault places Chauga River and Poor Mountain Formations westward over Henderson Gneiss. This area has had a very complex history, with early Paleozoic deformation involving west- and southwest-directed folds, thrust faults, and oblique-slip faults, overprinted by Alleghenian deformation and retrograde metamorphism.

Sassafras Mountain lies just southeast of the Brevard fault zone, which is a tectonic boundary between the Blue Ridge and Inner Piedmont, but no longer thought of as a major terrane boundary because similar stratigraphic sequences (the Tugaloo terrane) occur on both sides of the Brevard zone. The contact between Inner Piedmont and the Carolina Slate belt to the southeast is now the preferred location for a Laurentia-Gondwana suture. An Ordovician or Neoacadian age for the terrane accretion is debated, since the suture itself (called the Central Piedmont suture) likely has been overridden by Alleghenian thrust faults.

Soil Series: Ashe sandy loam: Shallow, somewhat excessively drained, steep dark gray-brown soil overlying bedrock at less than three feet, formed under hardwood forests.

Additional Photos:
Left: Gneiss outcrop near north overlook. Note white feldspar nubbles on the surface, which are more resistant
to weathering than the rest of the schist. Also note sassafras shrubs to the left, with mitten-shaped leaves.
Right: Sassafras leaves adorn the USGS benchmark. Photos by Tom Spinek.
Selected References:
Byrd, H.S. and others, 1972, Soil Survey of Pickens County, South Carolina: U.S. Soil Conservation Service.

Cazeau, C.J. and C.Q. Brown, 1963, Guide to the Geology of Pickens and Oconee Counties, South Carolina: Geologic Notes, Division of Geology, State Development Board, v.7, no.5, p.32-40. Available on web at: www.carolinageologicalsociety.org.

Garihan, J.M., 2005, Geologic Map of the Eastatoe Gap 7.5-minute quadrangle, Greenville and Pickens Counties, South Carolina and Transylvania County, North Carolina: GQM-29, South Carolina Geological Survey.

Hatcher, R.D., Jr., and T.L. Davis, editors, 1993, Studies of Inner Piedmont Geology with a focus on the Columbus Promontory: Carolina Geological Society Annual Field Trip, 114 p.


Other suggested sources of information:
Glossary: http://www2.nature.nps.gov/geology/usgsnps/misc/glossaryAtoC.html
Time scale: http://www.ucmp.berkeley.edu/help/timeform.html
South Carolina Geological Survey: http://www.dnr.state.sc.us/geology/