Spring Creek Granitoid Gneiss is here defined and formally named in the central Blue Ridge of NC. It is one of five map units composing the Middle Proterozoic basement sequence that underlies 60% of the study area. Unit crops out in the northwest part of the Sandymush quad. where it is at least 4,000 ft thick and composed primarily of poorly foliated to foliated, coarse-grained biotite granitic gneiss, light gray and mottled with pinkish gray to pale reddish brown. Also contains interlayers of well-foliated biotite granitic gneiss, protomylonitic to mylonitic granodioritic gneiss, amphibolite, and rare calc-silicate granofels. The Spring Creek is thought to intrude the Sandymush Felsic Gneiss (new name) and in turn is intruded by the Doggett Gap Protomylonitic Granitoid Gneiss (new name). Previously mapped as part of the Cranberry Granite by Keith (1904) and now correlated with the Elk Park Plutonic Suite. Absolute age not precisely known but approximately 1.1 Ga.

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