Sample of metamorphosed gabbro with an amphibolitic-like texture associated with unit mm of Goldsmith et al. (1988).


According to Goldsmith et al. (1988), the rock is part of the mm unit: Metamorphosed mafic complex – Includes metamorphosed equivalents of gabbroic and ultramafic intrusive, hypabyssal and probably extrusive basalts.

Rock Type: Metamorphosed gabbroic rock

Association:  Example of mafic composition country rock in parts of the Charlotte terrane

Terrane: Charlotte terrane

 

 

 

Sample collected on a portion of the North Carolina Department of Agriculture Piedmont Research Station, 8350 Sherrills Ford Rd., west of Salisbury, North Carolina

Amphibolite

Close up of above sample: metamorphosed gabbro with an amphibolitic-like texture associated with unit mm of Goldsmith et al. (1988).


According to Goldsmith et al. (1988), the rock is part of the mm unit: Metamorphosed mafic complex – Includes metamorphosed equivalents of gabbroic and ultramafic intrusive, hypabyssal and probably extrusive basalts.

Rock Type: Metamorphosed gabbroic rock

Association:  Example of mafic composition country rock in parts of the Charlotte terrane

Terrane: Charlotte terrane

Amphibolite
View showing typical brown colored weathering rind of mafic composition. Sample is a metamorphosed gabbro with an amphibolitic-like texture associated with unit mm of Goldsmith et al. (1988).


According to Goldsmith et al. (1988), the rock is part of the mm unit: Metamorphosed mafic complex – Includes metamorphosed equivalents of gabbroic and ultramafic intrusive, hypabyssal and probably extrusive basalts.

Rock Type: Metamorphosed gabbroic rock

Association:  Example of mafic composition country rock in parts of the Charlotte terrane

Terrane: Charlotte terrane

Amphibolite
Sample of talc + chlorite schist associated with unit mm of Goldsmith et al. (1988).

View is perpendicular to foliation.


According to Goldsmith et al. (1988), the rock is part of the mm unit: Metamorphosed mafic complex – Includes metamorphosed equivalents of gabbroic and ultramafic intrusive, hypabyssal and probably extrusive basalts.

Rock Type: Metamorphosed ultramafic rock

Association:  Example of ultramafic composition country rock in parts of the Charlotte terrane

Terrane: Charlotte terrane

Sample collected on a portion of the North Carolina Department of Agriculture Piedmont Research Station, 8350 Sherrills Ford Rd., west of Salisbury, North Carolina

Talc + Chlorite schist
Sample of talc + chlorite schist associated with unit mm of Goldsmith et al. (1988).

View is parallel to foliation.


According to Goldsmith et al. (1988), the rock is part of the mm unit: Metamorphosed mafic complex – Includes metamorphosed equivalents of gabbroic and ultramafic intrusive, hypabyssal and probably extrusive basalts.

Rock Type: Metamorphosed ultramafic rock

Association:  Example of ultramafic composition country rock in parts of the Charlotte terrane

Terrane: Charlotte terrane

Sample collected on a portion of the North Carolina Department of Agriculture Piedmont Research Station, 8350 Sherrills Ford Rd., west of Salisbury, North Carolina

Talc + Chlorite schist

Geoprobe core of soil and saprolite derived from a metamorphosed medium-grained diorite.


According to Carpenter (1982) this sample is associated with unit di: [Diorite of] Intermediate intrusive rock – Gray to greenish-gray, medium- to coarse-grained, massive, well-jointed metamorphosed bodies, probably dioritic in composition; composed primarily of hornblende, plagioclase, biotite, epidote, chlorite, magnetite, and minor quartz; frequently forms narrow dikes, primarily within felsic intrusive units.

Rock Type: Diorite

Association:  Example of intrusive rocks in the Greensboro area

Terrane: Carolina terrane

 

 

 

 

Sample location from immediately southeast of Greensboro airport.

Diorite saprolite

Geoprobe core of saprolite derived from a metamorphosed medium-grained diorite with inset photograph of diorite rock for comparison of texture.


According to Carpenter (1982) this sample is associated with unit di: [Diorite of] Intermediate intrusive rock – Gray to greenish-gray, medium- to coarse-grained, massive, well-jointed metamorphosed bodies, probably dioritic in composition; composed primarily of hornblende, plagioclase, biotite, epidote, chlorite, magnetite, and minor quartz; frequently forms narrow dikes, primarily within felsic intrusive units.

Rock Type: Diorite

Association:  Example of intrusive rocks in the Greensboro area

Terrane: Carolina terrane

 

 

 

Sample location from immediately southeast of Greensboro airport.

Diorite saprolite

Photograph of erosional gully exposing saprolitic schists of the Milton terrane capped by alluvium.  Compositional layering appears to form a synform structure (Photograph by Thomas Moore).


The location is within the CZbg unit of NCGS (1985):  Biotite gneiss and schist – inequigranular and megacrystic; abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolites.  Contains small masses of granitic rock.

The Milton terrane typically has compositional layering parallel to foliation with dips ranging from 45 degrees to almost horizontal.

Rock Type: Schist

Terrane: Milton terrane

 

 

 

Photographs taken in the vicinity of University Parkway and Coliseum Drive intersection, Winston-Salem.

Milton terrane schist
Close up of a portion of same photograph of above showing a pronounced unconformity where compositional layering (dipping at approximately 45 degrees) is capped by alluvium (flood plain deposits) (Photograph by Thomas Moore).


The location is within the CZbg unit of NCGS (1985):  Biotite gneiss and schist – inequigranular and megacrystic; abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolites.  Contains small masses of granitic rock.

The Milton terrane typically has compositional layering parallel to foliation with dips ranging from 45 degrees to almost horizontal.

Rock Type: Schist

Terrane: Milton terrane

Milton terrane schist
Close up of a quartz-feldspar knot within saprolitic schists of above location (Photograph by Thomas Moore).


The location is within the CZbg unit of NCGS (1985):  Biotite gneiss and schist – inequigranular and megacrystic; abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolites.  Contains small masses of granitic rock.

The Milton terrane typically has compositional layering parallel to foliation with dips ranging from 45 degrees to almost horizontal.

Rock Type: Schist

Terrane: Milton terrane

Milton terrane schist