North Goucher Metagabbro is here named as a unit within the Hammett Grove Meta-igneous Suite (new name), a dismembered ophiolite in the northwestern Piedmont of SC. The medium to coarsely crystalline metagabbro is composed mostly of pale green magnesio-hornblende and relict plagioclase. and varying amounts of actinolite, clinozoisite, relict diopside-salite, muscovite, titanite, chlorite, quartz, and pyrite. Gabbroic pegmatite dikes occur locally within the lithodeme and fine- to medium-crystalline leucocratic intrusives occur throughout. Unit represents, in part, the gabbroic complex of an idealized ophiolite section. Presumed to underlie White Plains Metabasalt and overlie South Goucher Metapyroxenite (new names). No real thicknesses of the Hammett Grove units are known, but mapping shows a maximum exposed thickness of 30 m. Author suggests that the Suite is not only allochthonous, but a thrust slice or klippe of Kings Mountain belt derivation, and documents a middle Paleozoic accretionary event.

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