White Plains Metabasalt is here named as a unit within the upper part of the Hammett Grove Meta-igneous Suite (new name), a dismembered ophiolite in the northwestern Piedmont of SC. The amphibolitic metabasalt at the type locality in Cherokee Co. is mylonitic and composed of green hornblende, plagioclase, epidote, chlorite, biotite, titanite, apatite, and opaques. Felsic segregations locally give rock a banded appearance. Presumed to overlie North Goucher Metagabbro (new name) and underlie an unnamed metachert that corresponds to pelagic sediments of ocean floor. No real thicknesses of the Hammett Grove units are known, but mapping shows a maximum of 30 m. Author suggests that the Hammett Grove 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).