BULK-ROCK GEOCHEMISTRY AND MINERAL COMPOSITIONS FROM THE MT. CARMEL COMPLEX, CAROLINA SUPERTERRANE, SOUTHERN APPALACHIANS

The Mt. Carmel complex outcrops in the Carolina superterrane in western central South Carolina. It is interpreted as an intrusive body into the Carolina superterrane. Metagabbroic samples were collected from thee Mt. Carmel complex in order to place some constrains on its origin. Plagioclase and amphibole grains show relict ophitic and sub-ophitic textures, with coarse plagioclase crystals typically enclosing fine amphibole grains. SiO₂ contents fall within a narrow range of 44-49 wt. %, whereas MgO contents fall within the 2-9 wt. % range. Normative plagioclase contents are high, ranging from 50-68%, whereas normative olivine contents are <20%. Incompatible trace elements such as Zr and Y show increasing concentrations with decreasing MgO contents. Plagioclase compositions have anorthite contents ranging from An_59.2-81.9, which plot within the labradorite-bytownite range. Amphiboles are zoned, ranging in composition from tschermakite and magnesiohornblende cores to actinolite rims. No pyroxenes were observed during the present investigation. Spider diagrams show negative anomalies of Nb, La, and Zr, and positive Ti anomalies. Spider diagrams also display enrichments in most of the large-ion lithophile elements and depletions in some high field strength elements, suggesting either contamination of the Mt. Carmel complex by upper crust, or derivation from an island arc-related setting.