Abstract
Foraminifera of St. Catherines Island, Georgia, display a vertical zonation within salt marshes that should prove useful in regional studies on Holocene sea-level fluctuations. This vertical zonation, however, differs somewhat from previous models and is based on taxa that are biogeographically more appropriate for this region. Specifically, three species (Reophax nana, Textularia palustris, Siphotrochammina lobata) occur throughout the low marsh and are limited to marsh habitats below approximately 1.4-1.5 m above MLW. Foraminiferal assemblages from the high marsh lack these three low-marsh taxa. No foraminifera are distributed only within the high marsh. Those species that are common in the high marsh (Trochammina inflata, T. macrescens, Arenoparrella mexicana) occur throughout the marsh (high, transitional, and low) and, therefore, cannot serve as the sole proxy for any specific marsh elevation in studies on Holocene changes in sea level for this region. A comparison of distributional patterns in surface (0-3 cm) and subsurface (19-21 cm) sediment shows that the most important species with regard to elevation in St. Catherines Island marshes also tend to be consistently preserved.
