ELEVATION AND THE DISTRIBUTION OF SALT-MARSH FORAMINIFERA, ST.-CATHERINES ISLAND, GEORGIA - A TAPHONOMIC APPROACH

Foraminifera of St. Catherines Island, Georgia, display a vertical zon ation 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 bi ogeographically 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 distr ibuted only within the high marsh. Those species that are common in th e high marsh (Trochammina inflata, T. macrescens, Arenoparrella mexica na) occur throughout the marsh (high, transitional, and low) and, ther efore, cannot serve as the sole proxy for any specific marsh elevation in studies on Holocene changes in sea level for this region. A compar ison 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 consistentl y preserved.