Paleoecology of Mid-Wisconsinan Peat Clasts from Skidaway Island, Georgia

Abstract

Twelve peat clasts were recovered from a paleochannel deposit on Skidaway Island, Chatham County, Georgia. An AMS radiocarbon date from a plant stem in one of these clasts indicates original peat deposition 36,830 ± 340 14C years B.P., and the stratigraphic position of the clasts supports this age assignment. Fossil Pinus needles, pollen, and testate amoebae provide a snapshot of the environment and biota at a time when most other sites in coastal Georgia were not accumulating sediment. Pollen from the peat clasts is dominated by Pinus and other genera common on the coastal plain today (e.g., Quercus , Carya ). Morphological and anatomical analyses of the fossil Pinus needles indicate they are either Pinus taeda or Pinus serotina , which both currently inhabit the Coastal Plain of Georgia. Seven testate amoeba taxa, all characteristic of relatively dry peatland conditions, were encountered in the clasts. Testate amoeba assemblages are dominated by Hyalosphenia subflava , a taxon that is not typically dominant in modern assemblages. More investigations describing the occurrence and distribution of Quaternary testate amoebae, as well as modern ecology and biogeography of testate amoebae, are necessary before the significance of these assemblages can be assessed fully. Deposition of the peat clasts occurred at a time when pollen evidence from Florida indicates warm and wet climatic conditions, and the paleoecology of the peat clasts indicates that a relatively warm climate also existed in coastal Georgia.