Interpreting the hydrological history of a temporary pond from chemical and microscopic characterization of siliceous microfossils

摘要: The hydrological history of a temporary pond in South Carolina was inferred from 5500-year record siliceous microfossils, including diatoms, freshwater sponge spicules, chrysophyte cysts, plates testate amoebae and plant phytoliths. Microfossil abundance estimated by microscopic quantification particles chemical extractions silica. Diatom, mineral particle volumes were correlated with silica concentrations attributable to these fractions. Both techniques suggested sequence four distinct community types. Basal sediments (4630–5520 14C YBP) containing phytoliths spicules indicative wetland covered dominated the remains planktonic protists (3750–4630 suggesting transition vegetated marsh an open-water, permanently flooded pond. assemblages above this zone indicate return ca. 3750 YBP that persisted until recently, when water levels stabilized as result seepage reservoir constructed nearby 1985. This study suggests suite microfossils commonly found can be used infer historical alternations between macrophyte plankton-dominated states shallow basins. Regional climate inferences include mid-Holocene maximum onset modern 3500 YBP.