Using foraminiferal transfer functions to produce high-resolution sea-level records from salt-marsh deposits, Maine, USA

Quantitative analyses of foraminiferal distributions along the coast of Maine are used to provide transfer functions for reconstruction of sea-level changes from fossil foraminiferal assemblages. The indicative meaning of fossil assemblages is most accurately predicted by a training set that incorporates live and dead foraminifera and that uses flooding duration, not height, as the predictor variable. Sea-level records are produced for two sites in Maine (USA): a middle marsh site in Scarboro and a high marsh site in Machiasport. These records offer temporal resolution of five to seven years and span the past century. They are compared with instrumental data from a nearby tidal station to assess their accuracy. Strong correlations are found between the geologic records and the observational data, in particular between the foraminiferal record from Machiasport and the tide-gauge record from Eastport (r(2) = 0.83, p = 0.005). Thus a foraminifera-based transfer-function approach offers great potential for resolving decadal-scale sea-level changes from the geologic record.