Radiocarbon Reservoir Ages from Freshwater Lakes, South Georgia, Sub-Antarctic

Modern Analogues from Particulate Organic Matter and Surface Sediments

Datos Bibliográficos

ID9243455
AutoresSteven G Moreton, Gunhild C Rosqvist (0000-0002-9195-607X), Sarah J Davies (0000-0003-3001-6006), Michael J Bentley
Año2004
Volumen46
Número2
Páginas621-626
Fecha de publicación2004-01-01
Peer ReviewedSí
Open AccessSí
TipoARTICLE
RevistaRadiocarbon (JOURNAL)
Identificadores de la revistaISSN: 0033-8222 • E-ISSN: 1945-5755
EditorialCambridge University Press (CUP) (PUBLISHER)
DOI10.1017/s0033822200035669
OpenAlexW1486937169
IdiomaEN
Citas recibidas18
Referencias citadas16

Lake sediments have the potential to preserve proxy records of past climate change. Organic material suitable for radiocarbon dating often provides age control of such proxy records. Six shallow freshwater lakes on the sub-Antarctic island of South Georgia were investigated for carbon reservoir effects that may influence age-depth profiles from lake sediment records in this important region. Paired samples of particulate organic matter (POM) from the water column and surface sediment (bulk organic carbon) were analyzed by accelerator mass spectrometry 14 C. POM in 4 lakes was found to be in equilibrium with the atmosphere (~107% modern), whereas 2 lakes showed significant depletion of 14 C. In each lake, the surface sediment ages were older than the paired POM age. Surface sediment ages showed a much greater range of ages compared to the equivalent POM ages, even for lakes located in close proximity. We conclude that sediment disturbance during coring, bioturbation, and periodic resuspension of sediments are likely factors causing the difference in the apparent age of surface sediments

Bioturbation · Coring · Drilling · Geochemistry · Organic matter · Particulates · Radiocarbon dating · Sediment · Surface water · Total organic carbon · Water column · Chemistry · Environmental Science · Geology and Paleoclimatology Research · Isotope Analysis in Ecology · Polar Research and Ecology · Ecology · Environmental Chemistry · Geology · Oceanography · Paleontology