HR: 1340h
AN: PP43B-1266    [Abstracts]
TI: Sphagnum δ¹³C Values as Potential Indicators of Palaeohydrological Changes in Peat Bogs
AU: * Loisel, J
EM: loisel.julie.2@courrier.uqam.ca
AF: GEOTOP-UQAM-McGILL and Département de Geographie, Université du Québec à Montréal, C.P.8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Garneau, M
EM: garneau.michelle@uqam.ca
AF: GEOTOP-UQAM-McGILL and Département de Geographie, Université du Québec à Montréal, C.P.8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Hélie, J
EM: helie.jean-francois@uqam.ca
AF: GEOTOP-UQAM-McGILL and Département des Sciences de la Terre, Université du Québec à Montréal, C.P.8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AB: Late-Holocene peat stratigraphy of a Canadian boreal peat bog was examined in order to evaluate the potential of Sphagnum δ¹³C values as a surface wetness proxy indicator. Carbon isotope-inferred past moisture levels were compared to testate amoebae-inferred water table depths, and to past decomposition levels inferred by colorimetric analyses, bulk density and carbon to nitrogen ratio measurements. Analyses were carried out at the same levels, allowing relations between the different proxies. In order to establish peat chronology, six AMS radiocarbon dates were coupled with ten ²¹⁰Pb dates. Proxy records were combined and compared, and since a strong correlation was found among proxies, a valuable high-resolution surface- moisture reconstruction was obtained from the core. Although the mechanisms underlying carbon fractionation processes in peatlands are not well understood, we demonstrate that Sphagnum δ¹³C values have a great potential for palaeohydrological reconstructions by providing a complementary source of information.
DE: 0424 Biosignatures and proxies
DE: 0454 Isotopic composition and chemistry (1041, 4870)
DE: 1890 Wetlands (0497)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting