An 8500 cal. year multi-proxy climate record from a bog in eastern Newfoundland: contributions of meltwater discharge and solar forcing

Abstract

Analyses of plant macrofossils, testate amoebae and the degree of peat humification have been combined into a single composite reconstruction of bog surface wetness (BSW) on a coastal plateau bog in eastern Newfoundland. The reconstruction reveals 14 distinctive phases of near-surface water tables commencing at 8270, 7500, 6800, 5700, 5200, 4900, 4400, 4000, 3100, 2500, 2050, 1700, 600 and 200 cal. BP, which may be used to infer changes in the atmospheric water balance of eastern Newfoundland. The first two major phases of pool development follow the final drainage of glacial Lake Agassiz at 8400 cal. BP and the Ungava lakes between ca 7500–6900 cal. BP, respectively. From 7500 cal. BP to the present there appears to be a strong correlation, within dating errors, between reconstructed BSW and the stacked ice rafted debris (IRD) record in the North Atlantic Ocean. Both records may reflect long-term changes in air masses. Comparisons of the BSW reconstruction with records of cosmogenic isotope flux also suggest a persistent link between reduced solar irradiance and increased BSW during the Holocene.