Deposition chronologies in a peat bog from Spitsbergen (High Arctic) using the 210Pb dating method

Abstract

This study reports on the accumulation rates and 210Pb fluxes in Spitsbergen, Svalbard archipelago, wetlands. Six peat cores were collected in the Hornsund region, SW Spitsbergen (77°N) in 2007. The ages of peat layers were obtained with the Constant Flux/Constant Sedimentation and Constant Rate of Supply models based on the 210Pb-dating technique. The obtained 210Pb flux values ranged from 28 to 50 Bq m –2 y –1, which was consistent with the level of 222Rn emanation estimated for northern latitudes. The values of vertical and mass accumulation rates were slightly lower than reference data for peatlands of 50°−70°N. Furthermore, the vertical variations of peat accumulation rates exhibited the highest values in the upper part of the examined cores. The increasing tendency may be due in part to low compaction and low decomposition in the youngest peat layers. The analysis of the peat accumulation rate as a function of organic matter content and bulk density revealed positive and negative correlations, respectively, rather strong in both cases. The air temperature and precipitation gradients in the last few decades may have affected peat growth rates, which should be thoroughly investigated in future projects. Undoubtedly, the reported findings have provided a valuable addition to the relatively sparse dataset on recent peat deposits in Spitsbergen.

Keywords

• arctic
• hornsund
• peat accumulation rate
• radiometric dating
• 210pb flux