Peat archives from Siberia: Synchrotron beam scanning with X-ray fluorescence measurements

Abstract

We used a new approach to measure the downcore distribution of some major and trace elements that record the Holocene history of peat-forming processes in peat from the Elovka mesotrophic swamp (West Siberia). The approach implies continuous non-destructive scanning of natural wet-core fragments under a sharp synchrotron beam combined with measurements of the excited X-ray fluorescence, in attempt to avoid errors due to the loss of volatiles abundant in peat. The obtained data are in good agreement with the results of the certified methods of neutron activation gamma-spectrometry (INAA) and classical SR XRF, though, as we expected, there is some discrepancy in the contents of volatiles (Br, Zn) which are most probably lost in INAA and/or in ignition. The precision of the suggested SR XRF scanning resolved the variability of 18 elements in the peat-core deposited during 0–8 kyr bp at no worse than 30 years in most cases. The distribution of the measured elements provided a clue to the evolution of peat deposition environments that controlled biogenic production, aerosol input, post-depositional processes, and Ca mineralization associated with pore water circulation in soil during the non-mesotrophic stages of the swamp history.