You are here: Home :: Area NEM :: Chemistry :: Physical chemistry

N. Schleich, D. Degering, S. Unterricker

Natural and artificial radionuclides in forest and bog soils: Tracers for migration processes and soil development

Radionuclide distributions in undisturbed forest and bog soils, mostly situated in Saxony, Germany (Erzgebirge), were studied. Low concentrations of naturally-occurring U and Th decay series nuclides, including ²¹⁰Pb, and artificial radioisotopes (¹²⁵Sb, ¹³⁴Cs, ¹³⁷Cs, ²⁴¹Am) were determined using low-level γ-spectrometry. In addition, the activities of ²³⁸Pu and ^239,240Pu were determined by radiochemical separation and α-spectrometry. ¹⁴C and excess ²¹⁰Pb dating methods were used to date the sampled bog profiles. The different radionuclides show characteristic depth distributions in the forest and bog soil horizons, which were sub-sampled as thin slices. ¹²⁵Sb, ²⁴¹Am, ²³⁸Pu and ^239,240Pu are strongly fixed in soil organic matter. In spruce forest soils, the influence of soil horizons with distinct properties dominates the vertical time-dependent distribution. In ombrotrophic bogs, the peak positions correlate with the year of maximum input of each nuclide. The Sb, Am and Pu “time markers“ and the ¹⁴C and ²¹⁰Pb dating results correspond very well. Although Cs seems to be relatively mobile in organic as well as mineral forest soil horizons, it is enriched in the organic material. In ombrotrophic bogs, Cs is very mobile in the peat deposit. In Sphagnum peat, Cs is translocated continuously towards the growing apices of the Sphagnum mosses, where it is accumulated.

Radiochimica Acta, Oldenbourg Wissenschaftsverlag

Print ISSN: 0033-8230
Volume: 88, 09/2000
Pages: 803

Journal homepage (external site)

Show all available items of this journal

 

Area NEM