Temporal variability of Pu signatures in a Pb-dated Sphagnum peat profile from the Northern Ural, Russian Federation.

The peat archives are one of the stratigraphic records revealing clearly physical, chemical and biological signals of human influence on the Earth System since the 1950s, at least. The presented study was aimed mainly to identify the level and origin of anthropogenic radionuclides such as Pu in a Pb-dated peat profile derived from the Northern Ural, Russian Federation. As stated, the vertical variability of Pu/Pu isotopic compositions reflects the nuclear weapons testing history with the maximum in the 1960s and small regional impact most likely of high-yielded tests in the 1950s as well as Chinese detonations in the 1970s. Peat accumulations rates were similar to those obtained in adjacent areas, whereas Pb flux slightly exceeded the reference level established for adequate latitude belt.