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Projects and Current Researchs:
         
210Pb:

The 210Pb CRS age model used for peat is based on simple assumptions:
1. the peat bog is receiving only atmospheric inputs, that is why the major part of 210Pb is unsupported 210Pb (coming from the atmosphere through the Rn) and not supported 210Pb (i.e. detrital and contained in the mineral matrix),
2. the flux of 210Pb is constant. From previous studies, this is verified on a yearly basis. One major explaination for spatial variations of 210Pb fluxes is the variations in precipitation (can we expect variations in the 210Pb fluxes due to climatic change?).

Because 210Pb has an half life of approximately 22,3 y, it i possible to age date samples back to the beginning of the industrial period.

The first part of the figure is an idealized age-depth model considering a peat bog growing with a linear rate. This figure is here to illustrate the growing errors on the age estimation with depth.

The second part is an illustration of the diluting effect. Indeed if the bog is growing faster  (slower), the 210Pb entering the bog will be dilute (concentrated)  for the corresponding depth interval and the profile won´t respect the tradtionnal decay curve.
This happens in most of the cases because peat bog growth is affected by different parameters.

For a mathematical approach of the 210Pb age dating, see the book chapter by P.G. Appleby:

Chronostratigraphic Techniques in Recent Sediments, in Tracking Environmental Change Using Lake Sediments, vol.1 (Eds. W.M. Last and J.P. Smol), Kluwer, Dordrecht, pp.171-202

If you have any question about interpretations and mesurements, mail me: [email protected]

LOCATIONS of samples measured by me using the Gamma Spectrometer from the Institute of Environmental Geochemistry

PEAT BOGS AS ARCHIVES!: the forum!

Environmental Geochemistry in Black Forest: the album!

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