A view of the wood charcoal stratigraphy and dating in soil: A case study of some soils from the French Alps.

The burial and fragmentation processes are investigated by anthracological analysis and by absolute C-14 dating of four pedological profiles from the French Alps. Absolute C-14 dates are essential but insufficient for the understanding of the mo;de of stratification. The dates must be considered after a detailed qualitative (taxonomic composition) and quantitative analysis of anthracological assemblages. The soil stratification process does not compare with that in lake or peat-bog sediments. Action of roots, soil fauna and erosion processes mean burial of wood charcoal in the soil occurs at different speeds. The result is a stratification in ''scales''. The assemblages and dates allow us to recognize three fire phases on the stand MAUR 6 at middle altitude (1770 m a.s.l.). On QUEYRAS 2, at high altitude (2670 m a.s.l.), wood charcoal assemblages did not reveal the oldest fire phases. The network of roots and mainly the frost-thaw reduces the size of wood charcoal fragments in the soil.