Hydrogen, carbon and sulphur isotope ratios in peat: the role of diagenessis and water regimes in reconstruction of past climates

We demonstrate that carbon, hydrogen and sulphur isotope ratios both, in the total peat (delta C-13(tp) = -25.52 to -28.27%, delta D-tp = -78.67 and -109.24%m delta S-34 = 4.35 to 19.87%), and in cellulose from the peat (delta C-13(nc) = -25.06 to -27.33% and delta D-nc = -92.43 to -118.02%) are not affected by postdepositional changes. Therefore, the original isotope composition of plants are in general preserved in the peat and represent an archive of the past environmental variations. These can be supported by (i) good correlations between delta C-13(tp) and delta C-13(nc), and between delta D-tp and delta D-nc, (ii) high horizontal homogeneity of delta C-13(tp) and delta C-13(nc) in the scale of one peat-bog - the same major factor(s) control(s) C isotopic ratios, (iii) no correlation between organic sulphur concentrations and delta S-34 value -delta S-34 results from variations in the water level.