SULFUR DURING EARLY DIAGENESIS IN SPHAGNUM PEAT - INSIGHTS FROM DELTA-S-34 RATIO PROFILES IN PB-210-DATED PEAT CORES

Pb-210 chronologies and depth profiles of stable S isotope ratios (del taS-34) and concentrations of organic and inorganic S fractions were d etermined in peat cores from nine sites in the U.S. and the Czech Repu blic. Results indicate that depth profiles in S concentrations, S accu mulation, and deltaS-34 ratios in peat deposits are affected not only by historical patterns in atmospheric S deposition but also by ongoing depth-dependent changes in S reduction-oxidation and S immobilization -mineralization processes within a peat deposit. These processes impar t a certain degree of mobility to S in peat, bringing into question th e validity of reconstructing historical records of S accumulation usin g dated peat profiles. Over long-term diagenesis, isotopically light S may be continually released from deep peat. This release may result i n redistribution of S and S isotopes in peat and suggests that short-t erm patterns in S accumulation may not persist over much longer time s cales.