CGRG Bibliography of Canadian Geomorphology
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Author : Eimers, M.C.; Paterson, A.M.; Dillon, P.J.; Schiff, S.L.; Cumming, B.F.; and Hall, R.I.
Date : 2006.
Title : Lake sediment core records of sulphur accumulation and sulphur isotopic composition in central Ontario, Canada lakes.
Publication : Journal of Paleolimnology
Issue : 35(1):
Page(s) : 99-109.
Abstract
Stable isotopic compositions and concentrations of total sedimentary sulphur (S) were determined in cores from 6 lakes in the acid-sensitive Muskoka-Haliburton region of south-central Ontario. The isotopic composition of S in deep sediment (> ~ 20 cm) was approximately constant in all lakes, and indicated a pre-industrial d 34S value between +4.0 and +5.3‰, which is similar to current bulk deposition. Similarly, total S concentrations in deep sediment were relatively low (1.9–5 mg S g-1 dwt) and approximately constant with depth within cores. All lakes exhibited up-core increases in total S and decreases in d 34S at a depth corresponding to the beginning of industrialization in the Great Lakes region ( ~ 1900), resulting in a generally reciprocal depth pattern between total S concentration and d 34S ratios. While initial shifts in total S and d 34S were likely due to enhanced SO4 reduction of newly available anthropogenic SO4, both the magnitude and pattern of up-core S enrichment and shifts in d 34S varied greatly among lakes, and did not match changes in S deposition post 1900. Differences between lakes in total S and d 34S were not related to any single hydrologic (e.g., residence time) or physical (e.g., catchment-area-to-lake area ratio) lake characteristic. This work indicates that sediment cores do not provide consistent records of changes in post-industrial S deposition in this region, likely due to redox-related mobility of S in upper sediment.
Bibliography of Canadian Geomorphology