Tracing bottom water oxygenation with sedimentary Mn/Fe ratios in Lake Zurich, Switzerland
MetadataShow full item record
Redox dynamics of manganese (Mn) were studied in the sediment of Lake Zurich using precise sediment core age models, monthly long-term oxygen (O2) monitoring data of the water column (1936–2010) and high-resolution XRF core scanning. The age models were based on bi-annual lamination and calcite precipitation cycles. If present, Mn exhibits distinct maxima, which coincide with the annual maximum deep-water O2 concentrations in spring according to the monitoring data. In contrast, the iron (Fe) signal is mainly the result of calcite dilution, as indicated by a strong negative correlation between Fe and calcium (Ca) XRF data. The Mn/Fe ratio in the core from the maximum lake depth (ZH10-15, 137 m) revealed a moderate correlation with O2 measurements in the lake bottom water confirming the successful application of the Mn/Fe ratio to semi-quantitatively reconstruct bottom water oxygenation in the lake. Mostly low ratios were observed between 1895 and the mid-1960s as a result of eutrophication. However, geochemical focusing and sedimentological factors can reduce the applicability of the Mn/Fe ratio in reconstructing O2 concentrations in the bottom water of lakes.
Showing items related by title, author, creator and subject.
Characterization of the sedimentary organic matter preserved in Messel oil shale by bulk geochemistry and stable isotopesBauersachs, T.; Schouten, S.; Schwark, Lorenz (2014)We investigated a 150 m thick drill core section of Messel oil shale using bulk geochemical and stable isotope techniques in order to determine the organic matter sources and the environmental conditions that prevailed ...
Imberger, J.; Marti, Clelia; Dallimore, C.; Hamilton, D.; Escriba, J.; Valerio, G. (2018)Lakes and reservoirs are increasingly threatened by anthropogenic activities, with serious environmental and financial consequences. In particular, nutrient loadings are increasing due to expanding human populations and ...
The distribution pattern of algal flora in saline lakes in Kambalda and Esperance, Western AustraliaHandley, Michelle Anne (2003)The study has attempted to characterise the physicochemical limnology and distribution of algal flora of two salt lake systems in Western Australia, one from the coastal Esperance region and the other from the inland ...