Biogenic silica as an estimate of siliceous microfossil abundance in Great Lakes sediments
نویسندگان
چکیده
منابع مشابه
Historic low-level phosphorus enrichment in the Great Lakes inferred from biogenic silica accumulation in sediments
Sedimentary biogenic silica (BSi) accumulation was used in conjunction with a hypothetical model of BSi accumulation to show that BSi is a sensitive proxy for low-level phosphorus enrichment in the Great Lakes. We hypothesize that historic nutrient-driven changes in diatom production altered silica biogeochemistry and induced biologically mediated silica depletion (BMSD) and that a record of th...
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Examination of surficial sediments at 16 stations shows minor, but consistent differences in the numbers and kinds of siliceous microfossils deposited in different regions of Lake Baikal. There is a general north-south decreasing trend in total microfossil abundance on a weight basis. Endemic plankton diatom species are the most abundant component of assemblages at all stations. Chrysophyte cys...
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Quantitative analysis of siliceous microfossils in 210Pb-dated Lake Michigan sediments shows five time zones in microfossil abundance and composition. Sediments deposited before 1885 contain low abundances comprising species associated with very oligotrophic lakes. Between 1885 and 1925 abundance increases slowly as does the ratio of planktonic diatoms to benthic diatoms and chrysophyte remains...
متن کاملMagnetite dissolution in siliceous sediments
[1] Magnetite dissolution, and consequent loss of magnetization, is widely observed in reducing sedimentary environments, where the decrease in Eh-pH values with depth is driven by bacterially mediated degradation of organic carbon. We have observed low magnetizations in sediments with elevated pore water silica concentrations that arise from diagenesis of biogenic silica and/or silicic volcani...
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As part of the international cooperative Baikal Drilling Project, siliceous microfossil assemblage succession was analyzed in two short (~ 30-cm) sediment cores from Lake Baikal. One core was recovered from the north basin (Core 324, 55°15~N, 109°30~E), a second from between the central and southern basins (Core 316, 52°28'N, 106°5rE). The northern core had higher amounts of biogenic silica (40...
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ژورنال
عنوان ژورنال: Biogeochemistry
سال: 1988
ISSN: 0168-2563,1573-515X
DOI: 10.1007/bf02182994