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[1] On average, 50–60% of diatomaceous opal produced in the euphotic zone redissolves within the upper 100 m of the water column. High specific silica dissolution rates in the surface ocean contrast with …
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Request PDF | Transfer and early diagenesis of biogenic silica oxygen isotope signals during settling and sedimentation of diatoms in a temperate freshwater lake (Lake Holzmaar, Germany) | We have ...
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A transfer function has been established to quantify the dissolution of diatom silica in Southern Ocean sediments. The relationship between the amount of silica dissolution and changes in diatom species distribution is built by controlled progressive dissolution of biogenic silica in five recent sediment samples from box-core tops, each …
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Furthermore, the Si/Al ratio correction to Si-Alk for estimating biogenic silica is feasible and repeatable. The biogenic silica sediment levels varied from 18.90 to 120.10 μmol Si/g, whereas Si-HCl and Si-Alk ranged from 17.43 to 73.56 and from 19.56 to 185.63 μmol Si/g, respectively. The diagenetic alteration ratio of biogenic silica
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A transfer function has been established to quantify the dissolution of diatom silica in Southern Ocean sediments. The relationship between the amount of silica …
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ABSTRACT Biogenic silica sediment constitutes one of the critical sources of particle income in the oceans. In this paper, satellite remote sensing of primary production, sinking flux, and molar ratio of Si/C were utilized to elucidate potential biogenic silica sediment in the Paleo-Yangtze Grand Underwater Delta. Primary production …
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Of the ~240 × 1012 mol year−1 of biogenic silica (bSi) produced by diatoms and other silicifying organisms, only roughly 3%–4% escapes dissolution to be …
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Sediment cores are commonly used for reconstructing historical events by determining the biogenic elements in sediment vertical profiles. The vertical flux of biogenic silica (BSi) can be enhanced by bivalve mollusks through biodeposition and can be subsequently recorded in the sediment core.
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2.2. Biogenic Silica Analysis [12] The Olivarez Lyle and Lyle [2002] KOH-digestion method for biogenic silica analysis was used to determine the concentration of bio-SiO 2 in the sediment samples. The method was modified to use 1 M KOH for the digestion rather than 2 M KOH, after testing showed that the weaker
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Particle fluxes of biogenic silica through the water column, silica burial fluxes into the sediments, and the flux of dissolved silica across the sediment-water interface estimated from pore water profiles are used to assess the behaviour of biogenic silica at two stations 80 and 270 km offshore along a transect off the Somali coast in the …
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To provide a more optimum method, BSi, clay minerals and marine sediments were subjected to tests on the dissolution of silica at 100°C using four different alkaline …
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Three comprehensive surveys were performed in the Changjiang (Yangtze River) Estuary (CJE) to understand the biogenic silica (BSi) composition, behavior and budget.
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Biogenic silica is a powerful palaeoproductivity proxy in palaeomarine environments and is significant within shale gas reservoirs, demonstrating the association of marine hydrocarbon source rocks with the abundance of micro-siliceous fossils, yet detailed studies that investigate this strong alliance in the Ordovician-Silurian transition are still …
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The biogenic silica particle (BSP) microfossil group mainly consists of siliceous plant remains (i.e., phytoliths) that are 3-30 µm in size and generally preserve under oxidizing conditions .
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Three comprehensive surveys were performed in the Changjiang (Yangtze River) Estuary (CJE) to understand the biogenic silica (BSi) composition, behavior and budget. It is indicated that the BSi is composed of phytoliths, phytoplankton and sponges; phytolith BSi has 16 forms and account for 23% to 83% of the bulk BSi in the maximum …
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Burial of biogenic silica (bSi total) in high sedimentation rate continental margins remains highly uncertain.Cosmogenic 32 Si (t 1/2 ~140 years) can be used to trace the fates of bSi total postdeposition, …
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The silica solubility profiles are best explained by the early diagenetic interactions between biogenic silica and soluble aluminum derived from detrital material. ... 1990; Fritz et al., 1991; Bareille et al., 1991; Berger and Herguera, 1992). The dissolution rate of biogenic silica in a sediment is a function of the intrinsic reactivity of ...
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Human activities are altering global biogeochemical cycles of nitrogen (N), phosphorus (P) and biogenic silica (BSi). In order to reveal nutrient dynamics in response to human disturbances, this study explores burial rates and ratios of N, P and BSi in 210 Pb-dated sediment cores from eight lakes in the middle Yangtze River floodplain. Mean …
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The percentage of biogenic silica (SiO 2) in the sediment (expressed as dry weight %) was measured following established procedures, . Five milliliters of a 10% hydrogen peroxide (H 2 O 2) solution was added to approximately 100–200 mg of dry sediment to remove the organic matter.
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cm below the water-sediment interface [e.g., Hurd, 1973; Jahnke et al., 1982; McManus et al., 1995]. The pore water concentration gradients drive the return of silicic acid to the …
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peaks in biogenic silica occur in intervals that are dominated by small, fragile Cyclotella sp. ; and ( 4) some cores, including those examined in detail here, have nearly constant sedimentation rates
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The present study reexamines sediment storage of biogenic silica in Amazon delta sediments and more fully evaluates the role of transformation of opaline Si into derivative minerals than done previously. We provide substantial additional quantitative and qualitative evidence from direct examinations of individual natural particles, …
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Biogenic silica concentration (BSi) in sediment cores from the Great Lakes is evaluated as an estimate of siliceous microfossil abundance. A significant linear relationship was found between measured BSi and diatom valve abundance for sediment cores from the Bay of Quinte, Lake Ontario, Lake Erie, Lake Michigan and Lake Superior and between …
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Two interlaboratory comparison sediment samples (Still Pond, R-64) were measured using Si/time and Si/Al alkaline digestion to assess the accuracy of the biogenic silica measurement. Similar results were obtained to previous works ( Table 2 ), but also showed dependence on the extraction method.
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1.. IntroductionDissolution of biogenic silica (opal) in marine sediments plays an important role in the biogeochemical silicon cycle. Opaline skeletals, exported from the euphotic zone, undergo dissolution not only during their descent to the sea floor but also after their deposition on top of the sediment.
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Sediments, Diagenesis and Sedimentary Rocks. D. Rickard, in Treatise on Geochemistry (Second Edition), 2014 9.10.8.3.2 Biogenic silica. Turner et al (2008) used biogenic silica (BSi) contents as a better proxy of labile sediment organic carbon contents, as some part of the organic carbon in the sediment is mineralized. Diatoms preserve well so that BSi …
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Highlights We investigate the origin of a laminated organic-rich chert formed at the PC–C boundary. It consists of non-annual couplets composed of organic and siliceous sediment. The δ 30 Si isotopic values indicate a marine, non-biogenic silica source of the chert. Chert formed in 2-steps, first sub-sea salt dissolution triggered silica …
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Biogenic silica was leached from the sediment trap samples and filters by alkaline pulping (0.1 M NaOH at 85 °C). After 135 min the leaching process was terminated with 0.05 M H 2 SO 4 and ...
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We collected two lake sediment cores (MC and DM) from the East Antarctic region for analysis of biogenic silica and other biogeochemical parameters (e.g., organic matter, C, N, S, H).
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Sediment cores as long as 20 m, dated by 14C, 210Pb, and 137Cs methods and pollen stratigraphy, provide a history of diatom productivity and sediment-accumulation rates in Chesapeake Bay. We calculated the flux of biogenic silica and total sediment for the past 1500 yr for two high-sedimentation-rate sites in the mesohaline section of the …
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