A methodological study on the determination of biogenic silica …
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).
Biogenic silica and organic carbon fluxes provide evidence …
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 …
Silicon flux and distribution of biogenic silica in deep-sea …
The surficial sediment biogenic silica content was high at high latitudes with the boundary running along the Kuroshio Extension, and maximum values (exceeding 20%) were found in the Oyashio ...
Early diagenesis of biogenic silica in the Amazon delta: …
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, …
Production and dissolution of biogenic silica in the ocean: …
We estimate the global rate of biogenic silica production in the ocean to be between 200 and 280 × 1012 mol Si yr−1. The upper limit is derived from information on …
Biogenic sedimentation in the equatorial Pacific: …
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
Biogenic silica as an estimate of siliceous microfossil …
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 …
The Missing Silica Sink: Revisiting the Marine …
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, …
A new method to remove biogenic silica from lake
The analyses consist of measurements of bulk sediment grain size and biogenic silica, together with microscope observations. Based on both light and scanning electronic microscope observations ...
Potential deposition of biogenic silica source sediment in …
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 …
Biogenic silica dissolution in sediments of the Southern …
The silica solubility profiles are best explained by the early diagenetic interactions between biogenic silica and soluble aluminum derived from detrital material. …
Settling, dissolution and burial of biogenic silica in the …
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 …
Biogenic silica in sediment core indicates the historical …
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. However, whether BSi in sediment core can indicate …
Primary silica precipitate at the Precambrian/Cambrian boundary in …
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 …
Biogenic silica dissolution in the oceans: …
[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 …
Anthropogenically induced changes in sediment and biogenic silica …
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 …
A Shift in the Biogenic Silica of Sediment in the Larsen B …
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.
Biogenic silica microfossils in sediments of the Permian
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 .
Biogenic silica dissolution in the oceans: Reconciling …
During diagenesis of biogenic silica in sediment, dissolution of detrital minerals (clay minerals) releases dissolved Al to pore waters, which then becomes structurally incorporated into the ...
Distribution of biogenic silica and quartz in recent deep …
All available quartz and biogenic silica concentrations from deep-sea surface sediments were intercalibrated, plotted, and contoured on a calcium-carbonate-free basis. The maps show highest concentrations of biogenic silica (opal) along the west African coast, along equatorial divergences in all oceans, and at the Polar Front in the southern ...
Revisiting the dissolution of biogenic Si in marine sediments: …
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 …
Measuring biogenic silica in marine sediments
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 …
Anthropogenically induced changes in sediment and biogenic silica …
Sediment cores as long as 20 m, dated by 14 C, 210 Pb, and 137 Cs 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 …
Biogenic silica dissolution in the oceans: Reconciling experimental and
[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 order-of-magnitude lower values in deep-sea sediments. The lack of a mechanistic understanding of these large variations in …
Biogenic Silica
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 …
The Diagenesis of Biogenic Silica: Chemical Transformations Occurring
Approximately 400 Mt of biogenic silica are buried each year in marine sediments, making this phase second only to calcium carbonate in terms of biogenic sediment burial rate. Prior to the evolution of siliceous biota in the Cambrian, dissolved silicate was likely to have been removed from the oceans via inorganic precipitation of opal-A and ...
Production and dissolution of biogenic silica in the ocean: …
That rate is only slightly higher than the global average, indicating that the silica produced in those regions is only 10–25% of the global total. The estimated production of biogenic silica in surface waters of the mid-ocean gyres is approximately equal to that for all major areas of opal sediment accumulation combined.
Enhanced silica export in a future ocean triggers global …
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 ...
Decoupling of nitrogen, phosphorus and biogenic silica in …
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 …
Continental climate response to orbital forcing from …
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