biogenic silica sedimentation
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biogenic silica sedimentation

Cenozoic biogenic silica sedimentation in the

Cenozoic biogenic silica sedimentation in the Antarctic Ocean NANCY ANN BREWSTER. NANCY ANN BREWSTER

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Biogenic silica sedimentation in the central equatorial ...

The percent of biogenic silica in the sediments varies synchronously with the accumulation rates, but is low to the east due to dilution by non-biogenic sediment from terrigenous and volcanic sources.

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Limnological investigation of biogenic silica ...

Biogenic silica concentrations were determined from core samples of laminated sediments collected from Lake Zürich and Lake St. Moritz and used to calculate rates of biogenic silica sedimentation. In Lake Zürich biogenic silica sedimentation increased from 65 g SiO2−2yr−1 in 1894 to nearly 900 g SiO2m−2yr−1 in 1896 and in Lake St. Moritz biogenic silica sedimentation increased about 6-fold

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Cenozoic biogenic silica sedimentation in the

Cenozoic biogenic silica sedimentation in the Antarctic Ocean, based on two deep sea drilling project sites Public Deposited

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Cenozoic biogenic silica sedimentation in the

The Antarctic Ocean during Cenozoic time experienced four periods of enhanced siliceous productivity. The beginning of the Miocene and the Pliocene-Quaternary are the two major periods. The Pliocene-Quaternary increase in productivity began 5 m.y. ago and has progressively increased to the present level of intense surface productivity. Two short-lived periods of slightly increased surface ...

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Biogenic Silica Profiles in the Sediments of Large ...

2002-1-1  Profiles of the abundance or mass accumulation rate of biogenic silica in sediment cores can provide important insight into the past productivity of diatoms and the climatic influence on a

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Biogenic Silica - an overview ScienceDirect Topics

III.E Biogenous Sedimentation Ocean sediments consist of biogenic silica (global average of 14%), calcite (48%), and aluminosilicate dust (abyssal clay derived from the weathering of continents) (38%). The silicic acid [Si (OH)4] and calcium bicarbonate [Ca (HCO 3) 2] introduced into the oceans from rivers are removed by biogenous sedimentation.

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Biogenic silica and phosphorus accumulation in

2019-2-2  Biogenic silica concentration vs. depth in cores from Lake Erie. The post-settlement rise in biogenic silica shown by the dashed line was dated at 1880 with 210Pb. Mass sedimentation rates calculated from 21 0Pb data for cores G-16-82 and Hs-82 were 0.108 and 0.474 mg cm-2 yr-1, respectively. P accumulation Much greater increases in P ...

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Fixation of dissolved silicate and sedimentation of ...

Some particulate biogenic silicate in river water settled in man-made sedimentation areas in the Rhine delta. The observations suggest that changes in silicate fixation in the Rhine may have contributed to the incidence of non-diatom phytoplankton blooms in receiving waters. Download to read the full article text.

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Production and dissolution of biogenic silica in the

1995-9-1  Globally, at least 50% of the silica produced by diatoms in the euphotic zone dissolves in the upper 100 m, resulting in an estimated export of 100–140 × 10 12 mol Si yr −l to the deep ocean. Our estimates correspond to a global mean rate of biogenic silica production between 0.6 and 0.8 mol Si m −2 yr −1. Incubation experiments indicate that silica production rates exceed that mean by a factor of

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Biogenic silica sedimentation in the central equatorial ...

Using a normative calculation, a portion of the analytical silica concentration of sediments is subtracted as non-biogenic in proportion to the concentration of aluminum in the sample. The ratio of SiO₂:Al₂O₃ used to characterize the non-biogenic sediment fraction was determined by X

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Biogenic Silica Profiles in the Sediments of Large ...

2002-1-1  Thomas C. Johnson, 2002. "Biogenic Silica Profiles in the Sediments of Large Tropical Lakes: Examples from East Africa", Sedimentation in Continental Rifts, Robin W. Renaut, Gail M. Ashley

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Biogenic silica record in the sediments of Little Round ...

2019-3-18  sedimentation rate resulting from deforestation. With the exceptions of an unexpected decrease in BSi input in Zone 3a and two pulses at 234 and 256 cm, the flux profile is consistent with the Biogenic Silica Flux (mg/cm2/yr) r c 200 250 0 0 50 Eu 100 150 1 2 3 Fig. 2. Biogenic silica flux vs. depth. 4 trophic development as well as with the ...

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Biogenic silica and phosphorus accumulation in

2019-2-2  Biogenic silica concentration vs. depth in cores from Lake Erie. The post-settlement rise in biogenic silica shown by the dashed line was dated at 1880 with 210Pb. Mass sedimentation rates calculated from 21 0Pb data for cores G-16-82 and Hs-82 were 0.108 and 0.474 mg cm-2 yr-1, respectively. P accumulation Much greater increases in P ...

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Lake sedimentary biogenic silica from diatoms

Diatoms play an important role in marine biogeochemical cycle of aluminum (Al), as dissolved Al is taken up by diatoms to build their siliceous frustules and is involved in the sedimentation of ...

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Lake sedimentary biogenic silica from diatoms

Diatoms play an important role in marine biogeochemical cycle of aluminum (Al), as dissolved Al is taken up by diatoms to build their siliceous frustules and is involved in the sedimentation of diatomaceous biogenic silica (BSi). The Al incorporation in BSi facilitates decreasing the dissolution of

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Biogenic Sediments - Geology

2007-8-25  Sponge spicules are also an important biogenic source of opalline silica in neretic waters, but are of minor importance in the deep sea. Silica is undersaturated throughout most of the world's oceans. As a result, extraction of silica from seawater for production of silica shells or skeletons requires substantial energy.

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Biogenic sedimentation in McMurdo Sound,

Despite this observation, if similar patterns of biogenic sedimentation exist on many other parts of the shelf, the Antarctic continental margin is an important sink for sedimentary organic carbon, as has been previously suggested for the silica system.

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Role of biogenic silica in the removal of iron from the ...

2013-6-10  Iron removal through incorporation into silica may be particularly important in the pelagic Southern Ocean, where iron often limits growth 24 and the sedimentation and burial of biogenic silica ...

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Oligocene biogenic siliceous deposits on the slope of

Abstract. The abundance of radiolarian, diatom and sponge spicule and H 4 SiO 4 in pore-waters increase abruptly at the boundary between Early and Late Oligocene (about 30-27.5 Ma) at Site 1148 of the northern South China Sea (SCS), indicating high biogenic silica accumulation during this time. At the same time (about 30-28 Ma), high biogenic silica deposition occurred in the central ...

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Distribution of biogenic silica in the surficial sediments ...

Distribution of biogenic silica in the surficial sediments of Lake Michigan Daniel J. Conley; . Daniel J. Conley

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Biogenic silica record in the sediments of Little Round ...

2019-3-18  sedimentation rate resulting from deforestation. With the exceptions of an unexpected decrease in BSi input in Zone 3a and two pulses at 234 and 256 cm, the flux profile is consistent with the Biogenic Silica Flux (mg/cm2/yr) r c 200 250 0 0 50 Eu 100 150 1 2 3 Fig. 2. Biogenic silica flux vs. depth. 4 trophic development as well as with the ...

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A Shift in the Biogenic Silica of Sediment in the Larsen

2013-1-2  2. Biogenic silica. 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.After 30 minutes (min), 5 ml of a 10% hydrochloric acid (HCl) solution was added to dissolve ...

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Evidence for reduced biogenic silica dissolution rates in ...

for dissolution, aggregation influences the balance between recycling of biogenic silica (bSiO 2) and its sedimentation and preservation at the seafloor. Additionally, aggregation may directly impact dis-solution rates of opal. Laboratory experiments were conducted to

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Recent and Glacial Age Organic Carbon and Biogenic

2020-1-30  Sedimentation rate data for the late Pleistocene and Holocene was compiled and mapped along with bulk sediment accumulation rate data estimated from the surface calcium carbonate concentration. This data was combined with surface organic carbon and opal (biogenic silica) concentration data in order to calculate the recent rate of

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"Recent and Glacial Age Organic Carbon and Biogenic

Sedimentation rate data for the late Pleistocene and Holocene was compiled and mapped along with bulk sediment accumulation rate data estimated from the surface calcium carbonate concentration. This data was combined with surface organic carbon and opal (biogenic silica) concentration data in order to calculate the recent rate of accumulation of these biogenically derived sedimentary components.

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Biogenic silica - snst-hu.lzu.edu.cn

2017-1-10  Biogenic silica (BSi) is the equivalent to the terms silica (SiO 2 •nH 2 O).. Diatoms in both fresh and salt water extract silica from the water to use as a component of their cell walls. Likewise, some holoplanktonic protozoa (Radiolaria), some sponges, and some plants (leaf phytoliths) use silicon as a structural material.

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Biogenic silica concentration as a highresolution ...

2015-10-9  Biogenic silica concentration as a high-resolution, quantitative temperature proxy at Hallet Lake, south-central Alaska Nicholas P. McKay,1 Darrell S. Kaufman,1 and Neal Michelutti2 Received 10 December 2007; revised 30 January 2008; accepted 4 February 2008; published 13 March 2008.

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Sedimentation of particulate material in stratified and ...

Sedimentation of organic carbon was correlated with sedimentation of biogenic silica, especially during January to March. There were positive and highly significant relationships between the flux of TCHO and those of TPM, POC. Chl a equiv. and Psi. From the latter 2 relationships, it was deduced that diatoms were the major source of TCHO at ...

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OF BIOGENIC SILICA ACCUMULATION IN THE LOW

OF BIOGENIC SILICA ACCUMULATION IN THE LOW-LATITUDE ATLANTIC 1 Naja Mikkelsen2 and John A. Barron3 ABSTRACT Pronounced biogenic silica accumulation has taken place in the Ceara Rise region during two episodes of the Cenozoic: the early Oligocene (33.5−30.5 Ma) and the early Miocene (23.0−15.5 Ma). The Paleogene deposits are dominated by ...

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