biogenic silica sedimentation
Early diagenesis of biogenic silica in the Amazon delta: …
Biogenic silica particles buried in suboxic Amazon delta deposits can be unaltered, partially dissolved, covered with aluminosilicate or metal-rich coatings, or completely reconstituted into authigenic K-Fe-rich aluminosilicate minerals. ... stored in high sedimentation rate environments such as deltas and continental rise deposits would …
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Transfer and early diagenesis of biogenic silica oxygen …
Furthermore, in a subsequent study Schmidt et al. (2001) concluded that the oxygen isotope composition of marine sedimentary diatomaceous silica does not solely reflect the sea surface temperature and that biogenic opal undergoes an 18 O enrichment during sedimentation. Consequently, a quantitative interpretation of sedimentary …
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Biogenic silica in surface sediments of the South China Sea
1. Introduction. Biogenic silica (BSi), which is mostly composed of diatom, radiolarian and sponge spicule remains, is a major biogenic component of marine …
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Biogeochemical Processes in the Ross Sea (Antarctica): …
Fluxes of particles, biogenic silica and organic carbon through the water column were obtained at three sites in the northwestern Ross Sea using 238 U/ 234 Th disequilibrium, drifting traps, and moored sediment traps. Burial rates of biogenic components were calculated by determining sediment mass accumulation rates, while inferences on the …
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Ocean Sediment
Oceanography, Chemical. James H. Mathewson, in Encyclopedia of Physical Science and Technology (Third Edition), 2003 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 …
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Biogenic Silica Accumulation in the Central Equatorial …
Cenozoic biogenic silica sedimentation in the Antarctic Ocean GSA Bulletin. Related Book Content. The role of clays in the performance of oil-sands tailings management options Introduction to Oil Sands Clays. Planktonic foraminiferal biostratigraphy, paleoceanographic implications, and deep-sea correlation of the Pliocene-Pleistocene ...
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Sedimentary biogeochemical gradients across the Sunda …
3.3 Spatial variation of sedimentary phosphorus speciation and biological silica. The spatial patterns of the TSP were the highest near 4°N and decreased towards the north, which could be attributed to the input of P from continental sources (Figures 4A-C).The distributions of POP and PIP were quite similar, suggesting a close connection …
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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 KOH solution was just as effective.
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Controls on the Recycling and Preservation of Biogenic Silica …
The recycling of biogenic silica (bSiO2) produced by diatoms is a vital process sustaining a significant fraction of primary production in the oceans. The efficiency with which bSiO2 dissolves controls the availability of nutrient silicon in the water column, and modulates the export of organic carbon to the deep sea. Environmental conditions …
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Biogenic silica contents of Lake Qinghai sediments and its
Changes in the levels of biogenic silica (BSi%) in lake sediments have been widely used in order to study lake productivity and palaeoclimatic changes. However, the provenance of biogenic silica (BSi) needs to be investigated for each lake, especially for large lakes, as does the relationship between levels of BSi and relevant environmental factors. In this …
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Enhanced silica export in a future ocean triggers global …
Vertical profiles of opal fluxes and dissolved silica are instantaneously computed based on biogenic silica production in the surface ocean and dissolution throughout the water column, and silica ...
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Lake sedimentary biogenic silica from diatoms constitutes …
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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Ocean 540: Marine Sedimentation
Active sedimentation processes (where the sediment modifies the properties and behavior of the suspension) include mass wasting and density currents. Such deposition tends to mask other …
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Differential dissolution of biogenic silica significantly affects …
The authors (Lihua Ran, Martin G. Wiesner, Yuzhao Liang, Wen Liang, Lanlan Zhang, Zhi Yang, Hongliang Li, Jianfang Chen) confirm that the study …
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The Sediment Green‐Blue Color Ratio as a Proxy for Biogenic Silica
The Sediment Green-Blue Color Ratio as a Proxy for Biogenic Silica Productivity Along the Chilean Margin. Chen Li, Corresponding Author. Chen Li [email protected] ... the opal percentages in the sediments are very low because of the extremely high sedimentation rates on the margin, which can exceed 200 cm/kyr ...
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Sedimentation patterns of diatoms in Lake Holzmaar, …
The seasonal sedimentation pattern of diatom valves in Lake Holzmaar was investigated during 1995 by deploying sediment traps at three different lake depths. According to the sedimentation pattern, the major reproduction zone of diatoms was ... (on the transfer of climate signals to biogenic silica oxygen isotope proxies)* Susanne Raubitschek ...
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Reviews and syntheses: The biogeochemical cycle …
So, the preservation ratio of biogenic silica in sediment can be calculated as (F B + F RW) / F Pgross = (13.9 / 255) = 5.45 %, which is ≈30 times larger than the carbon preservation efficiency. Figure 4 …
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Riverine contribution of biogenic silica to the oceanic silica …
The results demonstrate that the contribution of biogenic silica carried in suspension by rivers is an important component in the world ocean Si budget that has not been recognized previously. Biological uptake of dissolved silicate (DSi) and formation of biogenic silica (BSi) during diatom growth modifies the form of Si carried from the …
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A new method to remove biogenic silica from lake …
The grain-size distribution of lake sediments is a crucial proxy for paleoclimate reconstruction, as it is closely related to the transport dynamics of clastic materials from the surrounding land. However, the presence of biogenic silica, particularly remains of diatom frustules, can significantly bias the grain-size distribution of lake …
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Distribution and dissolution kinetics of biogenic silica in …
1 Introduction. Biogenic silica (bSiO 2) is one of the most important components in marine sediments and believed to be a potentially powerful proxy to …
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Frontiers | Revisiting the biogenic silica burial flux …
1. Introduction. Coastal and Continental Margin Zones (CCMZs) are distinct settings for the interrogation of global marine biogeochemical cycling of silica (Si), climate change and marine ecological processes (Jeandel and Oelkers, 2015; Jeandel, 2016; Tréguer et al., 2018; Rahman et al., 2019).The CCMZs represent approximately 10% of …
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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 …
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The Missing Silica Sink: Revisiting the Marine Sedimentary Si …
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, including as opal (bSi opal) and diagenetically altered opal (bSi altered), the latter dominantly authigenic clay (bSi clay).To determine the …
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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 …
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Biogenic silica concentration as a marine primary …
We analyzed the biogenic silica (BSi) content and produced a diatom-based summer sea-surface temperature (SST) reconstruction for sediment core GC4 from the Holsteinsborg Dyb, West Greenland. Our aim was to reconstruct marine productivity and climatic fluctuations during the last millennium. Increased BSi content and diatom …
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Biogenic silica and chert in the Pacific Ocean
Evidence for the dissolution of biogenic silica at the base of pelagic sections supports the hypothesis that much of the chert formed in the Pacific derives from the dissolution and reprecipitation of this silica by hydrothermal waters. As ocean bottom waters flow into and through the crust, they become warmer. Initially they remain less saturated with respect …
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Dissolution kinetics of biogenic silica and the recalculated …
Introduction. Silicon is an essential nutrient for the growth of siliceous organisms, such as diatoms, radiolarians, silicoflagellates, and siliceous sponges, which utilize dissolved silica to form their amorphous hydrated silica shells (also referred to as biogenic silica (bSiO 2) or opal) (Van Cappellen et al., 2002).Diatoms are the dominant …
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Biogenic silica in sediment core indicates the historical …
Sediment serves as the ultimate sink for the biogenic elements that are buried and stocked during sedimentation processes ( et al., 2013). Anthropogenic and natural disturbances that alter the deposition could eventually influence the contents of the biogenic elements in the sediment core (Heathcote et al., 2015; Wang et al., 2019).
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A new method to remove biogenic silica from lake
Fresh biogenic silica from the water column usually has a high reactivity and a low Al content. Aged biogenic silica from the sediments has a lower reactivity, but Si/Al ratios as low as 5 were found.
ادامه مطلبPaleoproductivity evolution in the northeastern Indian …
Based on the analysis of biogenic silica (BSi) in core ADM-159 and core BoB-56 from the northeastern Indian Ocean, high-resolution curves of paleoproductivity evolution were obtained. The results show that the BSi contents in these two core sediments are less than 1.8%, mainly affected by the low supply of silica skeleton and …
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