Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen
The chemistry and isotopic composition of siliceous diatom frustules and the organic matter bound within them have been used to reconstruct past changes in the environment. However, the alteration of biogenic silica in the sediments and its influence on the chemical properties of the diatom opal and...
Published in: | Marine Chemistry |
---|---|
Main Authors: | , , , |
Format: | Text |
Language: | unknown |
Published: |
DigitalCommons@URI
2013
|
Subjects: | |
Online Access: | https://digitalcommons.uri.edu/gsofacpubs/2211 https://doi.org/10.1016/j.marchem.2013.05.016 |
id |
ftunivrhodeislan:oai:digitalcommons.uri.edu:gsofacpubs-3180 |
---|---|
record_format |
openpolar |
spelling |
ftunivrhodeislan:oai:digitalcommons.uri.edu:gsofacpubs-3180 2024-02-11T10:02:33+01:00 Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen Ren, Haojia Brunelle, Brigitte G. Sigman, Daniel M. Robinson, Rebecca S. 2013-09-20T07:00:00Z https://digitalcommons.uri.edu/gsofacpubs/2211 https://doi.org/10.1016/j.marchem.2013.05.016 unknown DigitalCommons@URI https://digitalcommons.uri.edu/gsofacpubs/2211 doi:10.1016/j.marchem.2013.05.016 https://doi.org/10.1016/j.marchem.2013.05.016 Graduate School of Oceanography Faculty Publications Aluminum incorporation Biogenic silica Diagenesis Diatom-bound organic matter Marine sediments text 2013 ftunivrhodeislan https://doi.org/10.1016/j.marchem.2013.05.016 2024-01-15T19:10:03Z The chemistry and isotopic composition of siliceous diatom frustules and the organic matter bound within them have been used to reconstruct past changes in the environment. However, the alteration of biogenic silica in the sediments and its influence on the chemical properties of the diatom opal and diatom-bound organic matter has not been broadly studied. We use inductively coupled plasma atomic emission spectrometry and energy dispersive X-ray analysis to investigate the concentrations of various cations, especially aluminum, in cleaned diatom frustules extracted from sediments at three sites from the Bering Sea, where the opal content in the sediments and preservation conditions vary both spatially and over the last glacial cycle. Relative to cultured diatoms, cleaned diatom frustules from the sediments are found to have a high Al/Si ratio, most likely by homogenous Al incorporation but possibly also by formation of an aluminosilicate coating of significant thickness relative to the diatom walls. Variations in the Al/Si ratio of the cleaned diatoms among samples are strongly correlated with the aluminosilicate to opal ratio of the bulk sediment, suggesting that sedimentary clays are the primary source of the aluminum taken up by the diatoms. The aluminum and nitrogen contents of the diatom frustules are negatively correlated, which is best explained by the loss of intrinsic N during the chemical changes associated with Al incorporation. The lack of a consistent relationship between nitrogen isotopic composition and the aluminum content of the cleaned opal suggests that the diagenetic organic N loss does not fractionate N isotopes, which is as expected given that this loss process relates to the geochemistry of the opal, not the organic matter. Our findings help to explain the previous observations that opal from clay-rich sediments (1) requires harsher chemical cleaning to remove diagenetic N and (2) has diatom-native N that is better protected from alteration by excessively harsh chemical cleaning. The ... Text Bering Sea University of Rhode Island: DigitalCommons@URI Bering Sea Marine Chemistry 155 92 101 |
institution |
Open Polar |
collection |
University of Rhode Island: DigitalCommons@URI |
op_collection_id |
ftunivrhodeislan |
language |
unknown |
topic |
Aluminum incorporation Biogenic silica Diagenesis Diatom-bound organic matter Marine sediments |
spellingShingle |
Aluminum incorporation Biogenic silica Diagenesis Diatom-bound organic matter Marine sediments Ren, Haojia Brunelle, Brigitte G. Sigman, Daniel M. Robinson, Rebecca S. Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
topic_facet |
Aluminum incorporation Biogenic silica Diagenesis Diatom-bound organic matter Marine sediments |
description |
The chemistry and isotopic composition of siliceous diatom frustules and the organic matter bound within them have been used to reconstruct past changes in the environment. However, the alteration of biogenic silica in the sediments and its influence on the chemical properties of the diatom opal and diatom-bound organic matter has not been broadly studied. We use inductively coupled plasma atomic emission spectrometry and energy dispersive X-ray analysis to investigate the concentrations of various cations, especially aluminum, in cleaned diatom frustules extracted from sediments at three sites from the Bering Sea, where the opal content in the sediments and preservation conditions vary both spatially and over the last glacial cycle. Relative to cultured diatoms, cleaned diatom frustules from the sediments are found to have a high Al/Si ratio, most likely by homogenous Al incorporation but possibly also by formation of an aluminosilicate coating of significant thickness relative to the diatom walls. Variations in the Al/Si ratio of the cleaned diatoms among samples are strongly correlated with the aluminosilicate to opal ratio of the bulk sediment, suggesting that sedimentary clays are the primary source of the aluminum taken up by the diatoms. The aluminum and nitrogen contents of the diatom frustules are negatively correlated, which is best explained by the loss of intrinsic N during the chemical changes associated with Al incorporation. The lack of a consistent relationship between nitrogen isotopic composition and the aluminum content of the cleaned opal suggests that the diagenetic organic N loss does not fractionate N isotopes, which is as expected given that this loss process relates to the geochemistry of the opal, not the organic matter. Our findings help to explain the previous observations that opal from clay-rich sediments (1) requires harsher chemical cleaning to remove diagenetic N and (2) has diatom-native N that is better protected from alteration by excessively harsh chemical cleaning. The ... |
format |
Text |
author |
Ren, Haojia Brunelle, Brigitte G. Sigman, Daniel M. Robinson, Rebecca S. |
author_facet |
Ren, Haojia Brunelle, Brigitte G. Sigman, Daniel M. Robinson, Rebecca S. |
author_sort |
Ren, Haojia |
title |
Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
title_short |
Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
title_full |
Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
title_fullStr |
Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
title_full_unstemmed |
Diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
title_sort |
diagenetic aluminum uptake into diatom frustules and the preservation of diatom-bound organic nitrogen |
publisher |
DigitalCommons@URI |
publishDate |
2013 |
url |
https://digitalcommons.uri.edu/gsofacpubs/2211 https://doi.org/10.1016/j.marchem.2013.05.016 |
geographic |
Bering Sea |
geographic_facet |
Bering Sea |
genre |
Bering Sea |
genre_facet |
Bering Sea |
op_source |
Graduate School of Oceanography Faculty Publications |
op_relation |
https://digitalcommons.uri.edu/gsofacpubs/2211 doi:10.1016/j.marchem.2013.05.016 https://doi.org/10.1016/j.marchem.2013.05.016 |
op_doi |
https://doi.org/10.1016/j.marchem.2013.05.016 |
container_title |
Marine Chemistry |
container_volume |
155 |
container_start_page |
92 |
op_container_end_page |
101 |
_version_ |
1790598574655930368 |