The isotope composition of inorganic Germanium in seawater and deep sea sponges
Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, howeve...
Published in: | Geochimica et Cosmochimica Acta |
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Online Access: | https://hdl.handle.net/1983/5e9ff25d-ecd6-4988-9148-2ad613332802 https://research-information.bris.ac.uk/en/publications/5e9ff25d-ecd6-4988-9148-2ad613332802 https://doi.org/10.1016/j.gca.2017.06.011 https://research-information.bris.ac.uk/ws/files/115786997/MS_OR_Guillermic_2017_05_30.pdf |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/5e9ff25d-ecd6-4988-9148-2ad613332802 2024-01-28T10:05:25+01:00 The isotope composition of inorganic Germanium in seawater and deep sea sponges Guillermic, Maxence Lalonde, Stefan Hendry, Kate Rouxel, Olivier 2017-09-01 application/pdf https://hdl.handle.net/1983/5e9ff25d-ecd6-4988-9148-2ad613332802 https://research-information.bris.ac.uk/en/publications/5e9ff25d-ecd6-4988-9148-2ad613332802 https://doi.org/10.1016/j.gca.2017.06.011 https://research-information.bris.ac.uk/ws/files/115786997/MS_OR_Guillermic_2017_05_30.pdf eng eng info:eu-repo/semantics/openAccess Guillermic , M , Lalonde , S , Hendry , K & Rouxel , O 2017 , ' The isotope composition of inorganic Germanium in seawater and deep sea sponges ' , Geochimica et Cosmochimica Acta , vol. 212 , pp. 99-118 . https://doi.org/10.1016/j.gca.2017.06.011 Stable isotopes Germanium Silicon Sponges Southern Oceans Chemical oceanography article 2017 ftubristolcris https://doi.org/10.1016/j.gca.2017.06.011 2024-01-04T23:52:44Z Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, however the low concentration of Ge in seawater presents an analytical challenge for isotopic measurement. Here, we present a new method of pre-concentration of inorganic Ge from seawater which was applied to measure three Ge isotope profiles in the Southern Ocean and deep seawater from the Atlantic and Pacific Oceans. Germanium isotopic measurements were performed on Ge amounts as low as 2.6 ng using a double-spike approach and a hydride generation system coupled to a MC-ICP-MS. Germanium was co-precipitated with iron hydroxide and then purified through anion-exchange chromatography. Results for the deep (i.e. > 1000 m depth) Pacific Ocean off Hawaii (nearby Loihi Seamount) and the deep Atlantic off Bermuda (BATS station) showed nearly identical δ74/70Ge values at 3.19 ± 0.31 ‰ (2SD, n = 9) and 2.93 ± 0.10 ‰ (2SD, n = 2), respectively. Vertical distributions of Ge concentration and isotope composition in the deep Southern Ocean for water depth > 1300 m yielded an average δ74/70Ge = 3.13 ± 0.25 ‰ (2SD, n = 14) and Ge/Si = 0.80 ± 0.09 mol/mol (2SD, n = 12). Significant variations in δ74/70Ge, from 2.62 to 3.71 ‰, were measured in the first 1000 m in one station of the Southern Ocean near Sars Seamount in the Drake Passage, with the heaviest values measured in surface waters. Isotope fractionation by diatoms during opal biomineralization may explain the enrichment in heavy isotopes for both Ge and Si in surface seawater. However, examination of both oceanographic parameters and δ74/70Ge values suggest also that water mass mixing and potential contribution of shelf-derived Ge also could contribute to the variations. Combining these results with new Ge isotope data for deep-sea sponges sampled nearby allowed us to ... Article in Journal/Newspaper Drake Passage Southern Ocean University of Bristol: Bristol Research Drake Passage Pacific Sars Seamount ENVELOPE(-69.000,-69.000,-59.583,-59.583) Southern Ocean Geochimica et Cosmochimica Acta 212 99 118 |
institution |
Open Polar |
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University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
topic |
Stable isotopes Germanium Silicon Sponges Southern Oceans Chemical oceanography |
spellingShingle |
Stable isotopes Germanium Silicon Sponges Southern Oceans Chemical oceanography Guillermic, Maxence Lalonde, Stefan Hendry, Kate Rouxel, Olivier The isotope composition of inorganic Germanium in seawater and deep sea sponges |
topic_facet |
Stable isotopes Germanium Silicon Sponges Southern Oceans Chemical oceanography |
description |
Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, however the low concentration of Ge in seawater presents an analytical challenge for isotopic measurement. Here, we present a new method of pre-concentration of inorganic Ge from seawater which was applied to measure three Ge isotope profiles in the Southern Ocean and deep seawater from the Atlantic and Pacific Oceans. Germanium isotopic measurements were performed on Ge amounts as low as 2.6 ng using a double-spike approach and a hydride generation system coupled to a MC-ICP-MS. Germanium was co-precipitated with iron hydroxide and then purified through anion-exchange chromatography. Results for the deep (i.e. > 1000 m depth) Pacific Ocean off Hawaii (nearby Loihi Seamount) and the deep Atlantic off Bermuda (BATS station) showed nearly identical δ74/70Ge values at 3.19 ± 0.31 ‰ (2SD, n = 9) and 2.93 ± 0.10 ‰ (2SD, n = 2), respectively. Vertical distributions of Ge concentration and isotope composition in the deep Southern Ocean for water depth > 1300 m yielded an average δ74/70Ge = 3.13 ± 0.25 ‰ (2SD, n = 14) and Ge/Si = 0.80 ± 0.09 mol/mol (2SD, n = 12). Significant variations in δ74/70Ge, from 2.62 to 3.71 ‰, were measured in the first 1000 m in one station of the Southern Ocean near Sars Seamount in the Drake Passage, with the heaviest values measured in surface waters. Isotope fractionation by diatoms during opal biomineralization may explain the enrichment in heavy isotopes for both Ge and Si in surface seawater. However, examination of both oceanographic parameters and δ74/70Ge values suggest also that water mass mixing and potential contribution of shelf-derived Ge also could contribute to the variations. Combining these results with new Ge isotope data for deep-sea sponges sampled nearby allowed us to ... |
format |
Article in Journal/Newspaper |
author |
Guillermic, Maxence Lalonde, Stefan Hendry, Kate Rouxel, Olivier |
author_facet |
Guillermic, Maxence Lalonde, Stefan Hendry, Kate Rouxel, Olivier |
author_sort |
Guillermic, Maxence |
title |
The isotope composition of inorganic Germanium in seawater and deep sea sponges |
title_short |
The isotope composition of inorganic Germanium in seawater and deep sea sponges |
title_full |
The isotope composition of inorganic Germanium in seawater and deep sea sponges |
title_fullStr |
The isotope composition of inorganic Germanium in seawater and deep sea sponges |
title_full_unstemmed |
The isotope composition of inorganic Germanium in seawater and deep sea sponges |
title_sort |
isotope composition of inorganic germanium in seawater and deep sea sponges |
publishDate |
2017 |
url |
https://hdl.handle.net/1983/5e9ff25d-ecd6-4988-9148-2ad613332802 https://research-information.bris.ac.uk/en/publications/5e9ff25d-ecd6-4988-9148-2ad613332802 https://doi.org/10.1016/j.gca.2017.06.011 https://research-information.bris.ac.uk/ws/files/115786997/MS_OR_Guillermic_2017_05_30.pdf |
long_lat |
ENVELOPE(-69.000,-69.000,-59.583,-59.583) |
geographic |
Drake Passage Pacific Sars Seamount Southern Ocean |
geographic_facet |
Drake Passage Pacific Sars Seamount Southern Ocean |
genre |
Drake Passage Southern Ocean |
genre_facet |
Drake Passage Southern Ocean |
op_source |
Guillermic , M , Lalonde , S , Hendry , K & Rouxel , O 2017 , ' The isotope composition of inorganic Germanium in seawater and deep sea sponges ' , Geochimica et Cosmochimica Acta , vol. 212 , pp. 99-118 . https://doi.org/10.1016/j.gca.2017.06.011 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.gca.2017.06.011 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
212 |
container_start_page |
99 |
op_container_end_page |
118 |
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1789331708700524544 |