Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core
Reactive phosphorus undergoes diagenetic transformation once transferred into marine sediments. The degree of regeneration and redistribution of phosphorus depends on early diagenetic and environmental conditions, which may be linked to larger scale phenomena, such as bottom water circulation, water...
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ftreroch:oai:doc.rero.ch:20050818115343-TX 2023-05-15T17:29:43+02:00 Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core Tamburini, Federica Huon, Sylvain Steinmann, Philipp Grousset, Francis E. Adatte, Thierry Föllmi, Karl B. 2005-08-18T09:53:53Z http://doc.rero.ch/record/5003/files/Tamburini_Federica_-_Dysaerobic_conditions_during_Heinrich_events_20050818.pdf eng eng http://doc.rero.ch/record/5003/files/Tamburini_Federica_-_Dysaerobic_conditions_during_Heinrich_events_20050818.pdf 2005 ftreroch 2023-02-16T17:21:41Z Reactive phosphorus undergoes diagenetic transformation once transferred into marine sediments. The degree of regeneration and redistribution of phosphorus depends on early diagenetic and environmental conditions, which may be linked to larger scale phenomena, such as bottom water circulation, water column ventilation, and organic carbon flux. Phosphorus phases of the <50-μm-sized fraction of deep-sea sediments from core SU 90-09 (North Atlantic, 43°31′N, 30°24′W, 3375 m below sea level) have been analyzed using a sequential extraction technique (SEDEX method) to reconstruct phosphorus geochemistry during Heinrich events 4 and 5. Comparison with Holocene samples from the same site indicates that postdeposition diagenetic transformation has not affected phosphorus distribution in the deep part of the sediments. Total and reactive phosphorus average 0.40 ± 0.04 mg/g and 0.30 ± 0.05 mg/g, respectively, and are comparable to values found in analog deep-sea environments in the North Atlantic. Detrital phosphorus, the phase linked to igneous- and metamorphic-derived material, sharply increases during Heinrich events and covaries with the ice-rafted debris record, whereas authigenic and Fe-bound phosphorus phases, both influenced by redox conditions, decrease or even disappear. These findings suggest that during the deposition of Heinrich layers (HLs), environmental parameters hampered the precipitation of these phases. Large freshwater discharges in relation to iceberg surges may have provoked a temporary stratification of the water column. Accordingly, dysaerobic conditions in the sediments may have fostered the loss of dissolved phosphorus from the sediments to the water column, in a direct and rapid response to the changed conditions. Decreasing trends in organic matter elemental ratios (total organic carbon/organic phosphorus) and Rock-Eval oxygen index values, along with the presence of partly authigenic dolomite and ankerite within HLs, also support this assumption. Other/Unknown Material North Atlantic RERO DOC Digital Library |
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Open Polar |
collection |
RERO DOC Digital Library |
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ftreroch |
language |
English |
description |
Reactive phosphorus undergoes diagenetic transformation once transferred into marine sediments. The degree of regeneration and redistribution of phosphorus depends on early diagenetic and environmental conditions, which may be linked to larger scale phenomena, such as bottom water circulation, water column ventilation, and organic carbon flux. Phosphorus phases of the <50-μm-sized fraction of deep-sea sediments from core SU 90-09 (North Atlantic, 43°31′N, 30°24′W, 3375 m below sea level) have been analyzed using a sequential extraction technique (SEDEX method) to reconstruct phosphorus geochemistry during Heinrich events 4 and 5. Comparison with Holocene samples from the same site indicates that postdeposition diagenetic transformation has not affected phosphorus distribution in the deep part of the sediments. Total and reactive phosphorus average 0.40 ± 0.04 mg/g and 0.30 ± 0.05 mg/g, respectively, and are comparable to values found in analog deep-sea environments in the North Atlantic. Detrital phosphorus, the phase linked to igneous- and metamorphic-derived material, sharply increases during Heinrich events and covaries with the ice-rafted debris record, whereas authigenic and Fe-bound phosphorus phases, both influenced by redox conditions, decrease or even disappear. These findings suggest that during the deposition of Heinrich layers (HLs), environmental parameters hampered the precipitation of these phases. Large freshwater discharges in relation to iceberg surges may have provoked a temporary stratification of the water column. Accordingly, dysaerobic conditions in the sediments may have fostered the loss of dissolved phosphorus from the sediments to the water column, in a direct and rapid response to the changed conditions. Decreasing trends in organic matter elemental ratios (total organic carbon/organic phosphorus) and Rock-Eval oxygen index values, along with the presence of partly authigenic dolomite and ankerite within HLs, also support this assumption. |
author |
Tamburini, Federica Huon, Sylvain Steinmann, Philipp Grousset, Francis E. Adatte, Thierry Föllmi, Karl B. |
spellingShingle |
Tamburini, Federica Huon, Sylvain Steinmann, Philipp Grousset, Francis E. Adatte, Thierry Föllmi, Karl B. Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
author_facet |
Tamburini, Federica Huon, Sylvain Steinmann, Philipp Grousset, Francis E. Adatte, Thierry Föllmi, Karl B. |
author_sort |
Tamburini, Federica |
title |
Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
title_short |
Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
title_full |
Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
title_fullStr |
Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
title_full_unstemmed |
Dysaerobic conditions during Heinrich events 4 and 5 : Evidence from phosphorus distribution in a North Atlantic deep-sea core |
title_sort |
dysaerobic conditions during heinrich events 4 and 5 : evidence from phosphorus distribution in a north atlantic deep-sea core |
publishDate |
2005 |
url |
http://doc.rero.ch/record/5003/files/Tamburini_Federica_-_Dysaerobic_conditions_during_Heinrich_events_20050818.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://doc.rero.ch/record/5003/files/Tamburini_Federica_-_Dysaerobic_conditions_during_Heinrich_events_20050818.pdf |
_version_ |
1766124503822237696 |