Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic
The (87)Rb/(86)Sr and (87)Sr/(86)Sr ratios of Laptev Sea sediments, of Arctic Ocean sediments and of suspended particulate matter (SPM) from Siberian rivers (Lena and Khatanga) form 'pseudo-isochrons' due to grain-size separation processes which are referred to as 'Lena Mixing Envelop...
Published in: | Chemical Geology |
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Language: | English |
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Elsevier
1999
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Online Access: | https://oceanrep.geomar.de/id/eprint/3043/ https://oceanrep.geomar.de/id/eprint/3043/1/1999_Eisenhauer-etal-Grain_ChemGeol-158.pdf https://doi.org/10.1016/S0009-2541(99)00026-1 |
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ftoceanrep:oai:oceanrep.geomar.de:3043 2024-09-15T17:53:42+00:00 Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic Eisenhauer, Anton Meyer, H. Rachold, Volker Tütken, Thomas Wiegand, B. T. Spielhagen, Robert F. Lindemann, Frank Kassens, Heidemarie 1999 text https://oceanrep.geomar.de/id/eprint/3043/ https://oceanrep.geomar.de/id/eprint/3043/1/1999_Eisenhauer-etal-Grain_ChemGeol-158.pdf https://doi.org/10.1016/S0009-2541(99)00026-1 en eng Elsevier https://oceanrep.geomar.de/id/eprint/3043/1/1999_Eisenhauer-etal-Grain_ChemGeol-158.pdf Eisenhauer, A. , Meyer, H., Rachold, V., Tütken, T., Wiegand, B. T., Spielhagen, R. F., Lindemann, F. and Kassens, H. (1999) Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic. Chemical Geology, 158 (3-4). pp. 173-188. DOI 10.1016/S0009-2541(99)00026-1 <https://doi.org/10.1016/S0009-2541%2899%2900026-1>. doi:10.1016/S0009-2541(99)00026-1 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1999 ftoceanrep https://doi.org/10.1016/S0009-2541(99)00026-1 2024-09-04T05:04:40Z The (87)Rb/(86)Sr and (87)Sr/(86)Sr ratios of Laptev Sea sediments, of Arctic Ocean sediments and of suspended particulate matter (SPM) from Siberian rivers (Lena and Khatanga) form 'pseudo-isochrons' due to grain-size separation processes which are referred to as 'Lena Mixing Envelope' (LME) and as 'Flood Basalt Envelope' (FBE). At the land-ocean transition the reduction of the particle velocity causes a deposition of coarser grained material and the contact with saline water enhances a precipitation of finer-grained material. The coarse-grained material is enriched in Sr showing less radiogenic (87)Sr/(86)Sr ratios whereas fine grained material is depleted in Sr relative to Rb showing more radiogenic (87)Sr/(86)Sr ratios, The experimentally determined spread of the (87)Rb/(86)Sr and (87)Sr/(86)Sr ratios as a function of grain size in one sediment sample is on the same order as the natural spread of the (87)Sr/(86)Sr ratios observed in all samples from the Arctic Ocean. Chemical Index of Alteration (CIA) for the Lena river SPM tend to confirm previous observations that chemical alteration is negligible in the Arctic environment. Thus, these 'pseudo-isochrons' reflect an average age and the average isotope composition in the river drainage area. Calculated apparent ages from the FBE reflect the age of the Siberian flood basalt of about 220 Ma and the initial ratio of 0.707(1) reflects their mantle origin. The age calculated from the LME of about 125 Ma reflects accidentally the Jurassic and Cretaceous age of the sediments drained by the Lena river and the initial ratio of 0.714(1) reflects the crustal origin of their source rocks. Comparison of geographical locations reveals that all samples from the eastern Laptev Sea (east of 120 degrees E) fall along the LME whereas all samples from the western Laptev Sea (west of 120 degrees E) fall between LME and FBE. Mixing calculations based on (143)Nd/(144)Nd measurements, not influenced by grain size, show that about 75% of the western Laptev Sea sediments originate ... Article in Journal/Newspaper Arctic Ocean khatanga laptev Laptev Sea lena river OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Chemical Geology 158 3-4 173 188 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
The (87)Rb/(86)Sr and (87)Sr/(86)Sr ratios of Laptev Sea sediments, of Arctic Ocean sediments and of suspended particulate matter (SPM) from Siberian rivers (Lena and Khatanga) form 'pseudo-isochrons' due to grain-size separation processes which are referred to as 'Lena Mixing Envelope' (LME) and as 'Flood Basalt Envelope' (FBE). At the land-ocean transition the reduction of the particle velocity causes a deposition of coarser grained material and the contact with saline water enhances a precipitation of finer-grained material. The coarse-grained material is enriched in Sr showing less radiogenic (87)Sr/(86)Sr ratios whereas fine grained material is depleted in Sr relative to Rb showing more radiogenic (87)Sr/(86)Sr ratios, The experimentally determined spread of the (87)Rb/(86)Sr and (87)Sr/(86)Sr ratios as a function of grain size in one sediment sample is on the same order as the natural spread of the (87)Sr/(86)Sr ratios observed in all samples from the Arctic Ocean. Chemical Index of Alteration (CIA) for the Lena river SPM tend to confirm previous observations that chemical alteration is negligible in the Arctic environment. Thus, these 'pseudo-isochrons' reflect an average age and the average isotope composition in the river drainage area. Calculated apparent ages from the FBE reflect the age of the Siberian flood basalt of about 220 Ma and the initial ratio of 0.707(1) reflects their mantle origin. The age calculated from the LME of about 125 Ma reflects accidentally the Jurassic and Cretaceous age of the sediments drained by the Lena river and the initial ratio of 0.714(1) reflects the crustal origin of their source rocks. Comparison of geographical locations reveals that all samples from the eastern Laptev Sea (east of 120 degrees E) fall along the LME whereas all samples from the western Laptev Sea (west of 120 degrees E) fall between LME and FBE. Mixing calculations based on (143)Nd/(144)Nd measurements, not influenced by grain size, show that about 75% of the western Laptev Sea sediments originate ... |
format |
Article in Journal/Newspaper |
author |
Eisenhauer, Anton Meyer, H. Rachold, Volker Tütken, Thomas Wiegand, B. T. Spielhagen, Robert F. Lindemann, Frank Kassens, Heidemarie |
spellingShingle |
Eisenhauer, Anton Meyer, H. Rachold, Volker Tütken, Thomas Wiegand, B. T. Spielhagen, Robert F. Lindemann, Frank Kassens, Heidemarie Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
author_facet |
Eisenhauer, Anton Meyer, H. Rachold, Volker Tütken, Thomas Wiegand, B. T. Spielhagen, Robert F. Lindemann, Frank Kassens, Heidemarie |
author_sort |
Eisenhauer, Anton |
title |
Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
title_short |
Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
title_full |
Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
title_fullStr |
Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
title_full_unstemmed |
Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic |
title_sort |
grain size seperation and sediment mixing in artic ocean sediments: evidence from the strontium isotope systematic |
publisher |
Elsevier |
publishDate |
1999 |
url |
https://oceanrep.geomar.de/id/eprint/3043/ https://oceanrep.geomar.de/id/eprint/3043/1/1999_Eisenhauer-etal-Grain_ChemGeol-158.pdf https://doi.org/10.1016/S0009-2541(99)00026-1 |
genre |
Arctic Ocean khatanga laptev Laptev Sea lena river |
genre_facet |
Arctic Ocean khatanga laptev Laptev Sea lena river |
op_relation |
https://oceanrep.geomar.de/id/eprint/3043/1/1999_Eisenhauer-etal-Grain_ChemGeol-158.pdf Eisenhauer, A. , Meyer, H., Rachold, V., Tütken, T., Wiegand, B. T., Spielhagen, R. F., Lindemann, F. and Kassens, H. (1999) Grain Size seperation and sediment mixing in Artic Ocean sediments: evidence from the strontium isotope systematic. Chemical Geology, 158 (3-4). pp. 173-188. DOI 10.1016/S0009-2541(99)00026-1 <https://doi.org/10.1016/S0009-2541%2899%2900026-1>. doi:10.1016/S0009-2541(99)00026-1 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/S0009-2541(99)00026-1 |
container_title |
Chemical Geology |
container_volume |
158 |
container_issue |
3-4 |
container_start_page |
173 |
op_container_end_page |
188 |
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1810429677430374400 |