Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere
The Cenozoic sediments sampled in ODP Leg 104 on the Vøring Plateau show a distinct variability of the total organic carbon content (TOC) and the accumulation rates of TOC. Based on the geochemical and organic-petrographic characterization of the sedimentary organic matter (OM), the allochthonous an...
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier
1994
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Online Access: | https://oceanrep.geomar.de/id/eprint/31400/ https://oceanrep.geomar.de/id/eprint/31400/1/H%C3%B6lemann_Henrich.pdf https://doi.org/10.1016/0025-3227(94)90159-7 |
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ftoceanrep:oai:oceanrep.geomar.de:31400 2023-05-15T15:39:09+02:00 Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere Hölemann, Jens A. Henrich, Rüdiger 1994 text https://oceanrep.geomar.de/id/eprint/31400/ https://oceanrep.geomar.de/id/eprint/31400/1/H%C3%B6lemann_Henrich.pdf https://doi.org/10.1016/0025-3227(94)90159-7 en eng Elsevier https://oceanrep.geomar.de/id/eprint/31400/1/H%C3%B6lemann_Henrich.pdf Hölemann, J. A. and Henrich, R. (1994) Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere. Marine Geology, 121 (1-2). pp. 87-103. DOI 10.1016/0025-3227(94)90159-7 <https://doi.org/10.1016/0025-3227%2894%2990159-7>. doi:10.1016/0025-3227(94)90159-7 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1994 ftoceanrep https://doi.org/10.1016/0025-3227(94)90159-7 2023-04-07T15:23:32Z The Cenozoic sediments sampled in ODP Leg 104 on the Vøring Plateau show a distinct variability of the total organic carbon content (TOC) and the accumulation rates of TOC. Based on the geochemical and organic-petrographic characterization of the sedimentary organic matter (OM), the allochthonous and autochthonous proportion of the OM could be quantified.The results clearly demonstrate that high TOC percentages and TOC accumulation rates in Cenozoic sediment sections display a generally high input of allochthonous organic matter. Oxidized and partly well-rounded organic particles built up the main portion of OM within the Miocene, TOC-rich sediments. The most probable source of this oxidized OM are reworked sediments from the Scandinavian shelf. Changes in the input of these organic particles are to some degree correlative with sea-level changes.The Cenozoic accumulation of autochthonous OM is low and does not reveal a clear variation during the Miocene and early Pliocene. In spite of a high accumulation rate of biogenic opal during the Early Miocene, the accumulation rate of autochthonous TOC is low. The autochthonous particle assemblage is dominated by relatively inert OM, like dinoflagellate cysts. This points to an intensive biological and/or early diagenetic degradation of the marine OM under well oxidized bottom water conditions during the last 23 Myr. Nevertheless, a continuation of marine OM degradation during later stages of diagenesis cannot be excluded.A prominent dominance of allochthonous OM over autochthonous is documented with the beginning of the Pliocene. At 2.45 Ma the episodic occurrence of ice-rafted, thermally mature OM reflects the onset of the glacial erosion of Mesozoic, coal and black shale bearing sediments on the Scandinavian and Barents Sea shelves. The first occurrence of these, in view of the actual burial depth, thermally overmature OM particles is, therefore, a marker for the beginning of the strong Scandinavian glaciation and the advance of the glacial front toward the shelves. Article in Journal/Newspaper Barents Sea Norwegian Sea OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Barents Sea Norwegian Sea Vøring Plateau ENVELOPE(4.000,4.000,67.000,67.000) Marine Geology 121 1-2 87 103 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The Cenozoic sediments sampled in ODP Leg 104 on the Vøring Plateau show a distinct variability of the total organic carbon content (TOC) and the accumulation rates of TOC. Based on the geochemical and organic-petrographic characterization of the sedimentary organic matter (OM), the allochthonous and autochthonous proportion of the OM could be quantified.The results clearly demonstrate that high TOC percentages and TOC accumulation rates in Cenozoic sediment sections display a generally high input of allochthonous organic matter. Oxidized and partly well-rounded organic particles built up the main portion of OM within the Miocene, TOC-rich sediments. The most probable source of this oxidized OM are reworked sediments from the Scandinavian shelf. Changes in the input of these organic particles are to some degree correlative with sea-level changes.The Cenozoic accumulation of autochthonous OM is low and does not reveal a clear variation during the Miocene and early Pliocene. In spite of a high accumulation rate of biogenic opal during the Early Miocene, the accumulation rate of autochthonous TOC is low. The autochthonous particle assemblage is dominated by relatively inert OM, like dinoflagellate cysts. This points to an intensive biological and/or early diagenetic degradation of the marine OM under well oxidized bottom water conditions during the last 23 Myr. Nevertheless, a continuation of marine OM degradation during later stages of diagenesis cannot be excluded.A prominent dominance of allochthonous OM over autochthonous is documented with the beginning of the Pliocene. At 2.45 Ma the episodic occurrence of ice-rafted, thermally mature OM reflects the onset of the glacial erosion of Mesozoic, coal and black shale bearing sediments on the Scandinavian and Barents Sea shelves. The first occurrence of these, in view of the actual burial depth, thermally overmature OM particles is, therefore, a marker for the beginning of the strong Scandinavian glaciation and the advance of the glacial front toward the shelves. |
format |
Article in Journal/Newspaper |
author |
Hölemann, Jens A. Henrich, Rüdiger |
spellingShingle |
Hölemann, Jens A. Henrich, Rüdiger Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
author_facet |
Hölemann, Jens A. Henrich, Rüdiger |
author_sort |
Hölemann, Jens A. |
title |
Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
title_short |
Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
title_full |
Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
title_fullStr |
Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
title_full_unstemmed |
Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere |
title_sort |
allochthonous versus autochthonous organic matter in cenozoic sediments of the norwegian sea: evidence for the onset of glaciations in the northern hemisphere |
publisher |
Elsevier |
publishDate |
1994 |
url |
https://oceanrep.geomar.de/id/eprint/31400/ https://oceanrep.geomar.de/id/eprint/31400/1/H%C3%B6lemann_Henrich.pdf https://doi.org/10.1016/0025-3227(94)90159-7 |
long_lat |
ENVELOPE(4.000,4.000,67.000,67.000) |
geographic |
Barents Sea Norwegian Sea Vøring Plateau |
geographic_facet |
Barents Sea Norwegian Sea Vøring Plateau |
genre |
Barents Sea Norwegian Sea |
genre_facet |
Barents Sea Norwegian Sea |
op_relation |
https://oceanrep.geomar.de/id/eprint/31400/1/H%C3%B6lemann_Henrich.pdf Hölemann, J. A. and Henrich, R. (1994) Allochthonous versus autochthonous organic matter in Cenozoic sediments of the Norwegian Sea: Evidence for the onset of glaciations in the northern hemisphere. Marine Geology, 121 (1-2). pp. 87-103. DOI 10.1016/0025-3227(94)90159-7 <https://doi.org/10.1016/0025-3227%2894%2990159-7>. doi:10.1016/0025-3227(94)90159-7 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/0025-3227(94)90159-7 |
container_title |
Marine Geology |
container_volume |
121 |
container_issue |
1-2 |
container_start_page |
87 |
op_container_end_page |
103 |
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1766370612288159744 |