Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean
To reconstruct Recent and past sedimentary environments, marine sediments of Upper Pleistocene and Holocene ages from the eastern Arctic Ocean and especially from the Nansen-Gakkel Ridge (NGR) were investigated by means of radioisotopic, geochemical and sedimentological methods. In combination with...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.809032 2023-05-15T14:25:42+02:00 Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean Bohrmann, Horst MEDIAN LATITUDE: 84.915980 * MEDIAN LONGITUDE: 23.699315 * SOUTH-BOUND LATITUDE: 78.750000 * WEST-BOUND LONGITUDE: 1.775000 * NORTH-BOUND LATITUDE: 86.135000 * EAST-BOUND LONGITUDE: 32.058333 * DATE/TIME START: 1987-06-08T00:00:00 * DATE/TIME END: 1987-10-08T00:00:00 2013-03-19 application/zip, 24 datasets https://doi.pangaea.de/10.1594/PANGAEA.809032 https://doi.org/10.1594/PANGAEA.809032 en eng PANGAEA Bohrmann, Horst (1991): Radioisotopenstratigraphie, Sedimentologie und Geochemie jungquartärer Sedimente des östlichen Arktischen Ozeans (Radioisotope Stratigraphy, Sedimentology and Geochemistry of Late Quaternary Sediments from the Eastern Arctic Ocean). Berichte zur Polarforschung = Reports on Polar Research, 95, 133 pp, https://doi.org/10.2312/BzP_0095_1991 https://doi.pangaea.de/10.1594/PANGAEA.809032 https://doi.org/10.1594/PANGAEA.809032 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY AWI_Paleo Paleoenvironmental Reconstructions from Marine Sediments @ AWI Dataset 2013 ftpangaea https://doi.org/10.1594/PANGAEA.809032 https://doi.org/10.2312/BzP_0095_1991 2023-01-20T07:32:56Z To reconstruct Recent and past sedimentary environments, marine sediments of Upper Pleistocene and Holocene ages from the eastern Arctic Ocean and especially from the Nansen-Gakkel Ridge (NGR) were investigated by means of radioisotopic, geochemical and sedimentological methods. In combination with mass physical property data and lithological analysis these investigations allow clearly to characterize the depositional environments. Age dating by using the radioisotope 230Th gives evidence that the investigated sediments from the NGR are younger than 250,000 years. Identical lithological sediment sequences within and between sediment cores from the NGR can be related to sedimentary processes which are clearly controlled by palaeoclimate. The sediments consist predominantly of siliciclastic, terrigenous ice-rafted detritus (IRD) deriving from assorted and redeposited sediments from the Siberian shelfs. By their geochemical composition the sediments are similar to mudstone, graywacke and arcose. Sea-ice as well as icebergs play a major roll in marine arctic sedimentation. In the NGR area rapid change in sedimentary conditions can be detected 128,000 years ago. This was due to drastic change in the kind of ice cover, resulting from rapid climatic change within only hundreds of years. So icebergs, deriving mostly from Siberian shelfs, vanished and sea-ice became dominant in the eastern Arctic Ocean. At least three short-period retreats of the shelf ice between 186,000 and 128,000 years are responsible for the change of coarse to fine-grained sediments in the NGR area. These warmer stages lasted between 1,000 and 3,000 years. By monitoring and comparing the distribution patterns of sedimentologic, mass physical and geochemical properties with 230Th ex activity distribution patterns in the sediment cores from the NGR, there is clear evidence that sediment dilution is responsible for high 230Th ex activity variations. Thus sedimentation rate is the controlling factor of 230Th ex activity variations. The 230Th flux ... Dataset Arctic Arctic Arctic Ocean Berichte zur Polarforschung Iceberg* Polar Research Polarforschung Reports on polar research Sea ice PANGAEA - Data Publisher for Earth & Environmental Science Arctic Arctic Ocean Gakkel Ridge ENVELOPE(90.000,90.000,87.000,87.000) ENVELOPE(1.775000,32.058333,86.135000,78.750000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
AWI_Paleo Paleoenvironmental Reconstructions from Marine Sediments @ AWI |
spellingShingle |
AWI_Paleo Paleoenvironmental Reconstructions from Marine Sediments @ AWI Bohrmann, Horst Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
topic_facet |
AWI_Paleo Paleoenvironmental Reconstructions from Marine Sediments @ AWI |
description |
To reconstruct Recent and past sedimentary environments, marine sediments of Upper Pleistocene and Holocene ages from the eastern Arctic Ocean and especially from the Nansen-Gakkel Ridge (NGR) were investigated by means of radioisotopic, geochemical and sedimentological methods. In combination with mass physical property data and lithological analysis these investigations allow clearly to characterize the depositional environments. Age dating by using the radioisotope 230Th gives evidence that the investigated sediments from the NGR are younger than 250,000 years. Identical lithological sediment sequences within and between sediment cores from the NGR can be related to sedimentary processes which are clearly controlled by palaeoclimate. The sediments consist predominantly of siliciclastic, terrigenous ice-rafted detritus (IRD) deriving from assorted and redeposited sediments from the Siberian shelfs. By their geochemical composition the sediments are similar to mudstone, graywacke and arcose. Sea-ice as well as icebergs play a major roll in marine arctic sedimentation. In the NGR area rapid change in sedimentary conditions can be detected 128,000 years ago. This was due to drastic change in the kind of ice cover, resulting from rapid climatic change within only hundreds of years. So icebergs, deriving mostly from Siberian shelfs, vanished and sea-ice became dominant in the eastern Arctic Ocean. At least three short-period retreats of the shelf ice between 186,000 and 128,000 years are responsible for the change of coarse to fine-grained sediments in the NGR area. These warmer stages lasted between 1,000 and 3,000 years. By monitoring and comparing the distribution patterns of sedimentologic, mass physical and geochemical properties with 230Th ex activity distribution patterns in the sediment cores from the NGR, there is clear evidence that sediment dilution is responsible for high 230Th ex activity variations. Thus sedimentation rate is the controlling factor of 230Th ex activity variations. The 230Th flux ... |
format |
Dataset |
author |
Bohrmann, Horst |
author_facet |
Bohrmann, Horst |
author_sort |
Bohrmann, Horst |
title |
Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
title_short |
Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
title_full |
Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
title_fullStr |
Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
title_full_unstemmed |
Radioisotope stratigraphy, sedimentology and geochemistry of Late Quaternary sediments from the Eastern Arctic Ocean |
title_sort |
radioisotope stratigraphy, sedimentology and geochemistry of late quaternary sediments from the eastern arctic ocean |
publisher |
PANGAEA |
publishDate |
2013 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.809032 https://doi.org/10.1594/PANGAEA.809032 |
op_coverage |
MEDIAN LATITUDE: 84.915980 * MEDIAN LONGITUDE: 23.699315 * SOUTH-BOUND LATITUDE: 78.750000 * WEST-BOUND LONGITUDE: 1.775000 * NORTH-BOUND LATITUDE: 86.135000 * EAST-BOUND LONGITUDE: 32.058333 * DATE/TIME START: 1987-06-08T00:00:00 * DATE/TIME END: 1987-10-08T00:00:00 |
long_lat |
ENVELOPE(90.000,90.000,87.000,87.000) ENVELOPE(1.775000,32.058333,86.135000,78.750000) |
geographic |
Arctic Arctic Ocean Gakkel Ridge |
geographic_facet |
Arctic Arctic Ocean Gakkel Ridge |
genre |
Arctic Arctic Arctic Ocean Berichte zur Polarforschung Iceberg* Polar Research Polarforschung Reports on polar research Sea ice |
genre_facet |
Arctic Arctic Arctic Ocean Berichte zur Polarforschung Iceberg* Polar Research Polarforschung Reports on polar research Sea ice |
op_relation |
Bohrmann, Horst (1991): Radioisotopenstratigraphie, Sedimentologie und Geochemie jungquartärer Sedimente des östlichen Arktischen Ozeans (Radioisotope Stratigraphy, Sedimentology and Geochemistry of Late Quaternary Sediments from the Eastern Arctic Ocean). Berichte zur Polarforschung = Reports on Polar Research, 95, 133 pp, https://doi.org/10.2312/BzP_0095_1991 https://doi.pangaea.de/10.1594/PANGAEA.809032 https://doi.org/10.1594/PANGAEA.809032 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.809032 https://doi.org/10.2312/BzP_0095_1991 |
_version_ |
1766298157769031680 |