Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp
Sediment cores from nine sites along a profile on the Antarctic continental margin off Kapp Norvegia were analysed sedimentologicaly. The carbonate and organic carbon content, grain size distribution, composition of the coarse fraction and clay minerals were determined. d18O- and d13C-isotope ratios...
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Format: | Article in Journal/Newspaper |
Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
1986
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Online Access: | https://dx.doi.org/10.1594/pangaea.818905 https://doi.pangaea.de/10.1594/PANGAEA.818905 |
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ftdatacite:10.1594/pangaea.818905 |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo |
spellingShingle |
Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo Grobe, Hannes Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
topic_facet |
Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo |
description |
Sediment cores from nine sites along a profile on the Antarctic continental margin off Kapp Norvegia were analysed sedimentologicaly. The carbonate and organic carbon content, grain size distribution, composition of the coarse fraction and clay minerals were determined. d18O- and d13C-isotope ratios were also measured. The distribution of ice rafted debris was determined by a new method. Sedimentation-rates were obtained from 230Th- and 14C-analyses.A segregation into seven different sediment facies was made possible by different sedimentological parameters, which can be attributed to different sedimentation environments and conditions. Thr profile can be divided morphologicaly into shelf, upper continental slope, slope terrace and lower continental slope. The paratill facies is deposited on the shelf during an interglacial phase and consists mainly of ice rafted sediments. A portion of the fine fraction is being carried away by the antarctic coastel current. The sedimentation rate lies between 0 and 3 cm/1000 a. The coarse grained deposits of the upper, relatively steep continental slope, were specified as a rest sediment. Current and gravity sediment transport are responsible for the intensive sorting of ice rafted material coming from the shelf. The fine sediment is carried away by currents while sand and silt are deposited as small turbidites on the slope terrace. The morainic facies only appears at the base of the upper continental slope and defines ice advances, beyond the shelf margin. The facies mainly consists of transported shelf sediments.The interglacial facies, deposited during the interglacial phases on the continental slope, are characterized by high proportions of ice raft, coarse mean grain size, low content of montmorillonite and a carbonate content, which mainly originates from planktonic foraminifera (N. pachyderma). At the central part of the slope the sedimentation rate is at its lowest (2 cm/1000 a) and increases to 3-4 cm/1000 a towards the sea, due to high production of biogenic components and towards the continent due to an increasing input of terrigenous material.Sedimentary conditions during glacial times are depicted in the glacial facies by a low content of ice rafted debris, a lower mean grain size and a high content of montmorillonite. Biogeneous components are absent. The sedimentation rate is generally about 1 cm/1000a. A transition facies is deposited during the transition from glacial to interglacial conditions. Typical for this facies, with a terrigenous composition similar to the interglacial facies, is a high content of radiolaria. The reason for the change of plankton from a siliceous to a carbonacous fauna may have been the changing hydrography caused by the sea ice.The surge facies is deposited at the continental margin under the ice shelf and is a sediment exclusively delivered by currents. With the aid of this facies it was, for the first time possible to prove the existence of Antarctic ice surges, an aspect wh ich has been discussed for the past 20 years. |
format |
Article in Journal/Newspaper |
author |
Grobe, Hannes |
author_facet |
Grobe, Hannes |
author_sort |
Grobe, Hannes |
title |
Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
title_short |
Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
title_full |
Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
title_fullStr |
Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
title_full_unstemmed |
Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp |
title_sort |
sedimentology of gravity cores from the eastern weddell sea, antarctica, supplement to: grobe, hannes (1986): spätpleistozäne sedimentationsprozesse am antarktischen kontinentalhang vor kapp norvegia, östliche weddell see. berichte zur polarforschung = reports on polar research, 27, 121 pp |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
1986 |
url |
https://dx.doi.org/10.1594/pangaea.818905 https://doi.pangaea.de/10.1594/PANGAEA.818905 |
long_lat |
ENVELOPE(18.064,18.064,69.390,69.390) |
geographic |
Antarctic The Antarctic Weddell Sea Weddell Hannes |
geographic_facet |
Antarctic The Antarctic Weddell Sea Weddell Hannes |
genre |
Antarc* Antarctic Antarctica Antarktis* Ice Shelf Planktonic foraminifera Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Antarktis* Ice Shelf Planktonic foraminifera Weddell Sea |
op_relation |
https://dx.doi.org/10.2312/bzp_0027_1986 |
op_rights |
Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.818905 https://doi.org/10.2312/bzp_0027_1986 |
_version_ |
1766263348615184384 |
spelling |
ftdatacite:10.1594/pangaea.818905 2023-05-15T13:56:06+02:00 Sedimentology of gravity cores from the eastern Weddell Sea, Antarctica, supplement to: Grobe, Hannes (1986): Spätpleistozäne Sedimentationsprozesse am antarktischen Kontinentalhang vor Kapp Norvegia, östliche Weddell See. Berichte zur Polarforschung = Reports on Polar Research, 27, 121 pp Grobe, Hannes 1986 application/zip https://dx.doi.org/10.1594/pangaea.818905 https://doi.pangaea.de/10.1594/PANGAEA.818905 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.2312/bzp_0027_1986 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo Collection article Supplementary Collection of Datasets 1986 ftdatacite https://doi.org/10.1594/pangaea.818905 https://doi.org/10.2312/bzp_0027_1986 2021-11-05T12:55:41Z Sediment cores from nine sites along a profile on the Antarctic continental margin off Kapp Norvegia were analysed sedimentologicaly. The carbonate and organic carbon content, grain size distribution, composition of the coarse fraction and clay minerals were determined. d18O- and d13C-isotope ratios were also measured. The distribution of ice rafted debris was determined by a new method. Sedimentation-rates were obtained from 230Th- and 14C-analyses.A segregation into seven different sediment facies was made possible by different sedimentological parameters, which can be attributed to different sedimentation environments and conditions. Thr profile can be divided morphologicaly into shelf, upper continental slope, slope terrace and lower continental slope. The paratill facies is deposited on the shelf during an interglacial phase and consists mainly of ice rafted sediments. A portion of the fine fraction is being carried away by the antarctic coastel current. The sedimentation rate lies between 0 and 3 cm/1000 a. The coarse grained deposits of the upper, relatively steep continental slope, were specified as a rest sediment. Current and gravity sediment transport are responsible for the intensive sorting of ice rafted material coming from the shelf. The fine sediment is carried away by currents while sand and silt are deposited as small turbidites on the slope terrace. The morainic facies only appears at the base of the upper continental slope and defines ice advances, beyond the shelf margin. The facies mainly consists of transported shelf sediments.The interglacial facies, deposited during the interglacial phases on the continental slope, are characterized by high proportions of ice raft, coarse mean grain size, low content of montmorillonite and a carbonate content, which mainly originates from planktonic foraminifera (N. pachyderma). At the central part of the slope the sedimentation rate is at its lowest (2 cm/1000 a) and increases to 3-4 cm/1000 a towards the sea, due to high production of biogenic components and towards the continent due to an increasing input of terrigenous material.Sedimentary conditions during glacial times are depicted in the glacial facies by a low content of ice rafted debris, a lower mean grain size and a high content of montmorillonite. Biogeneous components are absent. The sedimentation rate is generally about 1 cm/1000a. A transition facies is deposited during the transition from glacial to interglacial conditions. Typical for this facies, with a terrigenous composition similar to the interglacial facies, is a high content of radiolaria. The reason for the change of plankton from a siliceous to a carbonacous fauna may have been the changing hydrography caused by the sea ice.The surge facies is deposited at the continental margin under the ice shelf and is a sediment exclusively delivered by currents. With the aid of this facies it was, for the first time possible to prove the existence of Antarctic ice surges, an aspect wh ich has been discussed for the past 20 years. Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarktis* Ice Shelf Planktonic foraminifera Weddell Sea DataCite Metadata Store (German National Library of Science and Technology) Antarctic The Antarctic Weddell Sea Weddell Hannes ENVELOPE(18.064,18.064,69.390,69.390) |