Pleistocene sedimentation in the Benguela Current, southeastern Atlantic
We infer variations in paleoproductivity and eolian input at ODP Site 1082 in the Walvis Basin from stable oxygen isotope compositions of the planktonic foraminifera Globorotalia inflata, total organic carbon mass accumulation rates (TOC MAR), and X-ray fluorescence analyses of Fe content. The most...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.703973 2023-05-15T18:01:14+02:00 Pleistocene sedimentation in the Benguela Current, southeastern Atlantic Jahn, Britta Donner, Barbara Müller, Peter J Röhl, Ursula Schneider, Ralph R Wefer, Gerold MEDIAN LATITUDE: -21.094096 * MEDIAN LONGITUDE: 11.820562 * SOUTH-BOUND LATITUDE: -21.094470 * WEST-BOUND LONGITUDE: 11.820520 * NORTH-BOUND LATITUDE: -21.093940 * EAST-BOUND LONGITUDE: 11.820580 * DATE/TIME START: 1997-09-13T04:45:00 * DATE/TIME END: 1997-09-16T08:55:00 2003-09-10 application/zip, 5 datasets https://doi.pangaea.de/10.1594/PANGAEA.703973 https://doi.org/10.1594/PANGAEA.703973 en eng PANGAEA Jahn, Britta (2002): Mid to Late Pleistocene variations of marine productivity in and terrigenous input to the southeast Atlantic. Berichte aus dem Fachbereich Geowissenschaften der Universität Bremen, 199, 97 pp, urn:nbn:de:gbv:46-ep000103218 https://doi.pangaea.de/10.1594/PANGAEA.703973 https://doi.org/10.1594/PANGAEA.703973 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Jahn, Britta; Donner, Barbara; Müller, Peter J; Röhl, Ursula; Schneider, Ralph R; Wefer, Gerold (2003): Pleistocene variations in dust input and marine productivity in the northern Benguela Current: Evidence of evolution of global glacial-interglacial cycles. Palaeogeography, Palaeoclimatology, Palaeoecology, 193(3-4), 515-533, https://doi.org/10.1016/S0031-0182(03)00264-5 175-1082A 175-1082B 175-1082C Benguela Current South Atlantic Ocean DRILL Drilling/drill rig GeoB Geosciences University of Bremen Joides Resolution Leg175 Ocean Drilling Program ODP XRF core scanner Dataset 2003 ftpangaea https://doi.org/10.1594/PANGAEA.703973 https://doi.org/10.1016/S0031-0182(03)00264-5 2023-01-20T07:31:13Z We infer variations in paleoproductivity and eolian input at ODP Site 1082 in the Walvis Basin from stable oxygen isotope compositions of the planktonic foraminifera Globorotalia inflata, total organic carbon mass accumulation rates (TOC MAR), and X-ray fluorescence analyses of Fe content. The most pronounced paleoclimatic changes correspond to the time at about 0.9 Ma, when glacial conditions in the northern hemisphere (NH) led to the onset of pronounced 100-kyr glacial-interglacial cycles. We used Fe intensity as a proxy for eolian terrigenous input, and TOC MAR as a paleoproductivity indicator. Paleoproductivity and eolian input show generally higher-amplitude variations of glacial-interglacial cyclicity from 1.5 to 0.58 Ma, indicating pronounced variations in upwellingfavorable winds in this area. At 0.58 Ma, paleoproductivity and eolian input shifted abruptly to lower-amplitude variations with a periodicity of 100 kyr while delta18O values show a trend toward more negative isotope values for the past 0.65 Myr. Especially during glacial periods, oxygen isotope values indicate increasingly warmer sea-surface temperatures toward the end of the Pleistocene. To evaluate the relative influences of NH glaciation and southern hemisphere (SH) insolation as potential forcing mechanisms for variations of eolian input and productivity in the northern Benguela system, we filtered our proxy records at orbital frequencies. The filtered records of Fe intensity and TOC MAR indicate a strong influence of the 100-kyr and 41-kyr frequency bands, supporting our assumption that strong ice buildup in the NH is the dominant trigger for climate changes on the continent and probably in trade-wind intensity. SH insolation and low-latitude precession-related insolation changes were important for paleoproductivity variations in the northern Benguela system, modifying the nutrient supply by southern ocean intermediate waters and the zonal direction of upwelling-inducing trades by the African monsoon system, respectively. Dataset Planktonic foraminifera South Atlantic Ocean Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science Southern Ocean ENVELOPE(11.820520,11.820580,-21.093940,-21.094470) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
175-1082A 175-1082B 175-1082C Benguela Current South Atlantic Ocean DRILL Drilling/drill rig GeoB Geosciences University of Bremen Joides Resolution Leg175 Ocean Drilling Program ODP XRF core scanner |
spellingShingle |
175-1082A 175-1082B 175-1082C Benguela Current South Atlantic Ocean DRILL Drilling/drill rig GeoB Geosciences University of Bremen Joides Resolution Leg175 Ocean Drilling Program ODP XRF core scanner Jahn, Britta Donner, Barbara Müller, Peter J Röhl, Ursula Schneider, Ralph R Wefer, Gerold Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
topic_facet |
175-1082A 175-1082B 175-1082C Benguela Current South Atlantic Ocean DRILL Drilling/drill rig GeoB Geosciences University of Bremen Joides Resolution Leg175 Ocean Drilling Program ODP XRF core scanner |
description |
We infer variations in paleoproductivity and eolian input at ODP Site 1082 in the Walvis Basin from stable oxygen isotope compositions of the planktonic foraminifera Globorotalia inflata, total organic carbon mass accumulation rates (TOC MAR), and X-ray fluorescence analyses of Fe content. The most pronounced paleoclimatic changes correspond to the time at about 0.9 Ma, when glacial conditions in the northern hemisphere (NH) led to the onset of pronounced 100-kyr glacial-interglacial cycles. We used Fe intensity as a proxy for eolian terrigenous input, and TOC MAR as a paleoproductivity indicator. Paleoproductivity and eolian input show generally higher-amplitude variations of glacial-interglacial cyclicity from 1.5 to 0.58 Ma, indicating pronounced variations in upwellingfavorable winds in this area. At 0.58 Ma, paleoproductivity and eolian input shifted abruptly to lower-amplitude variations with a periodicity of 100 kyr while delta18O values show a trend toward more negative isotope values for the past 0.65 Myr. Especially during glacial periods, oxygen isotope values indicate increasingly warmer sea-surface temperatures toward the end of the Pleistocene. To evaluate the relative influences of NH glaciation and southern hemisphere (SH) insolation as potential forcing mechanisms for variations of eolian input and productivity in the northern Benguela system, we filtered our proxy records at orbital frequencies. The filtered records of Fe intensity and TOC MAR indicate a strong influence of the 100-kyr and 41-kyr frequency bands, supporting our assumption that strong ice buildup in the NH is the dominant trigger for climate changes on the continent and probably in trade-wind intensity. SH insolation and low-latitude precession-related insolation changes were important for paleoproductivity variations in the northern Benguela system, modifying the nutrient supply by southern ocean intermediate waters and the zonal direction of upwelling-inducing trades by the African monsoon system, respectively. |
format |
Dataset |
author |
Jahn, Britta Donner, Barbara Müller, Peter J Röhl, Ursula Schneider, Ralph R Wefer, Gerold |
author_facet |
Jahn, Britta Donner, Barbara Müller, Peter J Röhl, Ursula Schneider, Ralph R Wefer, Gerold |
author_sort |
Jahn, Britta |
title |
Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
title_short |
Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
title_full |
Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
title_fullStr |
Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
title_full_unstemmed |
Pleistocene sedimentation in the Benguela Current, southeastern Atlantic |
title_sort |
pleistocene sedimentation in the benguela current, southeastern atlantic |
publisher |
PANGAEA |
publishDate |
2003 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.703973 https://doi.org/10.1594/PANGAEA.703973 |
op_coverage |
MEDIAN LATITUDE: -21.094096 * MEDIAN LONGITUDE: 11.820562 * SOUTH-BOUND LATITUDE: -21.094470 * WEST-BOUND LONGITUDE: 11.820520 * NORTH-BOUND LATITUDE: -21.093940 * EAST-BOUND LONGITUDE: 11.820580 * DATE/TIME START: 1997-09-13T04:45:00 * DATE/TIME END: 1997-09-16T08:55:00 |
long_lat |
ENVELOPE(11.820520,11.820580,-21.093940,-21.094470) |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Planktonic foraminifera South Atlantic Ocean Southern Ocean |
genre_facet |
Planktonic foraminifera South Atlantic Ocean Southern Ocean |
op_source |
Supplement to: Jahn, Britta; Donner, Barbara; Müller, Peter J; Röhl, Ursula; Schneider, Ralph R; Wefer, Gerold (2003): Pleistocene variations in dust input and marine productivity in the northern Benguela Current: Evidence of evolution of global glacial-interglacial cycles. Palaeogeography, Palaeoclimatology, Palaeoecology, 193(3-4), 515-533, https://doi.org/10.1016/S0031-0182(03)00264-5 |
op_relation |
Jahn, Britta (2002): Mid to Late Pleistocene variations of marine productivity in and terrigenous input to the southeast Atlantic. Berichte aus dem Fachbereich Geowissenschaften der Universität Bremen, 199, 97 pp, urn:nbn:de:gbv:46-ep000103218 https://doi.pangaea.de/10.1594/PANGAEA.703973 https://doi.org/10.1594/PANGAEA.703973 |
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.703973 https://doi.org/10.1016/S0031-0182(03)00264-5 |
_version_ |
1766170600962785280 |