Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles
Radiogenic neodymium isotope compositions (epsilon Nd) are used as a tracer for water mass circulation and continental weathering at different timescales. However, uncertainties remain in the relative roles of these two factors in driving past seawater epsilon Nd variability in settings under the in...
Published in: | Earth and Planetary Science Letters |
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Online Access: | http://ir.qdio.ac.cn/handle/337002/185349 https://doi.org/10.1016/j.epsl.2024.118902 |
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ftchinacasciocas:oai:ir.qdio.ac.cn:337002/185349 2024-09-15T18:31:07+00:00 Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles Huang, Yi Colin, Christophe Bassinot, Franck Yu, Zhaojie Dubois-Dauphin, Quentin Dapoigny, Arnaud Wilson, David J. Bayon, Germain 2024-10-01 http://ir.qdio.ac.cn/handle/337002/185349 https://doi.org/10.1016/j.epsl.2024.118902 英语 eng ELSEVIER EARTH AND PLANETARY SCIENCE LETTERS http://ir.qdio.ac.cn/handle/337002/185349 doi:10.1016/j.epsl.2024.118902 Foraminiferal epsilon Nd Weathering River discharge Mineralogy Bay of Bengal Geochemistry & Geophysics DEEP-WATER FORMATION DISSOLVED NEODYMIUM BAY CIRCULATION ATLANTIC BENGAL HIMALAYAN NORTHERN HOLOCENE PENETRATION 期刊论文 2024 ftchinacasciocas https://doi.org/10.1016/j.epsl.2024.118902 2024-08-29T23:34:26Z Radiogenic neodymium isotope compositions (epsilon Nd) are used as a tracer for water mass circulation and continental weathering at different timescales. However, uncertainties remain in the relative roles of these two factors in driving past seawater epsilon Nd variability in settings under the influence of terrestrial or riverine sediment inputs. In this study, Nd isotopes of mixed planktonic foraminifera species and delta O-18 and delta C-13 of Cibicidoides wuellerstorfi were analyzed on three cores from the northeastern Indian Ocean to better assess the impact of lithogenic inputs from Himalayan rivers and deep-water hydrological changes on the past epsilon Nd distribution in the Bay of Bengal (BoB). Our epsilon Nd data indicate relatively homogenous and radiogenic values (from -8.4 to -7.5) during glacial periods in the BoB, similar to the composition of glacial water masses of the Southern Ocean. In contrast, interglacials were characterized by more unradiogenic epsilon Nd and a pronounced north-south gradient of similar to 4.5 epsilon Nd units (from -12.9 to -8.5) in bottom water, similar to the present-day distribution in the BoB, pointing to a strong lithogenic control by seawater-particulate interactions. Notably, this significant decoupling of the local Nd isotope signature from the Southern Ocean composition occurred when Himalayan riverine inputs were dominated by the erosion of Indo-Gangetic plain soils during interglacial periods, whereas the preferential delivery of fresh primary mineral assemblages during glacial periods appears to have had little impact on Nd exchange with seawater. These findings provide direct evidence that the degree of seawater-particulate exchange at continental margins is governed by the mineralogy of riverine inputs, with further implications for the use of Nd isotopes as palaeoceanographic tracers. Report Planktonic foraminifera Southern Ocean Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR Earth and Planetary Science Letters 643 118902 |
institution |
Open Polar |
collection |
Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR |
op_collection_id |
ftchinacasciocas |
language |
English |
topic |
Foraminiferal epsilon Nd Weathering River discharge Mineralogy Bay of Bengal Geochemistry & Geophysics DEEP-WATER FORMATION DISSOLVED NEODYMIUM BAY CIRCULATION ATLANTIC BENGAL HIMALAYAN NORTHERN HOLOCENE PENETRATION |
spellingShingle |
Foraminiferal epsilon Nd Weathering River discharge Mineralogy Bay of Bengal Geochemistry & Geophysics DEEP-WATER FORMATION DISSOLVED NEODYMIUM BAY CIRCULATION ATLANTIC BENGAL HIMALAYAN NORTHERN HOLOCENE PENETRATION Huang, Yi Colin, Christophe Bassinot, Franck Yu, Zhaojie Dubois-Dauphin, Quentin Dapoigny, Arnaud Wilson, David J. Bayon, Germain Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
topic_facet |
Foraminiferal epsilon Nd Weathering River discharge Mineralogy Bay of Bengal Geochemistry & Geophysics DEEP-WATER FORMATION DISSOLVED NEODYMIUM BAY CIRCULATION ATLANTIC BENGAL HIMALAYAN NORTHERN HOLOCENE PENETRATION |
description |
Radiogenic neodymium isotope compositions (epsilon Nd) are used as a tracer for water mass circulation and continental weathering at different timescales. However, uncertainties remain in the relative roles of these two factors in driving past seawater epsilon Nd variability in settings under the influence of terrestrial or riverine sediment inputs. In this study, Nd isotopes of mixed planktonic foraminifera species and delta O-18 and delta C-13 of Cibicidoides wuellerstorfi were analyzed on three cores from the northeastern Indian Ocean to better assess the impact of lithogenic inputs from Himalayan rivers and deep-water hydrological changes on the past epsilon Nd distribution in the Bay of Bengal (BoB). Our epsilon Nd data indicate relatively homogenous and radiogenic values (from -8.4 to -7.5) during glacial periods in the BoB, similar to the composition of glacial water masses of the Southern Ocean. In contrast, interglacials were characterized by more unradiogenic epsilon Nd and a pronounced north-south gradient of similar to 4.5 epsilon Nd units (from -12.9 to -8.5) in bottom water, similar to the present-day distribution in the BoB, pointing to a strong lithogenic control by seawater-particulate interactions. Notably, this significant decoupling of the local Nd isotope signature from the Southern Ocean composition occurred when Himalayan riverine inputs were dominated by the erosion of Indo-Gangetic plain soils during interglacial periods, whereas the preferential delivery of fresh primary mineral assemblages during glacial periods appears to have had little impact on Nd exchange with seawater. These findings provide direct evidence that the degree of seawater-particulate exchange at continental margins is governed by the mineralogy of riverine inputs, with further implications for the use of Nd isotopes as palaeoceanographic tracers. |
format |
Report |
author |
Huang, Yi Colin, Christophe Bassinot, Franck Yu, Zhaojie Dubois-Dauphin, Quentin Dapoigny, Arnaud Wilson, David J. Bayon, Germain |
author_facet |
Huang, Yi Colin, Christophe Bassinot, Franck Yu, Zhaojie Dubois-Dauphin, Quentin Dapoigny, Arnaud Wilson, David J. Bayon, Germain |
author_sort |
Huang, Yi |
title |
Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
title_short |
Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
title_full |
Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
title_fullStr |
Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
title_full_unstemmed |
Impact of riverine sediment mineralogy on seawater Nd isotope compositions in the northeastern part of the Indian Ocean during the last two glacial cycles |
title_sort |
impact of riverine sediment mineralogy on seawater nd isotope compositions in the northeastern part of the indian ocean during the last two glacial cycles |
publisher |
ELSEVIER |
publishDate |
2024 |
url |
http://ir.qdio.ac.cn/handle/337002/185349 https://doi.org/10.1016/j.epsl.2024.118902 |
genre |
Planktonic foraminifera Southern Ocean |
genre_facet |
Planktonic foraminifera Southern Ocean |
op_relation |
EARTH AND PLANETARY SCIENCE LETTERS http://ir.qdio.ac.cn/handle/337002/185349 doi:10.1016/j.epsl.2024.118902 |
op_doi |
https://doi.org/10.1016/j.epsl.2024.118902 |
container_title |
Earth and Planetary Science Letters |
container_volume |
643 |
container_start_page |
118902 |
_version_ |
1810472730233929728 |