Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period
The late Neoproterozoic witnessed series of remarkable geological evolutions, including the Sturtian and Marinoan glaciation events during the Cryogenian. A stratified oceanic redox structure has been proposed for this period, and the dynamics of the deep water redox conditions have been well illust...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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Online Access: | http://ir.gig.ac.cn/handle/344008/76146 http://ir.gig.ac.cn/handle/344008/76147 https://doi.org/10.1016/j.palaeo.2023.112005 |
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ftchacadscgigcas:oai:ir.gig.ac.cn:344008/76147 2024-09-30T14:44:39+00:00 Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period Wu, Jinxiang Tan, Zhaozhao Jia, Wanglu Chen, Jian Peng, Ping 'an 2024-03-01 http://ir.gig.ac.cn/handle/344008/76146 http://ir.gig.ac.cn/handle/344008/76147 https://doi.org/10.1016/j.palaeo.2023.112005 英语 eng PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY http://ir.gig.ac.cn/handle/344008/76146 http://ir.gig.ac.cn/handle/344008/76147 doi:10.1016/j.palaeo.2023.112005 Physical Geography Geology Paleontology The Datangpo Formation Black shales Mn carbonates Nitrogen isotopes Redox conditions Cryogenian bioevolution 期刊论文 2024 ftchacadscgigcas https://doi.org/10.1016/j.palaeo.2023.112005 2024-09-16T14:26:10Z The late Neoproterozoic witnessed series of remarkable geological evolutions, including the Sturtian and Marinoan glaciation events during the Cryogenian. A stratified oceanic redox structure has been proposed for this period, and the dynamics of the deep water redox conditions have been well illustrated by trace metals and their isotopes. However, variations in the redox conditions of the upper water column have received much less attention. Sedimentary nitrogen isotopes (815N) are critical for reconstructing the redox conditions in the upper water columns of ancient oceans. Existing research on the N cycle during the Cryogenian period is scarce, and the majority of studied samples were collected from shallow and medium water depth facies. To address this paucity of studies, we conducted a high -resolution N isotope study in combination with Fe speciation and Mo concentration data from two deep -water sections of black shales in the basal Datangpo Formation in the Nanhua Basin, a typical organic -rich stratum deposited during the Cryogenian interglaciation period. While the trace metal proxies suggest a fluctuating euxinic-ferruginous bottom water column for the lower interval and a stable euxinic bottom water column for the upper interval, the redox conditions of the upper water column were relatively stable, as indicated by minimal changes in the recorded 815N values. Furthermore, the 815N values of black shales in the basal Datangpo Formation of the Nanhua Basin have a limited range (3.1%o - 5.8%o, average of 4.3%o, standard deviation (SD) = 0.5%o, n = 104) and show no water -depth gradient, indicating the presence of a relatively large and stable nitrate reservoir and a deep redox chemocline in the Nanhua Basin. The characteristic of the nitrate reservoir reflected by these 815N signals can be roughly analogized to the global interglacial ocean, although only the counterpart northeast Svalbard can be used for comparison. Therefore, the nitrate availability in the marine water column may have had little ... Report Svalbard Guangzhou Institute of Geochemistry: GIG OpenIR (Chinese Academy of Sciences) Svalbard Palaeogeography, Palaeoclimatology, Palaeoecology 637 112005 |
institution |
Open Polar |
collection |
Guangzhou Institute of Geochemistry: GIG OpenIR (Chinese Academy of Sciences) |
op_collection_id |
ftchacadscgigcas |
language |
English |
topic |
Physical Geography Geology Paleontology The Datangpo Formation Black shales Mn carbonates Nitrogen isotopes Redox conditions Cryogenian bioevolution |
spellingShingle |
Physical Geography Geology Paleontology The Datangpo Formation Black shales Mn carbonates Nitrogen isotopes Redox conditions Cryogenian bioevolution Wu, Jinxiang Tan, Zhaozhao Jia, Wanglu Chen, Jian Peng, Ping 'an Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
topic_facet |
Physical Geography Geology Paleontology The Datangpo Formation Black shales Mn carbonates Nitrogen isotopes Redox conditions Cryogenian bioevolution |
description |
The late Neoproterozoic witnessed series of remarkable geological evolutions, including the Sturtian and Marinoan glaciation events during the Cryogenian. A stratified oceanic redox structure has been proposed for this period, and the dynamics of the deep water redox conditions have been well illustrated by trace metals and their isotopes. However, variations in the redox conditions of the upper water column have received much less attention. Sedimentary nitrogen isotopes (815N) are critical for reconstructing the redox conditions in the upper water columns of ancient oceans. Existing research on the N cycle during the Cryogenian period is scarce, and the majority of studied samples were collected from shallow and medium water depth facies. To address this paucity of studies, we conducted a high -resolution N isotope study in combination with Fe speciation and Mo concentration data from two deep -water sections of black shales in the basal Datangpo Formation in the Nanhua Basin, a typical organic -rich stratum deposited during the Cryogenian interglaciation period. While the trace metal proxies suggest a fluctuating euxinic-ferruginous bottom water column for the lower interval and a stable euxinic bottom water column for the upper interval, the redox conditions of the upper water column were relatively stable, as indicated by minimal changes in the recorded 815N values. Furthermore, the 815N values of black shales in the basal Datangpo Formation of the Nanhua Basin have a limited range (3.1%o - 5.8%o, average of 4.3%o, standard deviation (SD) = 0.5%o, n = 104) and show no water -depth gradient, indicating the presence of a relatively large and stable nitrate reservoir and a deep redox chemocline in the Nanhua Basin. The characteristic of the nitrate reservoir reflected by these 815N signals can be roughly analogized to the global interglacial ocean, although only the counterpart northeast Svalbard can be used for comparison. Therefore, the nitrate availability in the marine water column may have had little ... |
format |
Report |
author |
Wu, Jinxiang Tan, Zhaozhao Jia, Wanglu Chen, Jian Peng, Ping 'an |
author_facet |
Wu, Jinxiang Tan, Zhaozhao Jia, Wanglu Chen, Jian Peng, Ping 'an |
author_sort |
Wu, Jinxiang |
title |
Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
title_short |
Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
title_full |
Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
title_fullStr |
Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
title_full_unstemmed |
Nitrogen isotopes and geochemistry of the basal Datangpo Formation: Contrasting redox conditions in the upper and lower water columns during the Cryogenian interglaciation period |
title_sort |
nitrogen isotopes and geochemistry of the basal datangpo formation: contrasting redox conditions in the upper and lower water columns during the cryogenian interglaciation period |
publishDate |
2024 |
url |
http://ir.gig.ac.cn/handle/344008/76146 http://ir.gig.ac.cn/handle/344008/76147 https://doi.org/10.1016/j.palaeo.2023.112005 |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_relation |
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY http://ir.gig.ac.cn/handle/344008/76146 http://ir.gig.ac.cn/handle/344008/76147 doi:10.1016/j.palaeo.2023.112005 |
op_doi |
https://doi.org/10.1016/j.palaeo.2023.112005 |
container_title |
Palaeogeography, Palaeoclimatology, Palaeoecology |
container_volume |
637 |
container_start_page |
112005 |
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1811645803435917312 |