Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions
Banded Iron Formations (BIFs) are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole...
Published in: | Geoscience Frontiers |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1016/j.gsf.2016.11.016 https://doaj.org/article/33b430c7727747dfb80dc9c42b37ac97 |
id |
ftdoajarticles:oai:doaj.org/article:33b430c7727747dfb80dc9c42b37ac97 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:33b430c7727747dfb80dc9c42b37ac97 2023-10-01T03:56:20+02:00 Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions Shogo Aoki Chiho Kabashima Yasuhiro Kato Takafumi Hirata Tsuyoshi Komiya 2018-07-01T00:00:00Z https://doi.org/10.1016/j.gsf.2016.11.016 https://doaj.org/article/33b430c7727747dfb80dc9c42b37ac97 EN eng Elsevier http://www.sciencedirect.com/science/article/pii/S1674987117300026 https://doaj.org/toc/1674-9871 1674-9871 doi:10.1016/j.gsf.2016.11.016 https://doaj.org/article/33b430c7727747dfb80dc9c42b37ac97 Geoscience Frontiers, Vol 9, Iss 4, Pp 1049-1072 (2018) Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.1016/j.gsf.2016.11.016 2023-09-03T00:35:56Z Banded Iron Formations (BIFs) are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole-rock compositions in order to decode the ancient seawater compositions because their compositions are highly variable. We analyzed major and trace element contents of the BIFs in the 3.8–3.7 Ga Isua supracrustal belt (ISB), southern West Greenland. The BIFs are petrographically classified into four types: Black-, Gray-, Green- and White-types, respectively. The Green-type BIFs contain more amphiboles, and are significantly enriched in Co, Ni, Cu, Zn, Y, heavy rare earth element (HREE) and U contents. However, their bulk compositions are not suitable for estimate of seawater composition because the enrichment was caused by secondary mobility of metamorphic Mg, Ca and Si-rich fluid, involvement of carbonate minerals and silicate minerals of olivine and pyroxene and/or later silicification or contamination of volcanic and clastic materials. The White-type BIFs are predominant in quartz, and have lower transition element and REE contents. The Gray-type BIFs contain both quartz and magnetite. The Black-type BIFs are dominated by magnetite, and contain moderate to high transition element and REE contents. But, positive correlations of V, Ni, Zn and U contents with Zr contents suggest that involvement of detrital, volcanic and exhalative materials influences on their contents. The evidence for significant influence of the materials on the transition element contents such as Ni in the BIFs indicates the transition element contents in the Archean ocean were much lower than previously estimated. We reconstructed secular variations of V, Co, Zn and U contents of BIFs through time, which show Ni and Co contents decreased whereas V, Zn and U contents increased through time. Especially, the Ni and Co contents drastically decreased ... Article in Journal/Newspaper Greenland Directory of Open Access Journals: DOAJ Articles Greenland Geoscience Frontiers 9 4 1049 1072 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 Shogo Aoki Chiho Kabashima Yasuhiro Kato Takafumi Hirata Tsuyoshi Komiya Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
topic_facet |
Geology QE1-996.5 |
description |
Banded Iron Formations (BIFs) are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole-rock compositions in order to decode the ancient seawater compositions because their compositions are highly variable. We analyzed major and trace element contents of the BIFs in the 3.8–3.7 Ga Isua supracrustal belt (ISB), southern West Greenland. The BIFs are petrographically classified into four types: Black-, Gray-, Green- and White-types, respectively. The Green-type BIFs contain more amphiboles, and are significantly enriched in Co, Ni, Cu, Zn, Y, heavy rare earth element (HREE) and U contents. However, their bulk compositions are not suitable for estimate of seawater composition because the enrichment was caused by secondary mobility of metamorphic Mg, Ca and Si-rich fluid, involvement of carbonate minerals and silicate minerals of olivine and pyroxene and/or later silicification or contamination of volcanic and clastic materials. The White-type BIFs are predominant in quartz, and have lower transition element and REE contents. The Gray-type BIFs contain both quartz and magnetite. The Black-type BIFs are dominated by magnetite, and contain moderate to high transition element and REE contents. But, positive correlations of V, Ni, Zn and U contents with Zr contents suggest that involvement of detrital, volcanic and exhalative materials influences on their contents. The evidence for significant influence of the materials on the transition element contents such as Ni in the BIFs indicates the transition element contents in the Archean ocean were much lower than previously estimated. We reconstructed secular variations of V, Co, Zn and U contents of BIFs through time, which show Ni and Co contents decreased whereas V, Zn and U contents increased through time. Especially, the Ni and Co contents drastically decreased ... |
format |
Article in Journal/Newspaper |
author |
Shogo Aoki Chiho Kabashima Yasuhiro Kato Takafumi Hirata Tsuyoshi Komiya |
author_facet |
Shogo Aoki Chiho Kabashima Yasuhiro Kato Takafumi Hirata Tsuyoshi Komiya |
author_sort |
Shogo Aoki |
title |
Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
title_short |
Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
title_full |
Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
title_fullStr |
Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
title_full_unstemmed |
Influence of contamination on banded iron formations in the Isua supracrustal belt, West Greenland: Reevaluation of the Eoarchean seawater compositions |
title_sort |
influence of contamination on banded iron formations in the isua supracrustal belt, west greenland: reevaluation of the eoarchean seawater compositions |
publisher |
Elsevier |
publishDate |
2018 |
url |
https://doi.org/10.1016/j.gsf.2016.11.016 https://doaj.org/article/33b430c7727747dfb80dc9c42b37ac97 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Geoscience Frontiers, Vol 9, Iss 4, Pp 1049-1072 (2018) |
op_relation |
http://www.sciencedirect.com/science/article/pii/S1674987117300026 https://doaj.org/toc/1674-9871 1674-9871 doi:10.1016/j.gsf.2016.11.016 https://doaj.org/article/33b430c7727747dfb80dc9c42b37ac97 |
op_doi |
https://doi.org/10.1016/j.gsf.2016.11.016 |
container_title |
Geoscience Frontiers |
container_volume |
9 |
container_issue |
4 |
container_start_page |
1049 |
op_container_end_page |
1072 |
_version_ |
1778525789105422336 |