Chromium Isotope Systematics in Modern and Ancient Microbialites
Changes in stable chromium isotopes (denoted as δ 53 Cr) in ancient carbonate sediments are increasingly used to reconstruct the oxygenation history in Earth’s atmosphere and oceans through time. As a significant proportion of marine carbonate older than the Cambrian is microbially-mediated, the uti...
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ftdoajarticles:oai:doaj.org/article:e67c3d31d4654c6f9be26d4848f7679d 2023-05-15T13:25:33+02:00 Chromium Isotope Systematics in Modern and Ancient Microbialites Sylvie Bruggmann Alexandra S. Rodler Robert M. Klaebe Steven Goderis Robert Frei 2020-10-01T00:00:00Z https://doi.org/10.3390/min10100928 https://doaj.org/article/e67c3d31d4654c6f9be26d4848f7679d EN eng MDPI AG https://www.mdpi.com/2075-163X/10/10/928 https://doaj.org/toc/2075-163X doi:10.3390/min10100928 2075-163X https://doaj.org/article/e67c3d31d4654c6f9be26d4848f7679d Minerals, Vol 10, Iss 928, p 928 (2020) Cr isotopes C isotopes O isotopes rare earth elements Proterozoic carbonates Mineralogy QE351-399.2 article 2020 ftdoajarticles https://doi.org/10.3390/min10100928 2023-01-08T01:35:18Z Changes in stable chromium isotopes (denoted as δ 53 Cr) in ancient carbonate sediments are increasingly used to reconstruct the oxygenation history in Earth’s atmosphere and oceans through time. As a significant proportion of marine carbonate older than the Cambrian is microbially-mediated, the utility of δ 53 Cr values in ancient carbonates hinges on whether these sediments accurately capture the isotope composition of their environment. We report Cr concentrations (Cr) and δ 53 Cr values of modern marginal marine and non-marine microbial carbonates. These data are supported by stable C and O isotope compositions, as well as rare earth elements and yttrium (REY) concentrations. In addition, we present data on ancient analogs from Precambrian strata. Microbial carbonates from Marion Lake (Australia, δ 53 Cr ≈ 0.99‰) and Mono Lake (USA, ≈0.78‰) display significantly higher δ 53 Cr values compared with ancient microbialites from the Andrée Land Group in Greenland (720 Ma, ≈0.36‰) and the Bitter Springs Formation in Australia (800 Ma, ≈−0.12‰). The δ 53 Cr values are homogenous within microbialite specimens and within individual study sites. This indicates that biological parameters, such as vital effects, causing highly variable δ 53 Cr values in skeletal carbonates, do not induce variability in δ 53 Cr values in microbialites. Together with stable C and O isotope compositions and REY patterns, δ 53 Cr values in microbialites seem to be driven by environmental parameters such as background lithology and salinity. In support, our Cr and δ 53 Cr results of ancient microbial carbonates agree well with data of abiotically precipitated carbonates of the Proterozoic. If detrital contamination is carefully assessed, microbialites have the potential to record the δ 53 Cr values of the waters from which they precipitated. However, it remains unclear if these δ 53 Cr values record (paleo-) redox conditions or rather result from other physico-chemical parameters. Article in Journal/Newspaper Andrée-Land Greenland Directory of Open Access Journals: DOAJ Articles Andrée ENVELOPE(-61.500,-61.500,-64.516,-64.516) Greenland Minerals 10 10 928 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Cr isotopes C isotopes O isotopes rare earth elements Proterozoic carbonates Mineralogy QE351-399.2 |
spellingShingle |
Cr isotopes C isotopes O isotopes rare earth elements Proterozoic carbonates Mineralogy QE351-399.2 Sylvie Bruggmann Alexandra S. Rodler Robert M. Klaebe Steven Goderis Robert Frei Chromium Isotope Systematics in Modern and Ancient Microbialites |
topic_facet |
Cr isotopes C isotopes O isotopes rare earth elements Proterozoic carbonates Mineralogy QE351-399.2 |
description |
Changes in stable chromium isotopes (denoted as δ 53 Cr) in ancient carbonate sediments are increasingly used to reconstruct the oxygenation history in Earth’s atmosphere and oceans through time. As a significant proportion of marine carbonate older than the Cambrian is microbially-mediated, the utility of δ 53 Cr values in ancient carbonates hinges on whether these sediments accurately capture the isotope composition of their environment. We report Cr concentrations (Cr) and δ 53 Cr values of modern marginal marine and non-marine microbial carbonates. These data are supported by stable C and O isotope compositions, as well as rare earth elements and yttrium (REY) concentrations. In addition, we present data on ancient analogs from Precambrian strata. Microbial carbonates from Marion Lake (Australia, δ 53 Cr ≈ 0.99‰) and Mono Lake (USA, ≈0.78‰) display significantly higher δ 53 Cr values compared with ancient microbialites from the Andrée Land Group in Greenland (720 Ma, ≈0.36‰) and the Bitter Springs Formation in Australia (800 Ma, ≈−0.12‰). The δ 53 Cr values are homogenous within microbialite specimens and within individual study sites. This indicates that biological parameters, such as vital effects, causing highly variable δ 53 Cr values in skeletal carbonates, do not induce variability in δ 53 Cr values in microbialites. Together with stable C and O isotope compositions and REY patterns, δ 53 Cr values in microbialites seem to be driven by environmental parameters such as background lithology and salinity. In support, our Cr and δ 53 Cr results of ancient microbial carbonates agree well with data of abiotically precipitated carbonates of the Proterozoic. If detrital contamination is carefully assessed, microbialites have the potential to record the δ 53 Cr values of the waters from which they precipitated. However, it remains unclear if these δ 53 Cr values record (paleo-) redox conditions or rather result from other physico-chemical parameters. |
format |
Article in Journal/Newspaper |
author |
Sylvie Bruggmann Alexandra S. Rodler Robert M. Klaebe Steven Goderis Robert Frei |
author_facet |
Sylvie Bruggmann Alexandra S. Rodler Robert M. Klaebe Steven Goderis Robert Frei |
author_sort |
Sylvie Bruggmann |
title |
Chromium Isotope Systematics in Modern and Ancient Microbialites |
title_short |
Chromium Isotope Systematics in Modern and Ancient Microbialites |
title_full |
Chromium Isotope Systematics in Modern and Ancient Microbialites |
title_fullStr |
Chromium Isotope Systematics in Modern and Ancient Microbialites |
title_full_unstemmed |
Chromium Isotope Systematics in Modern and Ancient Microbialites |
title_sort |
chromium isotope systematics in modern and ancient microbialites |
publisher |
MDPI AG |
publishDate |
2020 |
url |
https://doi.org/10.3390/min10100928 https://doaj.org/article/e67c3d31d4654c6f9be26d4848f7679d |
long_lat |
ENVELOPE(-61.500,-61.500,-64.516,-64.516) |
geographic |
Andrée Greenland |
geographic_facet |
Andrée Greenland |
genre |
Andrée-Land Greenland |
genre_facet |
Andrée-Land Greenland |
op_source |
Minerals, Vol 10, Iss 928, p 928 (2020) |
op_relation |
https://www.mdpi.com/2075-163X/10/10/928 https://doaj.org/toc/2075-163X doi:10.3390/min10100928 2075-163X https://doaj.org/article/e67c3d31d4654c6f9be26d4848f7679d |
op_doi |
https://doi.org/10.3390/min10100928 |
container_title |
Minerals |
container_volume |
10 |
container_issue |
10 |
container_start_page |
928 |
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1766386003001475072 |