Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases
The evolution of oxygenic photosynthesis was the most important geochemical event in Earth history, causing the Great Oxidation Event (GOE) ~2.4 b.y. ago. However, evidence is mixed as to whether O2 production occurred locally as much as 2.8 b.y. ago, creating O2 oases, or initiated just prior to th...
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ftcdlib:oai:escholarship.org/ark:/13030/qt9gr788vv 2023-05-15T14:02:59+02:00 Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases Sumner, DY Hawes, I Mackey, TJ Jungblut, AD Doran, PT 887 - 890 2015-10-01 application/pdf https://escholarship.org/uc/item/9gr788vv unknown eScholarship, University of California qt9gr788vv https://escholarship.org/uc/item/9gr788vv public Geology, vol 43, iss 10 Geochemistry & Geophysics Earth Sciences article 2015 ftcdlib 2021-06-20T14:23:13Z The evolution of oxygenic photosynthesis was the most important geochemical event in Earth history, causing the Great Oxidation Event (GOE) ~2.4 b.y. ago. However, evidence is mixed as to whether O2 production occurred locally as much as 2.8 b.y. ago, creating O2 oases, or initiated just prior to the GOE. The biogeochemical dynamics of possible O2 oases have been poorly constrained due to the absence of modern analogs. However, cyanobacteria in microbial mats in a perennially anoxic region of Lake Fryxell, Antarctica, create a 1-2 mm O2-containing layer in the upper mat during summer, providing the first known modern analog for formation of benthic O2 oases. In Lake Fryxell, benthic cyanobacteria are present below the oxycline in the lake. Mat photosynthesis rates were slow due to low photon flux rate (1-2 μmol m-2 s-1) under thick ice cover, but photosynthetic O2 production was sufficient to sustain up to 50 μmol O2 L-1, sandwiched between anoxic overlying water and anoxic sediments. We hypothesize that Archean cyanobacteria could have similarly created O2 oases in benthic mats prior to the GOE. Analogous mats may have been at least partly responsible for geological evidence of oxidative weathering prior to the GOE, and habitats such as Lake Fryxell provide natural laboratories where the impact of benthic O2 oases on biogeochemical signatures can be investigated. Article in Journal/Newspaper Antarc* Antarctic Antarctica University of California: eScholarship Antarctic Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Lake Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Geochemistry & Geophysics Earth Sciences |
spellingShingle |
Geochemistry & Geophysics Earth Sciences Sumner, DY Hawes, I Mackey, TJ Jungblut, AD Doran, PT Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
topic_facet |
Geochemistry & Geophysics Earth Sciences |
description |
The evolution of oxygenic photosynthesis was the most important geochemical event in Earth history, causing the Great Oxidation Event (GOE) ~2.4 b.y. ago. However, evidence is mixed as to whether O2 production occurred locally as much as 2.8 b.y. ago, creating O2 oases, or initiated just prior to the GOE. The biogeochemical dynamics of possible O2 oases have been poorly constrained due to the absence of modern analogs. However, cyanobacteria in microbial mats in a perennially anoxic region of Lake Fryxell, Antarctica, create a 1-2 mm O2-containing layer in the upper mat during summer, providing the first known modern analog for formation of benthic O2 oases. In Lake Fryxell, benthic cyanobacteria are present below the oxycline in the lake. Mat photosynthesis rates were slow due to low photon flux rate (1-2 μmol m-2 s-1) under thick ice cover, but photosynthetic O2 production was sufficient to sustain up to 50 μmol O2 L-1, sandwiched between anoxic overlying water and anoxic sediments. We hypothesize that Archean cyanobacteria could have similarly created O2 oases in benthic mats prior to the GOE. Analogous mats may have been at least partly responsible for geological evidence of oxidative weathering prior to the GOE, and habitats such as Lake Fryxell provide natural laboratories where the impact of benthic O2 oases on biogeochemical signatures can be investigated. |
format |
Article in Journal/Newspaper |
author |
Sumner, DY Hawes, I Mackey, TJ Jungblut, AD Doran, PT |
author_facet |
Sumner, DY Hawes, I Mackey, TJ Jungblut, AD Doran, PT |
author_sort |
Sumner, DY |
title |
Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
title_short |
Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
title_full |
Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
title_fullStr |
Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
title_full_unstemmed |
Antarctic microbial mats: A modern analog for Archean lacustrine oxygen oases |
title_sort |
antarctic microbial mats: a modern analog for archean lacustrine oxygen oases |
publisher |
eScholarship, University of California |
publishDate |
2015 |
url |
https://escholarship.org/uc/item/9gr788vv |
op_coverage |
887 - 890 |
long_lat |
ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(163.183,163.183,-77.617,-77.617) |
geographic |
Antarctic Fryxell Lake Fryxell |
geographic_facet |
Antarctic Fryxell Lake Fryxell |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Geology, vol 43, iss 10 |
op_relation |
qt9gr788vv https://escholarship.org/uc/item/9gr788vv |
op_rights |
public |
_version_ |
1766273432342757376 |