Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica
The floors of two shallow endorheic lakes, located on volcanic surfaces on James Ross Island, are covered with calcareous organosedimentary structures. Their biological and chemical composition, lake water characteristics, and seasonal variability of the thermal regime are introduced. The lakes are...
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ftdoajarticles:oai:doaj.org/article:b491d6c4b8bf48c5b5f3e1ebed3f97ac 2023-05-15T14:03:24+02:00 Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica J. Elster L. Nedbalová R. Vodrážka K. Láska J. Haloda J. Komárek 2016-01-01T00:00:00Z https://doi.org/10.5194/bg-13-535-2016 https://doaj.org/article/b491d6c4b8bf48c5b5f3e1ebed3f97ac EN eng Copernicus Publications http://www.biogeosciences.net/13/535/2016/bg-13-535-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-535-2016 https://doaj.org/article/b491d6c4b8bf48c5b5f3e1ebed3f97ac Biogeosciences, Vol 13, Iss 2, Pp 535-549 (2016) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/bg-13-535-2016 2022-12-31T15:39:46Z The floors of two shallow endorheic lakes, located on volcanic surfaces on James Ross Island, are covered with calcareous organosedimentary structures. Their biological and chemical composition, lake water characteristics, and seasonal variability of the thermal regime are introduced. The lakes are frozen down to the bottom for 8–9 months a year and their water chemistry is characterised by low conductivity and neutral to slightly alkaline pH. The photosynthetic microbial mat is composed of filamentous cyanobacteria and microalgae that are considered to be Antarctic endemic species. The mucilaginous black biofilm is covered by green spots formed by a green microalga and the macroscopic structures are packed together with fine material. Thin sections consist of rock substrate, soft biofilm, calcite spicules and mineral grains originating from different sources. The morphology of the spicules is typical of calcium carbonate monocrystals having a layered structure and specific surface texture, which reflect growth and degradation processes. The spicules' chemical composition and structure correspond to pure calcite. The lakes' age, altitude, morphometry, geomorphological and hydrological stability, including low sedimentation rates, together with thermal regime predispose the existence of this community. We hypothesise that the precipitation of calcite is connected with the photosynthetic activity of the green microalgae that were not recorded in any other lake in the region. This study has shown that the unique community producing biogenic calcite spicules is quite different to any yet described. Article in Journal/Newspaper Antarc* Antarctic Antarctica James Ross Island Ross Island Directory of Open Access Journals: DOAJ Articles Antarctic Ross Island Biogeosciences 13 2 535 549 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 J. Elster L. Nedbalová R. Vodrážka K. Láska J. Haloda J. Komárek Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The floors of two shallow endorheic lakes, located on volcanic surfaces on James Ross Island, are covered with calcareous organosedimentary structures. Their biological and chemical composition, lake water characteristics, and seasonal variability of the thermal regime are introduced. The lakes are frozen down to the bottom for 8–9 months a year and their water chemistry is characterised by low conductivity and neutral to slightly alkaline pH. The photosynthetic microbial mat is composed of filamentous cyanobacteria and microalgae that are considered to be Antarctic endemic species. The mucilaginous black biofilm is covered by green spots formed by a green microalga and the macroscopic structures are packed together with fine material. Thin sections consist of rock substrate, soft biofilm, calcite spicules and mineral grains originating from different sources. The morphology of the spicules is typical of calcium carbonate monocrystals having a layered structure and specific surface texture, which reflect growth and degradation processes. The spicules' chemical composition and structure correspond to pure calcite. The lakes' age, altitude, morphometry, geomorphological and hydrological stability, including low sedimentation rates, together with thermal regime predispose the existence of this community. We hypothesise that the precipitation of calcite is connected with the photosynthetic activity of the green microalgae that were not recorded in any other lake in the region. This study has shown that the unique community producing biogenic calcite spicules is quite different to any yet described. |
format |
Article in Journal/Newspaper |
author |
J. Elster L. Nedbalová R. Vodrážka K. Láska J. Haloda J. Komárek |
author_facet |
J. Elster L. Nedbalová R. Vodrážka K. Láska J. Haloda J. Komárek |
author_sort |
J. Elster |
title |
Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
title_short |
Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
title_full |
Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
title_fullStr |
Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
title_full_unstemmed |
Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica |
title_sort |
unusual biogenic calcite structures in two shallow lakes, james ross island, antarctica |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/bg-13-535-2016 https://doaj.org/article/b491d6c4b8bf48c5b5f3e1ebed3f97ac |
geographic |
Antarctic Ross Island |
geographic_facet |
Antarctic Ross Island |
genre |
Antarc* Antarctic Antarctica James Ross Island Ross Island |
genre_facet |
Antarc* Antarctic Antarctica James Ross Island Ross Island |
op_source |
Biogeosciences, Vol 13, Iss 2, Pp 535-549 (2016) |
op_relation |
http://www.biogeosciences.net/13/535/2016/bg-13-535-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-535-2016 https://doaj.org/article/b491d6c4b8bf48c5b5f3e1ebed3f97ac |
op_doi |
https://doi.org/10.5194/bg-13-535-2016 |
container_title |
Biogeosciences |
container_volume |
13 |
container_issue |
2 |
container_start_page |
535 |
op_container_end_page |
549 |
_version_ |
1766274038705946624 |