Discovery of large conical stromatolites in Lake Untersee, Antarctica
Abstract Lake Untersee is one of the largest (11.4 km 2 ) and deepest (>160 m) freshwater lakes in East Antarctica. Located at 71°S the lake has a perennial ice cover, a water column that, with the exception of a small anoxic basin in the southwest of the lake, is well mixed, supersaturated with...
Published in: | Geobiology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2011
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1111/j.1472-4669.2011.00279.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1472-4669.2011.00279.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1472-4669.2011.00279.x |
id |
crwiley:10.1111/j.1472-4669.2011.00279.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1111/j.1472-4669.2011.00279.x 2024-09-15T17:45:57+00:00 Discovery of large conical stromatolites in Lake Untersee, Antarctica ANDERSEN, D. T. SUMNER, D. Y. HAWES, I. WEBSTER‐BROWN, J. MCKAY, C. P. 2011 http://dx.doi.org/10.1111/j.1472-4669.2011.00279.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1472-4669.2011.00279.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1472-4669.2011.00279.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Geobiology volume 9, issue 3, page 280-293 ISSN 1472-4677 1472-4669 journal-article 2011 crwiley https://doi.org/10.1111/j.1472-4669.2011.00279.x 2024-08-22T04:15:11Z Abstract Lake Untersee is one of the largest (11.4 km 2 ) and deepest (>160 m) freshwater lakes in East Antarctica. Located at 71°S the lake has a perennial ice cover, a water column that, with the exception of a small anoxic basin in the southwest of the lake, is well mixed, supersaturated with dissolved oxygen, alkaline (pH 10.4) and exceedingly clear. The floor of the lake is covered with photosynthetic microbial mats to depths of at least 100 m. These mats are primarily composed of filamentous cyanophytes and form two distinct macroscopic structures, one of which – cm‐scale cuspate pinnacles dominated by Leptolyngbya spp. – is common in Antarctica, but the second – laminated, conical stromatolites that rise up to 0.5 m above the lake floor, dominated by Phormidium spp. – has not previously been reported in any modern environment. The laminae that form the conical stromatolites are 0.2–0.8 mm in thickness consisting of fine clays and organic material; carbon dating implies that laminations may occur on near decadal timescales. The uniformly steep sides (59.6 ± 2.5°) and the regular laminar structure of the cones suggest that they may provide a modern analog for growth of some of the oldest well‐described Archean stromatolites. Mechanisms underlying the formation of these stromatolites are as yet unclear, but their growth is distinct from that of the cuspate pinnacles. The sympatric occurrence of pinnacles and cones related to microbial communities with distinct cyanobacterial compositions suggest that specific microbial behaviors underpin the morphological differences in the structures. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Wiley Online Library Geobiology 9 3 280 293 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Lake Untersee is one of the largest (11.4 km 2 ) and deepest (>160 m) freshwater lakes in East Antarctica. Located at 71°S the lake has a perennial ice cover, a water column that, with the exception of a small anoxic basin in the southwest of the lake, is well mixed, supersaturated with dissolved oxygen, alkaline (pH 10.4) and exceedingly clear. The floor of the lake is covered with photosynthetic microbial mats to depths of at least 100 m. These mats are primarily composed of filamentous cyanophytes and form two distinct macroscopic structures, one of which – cm‐scale cuspate pinnacles dominated by Leptolyngbya spp. – is common in Antarctica, but the second – laminated, conical stromatolites that rise up to 0.5 m above the lake floor, dominated by Phormidium spp. – has not previously been reported in any modern environment. The laminae that form the conical stromatolites are 0.2–0.8 mm in thickness consisting of fine clays and organic material; carbon dating implies that laminations may occur on near decadal timescales. The uniformly steep sides (59.6 ± 2.5°) and the regular laminar structure of the cones suggest that they may provide a modern analog for growth of some of the oldest well‐described Archean stromatolites. Mechanisms underlying the formation of these stromatolites are as yet unclear, but their growth is distinct from that of the cuspate pinnacles. The sympatric occurrence of pinnacles and cones related to microbial communities with distinct cyanobacterial compositions suggest that specific microbial behaviors underpin the morphological differences in the structures. |
format |
Article in Journal/Newspaper |
author |
ANDERSEN, D. T. SUMNER, D. Y. HAWES, I. WEBSTER‐BROWN, J. MCKAY, C. P. |
spellingShingle |
ANDERSEN, D. T. SUMNER, D. Y. HAWES, I. WEBSTER‐BROWN, J. MCKAY, C. P. Discovery of large conical stromatolites in Lake Untersee, Antarctica |
author_facet |
ANDERSEN, D. T. SUMNER, D. Y. HAWES, I. WEBSTER‐BROWN, J. MCKAY, C. P. |
author_sort |
ANDERSEN, D. T. |
title |
Discovery of large conical stromatolites in Lake Untersee, Antarctica |
title_short |
Discovery of large conical stromatolites in Lake Untersee, Antarctica |
title_full |
Discovery of large conical stromatolites in Lake Untersee, Antarctica |
title_fullStr |
Discovery of large conical stromatolites in Lake Untersee, Antarctica |
title_full_unstemmed |
Discovery of large conical stromatolites in Lake Untersee, Antarctica |
title_sort |
discovery of large conical stromatolites in lake untersee, antarctica |
publisher |
Wiley |
publishDate |
2011 |
url |
http://dx.doi.org/10.1111/j.1472-4669.2011.00279.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1472-4669.2011.00279.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1472-4669.2011.00279.x |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
Geobiology volume 9, issue 3, page 280-293 ISSN 1472-4677 1472-4669 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1472-4669.2011.00279.x |
container_title |
Geobiology |
container_volume |
9 |
container_issue |
3 |
container_start_page |
280 |
op_container_end_page |
293 |
_version_ |
1810493888886996992 |