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dc.contributor.author
Ariztegui, Daniel
dc.contributor.author
Pacton, Muriel
dc.contributor.author
Hunger, Gabriel
dc.contributor.author
Martinuzzi, Vincent
dc.contributor.author
Cusminsky, Gabriela
dc.contributor.author
Burdin, Beatrice
dc.contributor.author
Barmettler, Kurt
dc.contributor.author
Vasconcelos, Crisógono
dc.date.accessioned
2019-09-09T09:42:38Z
dc.date.available
2017-06-12T06:39:48Z
dc.date.available
2019-09-09T09:42:38Z
dc.date.issued
2015-12
dc.identifier.issn
2055-4877
dc.identifier.other
10.1002/dep2.7
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/116870
dc.identifier.doi
10.3929/ethz-b-000116870
dc.description.abstract
Living stromatolites have been mostly described within shallow marine and (hyper)saline lacustrine environments. Southernmost South America lacks detailed investigations of these (organo)sedimentary buildups, particularly in regions experiencing extreme and variable environmental conditions. Here, we report and describe living freshwater stromatolites in the Maquinchao region, north‐western Patagonia, Argentina. Fossil stromatolites characterized by globular and cauliflower shapes are also present in a continuous palaeoshoreline of a former lake at an altitude of 830 m, whereas their living counterparts only occur in the calm waters of sheltered or meandering sections of the Maquinchao River. The living stromatolites and their host waters have been sampled and studied using various chemical and microscopic techniques to better constrain the environmental versus biological factors controlling their development. Our results indicate that today stromatolites only proliferate in freshwater when Ca2+ levels are high. A microscopic inspection of the living stromatolite mat indicates stronger photosynthetic activity in the upper green layer associated with crypto/microcrystalline calcite (nanoglobules) compared to the lower beige‐white biofilm. This biofilm contains more low‐Mg calcite (rhombohedra) precipitates, which can form millimetre‐sized aggregates in the underlying anoxic layer. Although sulphate‐reducing bacteria are living in the entire mat, they appear more abundant and widely distributed in the lower beige‐white layer and are always associated with Mg calcite. Low salinity and low‐turbidity water along with microbial (photosynthetic and heterotrophic) activity are the most important factors promoting low‐Mg calcite precipitation in the Maquinchao Basin. These conditions are very different from those proposed for recently described lacustrine stromatolites at high altitude in the subtropical and tropical Andes as well as in Chilean Patagonia. Hence, all these observations in modern freshwater stromatolites show the importance of geomicrobiological studies in identifying proxies of the hydrological conditions prevailing during their formation.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
Wiley
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/4.0/
dc.subject
Bacterial fossils
en_US
dc.subject
Biomineralization
en_US
dc.subject
Extracellular polymeric substances
en_US
dc.subject
Freshwater microbialite
en_US
dc.subject
nanoglobules
en_US
dc.subject
stromatolites
en_US
dc.title
Organomineralization processes in freshwater stromatolites: a living example from eastern Patagonia
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 4.0 International
dc.date.published
2016-01-12
ethz.journal.title
The Depositional Record
ethz.journal.volume
1
en_US
ethz.journal.issue
2
en_US
ethz.pages.start
130
en_US
ethz.pages.end
146
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.publication.place
Chichester
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02721 - Inst. f. Biogeochemie u. Schadstoffdyn. / Inst. Biogeochem. and Pollutant Dynamics::03541 - Kretzschmar, Ruben / Kretzschmar, Ruben
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02721 - Inst. f. Biogeochemie u. Schadstoffdyn. / Inst. Biogeochem. and Pollutant Dynamics::03541 - Kretzschmar, Ruben / Kretzschmar, Ruben
ethz.date.deposited
2017-06-12T06:43:36Z
ethz.source
ECIT
ethz.identifier.importid
imp5936546e05ed538513
ethz.ecitpid
pub:178759
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-07-17T12:13:45Z
ethz.rosetta.lastUpdated
2019-09-09T09:42:50Z
ethz.rosetta.versionExported
true
ethz.COinS
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