Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)

Many ferromanganese stromatolites of El Soplao Cave (N Spain) are characterized for the exceptional preser-vation and high diversity of microbial fossils, probably representing the best example of microbial preserva-tion described in ferromanganese deposits so far.The El Soplao stromatolites are mai...

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Detalles Bibliográficos
Autores: Lozano Fernández, Rafael Pablo, Rossi, Carlos
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/276845
Acceso en línea:http://hdl.handle.net/10261/276845
https://doi.org/10.1016/j.sedgeo.2012.02.003
Access Level:acceso abierto
Palabra clave:stromatolites
manganese oxides
Mn-oxidizing microbes
fossil microbes
Cueva El Soplao
España
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spelling Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)Lozano Fernández, Rafael PabloRossi, Carlosstromatolitesmanganese oxidesMn-oxidizing microbesfossil microbesCueva El SoplaoEspañaMany ferromanganese stromatolites of El Soplao Cave (N Spain) are characterized for the exceptional preser-vation and high diversity of microbial fossils, probably representing the best example of microbial preserva-tion described in ferromanganese deposits so far.The El Soplao stromatolites are mainly formed by polymetallic Mn-rich oxides with subordinate and variableamounts of detrital material, and consist of both dendritic and laminar microfacies. In both microfacies, mi-crobial forms are abundant in the relatively pure Mn-oxide rich material, whereas they are scarce in areaswith significant detrital material. Microbial forms are observed either in cross section, completely embeddedin the Mn-oxide-rich matrix, or in three dimensions lining the walls of pores. Based on their morphology, wehave separated the most abundant microbial forms into six main morphotypes and six additional submor-photypes, most of which can be assigned to bacteria. Most morphotypes consist of coccoid, coccobacilus, orfilamentous forms. Therefore they are not diagnostic of any particular bacterial group. However, the ovoidcells of morphotype B show cylindrical polar protuberances typical of prosthecate alpha-Proteobacteria.Onthe basis of characteristic morphological features, three submorphotypes of morphotype B can be assignedto three alpha-Proteobacteriagenera: Hyphomicrobium, Pedomicrobium, and Caulobacter. This ascription issupported by the well known Mn-oxidizing behavior of bothPedomicrobiumandCaulobacter, and by thecommon presence ofHyphomicrobiumin ferromanganese deposits elsewhere.The excellent microbial preservation is partly related to the origin of the ferromanganese oxides, i.e. extracel-lular precipitation induced by microbial metabolism. Other factors contributing to the good microbial preser-vation are the relatively low degree of diagenetic alteration, and the relatively high accretion rates ofstromatolites compared to other ferromanganese deposits. The generally low degree of diagenesis is likelybecause the stromatolites have remained relatively stable and at a rather low temperature since they wereformed at least 1 Ma ago. Still, some stromatolites have suffered diagenetic alteration (partial dissolutionand replacement by calcium carbonates and Fe-rich oxides), obscuring or even obliterating their bioforms.The El Soplao case represents an example of how easily biogenic Mn oxides can be altered, and their bioformsblurred, in a relatively short geological time span in spite of being in a relatively stable, alkaline, and low-temperature setting. A geological implication is that the absence of bioforms in other ferromanganese deposits,including rock varnish and Precambrian iron formations, does not disprove their possible biogenic origin, sincethe high chemical reactivity of biogenic manganese oxides makes them highly vulnerable to diagenesisMuseo Geominero, Instituto Geológico y Minero de España, EspañaDepartamento de Petrología y Geoquímica, Universidad Complutense de Madrid, EspañaElsevierCSIC - Instituto Geológico y Minero de España (IGME)Gobierno de CantabriaTurismo Del Nansa202220222012info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/276845https://doi.org/10.1016/j.sedgeo.2012.02.003reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés#PLACEHOLDER_PARENT_METADATA_VALUE#ICT-Soplao-53.5.00.12.00https://reader.elsevier.com/reader/sd/pii/S0037073812000395?token=86715143E70A7713994063DA2D5A9E9E065CEA0920595D351F4048A441E5EE935557AB6153890A9D1F99B0603C4AD9D3info:eu-repo/semantics/openAccessoai:digital.csic.es:10261/2768452026-05-22T06:33:51Z
dc.title.none.fl_str_mv Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
title Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
spellingShingle Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
Lozano Fernández, Rafael Pablo
stromatolites
manganese oxides
Mn-oxidizing microbes
fossil microbes
Cueva El Soplao
España
title_short Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
title_full Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
title_fullStr Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
title_full_unstemmed Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
title_sort Exceptional preservation of Mn-oxidizing microbes in cave stromatolites (El Soplao, Spain)
dc.creator.none.fl_str_mv Lozano Fernández, Rafael Pablo
Rossi, Carlos
author Lozano Fernández, Rafael Pablo
author_facet Lozano Fernández, Rafael Pablo
Rossi, Carlos
author_role author
author2 Rossi, Carlos
author2_role author
dc.contributor.none.fl_str_mv CSIC - Instituto Geológico y Minero de España (IGME)
Gobierno de Cantabria
Turismo Del Nansa
dc.subject.none.fl_str_mv stromatolites
manganese oxides
Mn-oxidizing microbes
fossil microbes
Cueva El Soplao
España
topic stromatolites
manganese oxides
Mn-oxidizing microbes
fossil microbes
Cueva El Soplao
España
description Many ferromanganese stromatolites of El Soplao Cave (N Spain) are characterized for the exceptional preser-vation and high diversity of microbial fossils, probably representing the best example of microbial preserva-tion described in ferromanganese deposits so far.The El Soplao stromatolites are mainly formed by polymetallic Mn-rich oxides with subordinate and variableamounts of detrital material, and consist of both dendritic and laminar microfacies. In both microfacies, mi-crobial forms are abundant in the relatively pure Mn-oxide rich material, whereas they are scarce in areaswith significant detrital material. Microbial forms are observed either in cross section, completely embeddedin the Mn-oxide-rich matrix, or in three dimensions lining the walls of pores. Based on their morphology, wehave separated the most abundant microbial forms into six main morphotypes and six additional submor-photypes, most of which can be assigned to bacteria. Most morphotypes consist of coccoid, coccobacilus, orfilamentous forms. Therefore they are not diagnostic of any particular bacterial group. However, the ovoidcells of morphotype B show cylindrical polar protuberances typical of prosthecate alpha-Proteobacteria.Onthe basis of characteristic morphological features, three submorphotypes of morphotype B can be assignedto three alpha-Proteobacteriagenera: Hyphomicrobium, Pedomicrobium, and Caulobacter. This ascription issupported by the well known Mn-oxidizing behavior of bothPedomicrobiumandCaulobacter, and by thecommon presence ofHyphomicrobiumin ferromanganese deposits elsewhere.The excellent microbial preservation is partly related to the origin of the ferromanganese oxides, i.e. extracel-lular precipitation induced by microbial metabolism. Other factors contributing to the good microbial preser-vation are the relatively low degree of diagenetic alteration, and the relatively high accretion rates ofstromatolites compared to other ferromanganese deposits. The generally low degree of diagenesis is likelybecause the stromatolites have remained relatively stable and at a rather low temperature since they wereformed at least 1 Ma ago. Still, some stromatolites have suffered diagenetic alteration (partial dissolutionand replacement by calcium carbonates and Fe-rich oxides), obscuring or even obliterating their bioforms.The El Soplao case represents an example of how easily biogenic Mn oxides can be altered, and their bioformsblurred, in a relatively short geological time span in spite of being in a relatively stable, alkaline, and low-temperature setting. A geological implication is that the absence of bioforms in other ferromanganese deposits,including rock varnish and Precambrian iron formations, does not disprove their possible biogenic origin, sincethe high chemical reactivity of biogenic manganese oxides makes them highly vulnerable to diagenesis
publishDate 2012
dc.date.none.fl_str_mv 2012
2022
2022
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/276845
https://doi.org/10.1016/j.sedgeo.2012.02.003
url http://hdl.handle.net/10261/276845
https://doi.org/10.1016/j.sedgeo.2012.02.003
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv #PLACEHOLDER_PARENT_METADATA_VALUE#
ICT-Soplao-53.5.00.12.00
https://reader.elsevier.com/reader/sd/pii/S0037073812000395?token=86715143E70A7713994063DA2D5A9E9E065CEA0920595D351F4048A441E5EE935557AB6153890A9D1F99B0603C4AD9D3
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
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