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Maldanis L, Hickman-Lewis K, Verezhak M, Gueriau P, Guizar-Sicairos M, Jaqueto P, Trindade RIF, Rossi AL, Berenguer F, Westall F, Bertrand L, Galante D. Nanoscale 3D quantitative imaging of 1.88 Ga Gunflint microfossils reveals novel insights into taphonomic and biogenic characters. Sci Rep 2020; 10:8163. [PMID: 32424216 PMCID: PMC7235231 DOI: 10.1038/s41598-020-65176-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 04/29/2020] [Indexed: 11/17/2022] Open
Abstract
Precambrian cellular remains frequently have simple morphologies, micrometric dimensions and are poorly preserved, imposing severe analytical and interpretational challenges, especially for irrefutable attestations of biogenicity. The 1.88 Ga Gunflint biota is a Precambrian microfossil assemblage with different types and qualities of preservation across its numerous geological localities and provides important insights into the Proterozoic biosphere and taphonomic processes. Here we use synchrotron-based ptychographic X-ray computed tomography to investigate well-preserved carbonaceous microfossils from the Schreiber Beach locality as well as poorly-preserved, iron-replaced fossil filaments from the Mink Mountain locality, Gunflint Formation. 3D nanoscale imaging with contrast based on electron density allowed us to assess the morphology and carbonaceous composition of different specimens and identify the minerals associated with their preservation based on retrieved mass densities. In the Mink Mountain filaments, the identification of mature kerogen and maghemite rather than the ubiquitously described hematite indicates an influence from biogenic organics on the local maturation of iron oxides through diagenesis. This non-destructive 3D approach to microfossil composition at the nanoscale within their geological context represents a powerful approach to assess the taphonomy and biogenicity of challenging or poorly preserved traces of early microbial life, and may be applied effectively to extraterrestrial samples returned from upcoming space missions.
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Affiliation(s)
- L Maldanis
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Av. Giuseppe Maximo Scolfaro, 10000, 13083-100, Campinas, Brazil. .,Institute of Physics of São Carlos, University of São Paulo, Av. Trabalhador são-carlense, 400, 13566-590, São Carlos, Brazil. .,ISterre, UGA, CNRS, Observatoire des Sciences de l'Univers, CS 40700, 38058, Grenoble, France.
| | - K Hickman-Lewis
- Centre de Biophysique Moléculaire, CNRS, Rue Charles Sadron, 45071, Orléans, France.,Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA), Università di Bologna, via Zamboni 67, I-40126, Bologna, Italy
| | - M Verezhak
- Paul Scherrer Institut, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - P Gueriau
- Université Paris-Saclay, CNRS, ministère de la culture, UVSQ, IPANEMA, 91192, Saint-Aubin, France.,Institute of Earth Sciences (ISTE), University of Lausanne, Lausanne, Switzerland
| | - M Guizar-Sicairos
- Paul Scherrer Institut, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - P Jaqueto
- Department of Geophysics, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, Rua do Matão, 1226, 05508-090, São Paulo, Brazil
| | - R I F Trindade
- Department of Geophysics, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, Rua do Matão, 1226, 05508-090, São Paulo, Brazil
| | - A L Rossi
- Brazilian Center for Research in Physics (CBPF), R. Dr. Xavier Sigaud, 150, 22290-180, Rio de Janeiro, Brazil
| | - F Berenguer
- Synchrotron Soleil, Saint-Aubin, L'Orme des Merisiers, BP 48 Saint-Aubin, 91192, Gif-sur-Yvette, France
| | - F Westall
- Centre de Biophysique Moléculaire, CNRS, Rue Charles Sadron, 45071, Orléans, France
| | - L Bertrand
- Université Paris-Saclay, CNRS, ministère de la culture, UVSQ, IPANEMA, 91192, Saint-Aubin, France.,Université Paris-Saclay, 91190, Saint-Aubin, France
| | - D Galante
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Av. Giuseppe Maximo Scolfaro, 10000, 13083-100, Campinas, Brazil
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