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Miner KR, Hollis JR, Miller CE, Uckert K, Douglas TA, Cardarelli E, Mackelprang R. Earth to Mars: A Protocol for Characterizing Permafrost in the Context of Climate Change as an Analog for Extraplanetary Exploration. ASTROBIOLOGY 2023; 23:1006-1018. [PMID: 37566539 PMCID: PMC10510695 DOI: 10.1089/ast.2022.0155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 07/02/2023] [Indexed: 08/13/2023]
Abstract
Abstract Permafrost is important from an exobiology and climate change perspective. It serves as an analog for extraplanetary exploration, and it threatens to emit globally significant amounts of greenhouse gases as it thaws due to climate change. Viable microbes survive in Earth's permafrost, slowly metabolizing and transforming organic matter through geologic time. Ancient permafrost microbial communities represent a crucial resource for gaining novel insights into survival strategies adopted by extremotolerant organisms in extraplanetary analogs. We present a proof-of-concept study on ∼22 Kya permafrost to determine the potential for coupling Raman and fluorescence biosignature detection technology from the NASA Mars Perseverance rover with microbial community characterization in frozen soils, which could be expanded to other Earth and off-Earth locations. Besides the well-known utility for biosignature detection and identification, our results indicate that spectral mapping of permafrost could be used to rapidly characterize organic carbon characteristics. Coupled with microbial community analyses, this method has the potential to enhance our understanding of carbon degradation and emissions in thawing permafrost. Further, spectroscopy can be accomplished in situ to mitigate sample transport challenges and in assessing and prioritizing frozen soils for further investigation. This method has broad-range applicability to understanding microbial communities and their associations with biosignatures and soil carbon and mineralogic characteristics relevant to climate science and astrobiology.
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Affiliation(s)
- Kimberley R. Miner
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - Charles E. Miller
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Kyle Uckert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - Emily Cardarelli
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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2
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Bassez MP. The Possible Role of Anoxic Alkaline High Subcritical Water in the Formation of Ferric Minerals, Methane and Disordered Graphitic Carbon in a BARB3 Drilled Sample of the 3.4 Ga Buck Reef Chert. ORIGINS LIFE EVOL B 2023; 53:1-41. [PMID: 37584846 DOI: 10.1007/s11084-023-09638-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/18/2023] [Indexed: 08/17/2023]
Abstract
The present article reports Raman spectroscopic observations of siderite, hematite, disordered graphitic carbon and possibly greenalite inside the quartz matrix of a banded iron sample from the BARB3 core drilled inside the 3.4 Ga Buck Reef Chert of the Barberton Greenstone Belt in South Africa. The article also reports Raman spectroscopic observations of quartz cavities, concluding in the presence of water, methane and sodium hydroxide at high concentration leading to pH ~ 15 inside the inclusion, suggesting an Archean water which was strongly basic. FeIII-greenalite may also be present inside the inclusion. The possible role of anoxic alkaline high subcritical water in the formation of ferric minerals and the CO required for the synthesis of molecules of biological interest has been demonstrated theoretically since 2013 and summarized in the concept of Geobiotropy. The present article experimentally confirms the importance of considering water in its anoxic strongly alkaline high subcritical domain for the formation of quartz, hematite, FeIII-greenalite, methane and disordered graphitic carbon. Methane is proposed to form locally when the carbon dioxide that is dissolved in the Archean anoxic alkaline high subcritical water, interacts with the molecular hydrogen that is emitted during the anoxic alkaline oxidation of ferrous silicates. The carbon matter is proposed to form as deposition from the anoxic methane-rich fluid. A detailed study of carbon matter from diverse origins is presented in a supplementary file. The study shows that the BARB3_23B sample has been submitted to ~ 335 °C, a temperature of the high subcritical domain, and that the graphitic structure contains very low amounts of oxygen and no hydroxyl functional groups. The importance of considering the structure of water is applied to the constructions of the Neoproterozoic and Archean banded iron formations. It is proposed that their minerals are produced inside chemical reaction chambers containing ferrous silicates, and ejected from the Earth's oceanic crust or upper mantle, during processes involving subduction events or not.
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Affiliation(s)
- Marie-Paule Bassez
- University of Strasbourg, Jean-Marie Lehn Foundation, Strasbourg, France.
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3
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Andreani M, Montagnac G, Fellah C, Hao J, Vandier F, Daniel I, Pisapia C, Galipaud J, Lilley MD, Früh Green GL, Borensztajn S, Ménez B. The rocky road to organics needs drying. Nat Commun 2023; 14:347. [PMID: 36681679 PMCID: PMC9867705 DOI: 10.1038/s41467-023-36038-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/13/2023] [Indexed: 01/22/2023] Open
Abstract
How simple abiotic organic compounds evolve toward more complex molecules of potentially prebiotic importance remains a missing key to establish where life possibly emerged. The limited variety of abiotic organics, their low concentrations and the possible pathways identified so far in hydrothermal fluids have long hampered a unifying theory of a hydrothermal origin for the emergence of life on Earth. Here we present an alternative road to abiotic organic synthesis and diversification in hydrothermal environments, which involves magmatic degassing and water-consuming mineral reactions occurring in mineral microcavities. This combination gathers key gases (N2, H2, CH4, CH3SH) and various polyaromatic materials associated with nanodiamonds and mineral products of olivine hydration (serpentinization). This endogenous assemblage results from re-speciation and drying of cooling C-O-S-H-N fluids entrapped below 600 °C-2 kbars in rocks forming the present-day oceanic lithosphere. Serpentinization dries out the system toward macromolecular carbon condensation, while olivine pods keep ingredients trapped until they are remobilized for further reactions at shallower levels. Results greatly extend our understanding of the forms of abiotic organic carbon available in hydrothermal environments and open new pathways for organic synthesis encompassing the role of minerals and drying. Such processes are expected in other planetary bodies wherever olivine-rich magmatic systems get cooled down and hydrated.
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Affiliation(s)
- Muriel Andreani
- Université de Lyon, Univ Lyon 1, CNRS UMR5276, ENS de Lyon, LGL-TPE, Villeurbanne Cedex, France.
- Institut Universitaire de France, Paris, France.
| | - Gilles Montagnac
- Université de Lyon, Univ Lyon 1, CNRS UMR5276, ENS de Lyon, LGL-TPE, Villeurbanne Cedex, France
| | - Clémentine Fellah
- Université de Lyon, Univ Lyon 1, CNRS UMR5276, ENS de Lyon, LGL-TPE, Villeurbanne Cedex, France
| | - Jihua Hao
- Deep Space Exploration Laboratory/CAS Key Laboratory of Crust-Mantle Materials and Environments, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei, Anhui, China
- Blue Marble Space Institute of Science, Seattle, WA, USA
| | - Flore Vandier
- Université de Lyon, Univ Lyon 1, CNRS UMR5276, ENS de Lyon, LGL-TPE, Villeurbanne Cedex, France
| | - Isabelle Daniel
- Université de Lyon, Univ Lyon 1, CNRS UMR5276, ENS de Lyon, LGL-TPE, Villeurbanne Cedex, France
| | - Céline Pisapia
- Université Paris Cité, Institut de physique du globe de Paris, CNRS UMR 7154, Paris, France
| | - Jules Galipaud
- Université de Lyon, Ecole Centrale de Lyon, LTDS, CNRS UMR 5513, 36, Ecully, France
- Université de Lyon INSA-Lyon, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Marvin D Lilley
- School of Oceanography, University of Washington, Seattle, WA, USA
| | | | - Stéphane Borensztajn
- Université Paris Cité, Institut de physique du globe de Paris, CNRS UMR 7154, Paris, France
| | - Bénédicte Ménez
- Université Paris Cité, Institut de physique du globe de Paris, CNRS UMR 7154, Paris, France
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4
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Razzell Hollis J, Sharma S, Abbey W, Bhartia R, Beegle L, Fries M, Hein JD, Monacelli B, Nordman AD. A Deep Ultraviolet Raman and Fluorescence Spectral Library of 51 Organic Compounds for the SHERLOC Instrument Onboard Mars 2020. ASTROBIOLOGY 2023; 23:1-23. [PMID: 36367974 PMCID: PMC9810352 DOI: 10.1089/ast.2022.0023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/01/2022] [Indexed: 06/16/2023]
Abstract
We report deep ultraviolet (DUV) Raman and Fluorescence spectra obtained on a SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) analog instrument for 51 pure organic compounds, including 5 carboxylic acids, 10 polycyclic aromatic hydrocarbons, 24 amino acids, 6 nucleobases, and 6 different grades of macromolecular carbon from humic acid to graphite. Organic mixtures were not investigated. We discuss how the DUV fluorescence and Raman spectra exhibited by different organic compounds allow for detection, classification, and identification of organics by SHERLOC. We find that 1- and 2-ring aromatic compounds produce detectable fluorescence within SHERLOC's spectral range (250-355 nm), but fluorescence spectra are not unique enough to enable easy identification of particular compounds. However, both aromatic and aliphatic compounds can be identified by their Raman spectra, with the number of Raman peaks and their positions being highly specific to chemical structure, within SHERLOC's reported spectral uncertainty of ±5 cm-1. For compounds that are not in the Library, classification is possible by comparing the general number and position of dominant Raman peaks with trends for different kinds of organic compounds.
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Affiliation(s)
- Joseph Razzell Hollis
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Department of Life Sciences, The Natural History Museum, London, United Kingdom
| | - Sunanda Sharma
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - William Abbey
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - Luther Beegle
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Marc Fries
- NASA Johnson Space Center, Houston, Texas, USA
| | - Jeffrey D. Hein
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Brian Monacelli
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Austin D. Nordman
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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5
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Anderson LA. Biomolecular histology as a novel proxy for ancient DNA and protein sequence preservation. Ecol Evol 2022; 12:e9518. [PMID: 36518622 PMCID: PMC9743065 DOI: 10.1002/ece3.9518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/03/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022] Open
Abstract
Researchers' ability to accurately screen fossil and subfossil specimens for preservation of DNA and protein sequences remains limited. Thermal exposure and geologic age are usable proxies for sequence preservation on a broad scale but are of nominal use for specimens of similar depositional environments. Cell and tissue biomolecular histology is thus proposed as a novel proxy for determining sequence preservation potential of ancient specimens with improved accuracy. Biomolecular histology as a proxy is hypothesized to elucidate why fossils/subfossils of some depositional environments preserve sequences while others do not and to facilitate selection of ancient specimens for use in molecular studies.
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Affiliation(s)
- Landon A Anderson
- Department of Biology North Carolina State University Raleigh North Carolina USA
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6
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Osterhout JT, Schopf JW, Kudryavtsev AB, Czaja AD, Williford KH. Deep-UV Raman Spectroscopy of Carbonaceous Precambrian Microfossils: Insights into the Search for Past Life on Mars. ASTROBIOLOGY 2022; 22:1239-1254. [PMID: 36194869 DOI: 10.1089/ast.2021.0135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The current strategy for detecting evidence of ancient life on Mars-a primary goal of NASA's ongoing Mars 2020 mission-is based largely on knowledge of Precambrian life and of its preservation in Earth's early rock record. The fossil record of primitive microorganisms consists mainly of stromatolites and other microbially influenced sedimentary structures, which occasionally preserve microfossils or other geochemical traces of life. Raman spectroscopy is an invaluable tool for identifying such signs of life and is routinely performed on Precambrian microfossils to help establish their organic composition, degree of thermal maturity, and biogenicity. The Mars 2020 rover, Perseverance, is equipped with a deep-ultraviolet (UV) Raman spectrometer as part of the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) instrument, which will be used in part to characterize the preservation of organic matter in the ancient sedimentary rocks of Jezero crater and therein search for possible biosignatures. To determine the deep-UV Raman spectra characteristic of ancient microbial fossils, this study analyzes individual microfossils from 14 Precambrian cherts using deep-UV (244 nm) Raman spectroscopy. Spectra obtained were measured and calibrated relative to a graphitic standard and categorized according to the morphology and depositional environment of the fossil analyzed and its Raman-indicated thermal maturity. All acquired spectra of the fossil kerogens include a considerably Raman-enhanced and prominent first-order Raman G-band (∼1600 cm-1), whereas its commonly associated D-band (∼1350 cm-1) is restricted to specimens of lower thermal maturity (below greenschist facies) that thus have the less altered biosignature indicative of relatively well-preserved organic matter. If comparably preserved, similar characteristics would be expected to be exhibited by microfossils or ancient organic matter in rock samples collected and cached on Mars in preparation for future sample return to Earth.
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Affiliation(s)
- Jeffrey T Osterhout
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - J William Schopf
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - Anatoliy B Kudryavtsev
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - Andrew D Czaja
- Department of Geology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kenneth H Williford
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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7
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Hickman-Lewis K, Moore KR, Hollis JJR, Tuite ML, Beegle LW, Bhartia R, Grotzinger JP, Brown AJ, Shkolyar S, Cavalazzi B, Smith CL. In Situ Identification of Paleoarchean Biosignatures Using Colocated Perseverance Rover Analyses: Perspectives for In Situ Mars Science and Sample Return. ASTROBIOLOGY 2022; 22:1143-1163. [PMID: 35862422 PMCID: PMC9508457 DOI: 10.1089/ast.2022.0018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
The NASA Mars 2020 Perseverance rover is currently exploring Jezero crater, a Noachian-Hesperian locality that once hosted a delta-lake system with high habitability and biosignature preservation potential. Perseverance conducts detailed appraisals of rock targets using a synergistic payload capable of geological characterization from kilometer to micron scales. The highest-resolution textural and chemical information will be provided by correlated WATSON (imaging), SHERLOC (deep-UV Raman and fluorescence spectroscopy), and PIXL (X-ray lithochemistry) analyses, enabling the distributions of organic and mineral phases within rock targets to be comprehensively established. Herein, we analyze Paleoarchean microbial mats from the ∼3.42 Ga Buck Reef Chert (Barberton greenstone belt, South Africa)-considered astrobiological analogues for a putative ancient martian biosphere-following a WATSON-SHERLOC-PIXL protocol identical to that conducted by Perseverance on Mars during all sampling activities. Correlating deep-UV Raman and fluorescence spectroscopic mapping with X-ray elemental mapping, we show that the Perseverance payload has the capability to detect thermally and texturally mature organic materials of biogenic origin and can highlight organic-mineral interrelationships and elemental colocation at fine spatial scales. We also show that the Perseverance protocol obtains very similar results to high-performance laboratory imaging, Raman spectroscopy, and μXRF instruments. This is encouraging for the prospect of detecting microscale organic-bearing textural biosignatures on Mars using the correlative micro-analytical approach enabled by WATSON, SHERLOC, and PIXL; indeed, laminated, organic-bearing samples such as those studied herein are considered plausible analogues of biosignatures from a potential Noachian-Hesperian biosphere. Were similar materials discovered at Jezero crater, they would offer opportunities to reconstruct aspects of the early martian carbon cycle and search for potential fossilized traces of life in ancient paleoenvironments. Such samples should be prioritized for caching and eventual return to Earth.
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Affiliation(s)
- Keyron Hickman-Lewis
- Department of Earth Sciences, The Natural History Museum, London, United Kingdom
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, Bologna, Italy
| | - Kelsey R. Moore
- NASA Jet Propulsion Laboratory, Pasadena, California, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | | | | | | | | | - John P. Grotzinger
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | | | - Svetlana Shkolyar
- Department of Astronomy, University of Maryland, College Park, Maryland, USA
- Planetary Geology, Geophysics and Geochemistry Lab, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Barbara Cavalazzi
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, Bologna, Italy
- Department of Geology, University of Johannesburg, Johannesburg, South Africa
| | - Caroline L. Smith
- Department of Earth Sciences, The Natural History Museum, London, United Kingdom
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, United Kingdom
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8
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Assessing the carbonisation temperatures recorded by ancient charcoals for δ 13C-based palaeoclimate reconstruction. Sci Rep 2022; 12:14662. [PMID: 36038621 PMCID: PMC9424292 DOI: 10.1038/s41598-022-17836-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 08/01/2022] [Indexed: 11/28/2022] Open
Abstract
Ancient charcoal fragments, produced by the use of wood as fuel in archaeological contexts or during natural or anthropic forest fires, persist in soil and sediments over centuries to millennia. They thus offer a unique window to reconstruct past climate, especially palaeo-precipitation regimes thanks to their stable carbon isotope composition. However, the initial δ13C of wood is slightly modified as a function of the carbonisation temperature. Carbonisation-induced 13C fractionation is classically investigated through a transfer function between experimental carbonisation temperatures and the carbon content. This approach assumes that the carbon content is conservative through time in ancient charcoals and neglects the potential impact of post-depositional oxidation occurring in soils and sediments. In the present study, we first show that post-depositional oxidation can lead to a large underestimation of past carbonisation temperatures, thereby minimising the estimation of carbonisation-induced 13C fractionations and possibly biasing δ13C-based climate reconstructions. Secondly, by combining carbon content, Fourier-transform infrared and Raman spectroscopy, we propose a new framework to assess the carbonisation temperatures registered in ancient charcoals. This new framework paves the way to reassessing δ13C-based climate reconstruction.
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9
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Baravkar MD, Prasad BLV. Selective electro-oxidation of phenol to 1,4-hydroquinone employing carbonaceous electrodes: surface modification is the key. NEW J CHEM 2022. [DOI: 10.1039/d1nj04640c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The oxidation of phenol to 1,4-hydroquinone with high conversion, remarkable selectivity and an excellent yield (87% isolated) has been accomplished under electrolytic conditions in an aqueous medium with surface modified carbon-based electrodes.
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Affiliation(s)
- Mayur D. Baravkar
- Physical and Materials Chemistry Division, National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovation Research (AcSIR), Ghaziabad 201002, India
| | - Bhagavatula L. V. Prasad
- Physical and Materials Chemistry Division, National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovation Research (AcSIR), Ghaziabad 201002, India
- Center for Nano and Soft Matter Sciences, Bangalore 562162, India
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10
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Nabhan S, Kah LC, Mishra B, Pollok K, Manning-Berg AR, van Zuilen MA. Structural and chemical heterogeneity of Proterozoic organic microfossils of the ca. 1 Ga old Angmaat Formation, Baffin Island, Canada. GEOBIOLOGY 2021; 19:557-584. [PMID: 34296512 DOI: 10.1111/gbi.12463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 10/11/2020] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
Organic microfossils in Meso- and Neoproterozoic rocks are of key importance to track the emergence and evolution of eukaryotic life. An increasing number of studies combine Raman spectroscopy with synchrotron-based methods to characterize these microfossils. A recurring observation is that Raman spectra of organic microfossils show negligible variation on a sample scale and that variation between different samples can be explained by differences in thermal maturation or in the biologic origin of organic precursor material. There is a paucity of work, however, that explores the extent to which the petrographic framework and diagenetic processes might influence the chemical structure of organic materials. We present a detailed Raman spectroscopy-based study of a complex organic microfossil assemblage in the ca. 1 Ga old Angmaat Formation, Baffin Island, Canada. This formation contains abundant early diagenetic chert that preserves silicified microbial mats with numerous, readily identifiable organic microfossils. Individual chert beds show petrographic differences with discrete episodes of cementation and recrystallization. Raman spectroscopy reveals measurable variation of organic maturity between samples and between neighboring organic microfossils of the same taxonomy and taphonomic state. Scanning transmission X-ray microscopy performed on taphonomically similar coccoidal microfossils from the same thin section shows distinct chemical compositions, with varying ratios of aromatic compounds to ketones and phenols. Such observations imply that geochemical variation of organic matter is not necessarily coupled to thermal alteration or organic precursor material. Variation of the Raman signal across single samples is most likely linked to the diagenetic state of analyzed materials and implies an association between organic preservation and access to diagenetic fluids. Variation in the maturity of individual microfossils may be a natural outcome of local diagenetic processes and potentially exceeds differences derived from precursor organic material. These observations stress the importance of detailed in situ characterization by Raman spectroscopy to identify target specimens for further chemical analysis.
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Affiliation(s)
- Sami Nabhan
- Université de Paris, Institut de Physique du Globe de Paris, CNRS, F-75005 Paris, France
| | - Linda C Kah
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - Bhoopesh Mishra
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
| | - Kilian Pollok
- Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany
| | - Ashley R Manning-Berg
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Mark A van Zuilen
- Université de Paris, Institut de Physique du Globe de Paris, CNRS, F-75005 Paris, France
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11
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Rouillard J, García-Ruiz JM, Kah L, Gérard E, Barrier L, Nabhan S, Gong J, van Zuilen MA. Identifying microbial life in rocks: Insights from population morphometry. GEOBIOLOGY 2020; 18:282-305. [PMID: 31876987 DOI: 10.1111/gbi.12377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 11/13/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
The identification of cellular life in the rock record is problematic, since microbial life forms, and particularly bacteria, lack sufficient morphologic complexity to be effectively distinguished from certain abiogenic features in rocks. Examples include organic pore-fillings, hydrocarbon-containing fluid inclusions, organic coatings on exfoliated crystals and biomimetic mineral aggregates (biomorphs). This has led to the interpretation and re-interpretation of individual microstructures in the rock record. The morphologic description of entire populations of microstructures, however, may provide support for distinguishing between preserved micro-organisms and abiogenic objects. Here, we present a statistical approach based on quantitative morphological description of populations of microstructures. Images of modern microbial populations were compared to images of two relevant types of abiogenic microstructures: interstitial spaces and silica-carbonate biomorphs. For the populations of these three systems, the size, circularity, and solidity of individual particles were calculated. Subsequently, the mean/SD, skewness, and kurtosis of the statistical distributions of these parameters were established. This allowed the qualitative and quantitative comparison of distributions in these three systems. In addition, the fractal dimension and lacunarity of the populations were determined. In total, 11 parameters, independent of absolute size or shape, were used to characterize each population of microstructures. Using discriminant analysis with parameter subsets, it was found that size and shape distributions are typically sufficient to discriminate populations of biologic and abiogenic microstructures. Analysis of ancient, yet unambiguously biologic, samples (1.0 Ga Angmaat Formation, Baffin Island, Canada) suggests that taphonomic effects can alter morphometric characteristics and complicate image analysis; therefore, a wider range of microfossil assemblages should be studied in the future before automated analyses can be developed. In general, however, it is clear from our results that there is great potential for morphometric descriptions of populations in the context of life recognition in rocks, either on Earth or on extraterrestrial bodies.
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Affiliation(s)
- Joti Rouillard
- Equipe Géomicrobiologie, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Juan Manuel García-Ruiz
- Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investígacìones Cientificas-Universidad de Granada, Granada, Spain
| | - Linda Kah
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - Emmanuelle Gérard
- Equipe Géomicrobiologie, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Laurie Barrier
- Equipe Tectonique et Mécanique de la Lithosphère, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Sami Nabhan
- Equipe Géomicrobiologie, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Jian Gong
- Equipe Géomicrobiologie, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - Mark A van Zuilen
- Equipe Géomicrobiologie, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
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12
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Alleon J, Summons RE. Organic geochemical approaches to understanding early life. Free Radic Biol Med 2019; 140:103-112. [PMID: 30858060 DOI: 10.1016/j.freeradbiomed.2019.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/02/2019] [Accepted: 03/05/2019] [Indexed: 11/25/2022]
Abstract
Here we discuss the early geological record of preserved organic carbon and the criteria that must be applied to distinguish biological from non-biological origins. Sedimentary graphite, irrespective of its isotopic composition, does not constitute a reliable biosignature because the rocks in which it is found are generally metamorphosed to the point where convincing signs of life have been erased. Rather, multiple lines of evidence, including sedimentary textures, microfossils, large accumulations of organic matter and isotopic data for co-existing carbon, nitrogen and sulfur are required before biological origin can be convincingly demonstrated.
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Affiliation(s)
- Julien Alleon
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Roger E Summons
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Bekaert DV, Broadley MW, Delarue F, Avice G, Robert F, Marty B. Archean kerogen as a new tracer of atmospheric evolution: Implications for dating the widespread nature of early life. SCIENCE ADVANCES 2018; 4:eaar2091. [PMID: 29507886 PMCID: PMC5834008 DOI: 10.1126/sciadv.aar2091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/30/2018] [Indexed: 06/08/2023]
Abstract
Understanding the composition of the Archean atmosphere is vital for unraveling the origin of volatiles and the environmental conditions that led to the development of life. The isotopic composition of xenon in the Archean atmosphere has evolved through time by mass-dependent fractionation from a precursor comprising cometary and solar/chondritic contributions (referred to as U-Xe). Evaluating the composition of the Archean atmosphere is challenging because limited amounts of atmospheric gas are trapped within minerals during their formation. We show that organic matter, known to be efficient at preserving large quantities of noble gases, can be used as a new archive of atmospheric noble gases. Xe isotopes in a kerogen isolated from the 3.0-billion-year-old Farrel Quartzite (Pilbara Craton, Western Australia) are mass fractionated by 9.8 ± 2.1 per mil (‰) (2σ) per atomic mass unit, in line with a progressive evolution toward modern atmospheric values. Archean atmospheric Xe signatures in kerogens open a new avenue for following the evolution of atmospheric composition through time. The degree of mass fractionation of Xe isotopes relative to the modern atmosphere can provide a time stamp for dating Archean kerogens and therefore narrowing the time window for the diversification of early life during the Archean eon.
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Affiliation(s)
- David V. Bekaert
- Centre de Recherches Pétrographiques et Géochimiques, CNRS, Université de Lorraine, UMR 7358, 15 rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre-lès-Nancy, France
| | - Michael W. Broadley
- Centre de Recherches Pétrographiques et Géochimiques, CNRS, Université de Lorraine, UMR 7358, 15 rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre-lès-Nancy, France
| | - Frédéric Delarue
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités—Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie, Université Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - Guillaume Avice
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Francois Robert
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités—Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie, Université Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - Bernard Marty
- Centre de Recherches Pétrographiques et Géochimiques, CNRS, Université de Lorraine, UMR 7358, 15 rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre-lès-Nancy, France
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Delarue F, Robert F, Sugitani K, Tartèse R, Duhamel R, Derenne S. Investigation of the Geochemical Preservation of ca. 3.0 Ga Permineralized and Encapsulated Microfossils by Nanoscale Secondary Ion Mass Spectrometry. ASTROBIOLOGY 2017; 17:1192-1202. [PMID: 29058452 PMCID: PMC5729882 DOI: 10.1089/ast.2016.1531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 04/14/2017] [Indexed: 05/31/2023]
Abstract
Observations of Archean organic-walled microfossils suggest that their fossilization took place through both encapsulation and permineralization. In this study, we investigated microfossils from the ca. 3.0 Ga Farrel Quartzite (Pilbara, Western Australia) using transmitted light microscopy, scanning electron microscopy, Raman microspectrometry, and nanoscale secondary ion mass spectrometry (NanoSIMS) ion microprobe analyses. In contrast to previous studies, we demonstrated that permineralized microfossils were not characterized by the micrometric spatial relationships between Si and C-N as observed in thin sections. Permineralized microfossils are composed of carbonaceous globules that did not survive the acid treatment, whereas encapsulated microfossils were characterized due to their resistance to the acid maceration procedure. We also investigated the microscale relationship between the 12C14N- and 12C2- ion emission as a proxy of the N/C atomic ratio in both permineralized and encapsulated microfossils. After considering any potential matrix and microtopography effects, we demonstrate that the encapsulated microfossils exhibit the highest level of geochemical preservation. This finding shows that the chemical heterogeneity of the microfossils, observed at a spatial resolution of a few hundreds of micrometers, can be related to fossilization processes. Key Words: Carbonaceous matter-Farrel Quartzite-Fossilization-NanoSIMS-Nitrogen-Permineralization. Astrobiology 17, 1192-1202.
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Affiliation(s)
- Frédéric Delarue
- IMPMC Sorbonne Universités–MNHN, UPMC Univ Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - François Robert
- IMPMC Sorbonne Universités–MNHN, UPMC Univ Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - Kenichiro Sugitani
- Department of Environmental Engineering and Architecture, Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Romain Tartèse
- IMPMC Sorbonne Universités–MNHN, UPMC Univ Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - Rémi Duhamel
- IMPMC Sorbonne Universités–MNHN, UPMC Univ Paris 06, UMR CNRS 7590, IRD UMR 206, Paris, France
| | - Sylvie Derenne
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7619 METIS, Paris, France
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