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2. Report of the iMOST Study

Author

Zorzano, M.P, Zipfel, J, Wheeler, R.M, Westall, F, Werner, S.C, Weiss, B.P, Wadhwa, M, Van Kranendonk, M.J, Usui, T, Tosca, N.J, Kate, I.L, Swindle, T.D, Steele, A, Spry, J.A, Smith, C.L, Siljeström, S, Shuster, D.L, Sharp, Z.D, Shaheen, R, Sephton, M.A, Schwenzer, S.P, Schmitz, N, Rucker, M.A, Rettberg, P, Raulin, F, Ori, G.G, Niles, P.B, Mustard, J.F, Moynier, F, Moser, D.E, McLennan, S.M, McCubbin, F.M, McCoy, J.T, Mayhew, L.E, Mangold, N, Mackelprang, R, Kleinhenz, J, Kleine, T, Humayun, M, Horgan, B, Herd, C.D.K, Hausrath, E.M, Harrington, A.D, Hallis, L.J, Goreva, Y.S, Glavin, D.P, Fogarty, J, Filiberto, J, Fernandez-Remolar, D.C, Farmer, J.D, Ehlmann, B.L, Dixon, M, Des Marais, D.J, Debaille, V, Czaja, A.D, Campbell, K.A, Busemann, H, Brucato, J.R, Boucher, D, Borg, L.E, Bishop, J.L, Benning, L.G, Anand, M, Ammannito, E, Amelin, Y, Altieri, F, Carrier, B. L, Sefton-Nash, E, McSween, H. Y, Grady, M. M, and Beaty, D. W

Abstract

UNKNOWN

Published
2018

3. Report of the iMOST Study

Author

Beaty, D. W, Grady, M. M, McSween, H. Y, Sefton-Nash, E, Carrier, B. L, Altieri, F, Amelin, Y, Ammannito, E, Anand, M, Benning, L.G, Bishop, J.L, Borg, L.E, Boucher, D, Brucato, J.R, Busemann, H, Campbell, K.A, Czaja, A.D, Debaille, V, Des Marais, D.J, Dixon, M, Ehlmann, B.L, Farmer, J.D, Fernandez-Remolar, D.C, Filiberto, J, Fogarty, J, Glavin, D.P, Goreva, Y.S, Hallis, L.J, Harrington, A.D, Hausrath, E.M, Herd, C.D.K, Horgan, B, Humayun, M, Kleine, T, Kleinhenz, J, Mackelprang, R, Mangold, N, Mayhew, L.E, McCoy, J.T, McCubbin, F.M, McLennan, S.M, Moser, D.E, Moynier, F, Mustard, J.F, Niles, P.B, Ori, G.G, Raulin, F, Rettberg, P, Rucker, M.A, Schmitz, N, Schwenzer, S.P, Sephton, M.A, Shaheen, R, Sharp, Z.D, Shuster, D.L, Siljeström, S, Smith, C.L, Spry, J.A, Steele, A, Swindle, T.D, Kate, I.L, Tosca, N.J, Usui, T, Van Kranendonk, M.J, Wadhwa, M, Weiss, B.P, Werner, S.C, Westall, F, Wheeler, R.M, Zipfel, J, and Zorzano, M.P

Published
2018

4. Report of the COSPAR mars special regions colloquium

Author

Kminek, G., Rummel, J.D., Cockell, C.S., Atlas, R., Barlow, N., Beaty, D., Boynton, W., Carr, M., Clifford, S., Conley, C.A., Davila, A.F., Debus, A., Doran, P., Hecht, M., Heldmann, J., Helbert, J., Hipkin, V., Horneck, G., Kieft, T.L., Klingelhoefer, G., Meyer, M., Newsom, H., Ori, G.G., Parnell, J., Prieur, D., Raulin, F., Schulze-Makuch, D., Spry, J.A., Stabekis, P.E., Stackebrandt, E., Vago, J., Viso, M., Voytek, M., Wells, L., and Westall, F.

Published
2010
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5. The sand seas of Titan: Cassini RADAR observations of longitudinal dunes

Author

Lorenz, R.D., Wall, S., Radebaugh, J., Boubin, G., Reffet, E., Janssen, M., Stofan, E., Lopes, R., Kirk, R., Elachi, C., Lunine, J., Mitchell, K., Paganelli, F., Soderblom, L., Wood, C., Wye, L., Zebker, H., Anderson, Y., Ostro, S., Allison, M., Boehmer, R., Callahan, P., Encrenaz, P., Ori, G.G., Francescetti, G., Gim, Y., Hamilton, G., Hensley, S., Johnson, W., Kelleher, K., Muhleman, D., Picardi, G., Posa, F., Roth, L., Seu, R., Shaffer, S., Stiles, B., Vetrella, S., Flamini, E., and West, R.

Subjects
Titan (Satellite) -- Observations, Titan (Satellite) -- Properties, Titan (Satellite) -- Research, Sand dunes -- Observations, Sand dunes -- Properties, Sand dunes -- Research
Published
2006

6. An inventory of potentially habitable environments on Mars: Geological and biological perspectives

Author

Dohm, J.M., primary, Miyamoto, H., additional, Ori, G.G., additional, Fairén, A.G., additional, Davila, A.F., additional, Komatsu, G., additional, Mahaney, W.C., additional, Williams, J.-P., additional, Joye, S.B., additional, Di Achille, G., additional, Oehler, D.Z., additional, Marzo, G.A., additional, Schulze-Makuch, D., additional, Acocella, V., additional, Glamoclija, M., additional, Pondrelli, M., additional, Boston, P., additional, Hart, K.M., additional, Anderson, R.C., additional, Baker, V.R., additional, Fink, W., additional, Kelleher, B.P., additional, Furfaro, R., additional, Gross, C., additional, Hare, T.M., additional, Frazer, A.R., additional, Ip, F., additional, Allen, C.C.R., additional, Kim, K.J., additional, Maruyama, S., additional, McGuire, P.C., additional, Netoff, D., additional, Parnell, J., additional, Wendt, L., additional, Wheelock, S.J., additional, Steele, A., additional, Hancock, R.G.V., additional, Havics, R.A., additional, Costa, P., additional, and Krinsley, D., additional

Published
2011
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7. Danakil Depression, Ethiopia - a unique field analog on Earth

Author

Cavalazzi, B., Barbieri, R., Hagos, M., Capaccioni, B., Gómez, F., Olsson-Francis, K., Hickman-Lewis, K., Agangi, A., Glamoclija, M., Rossi, A.P., Gasparotto, G., Rodriguez, N., Ori, G.G., School of Environment, Earth and Ecosystem Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), International Research School of Planetary Sciences [Pescara] (IRSPS), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), and Frapart, Isabelle

Subjects
[SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

10. The Dallol Geothermal Area, Northern Afar (Ethiopia)—An Exceptional Planetary Field Analog on Earth

Author

Cavalazzi, B., primary, Barbieri, R., additional, Gómez, F., additional, Capaccioni, B., additional, Olsson-Francis, K., additional, Pondrelli, M., additional, Rossi, A.P., additional, Hickman-Lewis, K., additional, Agangi, A., additional, Gasparotto, G., additional, Glamoclija, M., additional, Ori, G.G., additional, Rodriguez, N., additional, and Hagos, M., additional

Published
2019
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12. Planning for Mars returned sample science: final report of the MSR End-to-End International Science Analysis Group (E2E-iSAG)

Author

Hofmann, B.A., Symes, S., Barbieri, R., Ruff, S.W., Allen, C., Rossi, A.P., Allwood, A.C., Grady, M., McLennan, S.M., Raulin, F., Boston, P., Herd, C.D.K., Grant, J., Heber, V.S., Sephton, M.A., Beaty, D.W., Ori, G.G., Wilson, M.G., Mangold, N., Sherwood Lollar, B., Carr, M., King, P., McLennan S.M., Sephton M.A., Allen C., Allwood A.C., Barbieri R., Beaty D.W., Boston P., Carr M., Grady M., Grant J., Heber V.S., Herd C.D.K., Hofmann B., King P., Mangold N., Ori G.G., Rossi A.P., Raulin F., Ruff S.W., Sherwood Lollar B., Symes S., Wilson, and M.G.

Subjects
Research Report, Mars sample return, Engineering, Extraterrestrial Environment, business.industry, International Cooperation, Mars Exploration Program Analysis Group, Mars, Sample (statistics), Mars Exploration Program, Astrobiology, Agricultural and Biological Sciences (miscellaneous), Mars Sample Return, White paper, Planetary science, Aeronautics, End-to-end principle, Space and Planetary Science, Exobiology, Martian environments, business, Planetary Science Decadal Survey
Abstract

Returning samples from Mars to Earth for scientific analysis has been, and continues to be, among the highest priority objectives of planetary science. Partly for this reason, the 2011 Planetary Science Decadal Survey placed high priority on a proposed 2018 rover mission that would conduct careful in situ science and use that scientific information to select and cache samples that could be returned to Earth by a potential future mission. In order to ensure that the potential contributions of the 2018 rover to the proposed MSR Campaign are properly planned, this study was undertaken to consider the science of the MSR Campaign concept from end to end. This white paper is the principal output of the Mars Sample Return (MSR) End-to-End International Science Analysis Group (E2E-iSAG): a group chartered by MEPAG (Mars Exploration Program Analysis Group).

Published
2012

21. The Dallol Geothermal Area, Northern Afar (Ethiopia) — An Exceptional Planetary Field Analog on Earth

Author

Cavalazzi, B., Barbieri, R., Gómez, F., Capaccioni, B., Olsson-Francis, K., Pondrelli, M., Rossi, A.P., Hickman-Lewis, K., Agangi, A., Gasparotto, G., Glamoclija, M., Ori, G.G., Rodriguez, N., Hagos, M., Cavalazzi, B., Barbieri, R., Gómez, F., Capaccioni, B., Olsson-Francis, K., Pondrelli, M., Rossi, A.P., Hickman-Lewis, K., Agangi, A., Gasparotto, G., Glamoclija, M., Ori, G.G., Rodriguez, N., and Hagos, M.

Abstract

The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperatureDallol: 36–38°C) and most acidic natural system (pHDallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation. The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiologica

22. The Dallol Geothermal Area, Northern Afar (Ethiopia) — An Exceptional Planetary Field Analog on Earth

Author

Cavalazzi, B., Barbieri, R., Gómez, F., Capaccioni, B., Olsson-Francis, K., Pondrelli, M., Rossi, A.P., Hickman-Lewis, K., Agangi, A., Gasparotto, G., Glamoclija, M., Ori, G.G., Rodriguez, N., Hagos, M., Cavalazzi, B., Barbieri, R., Gómez, F., Capaccioni, B., Olsson-Francis, K., Pondrelli, M., Rossi, A.P., Hickman-Lewis, K., Agangi, A., Gasparotto, G., Glamoclija, M., Ori, G.G., Rodriguez, N., and Hagos, M.

Abstract

The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperatureDallol: 36–38°C) and most acidic natural system (pHDallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation. The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiologica

23. Venus radar for subsurface and ionosphere sounding (VENSIS)

Author

Biccari, D., primary, Gurnett, D., additional, Johnson, W., additional, Huff, R., additional, Marinangeli, L., additional, Jordan, R., additional, Nielsen, E., additional, Ori, G.G., additional, Picardi, G., additional, Plaut, J., additional, Provvedi, F., additional, Seu, R., additional, and Zampolini, E., additional

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25. Erratum: Author Correction: Ultra-small microorganisms in the polyextreme conditions of the Dallol volcano, Northern Afar, Ethiopia (Scientific reports (2019) 9 1 (7907))

Author

Gomez F., Cavalazzi B., Rodriguez N., Amils R., Ori G. G., Olsson-Francis K., Escudero C., Martinez J. M., Miruts H., Gomez F., Cavalazzi B., Rodriguez N., Amils R., Ori G.G., Olsson-Francis K., Escudero C., Martinez J.M., and Miruts H.

Subjects
Ultra-small microorganisms, Dallol volcano
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020

26. The Dallol Geothermal Area, Northern Afar (Ethiopia) — An Exceptional Planetary Field Analog on Earth

Author

Nuria Rodríguez, Giorgio Gasparotto, Miruts Hagos, Andrea Agangi, Gian Gabriele Ori, Felipe Gómez, Roberto Barbieri, Bruno Capaccioni, Angelo Pio Rossi, Barbara Cavalazzi, Mihaela Glamoclija, Monica Pondrelli, Keyron Hickman-Lewis, Karen Olsson-Francis, Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), School of Environment, Earth and Ecosystem Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Jacobs University [Bremen], Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Department of Geology [University of Johannesburg], Department of Geology, University of Johannesburg, International Research School of Planetary Sciences [Pescara] (IRSPS), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), UAM. Departamento de Química Orgánica, Cavalazzi B., Barbieri R., Gómez F., Capaccioni B., Olsson-Francis K., Pondrelli M., Rossi A.P., Hickman-Lewis K., Agangi A., Gasparotto G., Glamoclija M., Ori G.G., Rodriguez N, and Hagos M.

Subjects
Recrystallization (geology), 010504 meteorology & atmospheric sciences, Extraterrestrial Environment, Earth, Planet, Earth science, Climate, Mars, Terrestrial analogs, 01 natural sciences, Hydrothermal circulation, Hot Springs, Hydrothermal systems, 0103 physical sciences, Biosignature, Exobiology, Planetary science, Polyextremophiles, 010303 astronomy & astrophysics, Geothermal gradient, Review Articles, 0105 earth and related environmental sciences, geography, Minerals, geography.geographical_feature_category, Geography, Temperature, Mars Exploration Program, Química, Extreme environments, Satellite Communications, Astrobiology, Agricultural and Biological Sciences (miscellaneous), East Africa, Fumarole, Volcano, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Salts, Ethiopia, Gases, Extreme environments, Hydrothermal system, Terrestrial analogues, East Africa, Astrobiology, Planetary science, Acids, Geology
Abstract

The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperature Dallol : 36-38°C) and most acidic natural systems (pH Dallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation. The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiological and exploration programs, This is a contribution to the Europlanet 2020 Research Infrastructure programme funded under the European Commission's Horizon 2020 programme (No. 654208

Published
2019
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27. Iron-framboids in the hydrocarbon-related Middle Devonian Hollard Mound of the Anti-Atlas mountain range in Morocco: Evidence of potential microbial biosignatures

Author

Gian Gabriele Ori, Annette D. George, Angelo Pio Rossi, Kamal Taj-Eddine, Barbara Cavalazzi, Salvatore Gennaro, Roberto Barbieri, Sherry L. Cady, Roberto Canteri, A. Lui, Frances Westall, Cavalazzi B., Barbieri R., Cady S.L., George A.D., Gennaro S., Westall F., Lui A., Canteri R., Rossi A.P., Ori G.G., TajHeddine K., Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Lethbridge Research and Development Centre, Agriculture and Agri-Food [Ottawa] (AAFC), Laboratoire d'Etude des Mécanismes Cognitifs (EMC), Université Lumière - Lyon 2 (UL2), Fondazione Bruno Kessler [Trento, Italy] (FBK), Laboratoire d'Etudes et de Recherche en Informatique d'Angers (LERIA), Université d'Angers (UA), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and 'European Integrated Activity of Excellence and Networking for Nano and Micro-Electronics Analysis/ANNA_UC1_RP006/UC9_RP005 (to BC), the EuroPlanet facility TNA1-2010 (to BC and APR) and the MIUR-PRIN program 'Comparative geomicrobiology of the mounds in the Moroccan Sahara: implications for Mars astrobiology' (to RB). We acknowledge funding for SLC from NASA under award no. NNG04GJ84G and NSF under award no. GEO0808211

Subjects
010506 paleontology, Stratigraphy, Mineralogy, High resolution, Context (language use), engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Hydrocarbon seep, Devonian, Framboids, Secondary Ion Mass Spectroscopy, chemistry.chemical_compound, Sulfide and iron mineral, Sulfate, Sulfide and iron minerals, 0105 earth and related environmental sciences, chemistry.chemical_classification, Geology, Hydrocarbon, chemistry, [SDU]Sciences of the Universe [physics], Anaerobic oxidation of methane, Framboid, engineering, Biosignatures, Pyrite
Abstract

International audience; Iron-framboids in the context of a Middle Devonian, hydrocarbon-seep conical mound (Anti-Atlas, Morocco) have been thoroughly investigated through a combination of techniques, including optical and high resolution scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, Raman microscopy and time-of-flight secondary ion mass spectroscopy. Framboids occur embedded in laminated carbonates of the mound and are precipitated along the veins that crosscut it and served as the conduits for (channeled) reduced hydrocarbon-rich fluids. The morphology, structure, and composition of the framboids contribute to the reconstruction of the complex interplay between the advected fluids and the associated biological and/or abiological processes. A comparison of our dataset with that from modern framboids formed under similar conditions indicates that the Fe-rich framboids represent replaced primary pyrite framboids produced as a consequence of bacterial sulfate reduction and the anaerobic oxidation of methane.

Published
2012
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28. Chemosynthetic microbialites in the Devonian carbonate mounds of Hamar Laghdad (Anti-Atlas, Morocco)

Author

Gian Gabriele Ori, Barbara Cavalazzi, Roberto Barbieri, Cavalazzi B., Barbieri R., and Ori G.G.

Subjects
Chemosynthesis, biology, Stratigraphy, fungi, Geology, engineering.material, biology.organism_classification, Seafloor spreading, Devonian, chemistry.chemical_compound, Paleontology, Petroleum seep, Stromatolite, chemistry, engineering, Carbonate, Pyrite, Oncolite
Abstract

Veins cutting across the Devonian conical mounds of the Hamar Laghdad Ridge (eastern Anti-Atlas, Morocco) were the carriers of geofluids. Although not completely determined, the composition of these fluids seems related to hydrothermal and seepage fluxes that were the primary contributors to the establishment of sub-seafloor (cryptic) environments linking deeper fluid sources to the seafloor. The optical and scanning electron microscope investigation of the laminated carbonate infill of these veins has revealed that they consist of stromatolite- and oncolite-like fabrics. In the Early and Middle Devonian mounds, the laminated carbonates contain morphologies that are attributable to microbially mediated processes that in turn suggest a direct biological contribution to the deposition of the veins infill. Microbial evidence include rod-shaped and cocci clusters embedded in amorphous membranes, iron-rich filaments organized as mat-like and biodictyon filamentous aggregates, or isolated filaments, microbial clotted textures and peloids. Moreover, the oncoids from the veins of the Middle Devonian (Hollard) mound have been interpreted as the mineral replacement of crypto-microorganisms as Frutexites . Other microbial evidence are biominerals and include carbonate with spheroids and pyrite framboids, in which typifying hydrocarbon seep environments. The Hollard Mound, which is the only one with a well-documented origin by hydrocarbon seepage, shares a number of geomicrobiological evidence with other Early Devonian mounds. These evidence, which are supplemented by δ 13 C-depleted data, suggest that the infill of the veins system in the Hamar Laghdad mounds would be the product of chemotrophic/chemosynthetic microbial communities that are adapted to crypto-habitats sustained by hydrocarbon (and other components) fluid fluxes.

Published
2007
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29. Microbial signatures in sabkha evaporite deposits of Chott el Gharsa (Tunisia) and their astrobiological implications

Author

Nunzia Stivaletta, Gian Gabriele Ori, Roberto Barbieri, Lucia Marinangeli, BARBIERI R., STIVALETTA N., MARINANGELI L., and ORI G.G.

Subjects
Sabkha, chemistry.chemical_classification, geography, Gypsum, Mineral, geography.geographical_feature_category, Evaporite, Dolomite, Geochemistry, Salt (chemistry), Astronomy and Astrophysics, engineering.material, chemistry.chemical_compound, chemistry, Space and Planetary Science, engineering, Pyrite, Sulfate, Geology
Abstract

This study investigates the geomicrobiological potential of Upper Pleistocene evaporite deposits of the Chott el Gharsa, a wide continental sabkha in southern Tunisia. Organic and inorganic-derived biosignatures are mostly contained in microcrystalline, laminated gypsum lithofacies consisting of light/dark alternations of concordant laminae, which have precipitated from high salt concentrated waters. These biosignatures include mineralized microbial-interpreted morphologies, such as mucilage, rods, and microfibers, and dumbbell morphologies in the hollow cores of dolomite crystals that are associated with sulfates. Mineral products that are induced by microbial activity and their organic compounds lead to the formation of lenticular-shaped gypsum crystals, with a high length/width ratio, dolomite precipitation and formation of pyrite framboids. Morphological and structural aspects of these biosignatures, and their composition, in laminated, dolomite-rich sulfate deposits could be detected through microscopic investigations and micro-analyses performed by the instrumentation that is planned for ongoing Mars sample return missions.

Published
2006
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32. Unusual Fe-rich framboids from Devonian carbonate mounds (Hamar Laghdad, Morocco) investigated by HR-SEM and TOF-SIMS: fossil analogues of MOA-SRB consortia?

Author

BARBARA CAVALAZZI, ROBERTO BARBIERI, Cady, S. L., Ori, G. G., Westall, F., Gennaro, S., Lui, A., Canteri, R., Kalender, W., Karolczak, M., Bersani, M., Lazzeri, P., Pepponi, G., Gamberini, F., Cavalazzi B., Barbieri R., Cady S.L., Ori G.G., Westall F., Gennaro S., Lui A., Canteri R., Kalender W., Karolczak M., Bersani M., Lazzeri P., Pepponi G., and Gamberini F.

Published
2009

34. Astrobiology of methane seeps

Author

ROBERTO BARBIERI, BARBARA CAVALAZZI, Ori, G. G., Dimitrov, L., Barbieri R., Cavalazzi B., Ori G.G., and Dimitrov L.

Published
2007

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