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1. High-resolution microstructural and compositional analyses of shock deformed apatite from the peak ring of the Chicxulub impact crater

Author

Cox, Morgan A., Erickson, Timmons M., Schmieder, Martin, Christoffersen, Roy, Ross, Daniel K., Cavosie, Aaron J., Bland, Phil A., Kring, David A., Gulick, Sean, Morgan, Joanna V., Carter, G., Chenot, E., Christeson, Gail, Claeys, Ph, Cockell, C., Coolen, M. J.L., Ferrière, L., Gebhardt, C., Goto, K., Jones, H., Kring, D. A., Lofi, J., Lowery, C., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A., Poelchau, M., Rae, A., Rasmussen, C., Rebolledo-Vieyra, M., Riller, U., Sato, H., Smit, Jan, Tikoo, S., Tomioka, N., Whalen, M., Wittmann, A., Urrutia-Fucugauchi, J., Yamaguchi, K. E., Analytical, Environmental & Geo-Chemistry, Earth System Sciences, Chemistry, RC Academic Unit, Geology and Geochemistry, Imperial College London, Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, geophysics, High resolution, Mineralogy, 010502 geochemistry & geophysics, Ring (chemistry), 01 natural sciences, Apatite, Shock (mechanics), Impact crater, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, visual_art, visual_art.visual_art_medium, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences
Abstract

The mineral apatite, Ca5(PO4)3(F,Cl,OH), is a ubiquitous accessory mineral, with its volatile content and isotopic compositions used to interpret the evolution of H2O on planetary bodies. During hypervelocity impact, extreme pressures shock target rocks resulting in deformation of minerals; however, relatively few microstructural studies of apatite have been undertaken. Given its widespread distribution in the solar system, it is important to understand how apatite responds to progressive shock metamorphism. Here, we present detailed microstructural analyses of shock deformation in ~560 apatite grains throughout ~550 m of shocked granitoid rock from the peak ring of the Chicxulub impact structure, Mexico. A combination of high-resolution backscattered electron (BSE) imaging, electron backscatter diffraction mapping, transmission Kikuchi diffraction mapping, and transmission electron microscopy is used to characterize deformation within apatite grains. Systematic, crystallographically controlled deformation bands are present within apatite, consistent with tilt boundaries that contain the 'c' (axis) and result from slip in ' (Formula presented.) ' (direction) on (Formula presented.) (plane) during shock deformation. Deformation bands contain complex subgrain domains, isolated dislocations, and low-angle boundaries of ~1° to 2°. Planar fractures within apatite form conjugate sets that are oriented within either { (Formula presented.), { (Formula presented.), { (Formula presented.), or (Formula presented.). Complementary electron microprobe analyses (EPMA) of a subset of recrystallized and partially recrystallized apatite grains show that there is an apparent change in MgO content in shock-recrystallized apatite compositions. This study shows that the response of apatite to shock deformation can be highly variable, and that application of a combined microstructural and chemical analysis workflow can reveal complex deformation histories in apatite grains, some of which result in changes to crystal structure and composition, which are important for understanding the genesis of apatite in both terrestrial and extraterrestrial environments.

Published
2020
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2. A steeply-inclined trajectory for the Chicxulub impact

Author

Collins, G. S., Patel, N., Davison, T. M., Rae, A. S. P., Morgan, J. V., Gulick, S. P. S., Christeson, G. L., Chenot, E., Claeys, P., Cockell, C. S., Coolen, M. J. L., Ferrière, L., Gebhardt, C., Goto, K., Jones, H., Kring, D. A., Lofi, J., Lowery, C. M., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A. E., Poelchau, M. H., Rasmussen, C., Rebolledo-Vieyra, M., Riller, U., Sato, H., Smit, J., Tikoo, S. M., Tomioka, N., Urrutia-Fucugauchi, J., Whalen, M. T., Wittmann, A., Xiao, L., Yamaguchi, K. E., Artemieva, N., Bralower, T. J., Geology and Geochemistry, Department of Earth Science and Engineering [Imperial College London], Imperial College London, Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-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)-Centre National de la Recherche Scientifique (CNRS), Science and Technology Facilities Council (STFC), and Natural Environment Research Council (NERC)

Subjects
010504 meteorology & atmospheric sciences, Science, Impact angle, General Physics and Astronomy, 010502 geochemistry & geophysics, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Article, Impact crater, EMPLACEMENT, DEFORMATION, CRATER, 10. No inequality, lcsh:Science, 0105 earth and related environmental sciences, Multidisciplinary, Science & Technology, Plane (geometry), ORIGIN, METEORITE, General Chemistry, ANGLE, Multidisciplinary Sciences, BOUNDARY, SIZE, Meteorite, PEAK-RING FORMATION, 13. Climate action, Asteroid, [SDU]Sciences of the Universe [physics], ASYMMETRY, Trajectory, Science & Technology - Other Topics, lcsh:Q, Third-Party Scientists, IODP-ICDP Expedition 364 Science Party, Asteroids, comets and Kuiper belt, Seismology, Geology
Abstract

The environmental severity of large impacts on Earth is influenced by their impact trajectory. Impact direction and angle to the target plane affect the volume and depth of origin of vaporized target, as well as the trajectories of ejected material. The asteroid impact that formed the 66 Ma Chicxulub crater had a profound and catastrophic effect on Earth’s environment, but the impact trajectory is debated. Here we show that impact angle and direction can be diagnosed by asymmetries in the subsurface structure of the Chicxulub crater. Comparison of 3D numerical simulations of Chicxulub-scale impacts with geophysical observations suggests that the Chicxulub crater was formed by a steeply-inclined (45–60° to horizontal) impact from the northeast; several lines of evidence rule out a low angle (, The authors here present a 3D model that simulates the formation of the Chicxulub impact crater. Based on asymmetries in the subsurface structure of the Chicxulub crater, the authors diagnose impact angle and direction and suggest a steeply inclined (60° to horizontal) impact from the northeast.

Published
2020
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3. New shock microstructures in titanite (CaTiSiO5) from the peak ring of the Chicxulub impact structure, Mexico

Author

Timms, NE, Pearce, MA, Erickson, TM, Cavosie, AJ, Rae, ASP, Wheeler, J, Wittmann, A, Ferriere, L, Poelchau, MH, Tomioka, N, Collins, GS, Gulick, SPS, Rasmussen, C, Morgan, JV, Chenot, E, Christeson, GL, Claeys, P, Cockell, CS, Coolen, MJL, Gebhardt, C, Goto, K, Green, S, Jones, H, Kring, DA, Lofi, J, Lowery, CM, Ocampo-Torres, R, Perez-Cruz, L, Pickersgill, AE, Rebolledo-Vieyra, M, Riller, U, Sato, H, Smit, J, Tikoo, SM, Urrutia-Fucugauchi, J, Whalen, MT, Xiao, L, Yamaguchi, KE, Curtin University [Perth], Planning and Transport Research Centre (PATREC), Australian Resources Research Centre, Kensington, NASA Johnson Space Center (JSC), NASA, Department of Earth Science and Technology [Imperial College London], Imperial College London, University of Liverpool, Arizona State University [Tempe] (ASU), Natural History Museum [Vienna] (NHM), Albert-Ludwigs-Universität Freiburg, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Department of Earth Science and Engineering [Imperial College London], University of Texas at Austin [Austin], Géosciences Montpellier, Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Université de Montpellier (UM)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-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)-Centre National de la Recherche Scientifique (CNRS), Earth and Ocean Sciences, LeRoy Eyring Center for Solid State Science, Department of Geology, University of Freiburg [Freiburg], DGS, Jackson School of Geosciences, Institute of Geophysics [Austin] (IG), Analytical, Environmental & Geo-Chemistry, Earth System Sciences, Chemistry, and Natural Environment Research Council (NERC)

Subjects
Geochemistry & Geophysics, PLASTIC-DEFORMATION, 010504 meteorology & atmospheric sciences, EBSD, Shock metamorphism, Metamorphism, Titanite, U-PB, Titanite, Shock metamorphism, Mechanical twinning, Dislocation slip system, Meteorite impact, EBSD, Mechanical twinning, Slip (materials science), engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, ELECTRON-BACKSCATTER DIFFRACTION, HIGH-PRESSURE, Meteorite impact, Planar deformation features, 0402 Geochemistry, [CHIM]Chemical Sciences, Petrology, ZIRCON, 0105 earth and related environmental sciences, Science & Technology, Energy, Mineralogy, Dislocation slip system, Baddeleyite, MONAZITE, Geophysics, 0403 Geology, [SDU]Sciences of the Universe [physics], 13. Climate action, Physical Sciences, [SDE]Environmental Sciences, PHASE-TRANSITION, REIDITE, engineering, VREDEFORT, Deformation bands, ORIENTATION, Geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy, Zircon
Abstract

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Accessory mineral geochronometers such as apatite, baddeleyite, monazite, xenotime and zircon are increasingly being recognized for their ability to preserve diagnostic microstructural evidence of hypervelocity-impact processes. To date, little is known about the response of titanite to shock metamorphism, even though it is a widespread accessory phase and a U–Pb geochronometer. Here we report two new mechanical twin modes in titanite within shocked granitoid from the Chicxulub impact structure, Mexico. Titanite grains in the newly acquired core from the International Ocean Discovery Program Hole M0077A preserve multiple sets of polysynthetic twins, most commonly with composition planes (K 1 ) = ~ { 1 ¯ 11 } , and shear direction (η 1 ) = < 110 > , and less commonly with the mode K 1 = {130}, η 1 = ~ . In some grains, {130} deformation bands have formed concurrently with the deformation twins, indicating dislocation slip with Burgers vector b = < 341 > can be active during impact metamorphism. Titanite twins in the modes described here have not been reported from endogenically deformed rocks; we, therefore, propose this newly identified twin form as a result of shock deformation. Formation conditions of the twins have not been experimentally calibrated, and are here empirically constrained by the presence of planar deformation features in quartz (12 ± 5 and ~ 17 ± 5 GPa) and the absence of shock twins in zircon (< 20 GPa). While the lower threshold of titanite twin formation remains poorly constrained, identification of these twins highlight the utility of titanite as a shock indicator over the pressure range between 12 and 17 GPa. Given the challenges to find diagnostic indicators of shock metamorphism to identify both ancient and recent impact evidence on Earth, microstructural analysis of titanite is here demonstrated to provide a new tool for recognizing impact deformation in rocks where other impact evidence may be erased, altered, or did not manifest due to generally low (< 20 GPa) shock pressure.

Published
2019
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4. Topography of the Balearic Promontory during the Messinian Salinity Crisis: Isostatic response to desiccation and evaporite deposition

Author

Heida, Hanneke, García-Castellanos, Daniel, Jimenez-Munt, Ivone, Maillard, Agnès, Lofi, J., and Raad, Fadl

Subjects
Mediterranean Sea, Geology, Messinian Salinity Crisis
Abstract

Topo-Europe Conference in Granada, Spain, 5–10 May 2019, The Messinian Salinity Crisis was a period of rapid and extreme environmental changes in the Mediterranean occurring from 5.96 to 5.33 Ma1¿, leading to deposition of a huge amount of evaporites in the deep basins and erosion on the margins. Erosional surfaces located deep below current sea level suggest a kilometric drop in base level commonly associated with the deposition of massive halite deposits at the `acme¿ of the crisis. However, the timing and magnitude of this sea level drawdown are not well constrained2¿, while this has important implications for the conditions under which the different MSC sedimentary units were deposited and the connectivity of various sub-basins during the crisis. Previous studies yield a sea level drop ranging from 400 m (Martínez et al. 2004) to 1500 m (Urgeles et al., 2010) for the Western Mediterranean, with values up to 2250 m reported for the Eastern Mediterranean. A pseudo 3-D (planform) flexural backstripping approach allows us to restore the Messinian topography in tectonically quiescent areas, estimating the isostatic subsidence due to the Plioquaternary sediment and restoring the elevation of paleoshorelines and the original depth of erosional surfaces and other stratigraphic markers.3¿ Here, we apply this method to the area spanning the Valencia Basin, Balearic Promontory and the Algero-Provençal Basin, to restore the Messinian Erosion Surface which formed above base level during the drawdown to its original elevation, constraining the minimum required base level drop for subaerial erosion at this elevation. Our results can be compared to previously obtained paleogeographies and checked for consistency with Messinian mammal migration onto the Balearic Islands (Mas et al., 2018).

Published
2019

5. Quantifying the Release of Climate‐Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub

Author

Artemieva , Natalia, Morgan , Joanna, Gulick , S.P.S., Chenot , E., Christeson , G.L., Claeys , P., Cockell , C.S., Coolen , M.J.L., Ferrière , L., Gebhardt , C., Goto , K., Green , S., Jones , H., Kring , D.A., Lofi , J., Lowery , C.M., Ocampo-Torres , R., Perez-Cruz , L., Pickersgill , A.E., Poelchau , M., Rae , A.S.P., Rasmussen , C., Rebolledo-Vieyra , M., Riller , U., Sato , H., Smit , J., Tikoo , S.M., Tomioka , N., Urrutia-Fucugauchi , J., Whalen , M.T., Wittmann , A., Xiao , L., Yamaguchi , K.E., Zylberman , W., Collins , G.S., Bralower , T.J., Biogéosciences [Dijon] ( BGS ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Géosciences Montpellier, Université des Antilles et de la Guyane ( UAG ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de chimie et procédés pour l'énergie, l'environnement et la santé ( ICPEES ), Université de Strasbourg ( UNISTRA ) -Centre National de la Recherche Scientifique ( CNRS ) -Matériaux et nanosciences d'Alsace, 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 ) -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 ), Centre européen de recherche et d'enseignement de géosciences de l'environnement ( CEREGE ), Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Collège de France ( CdF ) -Institut National de la Recherche Agronomique ( INRA ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Funding from the International Ocean Discovery Program (IODP), the International Continental scientific Drilling Project (ICDP), NASA grant 15-EXO15_2-0054 and NERC grant NE/P005217/1., Natural Environment Research Council (NERC), The Leverhulme Trust, Biogéosciences [UMR 6282] [Dijon] (BGS), Centre National de la Recherche Scientifique (CNRS)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-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)-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), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, 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)-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), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Biogéosciences [UMR 6282] (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), 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)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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 Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Earth science, Potentially hazardous object, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Sediment, [ SDU.STU ] Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Shock (mechanics), Water depth, Geophysics, Meteorite, Volume (thermodynamics), 13. Climate action, Meteorology & Atmospheric Sciences, General Earth and Planetary Sciences, Sedimentary rock, Porosity, Geology, 0105 earth and related environmental sciences
Abstract

9 pages; International audience; Potentially hazardous asteroids and comets have hit Earth throughout its history, with catastrophic consequences in the case of the Chicxulub impact. Here we reexamine one of the mechanisms that allow an impact to have a global effect—the release of climate-active gases from sedimentary rocks. We use the SOVA hydrocode and model ejected materials for a sufficient time after impact to quantify the volume of gases that reach high enough altitudes (> 25 km) to have global consequences. We vary impact angle, sediment thickness and porosity, water depth, and shock pressure for devolatilization and present the results in a dimensionless form so that the released gases can be estimated for any impact into a sedimentary target. Using new constraints on the Chicxulub impact angle and target composition, we estimate that 325 ± 130 Gt of sulfur and 425 ± 160 Gt CO2 were ejected and produced severe changes to the global climate.

Published
2017
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6. IODP Expedition 339 in the Gulf of Cadiz and off West Iberia: decoding the environmental significance of the Mediterranean outflow water and its global influence

Author

Hernández-Molina, F.J., Stow, D.A.V., Alvarez-Zarikian, C., Acton, G., Bahr, A., Balestra, B., Ducassou, E., Flood, R., Flores, J.-A., Furota, S., Grunert, P., Hodell, D., Jimenez-Espejo, F., Kim, J.K., Krissek, L., Kuroda, J., Li, B., Llave, E., Lofi, J., Lourens, L., Miller, M., Nanayama, F., Nishida, N., Richter, C., Roque, C., Pereira, H., Sanchez Goñi, M.F., Sierro, F.J., Singh, A.D., Sloss, C., Takashimizu, Y., Tzanova, A., Voelker, A., Williams, T., Xuan, C., Stratigraphy & paleontology, and Stratigraphy and paleontology

Subjects
Shore, geography, geography.geographical_feature_category, Mechanical Engineering, lcsh:QE1-996.5, Energy Engineering and Power Technology, Contourite, Unconformity, Sedimentary depositional environment, lcsh:Geology, Tectonics, Paleontology, Oceanography, Sedimentary rock, Quaternary, Sediment transport, Geology
Abstract

IODP Expedition 339 drilled five sites in the Gulf of Cadiz and two off the west Iberian margin (November 2011 to January 2012), and recovered 5.5 km of sediment cores with an average recovery of 86.4%. The Gulf of Cadiz was targeted for drilling as a key location for the investigation of Mediterranean outflow water (MOW) through the Gibraltar Gateway and its influence on global circulation and climate. It is also a prime area for understanding the effects of tectonic activity on evolution of the Gibraltar Gateway and on margin sedimentation. We penetrated into the Miocene at two different sites and established a strong signal of MOW in the sedimentary record of the Gulf of Cadiz, following the opening of the Gibraltar Gateway. Preliminary results show the initiation of contourite deposition at 4.2–4.5 Ma, although subsequent research will establish whether this dates the onset of MOW. The Pliocene succession, penetrated at four sites, shows low bottom current activity linked with a weak MOW. Significant widespread unconformities, present in all sites but with hiatuses of variable duration, are interpreted as a signal of intensified MOW, coupled with flow confinement. The Quaternary succession shows a much more pronounced phase of contourite drift development, with two periods of MOW intensification separated by a widespread unconformity. Following this, the final phase of drift evolution established the contourite depositional system (CDS) architecture we see today. There is a significant climate control on this evolution of MOW and bottom-current activity. However, from the closure of the Atlantic–Mediterranean gateways in Spain and Morocco just over 6 Ma and the opening of the Gibraltar Gateway at 5.3 Ma, there has been an even stronger tectonic control on margin development, downslope sediment transport and contourite drift evolution. The Gulf of Cadiz is the world's premier contourite laboratory and thus presents an ideal testing ground for the contourite paradigm. Further study of these contourites will allow us to resolve outstanding issues related to depositional processes, drift budgets, and recognition of fossil contourites in the ancient record on shore. The expedition also verified an enormous quantity and extensive distribution of contourite sands that are clean and well sorted. These represent a relatively untapped and important exploration target for potential oil and gas reservoirs.

Published
2013

7. The Messinian Salinity Crisis: Past and future of a great challenge for marine sciences

Author

Roveri, M., Flecker, R., Krijgsman, W., Lofi, J., Lugli, S., Manzi, V., Sierro, F.J., Bertini, A., Camerlenghi, A., de Lange, G., Govers, R., Hilgen, F.J., Hübscher, C., Meijer, P.Th., Stoica, M., Marine geochemistry & chemical oceanography, Paleomagnetism, Stratigraphy & paleontology, Tectonophysics, Marine geochemistry, Stratigraphy and paleontology, Università degli studi di Parma [Parme, Italie], University of Bristol [Bristol], Utrecht University [Utrecht], Géosciences Montpellier, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Transferts en milieux poreux, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Modena e Reggio Emilia (UNIMORE), University of Salamanca, Università degli Studi di Firenze [Firenze], Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), Faculty of Geosciences, Utrecht University, Center for Marine and Climate Research, University of Hamburg, Department of Geology, Bucharest University, Marine geochemistry & chemical oceanography, Paleomagnetism, Stratigraphy & paleontology, Tectonophysics, Marine geochemistry, Stratigraphy and paleontology, University of Parma = Università degli studi di Parma [Parme, Italie], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), and Universität Hamburg (UHH)

Subjects
Mediterranean climate, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Environmental change, Evaporite, Outcrop, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Evaporites, Marine geology, Geology, Ecological succession, Late Miocene, Mediterranean, Messinian Salinity Crisis, Oceanography, Paleontology, Palaeoceanography, 13. Climate action, Geochemistry and Petrology, Stage (stratigraphy), 14. Life underwater, Messinian Salinity Crisis Marine geology Mediterranean Evaporites Palaeoceanography
Abstract

International audience; Forty years after the image of the Mediterranean transformed into a giant salty lake was first conceived, the fascinating history of the Messinian Salinity Crisis (MSC) still arouses great interest across a large and diverse scientific community. Early outcrop studies which identified severe palaeoenvironmental changes affecting the circum-Mediterranean at the end of the Miocene, were followed by investigations of the marine geology during the 1950s to 1970s. These were fundamental to understanding the true scale and importance of the Messinian event. Now, after a long period of debate over several entrenched but largely untested hypotheses, a unifying stratigraphic framework of MSC events has been constructed. This scenario is derived mainly from onshore data and observations, but incorporates different perspectives for the offshore and provides hypotheses that can be tested by drilling the deep Mediterranean basins.The MSC was an ecological crisis, induced by a powerful combination of geodynamic and climatic drivers, which had a great impact on the subsequent geological history of the Mediterranean area, and on the salinity of the global oceans. These changed the Mediterranean's connections with both the Atlantic Ocean and the freshwater Paratethyan basins, causing high-amplitude fluctuations in the hydrology of the Mediterranean. The MSC developed in three main stages, each of them characterized by different palaeoenvironmental conditions. During the first stage, evaporites precipitated in shallow sub-basins; the MSC peaked in the second stage, when evaporite precipitation shifted to the deepest depocentres; and the third stage was characterized by large-scale environmental fluctuations in a Mediterranean transformed into a brackish water lake.The very high-resolution timescale available for some Late Miocene intervals in the Mediterranean makes it possible to consider environmental variability on extremely short time scales including, in some places, annual changes. Despite this, fundamental questions remain, some of which could be answered through new cores from the deepest Mediterranean basins. Improvements in seismic imaging and drilling techniques over the last few decades make it possible to plan to core the entire basinal Messinian succession for the first time. The resulting data would allow us to decipher the causes of this extreme environmental change and its global-scale consequences.

Published
2014
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8. Freshening of the Mediterranean Salt Giant: controversies and certainties around the terminal (Upper Gypsum and Lago-Mare) phases of the Messinian Salinity Crisis

Author

Andreetto, Federico, Aloisi, Giovannni, Raad, Fadl, Heida, Hanneke, Flecker, Rachel, Agiadi, Konstantina, Lofi, Johanna, Blondel, Simon, Bulian, Francesca, Camerlenghi, Angelo, Caruso, Antonio, Ebner, Ronja, Garcia-Castellanos, Daniel, Gaullier, Virginie, Guibourdenche, Laetitia, Gvirtzman, Zohar, Hoyle, Tom, Meijer, Paul, Moneron, Jimmy, Sierro, Francisco J., Travan, Gaia, Tzevahirtzian, Athina, Vasiliev, Iuliana, Krijgsman, Wout, Paleomagnetism, Tectonophysics, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Andreetto F, Aloisi G, Raad F, Heida H, Flecker R, Agiadi K, Lofi J, Blondel S, Bulian F, Camerlenghi A, Caruso A, Ebner R, Garcia-Castellanos D, Gaullier V, Guibourdenche L, Gvirtzman Z, Hoyle TM, Meijer PT, Moneron JI, Sierro FJ, Travan G, Tzevahirtzian A, Vasiliev I, Krijgsman W, European Commission, García-Castellanos, Daniel [0000-0001-8454-8572], García-Castellanos, Daniel, Paleomagnetism, and Tectonophysics

Subjects
Mediterranean climate, 010504 meteorology & atmospheric sciences, Settore GEO/02 - Geologia Stratigrafica E Sedimentologica, Geochemistry, Mediterranean stratigraphy, Earth and Planetary Sciences(all), [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Structural basin, engineering.material, Late Miocene, Messinian Salinity Crisis, 010502 geochemistry & geophysics, 01 natural sciences, Mediterranean Basin, Paratethy, Lago-Mare, Connectivity proxie, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Paratethys, Brackish water, Terrigenous sediment, Messinian Salinity Crisi, Settore GEO/01 - Paleontologia E Paleoecologia, Settore GEO/08 - Geochimica E Vulcanologia, 13. Climate action, Paleogeography, Facies, engineering, General Earth and Planetary Sciences, Halite, Geology, Connectivity proxies
Abstract

The late Miocene evolution of the Mediterranean Basin is characterized by major changes in connectivity, climate and tectonic activity resulting in unprecedented environmental and ecological disruptions. During the Messinian Salinity Crisis (MSC, 5.97-5.33 Ma) this culminated in most scenarios first in the precipitation of gypsum around the Mediterranean margins (Stage 1, 5.97-5.60 Ma) and subsequently > 2 km of halite on the basin floor, which formed the so-called Mediterranean Salt Giant (Stage 2, 5.60-5.55 Ma). The final MSC Stage 3, however, was characterized by a "low-salinity crisis", when a second calcium-sulfate unit (Upper Gypsum; substage 3.1, 5.55-5.42 Ma) showing (bio)geochemical evidence of substantial brine dilution and brackish biota-bearing terrigenous sediments (substage 3.2 or Lago-Mare phase, 5.42-5.33 Ma) deposited in a Mediterranean that received relatively large amounts of riverine and Paratethys-derived low-salinity waters. The transition from hypersaline evaporitic (halite) to brackish facies implies a major change in the Mediterranean’s hydrological regime. However, even after nearly 50 years of research, causes and modalities are poorly understood and the original scientific debate between a largely isolated and (partly) desiccated Mediterranean or a fully connected and filled basin is still vibrant. Here we present a comprehensive overview that brings together (chrono)stratigraphic, sedimentological, paleontological, geochemical and seismic data from all over the Mediterranean. We summarize the paleoenvironmental, paleohydrological and paleoconnectivity scenarios that arose from this cross-disciplinary dataset and we discuss arguments in favour of and against each scenario., We thank the entire SALTGIANT community for many profitable workshops that inspired the development of this manuscript. This research was supported by the project SALTGIANT-Understanding the Mediterranean Salt Giant, a European project which has received funding from the European Union's Horizon 2020 research and innovation program, under the Marie Sklodowska-Curie [grant agreement No 765256

Published
2021
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9. The Messinian Salinity Crisis deposits in the Balearic Promontory: An undeformed analog of the MSC Sicilian basins??

Author

Athina Tzevahirtzian, Johanna Lofi, Antonio Caruso, Agnès Maillard, Fadl Raad, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Dipartimento di Scienze della Terra e del Mare [Palermo] (DiSTeM), Università degli studi di Palermo - University of Palermo, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Raad F, Lofi J, Maillard A, Tzevahirtzian A, and Caruso A

Subjects
Settore GEO/02 - Geologia Stratigrafica E Sedimentologica, 010504 meteorology & atmospheric sciences, Outcrop, Stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Late Miocene, Structural basin, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Sedimentary depositional environment, Paleontology, Balearic promontory, Caltanissetta basin, Central Mallorca depression, Messinian salinity crisis, Outcrops, 14. Life underwater, 0105 earth and related environmental sciences, geography, Promontory, geography.geographical_feature_category, Continental shelf, Geology, Settore GEO/01 - Paleontologia E Paleoecologia, language.human_language, Tectonics, Geophysics, 13. Climate action, language, Economic Geology, Sicilian
Abstract

International audience; The Messinian Salinity Crisis (MSC) is a controversial geological event that influenced the Mediterranean Basin in the late Miocene leaving behind a widespread Salt Giant. Today, more than 90% of the Messinian evaporitic deposits are located offshore, buried below the Plio-Quaternary sediments and have thus been studied mainly by marine seismic reflection imaging. Onshore-offshore records’ comparisons and correlations should be considered a key approach to progress in our understanding of the MSC.This approach has however not been widely explored so far. Indeed, because of the erosion on the Messinian continental shelves and slopes during the MSC, only few places in the Mediterranean domain offers the opportunity to compare onshore and offshore records that have been preserved from erosion. In this paper, we compare for the first time the MSC records from two basins that were lying at intermediate water depths during the MSC and in which salt layers emplaced in topographic lows: the Central Mallorca Depression (CMD) in the Balearic Promontory, and the Caltanissetta Basin (CB) in Sicily. The reduced tectonic movements in the CMD since the late Miocene (Messinian) till recent days, favored the conservation of most of the MSC records in a configuration relatively close to their original configuration, thus allowing a comparison with the reference records outcropping in Sicily. We perform seismic interpretation of a wide seismic reflection dataset in the study area with the aim of refining the mapping of the Messinian units covering the Balearic Promontory (BP) and restituting their depositional history based on a detailed comparison with the Messinian evaporitic units of the Sicilian Caltanissetta Basin. We discuss how this history matches with the existing 3-stages chrono-stratigraphic model. We show that the Messinian units of Central Mallorca Depression could be an undeformed analog of those outcropping on-land in the Sicilian Caltanissetta Basin, thus questioning the contemporaneous onset of the salt deposition on the Mediterranean scale. We show a change in seismic facies at a certain range of depth between stage 1 MSC units, and wonder if this could reflect the threshold/maximum depth of deposition of bottom growth PLG selenites passing more distally to pelagic snowfall cumulate gypsum. Moreover, we confirm that PLG could be deposited in water depths exceeding 200m.

Published
2021
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