Search

Your search keyword '"Schwenzer, S.P"' showing total 3 results
Start Over Author "Schwenzer, S.P" Topic msl
3 results on '"Schwenzer, S.P"'

1. Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars

Author

McLennan, S.M., Anderson, R.B., Bell III, J.F., Bridges, J.C., Calef III, F., Campbell, J.L., Clark, B.C., Clegg, S., Conrad, P., Cousin, A., Des Marais, D.J., Dromart, G., Dyar, M.D., Edgar, L.A., Ehlmann, B.L., Fabre, C., Forni, O., Gasnault, O., Gellert, R., Gordon, S., Grant, J.A., Grotzinger, J.P., Gupta, S., Herkenhoff, K.E., Hurowitz, J.A., King, P.L., Mouélic, S.L., Leshin, L.A., Léveillé, R., Lewis, K.W., Mangold, N., Maurice, S., Ming, D.W., Morris, R.V., Nachon, M., Newsom, H.E., Ollila, A.M., Perrett, G.M., Rice, M.S., Schmidt, M.E., Schwenzer, S.P., Stack, K., Stolper, E.M., Sumner, D.Y., Treiman, A.H., VanBommel, S., Vaniman, D.T., Vasavada, A., Wiens, R.C., NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), MSL Science Team, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Geologic Sediments, 010504 meteorology & atmospheric sciences, Extraterrestrial Environment, Iron, Curiosity rover, Geochemistry, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Weathering, 01 natural sciences, Calcium Sulfate, Sedimentary depositional environment, Halogens, 0103 physical sciences, Exobiology, MSL, Magnesium, Geochemistry of sedimentary rocks, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Basalt, Martian, Multidisciplinary, Silicates, Water, Mars Exploration Program, Hydrogen-Ion Concentration, Ferrosoferric Oxide, Diagenesis, Bays, Rocknest, Sedimentary rock, Chlorine, Geology
Abstract

International audience; Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron-and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.

Published
2014
Full Text
View/download PDF

2. In situ radiometric and exposure age dating of the martian surface

Author

Farley, K.A., Malespin, C., Mahaffy, P., Grotzinger, J.P., Vasconcelos, P.M., Milliken, R.E., Malin, M., Edgett, K.S., Pavlov, A.A., Hurowitz, J.A., Grant, J.A., Miller, H.B., Arvidson, R., Beegle, L., Calef, F., Conrad, P.G., Dietrich, W.E., Eigenbrode, J., Gellert, R., Gupta, S., Hamilton, V., Hassler, D.M., Lewis, K.W., McLennan, S.M., Ming, D., Navarro-González, R., Schwenzer, S.P., Steele, A., Stolper, E.M., Sumner, D.Y., Vaniman, D., Vasavada, A., Williford, K., Wimmer-Schweingruber, R.F., MSL Science Team, the, NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, California Institute of Technology (CALTECH), NASA Goddard Space Flight Center (GSFC), University of Queensland [Brisbane], Department of Geological Sciences [Providence], Brown University, Department of Geosciences [Stony Brook], Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Center for Earth and Planetary Studies [Washington] (CEPS), Smithsonian National Air and Space Museum, Smithsonian Institution-Smithsonian Institution, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, Department of Physics [Guelph], University of Guelph, Department of Earth Science and Technology [Imperial College London], Imperial College London, Southwest Research Institute [Boulder] (SwRI), Princeton University, NASA Johnson Space Center (JSC), NASA, Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México (UNAM), Dept. of Physical Sciences, The Open University [Milton Keynes] (OU), Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], Planetary Science Institute [Tucson] (PSI), Kiel University, GeoRessources, and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Geologic Sediments, Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Surface Properties, Curiosity rover, Geochemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mars, mudstone, Radiation Dosage, Noble Gases, 01 natural sciences, Isotopes, Impact crater, Exobiology, 0103 physical sciences, MSL, Organic Chemicals, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Radiogenic nuclide, Radiometric Dating, Authigenic, Gale Crater, Scarp retreat, 13. Climate action, Erosion, Radiometric dating, Sedimentary rock, Evolution, Planetary, Deposition (chemistry), Biomarkers, Cosmic Radiation
Abstract

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray–produced 3 He, 21 Ne, and 36 Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

Published
2013
Full Text
View/download PDF

3. Alteration trends and geochemical source region characteristics preserved in the fluviolacustrine sedimentary record of Gale crater, Mars.

Author

Bedford, C.C., Bridges, J.C., Schwenzer, S.P., Wiens, R.C., Rampe, E.B., Frydenvang, J., and Gasda, P.J.

Subjects
*SEDIMENTARY rocks, *DIAGENESIS, *GALE Crater (Mars), *GEOCHEMISTRY, *TRIDYMITE, *MARTIAN geology
Abstract

Abstract The Mars Science Laboratory's Chemistry and Camera (ChemCam) instrument suite on-board the Curiosity rover has analysed ∼1200 sedimentary targets during the mission up to sol 1482. These targets have included sedimentary rock, diagenetic features (e.g., fracture-associated alteration halos, mineral veins, nodules, and erosion resistant raised ridges), active aeolian fines, soils and float. We have isolated ChemCam geochemical trends relating to diagenetic features and alteration products from those of the sedimentary rock in order to identify the compositional characteristics of Gale crater's sediment source regions. The effects of grain size variation on sedimentary unit geochemistry have been taken into account by grouping and analysing geological units according to grain size. With obvious diagenetic features removed from the database, and predominately isochemical aqueous alteration inferred for the Mt Sharp Group samples, we propose that source region composition is a stronger source of geochemical change between the Bradbury and Mt Sharp Groups than open-system alteration. Additionally, a lack of correlation between the Chemical Index of Alteration (CIA) values and SiO 2 , MgO or FeO T indicates that the slight increase in chemical weathering of the Mt Sharp Group sediments was insufficient to overprint sediment source compositional signatures. This has led to the identification of five unique igneous endmember compositions which we hypothesise to have contributed to Gale crater's stratigraphic record. These endmembers are: (1) a subalkaline basalt, compositionally similar to the tholeiitic Adirondack Class basalts of Gusev crater, and dominant within the finer grained units up to the base of Mt Sharp; (2) a trachybasalt, mostly identified within conglomerate units from the Darwin waypoint to the base of Mt Sharp; (3) a potassium-rich volcanic source, determined from strong potassium enrichment and a high abundance of sanidine that is most dominant in the fluvial sandstones and conglomerates of the Kimberley formation; (4) a highly evolved, silica-rich igneous source that correlates with the presence of tridymite, and is recorded in the lacustrine mudstone of Mt Sharp's Marias Pass locality; and, (5) a fractionated, relatively SiO 2 -rich subalkaline basalt, seen to have influenced the composition of mudstone deposited in the lower part of the Mt Sharp Group. Endmembers (1), (2), (3), and (4) have previously been identified at specific waypoints along the rover's traverse, but we show that their influence extends throughout Gale's stratigraphic record. The occurrence of detected endmembers is also strongly correlated with stratigraphic position, which suggests changing sediment source regions with time. We conclude that Gale sediment provenances were much more varied than suggested by the largely homogenous, globally-distributed Martian basalt inferred from orbit, showing that complex magmatic assemblages exist within the ancient highland crust surrounding Gale. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results