DOCSLIB.ORG

The Southern Polar Giant Impact Hypothesis for the Origin of the Martian Dichotomy and the Evolution of Volcanism on Mars

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Southern Polar Giant Impact Hypothesis for the Origin of the Martian Dichotomy and the Evolution of Volcanism on Mars Research Collection Doctoral Thesis The Southern polar giant impact hypothesis for the origin of the Martian dichotomy and the evolution of volcanism on mars Author(s): Leone, Giovanni Publication Date: 2016 Permanent Link: https://doi.org/10.3929/ethz-a-010652097 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library DISS. ETH NO. 22390 THE SOUTHERN POLAR GIANT IMPACT HYPOTHESIS FOR THE ORIGIN OF THE MARTIAN DICHOTOMY AND THE EVOLUTION OF VOLCANISM ON MARS A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. Sc. ETH Zurich) presented by GIOVANNI LEONE PhD, Lancaster University born on 10.02.1967 citizen of Italy accepted on the recommendation of Prof. Paul James Tackley Prof. Olivier Bachmann Prof. Nicholas Lang Dr. Dave Alexander May 2016 … to my father and his loving memory. 2 Acknowledgements Completing my second PhD and writing this thesis was an amazing journey that would not have been possible without the support and encouragement of many people at ETH, outside the ETH, and abroad. I am very thankful to my family, my mother Rosalia and my sister Cetty, my wife Patrizia and my daughter Laura, who had the patience to support my dedication to this research. My gratitude goes to my advisor Paul Tackley, who gave me the opportunity to work at ETH thus allowing me to get out from a difficult moment of my life, and my collaborators of research (Dave May, Taras Gerya and Guizhi Zhu), who provided and assisted me with their codes. My gratitude goes to Nick Lang, the only one who accepted to be the external co-referee without prejudice on my Mars science, and who reviewed my paper on Valles Marineris with open mind. Many thanks to Tim Eglinton for chairing my defense and for his much appreciated interest in my new ideas of research. I am grateful to my former supervisor at Lancaster University, Lionel Wilson. As editor of the Journal of Volcanology and Geothermal Research, he allowed the publication of my independent papers on Mars against the prejudice of some reviewers. I am also grateful to Andrew Dombard who solicited my paper about the Southern Polar Giant Impact for publication on the Geophysical Research Letters. Very many thanks to Joseph Doetsch who completed the software necessary to produce the crucial Figure 3 of my paper on the volcanic alignments of Mars. Very many thanks also to Elisabeth Läderach, André Blanchard, Monika Bolliger, and Siegrid Trindler for being always kind and supportive with me. Special mention to the always helpful and Italian speaking Alfredo Picariello, he was my shield from mad bureaucracy. My gratitude to Uli Kastrup, Gillian Grün, and Bettina Gutbrodt for the organization of my talk (with flowers) about life on Mars held last July 2, 2014, in the C60 room at Focus Terra. A special thought goes to Elisabeth Huwyler for her much appreciated advice and support in my job search and to Martina Bach for her advice in the social support documents. My greatest appreciation and gratitude goes to my friend Monika Kohler who kindly supported me with translations in every matter outside the ETH domain. I also appreciated very much the Friday Beer friendly conversations with Jean-Pierre Burg, Stewart Greenhalgh, and many others during my stay at ETH. 3 Summary Summary .............................................................................................................................................. 4 Abstract ................................................................................................................................................. 6 Sommario.............................................................................................................................................. 6 .............................................................................................................................................. 7 Chapter 1 The Martian dichotomy and the volcanic history of Mars.................................................................. 7 1. The Martian dichotomy ................................................................................................................................. 8 1.1 Connection with the current state of astronomical research..........................................................14 1.2 The volcanic history of Mars...................................................................................................................16 1.3 Modification of the Martian dichotomy................................................................ ............................... 18 Chapter 2 ........................................................................................................................................... 23 Technical details of the numerical method .......................................................................................... 23 2.1 Model and Numerical Method................................................................................................................24 2.2 The I3ELVIS code......................................................................................................................................24 2.3 The StagYY code................................ ........................................................................................................ 38 2.4 Transferring composition and temperature from I3ELVIS to StagYY...................................... 41 2.5 Model parameters ........................................................................................................................................ 42 Chapter 3 ........................................................................................................................................... 45 Three-dimensional simulations of the southern polar giant impact hypothesis for the origin of the Martian dichotomy ............................................................................................................................. 45 3.1 Introduction...................................................................................................................................................47 3.2 Method............................................................................................................................................................48 3.3 Results ................................ ............................................................................................................................ 51 3.4 Discussion ..................................................................................................................................................... 58 3.5 Conclusions ................................................................................................................................................... 59 ........................................................................................................................................... 62 Chapter 4 Alignments of Volcanic Features in the Southern Hemisphere of Mars produced by Migrating Mantle Plumes ............................................................................................................................................. 62 4.1 Introduction...................................................................................................................................................64 4.2 Criteria for the identification and mapping of the volcanic features ..........................................66 4.3 Description and interpretation of the alignments.............................................................................. 89 4.3.1 Alignment 1................................................................................................................................ ................ 94 4.3.2 Alignment 2................................................................................................ ................................................ 97 4.3.3 Alignment 3............................................................................................................................................. 103 4.3.4 Alignment 4............................................................................................................................................. 108 4.3.5 Alignment 5............................................................................................................................................. 112 4.3.6 Alignment 6............................................................................................................................................. 120 4.3.7 Alignment 7............................................................................................................................................. 123 4.3.8 Alignment 8............................................................................................................................................. 128 4.3.9 Alignment 9............................................................................................................................................. 138 4.3.10 Alignment 10........................................................................................................................................ 143 4.3.11 Alignment 11.......................................................................................................................................
Load more

Recommended publications
  • Planetary Geologic Mappers Annual Meeting
    Program Lunar and Planetary Institute 3600 Bay Area Boulevard Houston TX 77058-1113 Planetary Geologic Mappers Annual Meeting June 12–14, 2018 • Knoxville, Tennessee Institutional Support Lunar and Planetary Institute Universities Space Research Association Convener Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Science Organizing Committee David Williams, Chair Arizona State University Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Robert Jacobsen Earth and Planetary Sciences Department, University of Tennessee Knoxville Bradley Thomson Earth and Planetary Sciences Department, University of Tennessee Knoxville Abstracts for this meeting are available via the meeting website at https://www.hou.usra.edu/meetings/pgm2018/ Abstracts can be cited as Author A. B. and Author C. D. (2018) Title of abstract. In Planetary Geologic Mappers Annual Meeting, Abstract #XXXX. LPI Contribution No. 2066, Lunar and Planetary Institute, Houston. Guide to Sessions Tuesday, June 12, 2018 9:00 a.m. Strong Hall Meeting Room Introduction and Mercury and Venus Maps 1:00 p.m. Strong Hall Meeting Room Mars Maps 5:30 p.m. Strong Hall Poster Area Poster Session: 2018 Planetary Geologic Mappers Meeting Wednesday, June 13, 2018 8:30 a.m. Strong Hall Meeting Room GIS and Planetary Mapping Techniques and Lunar Maps 1:15 p.m. Strong Hall Meeting Room Asteroid, Dwarf Planet, and Outer Planet Satellite Maps Thursday, June 14, 2018 8:30 a.m. Strong Hall Optional Field Trip to Appalachian Mountains Program Tuesday, June 12, 2018 INTRODUCTION AND MERCURY AND VENUS MAPS 9:00 a.m. Strong Hall Meeting Room Chairs: David Williams Devon Burr 9:00 a.m.
    [Show full text]
  • MODELED CATASTROPHIC OUTFLOW at ARAM CHAOS CHANNEL, MARS. DA Howard, Earth & Planetary Sciences, University of Tennessee
    40th Lunar and Planetary Science Conference (2009) 2179.pdf MODELED CATASTROPHIC OUTFLOW AT ARAM CHAOS CHANNEL, MARS. D. A. Howard, Earth & Planetary Sciences, University of Tennessee, 306 Earth & Planetary Sciences Bldg., 1412 Circle Drive, Knoxville, TN 37996, [email protected]. Introduction: The Aram Chaos channel located at tional algorithms relied on in this study were devel- 2.8°N, 18.5°W, is approximately 100 km long, ranges oped by Komar [1] and I have adapted them for use from 8 to 14 km wide, and has a maximum depth of with the Hydrologic Engineering Center’s River Anal- 2000 m (Figure 1). The confined innermost approx- ysis System (HEC-RAS) based on solution of the con- imately 67 km reach selected for this study includes tinuity and momentum equations [2]. HEC-RAS ad- the area of the channel where the trimline is evident justed for Mars’ gravitational acceleration was only for the stream head at the time of initial catastrophic applied to Mars channels once previously by Burr [3] flow and the outflow height at the channel’s mouth. at Athabasca Vallis and therefore provides the oppor- tunity to further develop the method here. The HEC- RAS model used for both Earth and Mars are identical except that the Mars version was adjusted for the gra- vitational acceleration and the specific weight of water differences between the two planets. Using the HEC- Ares Valles GeoRAS ArcGIS geospatial tool to generate the chan- nel geometry for input to the HEC-RAS flow model, Aram Chaos the hypothesized output potentially quantifies the hy- draulics of the channels more accurately than previous orders-of-magnitude estimates reported in the litera- ture.
    [Show full text]
  • Formation of Mangala Valles Outflow Channel, Mars: Morphological Development and Water Discharge and Duration Estimates Harald J
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, E08003, doi:10.1029/2006JE002851, 2007 Click Here for Full Article Formation of Mangala Valles outflow channel, Mars: Morphological development and water discharge and duration estimates Harald J. Leask,1 Lionel Wilson,1 and Karl L. Mitchell1,2 Received 24 October 2006; revised 3 April 2007; accepted 24 April 2007; published 4 August 2007. [1] The morphology of features on the floor of the Mangala Valles suggests that the channel system was not bank-full for most of the duration of its formation by water being released from its source, the Mangala Fossa graben. For an estimated typical 50 m water depth, local slopes of sin a = 0.002 imply a discharge of 1 Â 107 m3 sÀ1, a water flow speed of 9msÀ1, and a subcritical Froude number of 0.7–0.8. For a range of published estimates of the volume of material eroded from the channel system this implies a duration of 17 days if the sediment carrying capacity of the 15,000 km3 of water involved had been 40% by volume. If the sediment load had been 20% by volume, the duration would have been 46 days and the water volume required would have been 40,000 km3. Implied bed erosion rates lie in the range 1to12 m/day. If the system had been bank-full during the early stages of channel development the discharge could have been up to 108 m3 sÀ1, with flow speeds of 15 m sÀ1 and a subcritical Froude number of 0.4–0.5.
    [Show full text]
  • No. 40. the System of Lunar Craters, Quadrant Ii Alice P
    NO. 40. THE SYSTEM OF LUNAR CRATERS, QUADRANT II by D. W. G. ARTHUR, ALICE P. AGNIERAY, RUTH A. HORVATH ,tl l C.A. WOOD AND C. R. CHAPMAN \_9 (_ /_) March 14, 1964 ABSTRACT The designation, diameter, position, central-peak information, and state of completeness arc listed for each discernible crater in the second lunar quadrant with a diameter exceeding 3.5 km. The catalog contains more than 2,000 items and is illustrated by a map in 11 sections. his Communication is the second part of The However, since we also have suppressed many Greek System of Lunar Craters, which is a catalog in letters used by these authorities, there was need for four parts of all craters recognizable with reasonable some care in the incorporation of new letters to certainty on photographs and having diameters avoid confusion. Accordingly, the Greek letters greater than 3.5 kilometers. Thus it is a continua- added by us are always different from those that tion of Comm. LPL No. 30 of September 1963. The have been suppressed. Observers who wish may use format is the same except for some minor changes the omitted symbols of Blagg and Miiller without to improve clarity and legibility. The information in fear of ambiguity. the text of Comm. LPL No. 30 therefore applies to The photographic coverage of the second quad- this Communication also. rant is by no means uniform in quality, and certain Some of the minor changes mentioned above phases are not well represented. Thus for small cra- have been introduced because of the particular ters in certain longitudes there are no good determi- nature of the second lunar quadrant, most of which nations of the diameters, and our values are little is covered by the dark areas Mare Imbrium and better than rough estimates.
    [Show full text]
  • Glossary Glossary
    Glossary Glossary Albedo A measure of an object’s reflectivity. A pure white reflecting surface has an albedo of 1.0 (100%). A pitch-black, nonreflecting surface has an albedo of 0.0. The Moon is a fairly dark object with a combined albedo of 0.07 (reflecting 7% of the sunlight that falls upon it). The albedo range of the lunar maria is between 0.05 and 0.08. The brighter highlands have an albedo range from 0.09 to 0.15. Anorthosite Rocks rich in the mineral feldspar, making up much of the Moon’s bright highland regions. Aperture The diameter of a telescope’s objective lens or primary mirror. Apogee The point in the Moon’s orbit where it is furthest from the Earth. At apogee, the Moon can reach a maximum distance of 406,700 km from the Earth. Apollo The manned lunar program of the United States. Between July 1969 and December 1972, six Apollo missions landed on the Moon, allowing a total of 12 astronauts to explore its surface. Asteroid A minor planet. A large solid body of rock in orbit around the Sun. Banded crater A crater that displays dusky linear tracts on its inner walls and/or floor. 250 Basalt A dark, fine-grained volcanic rock, low in silicon, with a low viscosity. Basaltic material fills many of the Moon’s major basins, especially on the near side. Glossary Basin A very large circular impact structure (usually comprising multiple concentric rings) that usually displays some degree of flooding with lava. The largest and most conspicuous lava- flooded basins on the Moon are found on the near side, and most are filled to their outer edges with mare basalts.
    [Show full text]
  • The Eastern Outlet of Valles Marineris: a Window Into the Ancient Geologic and Hydrologic Evolution of Mars
    First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars (2015) 1054.pdf The Eastern Outlet of Valles Marineris: A Window into the Ancient Geologic and Hydrologic Evolution of Mars Stephen M. Clifford, David A. Kring, and Allan H. Treiman, Lunar and Planetary Institute/USRA, 3600 Bay Area Bvld., Houston, TX 77058 Over its 3,500 km length, Valles Marineris exhibits enormous range of geologic and environmental diversity. At its western end, the canyon is dominated by the tectonic complex of Noctis Labyrinthus while, in the east, it grades into an extensive region of chaos - where scoured channels and streamlined islands provide evidence of catastrophic floods that spilled into the northern plains [1-4]. In the central portion of the system, debris derived from the massive interior layered deposits of Candor, Ophir and Hebes Chasmas spills into the central trough have been identified as possible lucustrine sediments that may have been laid down in long-standing ice-covered lakes [3-6]. The potential survival and growth of Martian organisms in such an environment, or in the aquifers whose disruption gave birth to the chaotic terrain at the east end of the canyon, raises the possibility that fossil indicators of life may be present in the local sediment and rock. In other areas, 6 km-deep exposures of Hesperian and Noachian-age canyon wall stratigraphy have collapsed in massive landslides that extend many tens of kilometers across the canyon floor. Ejecta from interior craters, aeolian sediments, and possible volcanics (which appear to have emanated from structurally controlled vents along the base of the scarps), further contribute to the canyon's geologic complexity [2,3].
    [Show full text]
  • Newsletter February Issue
    Monthly Digital Newsletter VOL. 1 • ISSUE 1 • FEB 2021 From the News Mars Rover Mission 2020: Things you This issue: need to know BY PRIYANKA KASTURIA From the news 2:31 a.m. Feb 19, 2021, a tweet by NASA’s Perseverance Mars Rover, Mars Rover Mission 2020: “Hello, world. My first look at my forever home.” NASA and the Things you need to know world celebrated the success of the landing of Mars Rover PAGE 01 “Perseverance” on the Mars’ landing site called Jezero Crater, one of the eight potential locations to explore Martian life. Blog of the Month One of the missions is to “search for ancient life by collecting Space Robotics: Leading rock samples and sending them back to the Earth.” The rover is the way to the cosmos itself a mini-scientific laboratory on Mars to collect thirty-eight rock samples, and testing experiments for various purposes. PAGE 02 The News Bulletin PAGE 07 SSERD Celebrates National Science Day PAGE 08 Internship and Projects Image Credits: NASA Division (IPD) - Batch 8 READ MORE AT: Mars Rover Mission 2020: Things you need to know PAGE 10 EDGE OF SPACE © 2021 All Rights Reserved, EdgeofSpace.in, Part of SSERD PAGE 01 Blog of the Month Space Robotics: Leading the way to the "The future, despite Cosmos being seemingly BY K SHREYAS SUVARNA ‘unpredictable’, is The space tech industry has been largely dependent on definitely ‘exciting’ automation right from the very beginning and now with advanced technological know-how, this dependence is bound to increase and most possibly, exponentially, and it’s robotics that steps in to assist humans in realize the dream of exploring the unknown.
    [Show full text]
  • Origin of Circular Collapsed Landforms in the Chryse Region of Mars ⇑ Manuel Roda A,B, , Maarten G
    Icarus 265 (2016) 70–78 Contents lists available at ScienceDirect Icarus journal homepage: www.journals.elsevier.com/icarus Origin of circular collapsed landforms in the Chryse region of Mars ⇑ Manuel Roda a,b, , Maarten G. Kleinhans b, Tanja E. Zegers b, Rob Govers b a Universitá degli Studi di Milano, Dipartimento di Scienze della Terra, Via Mangiagalli, 34, 20133 Milano, Italy b Universiteit Utrecht, Faculty of Geosciences, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands article info abstract Article history: The quasi-circular collapsed landforms occurring in the Chryse region of Mars share similar morpholog- Received 29 June 2015 ical characteristics, such as depth of collapse and polygonally fractured floors. Here, we present a statis- Revised 20 October 2015 tical analysis of diameter, maximum and minimum depth, and amount of collapse of these features. Accepted 21 October 2015 Based on their morphometric characteristics, we find that these landforms have a common origin. In par- Available online 27 October 2015 ticular, the investigated landforms show diameter-depth correlations similar to those that impact craters of equivalent diameters exhibit. We also find that the observed amount of collapse of the collected fea- Keywords: tures is strongly correlated to their diameter. Furthermore, the linear relation between minimum filling Geological processes and pristine depth of craters, the constant ratio between collapse and the amount of filling and the frac- Ices Impact processes tured and chaotic aspect of the filling agree with melting and subsequent collapse of an ice layer below a Mars, surface sediment layer. This interpretation is consistent with a buried sub-ice lake scenario, which is a non-climatic mechanism for producing and storing abundant liquid water under martian conditions.
    [Show full text]
  • Widespread Crater-Related Pitted Materials on Mars: Further Evidence for the Role of Target Volatiles During the Impact Process ⇑ Livio L
    Icarus 220 (2012) 348–368 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Widespread crater-related pitted materials on Mars: Further evidence for the role of target volatiles during the impact process ⇑ Livio L. Tornabene a, , Gordon R. Osinski a, Alfred S. McEwen b, Joseph M. Boyce c, Veronica J. Bray b, Christy M. Caudill b, John A. Grant d, Christopher W. Hamilton e, Sarah Mattson b, Peter J. Mouginis-Mark c a University of Western Ontario, Centre for Planetary Science and Exploration, Earth Sciences, London, ON, Canada N6A 5B7 b University of Arizona, Lunar and Planetary Lab, Tucson, AZ 85721-0092, USA c University of Hawai’i, Hawai’i Institute of Geophysics and Planetology, Ma¯noa, HI 96822, USA d Smithsonian Institution, Center for Earth and Planetary Studies, Washington, DC 20013-7012, USA e NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA article info abstract Article history: Recently acquired high-resolution images of martian impact craters provide further evidence for the Received 28 August 2011 interaction between subsurface volatiles and the impact cratering process. A densely pitted crater-related Revised 29 April 2012 unit has been identified in images of 204 craters from the Mars Reconnaissance Orbiter. This sample of Accepted 9 May 2012 craters are nearly equally distributed between the two hemispheres, spanning from 53°Sto62°N latitude. Available online 24 May 2012 They range in diameter from 1 to 150 km, and are found at elevations between À5.5 to +5.2 km relative to the martian datum. The pits are polygonal to quasi-circular depressions that often occur in dense clus- Keywords: ters and range in size from 10 m to as large as 3 km.
    [Show full text]
  • The State of Anthro–Earth
    The Rosette Gazette Volume 22,, IssueIssue 7 Newsletter of the Rose City Astronomers July, 2010 RCA JULY 19 GENERAL MEETING The State Of Anthro–Earth THE STATE OF ANTHRO-EARTH: A Visitor From Far, Far Away Reviews the Status of Our Planet In This Issue: A Talk (in Earth-English) By Richard Brenne 1….General Meeting Enrico Fermi famously wondered why we hadn't heard from any other planetary 2….Club Officers civilizations, and Richard Brenne, who we'd always suspected was probably from another planet, thinks he might know the answer. Carl Sagan thought it was likely …...Magazines because those on other planets blew themselves up with nuclear weapons, but Richard …...RCA Library thinks its more likely that burning fossil fuels changed the climates and collapsed the 3….Local Happenings civilizations of those we might otherwise have heard from. Only someone from another planet could discuss this most serious topic with Richard's trademark humor 4…. Telescope (in a previous life he was an award-winning screenwriter - on which planet we're not Transformation sure) and bemused detachment. 5….Special Interest Groups Richard Brenne teaches a NASA-sponsored Global Climate Change class, serves on 6….Star Party Scene the American Meteorological Society's Committee to Communicate Climate Change, has written and produced documentaries about climate change since 1992, and has 7.…Observers Corner produced and moderated 50 hours of panel discussions about climate change with 18...RCA Board Minutes many of the world's top climate change scientists. Richard writes for the blog "Climate Progress" and his forthcoming book is titled "Anthro-Earth", his new name 20...Calendars for his adopted planet.
    [Show full text]
  • Volcanism on Mars
    Author's personal copy Chapter 41 Volcanism on Mars James R. Zimbelman Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC, USA William Brent Garry and Jacob Elvin Bleacher Sciences and Exploration Directorate, Code 600, NASA Goddard Space Flight Center, Greenbelt, MD, USA David A. Crown Planetary Science Institute, Tucson, AZ, USA Chapter Outline 1. Introduction 717 7. Volcanic Plains 724 2. Background 718 8. Medusae Fossae Formation 725 3. Large Central Volcanoes 720 9. Compositional Constraints 726 4. Paterae and Tholi 721 10. Volcanic History of Mars 727 5. Hellas Highland Volcanoes 722 11. Future Studies 728 6. Small Constructs 723 Further Reading 728 GLOSSARY shield volcano A broad volcanic construct consisting of a multitude of individual lava flows. Flank slopes are typically w5, or less AMAZONIAN The youngest geologic time period on Mars identi- than half as steep as the flanks on a typical composite volcano. fied through geologic mapping of superposition relations and the SNC meteorites A group of igneous meteorites that originated on areal density of impact craters. Mars, as indicated by a relatively young age for most of these caldera An irregular collapse feature formed over the evacuated meteorites, but most importantly because gases trapped within magma chamber within a volcano, which includes the potential glassy parts of the meteorite are identical to the atmosphere of for a significant role for explosive volcanism. Mars. The abbreviation is derived from the names of the three central volcano Edifice created by the emplacement of volcanic meteorites that define major subdivisions identified within the materials from a centralized source vent rather than from along a group: S, Shergotty; N, Nakhla; C, Chassigny.
    [Show full text]
  • LAYERED SULFATE-BEARING TERRAINS on MARS: INSIGHTS from GALE CRATER and MERIDIANI PLANUM. K.E. Powell1,2, R.E. Arvidson3, and C.S
    Ninth International Conference on Mars 2019 (LPI Contrib. No. 2089) 6316.pdf LAYERED SULFATE-BEARING TERRAINS ON MARS: INSIGHTS FROM GALE CRATER AND MERIDIANI PLANUM. K.E. Powell1,2, R.E. Arvidson3, and C.S. Edwards1, 1Department of Physics & Astrono- my, Northern Arizona University, 2School of Earth & Space Exploration, Arizona State University, 3Department of Earth & Planetary Sciences, Washington University in St. Louis. Introduction: Sulfate species have been detected ronment, with episodes of diagenesis and weathering in late Noachian and Hesperian terrains on Mars lying to form a crystalline hematite lag deposit [4, 5]. The stratigraphically above clay minerals, which has been lag deposit masks the CRISM spectral signature of interpreted as documenting a shift from wetter to more sulfate in most locations. Sulfate minerals including arid environments on the surface. Sulfate detections kieserite and gypsum have been detected in impact are associated with layered deposits in numerous loca- crater walls and windswept regions [6]. The Oppor- tions including Gale Crater, Meridiani Planum, Vallis tunity rover explored southern Meridiani Planum Marineris, and Terra Sirenum, and Aram Chaos [1]. through a campaign of crater-hopping, using craters as These sulfates and clays been identified using their a natural drill to expose strata [6]. The deepest expo- diagnostic absorption features in visible and near- sures explored by Opportunity directly are ~10 meters infrared reflectance (VNIR) data acquired from Mars thick at Victoria Crater. Opportunity results indicate orbit. Additionally, two rover missions have explored that the top layers of Burns formation contain up to sites with massive sulfate deposits. The first, the MER 40% sulfate and included Mg, Ca, and Fe species.
    [Show full text]