The Surface of Mars Our knowledge of Mars has grown enormously over the last decade as a result of the Mars Global Surveyor, Mars Odyssey, Mars Express, and the two Mars Rover missions This book is a systematic summary of what we have learnt about the geological evolution of Mars as a result of these missions, and builds on the themes of the author’s previous book on this topic The surface of Mars has many geological features that have recognizable counterparts on Earth Many are huge in comparison to those on Earth, including volcanoes, canyons and river channels that are ten times larger than their terrestrial equivalents The book describes the diverse Martian surface features and summarizes current ideas as to how, when, and under what conditions they formed It explores how Earth and Mars differ and why the two planets evolved so differently While the author’s main focus is on geology, he also discusses possible implications of the geological history for the origin and survival of indigenous Martian life Up-to-date and richly illustrated with over two hundred figures, the book will be a principal reference for researchers and students in planetary science The comprehensive list of references will also assist readers in pursuing further information on the subject M I C H A E L C A R R is a Geologist Emeritus at the U.S Geological Survey, and has over 40 years’ experience of planetary science research In the early 1970s Dr Carr was a member of the Mariner team and leader of the Viking Orbiter Imaging team He was co-investigator on the Mars Global Surveyor, the Mars Exploration Rovers, and the High Resolution Stereo Camera on Mars Express He is a Fellow of the Geological Society of America, the American Geophysical Union, and the American Association for the Advancement of Science, and was awarded the 1994 National Air and Space Museum Lifetime Achievement Award for his work on Mars He is also the author of The Surface of Mars (1981) and Water on Mars (1996) Cambridge Planetary Science Series Series editors: F Bagenal, F Nimmo, C Murray, D Jewitt, R Lorenz and S Russell Books in the series Jupiter: The Planet, Satellites and Magnetosphere F Bagenal, T E Dowling and W B McKinnon Meteorites: A Petrologic, Chemical and Isotopic Synthesis R Hutchinson The Origin of Chondrules and Chondrites D W G Sears Planetary Rings L Esposito The Geology of Mars: Evidence from Earth-Based Analogs M Chapman The Surface of Mars M Carr The Surface of Mars MICHAEL H CARR U.S Geological Survey Menlo Park, CA CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521872010 © Michael H Carr 2006 This publication is in copyright Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press First published in print format 2006 ISBN-13 ISBN-10 978-0-511-27041-3 eBook (NetLibrary) 0-511-27041-0 eBook (NetLibrary) ISBN-13 ISBN-10 978-0-521-87201-0 hardback 0-521-87201-4 hardback Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate Contents Preface Maps page ix xi Overview Telescopic observations Orbital and rotational motions Global structure and topography Atmosphere Surface temperatures Stability of water Global geology Meteorites Carbonaceous chondrites and chemical fractionation Martian meteorites 1 5 11 14 19 19 20 Impact craters Crater-forming objects Crater morphology Simple craters Complex craters Multi-ringed basins Crater formation Ejecta morphology Crater modification Crater size frequencies and ages Summary 23 23 24 24 25 26 27 31 34 36 41 Volcanism Basaltic volcanism Effect of Martian conditions Tharsis Tharsis Montes Olympus Mons Alba Patera Small Tharsis shields Elysium Lahars and dikes CerberusÀAmazonis HellasÀHesperia Plains volcanism VolcanoÀice interactions Summary 43 43 44 46 46 51 54 57 59 60 64 68 70 73 74 Global structure and tectonics Formation of the core Global dichotomy Thickness of the lithosphere Formation of Tharsis Surface indicators of stress Extensional structures Compressional structures Deformational features related to Tharsis 77 77 78 84 84 86 86 89 90 Canyons Physiography Canyon walls Landslides Interior layered deposits Formation of the canyons Summary 95 96 102 103 105 110 111 Channels, valleys, and gullies Outflow channels Circum-Chryse channels Description Mode of formation Tharsis Amazonis and Elysium Planitiae Description Mode of formation Utopia Planitia Hellas Argyre The poles Valley networks General description Drainage basins Origin Noachian valleys Post-Noachian valleys Gullies Summary 113 113 114 114 116 121 122 122 126 127 129 130 130 131 132 137 139 140 144 144 147 Lakes and oceans Paleolakes in the cratered uplands Argyre and Hellas 149 149 156 vii Contents viii Northern oceans Shorelines Evidence for marine sediments Evidence for ice Possible fate of a northern ocean Summary 160 164 167 168 168 171 Ice The stability of ice Spectral evidence for ice Permafrost Ice-rich surficial deposits at high latitudes Fretted terrain Terrain softening Lobate debris aprons Lineated valley fill Origin of the fretted valleys Glaciers Other possible indicators of ground ice Crater ejecta patterns Polygonal fractures Thermokarst Summary 173 174 175 175 177 178 179 180 184 185 187 188 188 189 191 191 Wind Entrainment of particles by the wind Dust storms Wind streaks and tails Dunes, ripples, and drifts Regional eolian deposits Wind erosion Summary 193 193 195 197 198 203 204 205 10 Poles The present polar environments General description of polar terrains Northern polar deposits Upper unit Basal unit Southern polar deposits The Dorsa Argentea Formation The CO2 residual cap Summary 211 211 212 212 212 218 221 222 225 226 11 The view from the surface Vikings and Mars Pathfinder Mars Exploration Rovers Spirit Gusev crater regional context Gusev plains Columbia Hills Clovis class Wishstone class Peace class Watchtower class Backstay class Opportunity Regional context The Meridiani rocks and soils The Burns Formation Post-depositional alteration Groundwater movement Evaporitic sources Summary 229 229 231 231 232 232 235 238 239 240 241 241 242 244 244 246 246 252 253 254 254 12 Climate change Noachian climate Greenhouse warming Retention of a dense CO2 atmosphere Post-Noachian climate history Recent climate changes Summary 257 257 258 260 262 265 265 13 Implications for life The origin of life Habitability Survival ALH84001 Looking for life Summary 267 268 271 272 273 274 274 14 Summary 277 Reference Index 283 297 Preface This book summarizes our knowledge of the morphology of the martian surface and speculates on how the surface evolved to its present state During the last three decades our knowledge of Mars has increased dramatically A succession of orbiting spacecraft (Table I) have observed the planet at ever-increasing resolution, rovers have traversed the surface, analyzing and scrutinizing rocks along the way, and ever more sophisticated techniques are being used to analyze increasing numbers of martian meteorites The planet has had a complicated history The aim of the book is to summarize our understanding of the nature and sequence of the processes that led to the present configuration of the surface While the book is intended for the serious student or researcher, technical jargon is avoided to the extent that it is possible without compromising precision It is hoped that the book will be readable to informed non-Mars specialists as well as those active in the field Sufficient documentation is provided to enable the reader to dig more deeply wherever he or she wishes Heavy reliance is placed on imaging data Other evidence is referred to where available, but at the present time, imaging is by far the most comprehensive global data set that we have in terms of areal coverage and resolution range Exploration of Mars has captured world-wide interest Mars is an alien planet yet not so alien as to be incomprehensible The landscape is foreign yet we can still recognize familiar features such as volcanoes and river channels We can transport ourselves through our surrogate rovers to a surface both strange and familiar and readily imagine some future explorers following in their paths While past speculations about martian civilization may now seem absurd, the possibility that Mars may at one time have hosted some form of life remains plausible It remains the strongest scientific driver of the Mars Exploration program The life Table I Mars missions Mariner Mariner Mariner Mars Mars Mariner Mariner Mars Mars Mars Mars Viking Viking Phobos Phobos Mars Observer Pathfinder Global Surveyor Odyssey Spirit Rover Opportunity Rover Mars Express Reconnaissance Orbiter US US US USSR USSR US US USSR USSR USSR USSR US US USSR USSR US US US US US US Europe US 11/28/1964 2/24/1969 3/27/1969 5/19/1971 5/28/1971 5/8/1971 5/30/1971 7/21/1973 7/25/1973 8/5/1973 8/9/1973 8/20/1975 9/9/1975 7/7/1988 7/12/1988 9/22/1992 12/4/1996 11/7/1996 4/7/2001 6/10/2003 7/7/2003 6/2/2003 8/12/2005 Flew by 7/15/1965; first S/C images Flew by 7/31/1969; imaging and other data Flew by 8/5/1969; imaging and other data Crash landed; no surface data Crash landed; no surface data Fell into Atlantic Ocean Into orbit 11/3/1971; mapped planet Failed to achieve Mars orbit Into orbit 2/12/1975; imaging and other data Crash landed Flew by Mars Landed on surface 7/20/1976; orbiter mapping Landed on surface 9/3/1976; orbiter mapping Lost 9/2/1988 Mars and Phobos remote sensing Failed Mars orbit insertion Landed 7/4/1997; lander and rover Into orbit 9/11/1997; imaging and other data Into orbit 10/24/2001: imaging, remote sensing Landed in Gusev 1/3/2004 Landed in Meridiani 1/24/2004 In orbit 12/25/2003; imaging, remote sensing In orbit 3/10/2006; imaging, remote sensing ix References Schultz, P H and Lutz, A B (1988) Polar wandering on Mars Icarus, 73, 91À141 Schultz, P H., Schultz, R A and Rogers, J (1982) The structure and evolution of ancient impact basins on Mars J Geophys Res., 87, 9803À20 Schultz, R A (1991) Structural development of Coprates Chasma and western Ophir Planum, central Marineris rift, Mars J Geophys Res., 96, 22,777À92 Schultz, R A and Frey, H V (1990) A new survey of multiring impact basins on Mars J Geophys Res., 95, 14,175À289 Schultz, R A and Lin, J (2001) Three-dimensional normal faulting models of Valles Marineris, Mars, and geodynamical implications J Geophys Res., 106, 16,549À66 Sclater, J G., Jaupart, C and Galson, D (1980) The heat flow through oceanic and continental crust and the heat loss of the earth Rev Geophys Space Phys., 18, 269À311 Scott, D H and Dohm, J M (1992) Mars highland channels: an age reassessment LPSC XXIII, pp 1251À2 Scott, D H and Tanaka, K L (1986) Geologic map of the western equatorial region of Mars U.S Geol Survey Misc Map I-1802-A Scott, E D and Wilson, L (2002) Plinian eruptions and passive collapse events as mechanisms of formation for martian pit chain craters J Geophys Res., 107(E4), 10.1029/2000JE001432 Segura, T L., Toon, O B., Colaprete, A and Zahnle, K (2002) Environmental effects of large impacts Science, 298, 1977À80 Seibert, N M and Kargel, J S (2001) Small-scale martian polygonal terrain: implications for liquid surface water Geophys Res Lett., 28, 899À902 Shaller, P J., Murray, B C and Albee, A L (1989) Subaqueous landslides on Mars? LPSC XX, pp 990À1 Sharp, R P (1963) Wind ripples J Geol., 71, 617À36 Sharp, R P (1973a) Mars: troughed terrains J Geophys Res., 78, 4063À72 Sharp, R P (1973b) Mars: fretted and chaotic terrains J Geophys Res., 78, 4222À30 Sharp, R P and Malin, M C (1975) Channels on Mars Geol Soc Am Bull., 86, 593À609 Shean, D E., Head, J W and Marchant, D R (2005) Origin and evolution of cold-based tropical mountain glacier on Mars: the Pavonis Mons fan-shaped deposit J Geophys Res., 110(E5), 10.1029/2004JR002360 Shoemaker, E M (1966) Preliminary analysis of the fine structure of the lunar surface in Mare Cognitum In The Nature of the Lunar Surface, ed W N Hess et al Baltimore: Johns Hopkins University Press, pp 23À121 Shoemaker, E M and Wolfe, R F (1982) Cratering time scales for the Galilean satellites In Satellites of Jupiter, ed D Morrison Tucson: University of Arizona Press, pp 277À339 Shreve, R L (1966a) Statistical law of stream numbers J Geol., 74, 17À37 Shreve, R L (1966b) Sherman landslide, Alaska Science, 154, 1639À43 Sleep, N H (1994) Martian plate tectonics J Geophys Res., 99, 5639À55 Sleep, N H and Zahnle, K (1998) Refugia from asteroid impact on early Mars and the early Earth J Geophys Res., 103(E12), 28,529À44 Smith, D E., Zuber, M T., Frey, H V., et al (12 authors) (1998) Topography of the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter Science, 279, 1686À92 Smith, D E., Sjogren, W L., Tyler, G L., Balmino, G., Lemoine, F G and Konopliv, A S (1999) The gravity field of Mars: results from Mars Global Surveyor Science, 286, 94À7 Smith, D E., Zuber, M T., Solomon, S C., et al (19 authors) (1999) The global topography of Mars and implications for surface evolution, Science, 284, 1495À1503 Smith, D E., Zuber, M T., Frey, H V., et al (2001) Mars Orbiter Laser Altimeter: experiment summary after the first year of global mapping J Geophys Res., 106(E10), 23,689À722 293 Smith, P H., Zuber, M T., Frey, H V., et al (19 authors) (1997) The imager for Mars Pathfinder experiment J Geophys Res., 102, 4003À25 Smrekar, S E., McGill, G E., Raymond, C A and Dimitriou, A M (2004) Geologic evolution of the martian dichotomy in the Ismenius area of Mars and implications for plains magnetization J Geophys Res., 109(E11), doi:10.1029/2004JE002260 Soderblom, L A., Kriedler, T J and Masursky, H (1973) Latitudinal distribution of debris mantles on the martian surface J Geophys Res., 78, 4117À22 Soderblom, L A., et al (2004) Soils of Eagle crater and Meridiani Planum at the Opportunity rover landing site Science, 306, 1723À6 Solomon, S C and Head, J W (1982) Evolution of the Tharsis province of Mars: the importance of heterogeneous lithospheric thickness and volcanic construction J Geophys Res., 87, 9755À74 Solomon, S C., et al (17 authors) (2005) New perspectives on ancient Mars Science, 307, 1214À20 Spencer, J R and Croft, S K (1986) Valles Marineris as karst NASA Tech Memo 88383, 193À5 Spencer, J R and Fanale, F P (1990) New models for the origin of Valles Marineris closed depressions J Geophys Res., 95, 14,301À13 Spohn, T., Acuna, M H., Breuer, D., et al (2001) Geophysical constraints on the evolution of Mars In Chronology and Evolution of Mars, ed R Kallenback et al Dordrecht: Kluwer, pp 231À62 Squyres, S W (1979) The distribution of lobate debris aprons and similar flows on Mars J Geophys Res., 84, 8087À96 Squyres, S W and Carr, M H (1986) Geomorphic evidence for the distribution of ground ice on Mars Science, 231, 249À52 Squyres, S W and Kasting, J F (1994) Early Mars: how warm and how wet? Science, 265, 744À8 Squyres, S W and Knoll, A H (2005) Sedimentary rock at Meridiani Planum: origin, diagenesis and implications for life Earth Planet Sci Lett., 240, 1À10 Squyres, S W., Arvidson, R E., Baumgartner, E T., et al (12 authors) (2003) Athena Mars rover science investigation J Geophys Res., 108(E12), doi:10.1029/2003JE002121 Squyres, S W., et al (50 authors) (2004a) The Opportunity Rover’s Athena science investigation at Meridiani Planum, Mars Science, 306, 1698À1714 Squyres, S W., Arvidson, R E., Bell, J F., et al (2004b) The Spirit rover’s Athena science investigation at Gusev crater, Mars Science, 305, 794À9 Squyres, S W., Grotzinger, J P., Arvidson, R E., et al (2004c) In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars Science, 306, 1709À14 Squyres, S W., Arvidon, R E., Blaney, D W., et al (14 authors) (2006) The rocks of the Columbia Hills J Geophys Res., 111, E02S11, doi:10.1029/2005JR002562 Stepinski, T F and Coradetti, S., (2004) Systematic differences in topography of martian and terrestrial drainage basins LPSC XXXV, Abstract 166 Stepinski, T F and O’Hara, W J (2003) Vertical analysis of martian drainage basins LPSC, XXXIV, Abstract 1659 Stetter, K O (1996) Hyperthermophiles in the history of life In Evolution of Hydrothermal Ecosystems on Earth (and Mars?), ed M Walter Ciba Foundation Symposium 202 New York: Wiley, pp 1À18 Stevens, T O and McKinley, J P (1995) Lithoautotrophic microbial ecosystems in deep basalt aquifers Science, 270, 450À4 Stevenson, D J (2001) Mars’ core and magnetism Nature, 412, 214À19 Stevenson, D J., Spohn, T and Schubert, G (1983) Magnetism and thermal evolution of the terrestrial planets Icarus, 54, 466À89 Stewart, E M and Head, J W (2001) Ancient martian volcanoes in the Aeolis region: new evidence from MOLA data J Geophys Res., 106, 17,505À13 294 Stewart, S T and Nimmo, F (2002) Surface runoff features on Mars: testing of the carbon dioxide hypothesis J Geophys Res., 107(E9), doi:10.1029/2000JE001465 Stoăffler, D and Ryder, G (2001) Stratigraphy and isotope ages of lunar geologic units: chronological standard for the inner Solar System In Chronology and Evolution of Mars, ed R Kallenbach et al Dordrecht: Kluwer, pp 9À54 Strahler, A N (1958) Dimensional analysis applied to fluvially eroded landforms Geol Soc Am Bull., 69, 279À300 Strahler, A N (1964) Quantitative geomorphology of drainage basins and channel networks In Handbook of Applied Hydrology, ed V T Chow New York: McGraw Hill Tanaka, K L (1985) Ice-lubricated gravity spreading of the Olympus Mons aureole deposits Icarus, 62, 191À206 Tanaka, K L (1986) The stratigraphy of Mars Proc 17th Lunar and Planet Sci Conf., J Geophys Res., 91, E139À58 Tanaka, K L (1999) Debris-flow origin for the Simud/Tiu deposit on Mars J Geophys Res., 104, 8637À52 Tanaka, K L and Golombek, M P (1989) Martian tension fractures and formation of grabens and collapse features in Valles Marineris LPSC XIX, pp 383À96 Tanaka, K L and Leonard, G J (1995) Geology and landscape evolution of the Hellas region of Mars J Geophys Res., 100(E3), 5407À32 Tanaka, K L and Scott, D H (1987) Geologic map of the polar regions of Mars U.S Geol Survey, Misc Inv Map I-1802C Tanaka, K L., Golombek, N P and Banerdt, W B (1991) Reconciliation of stress and structural histories of the Tharsis region of Mars J Geophys Res., 96, 15,617À33 Tanaka, K L., Banerdt, W B., Kargel, J S and Hoffman, N (2001) Huge CO2 charged debris flow deposit and tectonic sagging in the northern plains of Mars Geology, 29, 427À30 Thomas, P C and Gierasch, P J (1985) Dust devils on Mars Science, 230, 175À7 Thomas, P C and Veverka, J (1979) Seasonal and secular variations of wind streaks on Mars: an analysis of Mariner and Viking data J Geophys Res., 84, 8131À46 Thomas, P C., Squyres, S W and Carr, M H (1990) Flank tectonics of martian volcanoes J Geophys Res., 95, 14,345À55 Thomas, P C., et al (1992) Polar deposits of Mars In Mars, ed H H Kieffer, B M Jakosky, C W Snyder and M S Matthews Tucson: University of Arizona Press, pp 767À95 Thomas, P C., Malin, M C., Edgett, K S., et al (2000) Northsouth geological differences between the residual polar caps of Mars Nature, 404, 161À5 Thomas, P C., Malin, M C., James, P B., Cantor, B A., Williams, R M., and Gierasch, P., et al (2005) South polar residual cap of Mars: Features, stratigraphy and changes Icarus, 174, 535À59 Thorarinsson, S (1957) The joăkulhlaup from the Katla area in 1955 compared with other joăkulhlaups in Iceland Reykjavik Mus Nat Hist., Misc Paper 18, 21À5 Toon, O B., Pollack, J B., Ward, W., Burns, J A and Bilski, K (1980) The astronomical theory of climate change on Mars Icarus, 44, 552À607 Tosca, N J., McLennan, S M., Clark, B C., et al (2005) Geochemical modeling of evaporative processes on Mars: insight from the sedimentary record at Meridiani Planum Earth Planet Sci Lett., 240, 122À48 Touma, J and Wisdom, J (1993) The chaotic obliquity of Mars Science, 259, 1294À6 Treiman, A H and Louge, M Y (2004) Martian slope streaks and gullies: origins as dry granular flows LPSC XXXV, Abstract 1323 Treiman, A H., Drake, M J., Janssens, N J., Wolff, R and Enihara, M (1986) Core formation in the Earth and the shergottite parent body Geochim Cosmochim Acta, 50, 1061À70 Turcotte, D L., Willeman, R J., Haxby, W F and Norberry, J (1981) Role of membrane stresses in support of planetary topography J Geophys Res., 86, 3951À9 References von Engelhardt, W., Bertsch, W., Stoffler, D., Groschopf, P and Reiff, W (1967) Anzeichen fuăr den meteoritischen Ursprung des Beckens von Steinheim Naturwissenschaften, 54, 198À9 Wahrhaftig, C and Cox, A (1959) Rock glaciers in the Alaska Range Geol Soc Am Bull., 70, 383À426 Wallace, D and Sagan, C (1979) Evaporation of ice in planetary atmospheres: ice-covered rivers on Mars Icarus, 39, 385À400 Walter, M R (1983) Archean stromatolites: evidence of the Earth’s earliest Benthos In Earth’s Earliest Biosphere, ed J W Schopf Princeton: Princeton University Press, pp 187213 Waănke, H (1981) Constitution of terrestrial planets Phil Trans Roy Soc London Ser A, 303, 287303 Waănke, H and Dreibus, G (1988) Chemical composition and accretion history of terrestrial planets Phil Trans Roy Soc London Ser A, 325, 545À57 Ward, W R (1992) Long term orbital and spin dynamics of Mars In Mars, ed H H Kieffer, B M Jakosky, C W Snyder and M S Matthews Tucson: University of Arizona Press, pp 298À320 Washburn, A L (1980) Geocryology New York: Wiley Watters, T R (1991) Origin of periodically spaced wrinkle ridges on the Tharsis plateau of Mars J Geophys Res., 96, 15,599À616 Watters, T R (1993) Compressional tectonism on Mars J Geophys Res., 98(E5), 17,049À60 Weiss, B P., Vali, H., Baundenbacher, F J., et al (2002) Records of an ancient magnetic field in ALH84001 Earth Planet Sci Lett., 201, 449À64 Weitz, C M and Parker, T J (2000) New evidence that the Valles Marineris interior deposits formed in standing bodies of water LPSC XXXI, Abstract 1693 Weitz, C M., Parker, T J., Mulmer, M H., Anderson, F S and Grant, J A (2003) Geology of the Melas Chasma landing site for the Mars Exploration Rover mission J Geophys Res., 108(E12), doi:10,1029/2002JE002014 Wenrich, M L and Christensen, P R (1996) A formational model for the martian polygonal terrains LSPC XXVII, pp 1419À20 Wentworth, C K (1922) A scale of grade and class terms for clastic sediments J Geol., 30, 377À92 Whalley, W B and Azizi, F (2003) Rheological models of active rock glaciers: evaluation, critique and possible test Permafrost and Periglacial Processes, 5, 37À51 Wilhelms, D E (1987) The geologic history of the Moon U.S Geol Survey, Prof Paper 1348 Wilhelms, D E and Squyres, S W (1984) The martian hemisphere dichotomy may be due to a large impact Nature, 309, 138À40 Williams, P J and Smith, M W (1989) The frozen Earth Cambridge: CUP Williams, R M and Phillips, R J (2001) Morphometric measurements of martian valley networks from Mars Orbiter Laser Altimeter (MOLA) data J Geophys Res., 106, 23,737À51 Williams, R M., Phillips, R J and Malin, M C (2000) Flow rates and duration within Kasei Vallis, Mars: implications for the formation of a martian ocean Geophys Res Lett., 27, 1073À6 Wilshire, H G., Offield, T W., Howard, K A and Cummings, D (1972) Geology of the Sierra Madera cryptovolcanic structure, Pecos County, Texas U.S Geol Survey, Prof Paper 599-H Wilson, L and Head, J W (1994) Mars: review and analysis of volcanic eruption theory and relationships to observed landforms Rev Geophys., 32, 221À63 Wilson, L and Head, J W (2001) Evidence for episodicity in the magma supply to the large Tharsis volcanoes J Geophys Res., 106, 1423À33 Wilson, L and Head, J W (2002) Tharsis-radial graben systems as the surface manifestations of plume related dike intrusion complexes: models and implications J Geophys Res., 107(E8), 10.1029/2001JE001593 References Wilson, L and Mouginis-Mark, P J (2003) Phreatomagmatic explosive origin of Hrad Vallis, Mars J Geophys Res., 108(E8), doi 10.1029/2002JE001927 Wilson, L., Ghatan, G J., Head, J W and Mitchell, K L (2004) Mars outflow channels: a reappraisal of the estimation of water flow velocities from water depths, regional slopes and channel floor properties J Geophys Res., 109(E9), doi:10.1029/2004JE002281 Wilson, M (1995) Igneous Petrogenesis London: Chapman & Hall Wise, D U., Golombek, M P and McGill, G E (1979) Tectonic evolution of Mars J Geophys Res., 84, 7934À9 Withers, P and Neumann, G A (2001) Enigmatic northern plains of Mars Nature, 410, 651 Woese, C R (1987) Bacterial evolution Microbiol Rev., 51, 221À71 Woese, C R (1990) Toward a natural system of organisms Proc Natl Acad Sci U.S.A., 87, 4576À9 Wood, C A and Ashwal, L D (1981) SNC meteorites: igneous rocks from Mars? LPSC XII, pp 1359À75 Wood, J A (1979) The Solar System Englewood Cliffs, N.J.: Prentice-Hall Wu, S S C (1978) Mars synthetic topographic mapping Icarus, 33, 417À40 Wyatt, M B and McSween, H Y (2002) Spectral evidence for weathered basalt as an alternative to andesite in the northern lowlands of Mars Nature, 417, 263À6 Wyatt, M B., McSween, H Y., Tanaka, K L and Head, J W (2004) Global geologic context for rock types and surface alteration on Mars Geology, 32, 645À8 Yin, G., Jacobsen, S B., Yamashita, K., Blichert-Toft, J., Tetork, P and Abarede, F (2000) A short timescale for terrestrial planet formation from Hf-W chronometry of meteorites Nature, 418, 949À52 Yung, Y L., Nair, H and Gerstell, M F (1997) CO2 greenhouse in the early martian atmosphere: SO2 inhibits condensation Icarus, 130, 222À4 295 Zahnle, K (1998) Origins of atmospheres In Origins, ed C E Woodward et al Astron Soc Pacific Conf Series, 148, 364À91 Zhong, S and Zuber, M T (2001) Degree-1 mantle convection and the crustal dichotomy on Mars Earth Planet Sci Lett., 189, 75À84 Zimbelman, J R and Greeley, R (1982) Surface properties of ancient cratered terrain in the northern hemisphere of Mars J Geophys Res., 87, 10,181À9 Zuber, M T., Smith, D E., Solomon, S C., et al (1998) Observations of the north pole region of Mars from the Mars Orbiter laser altimeter Science, 282, 2053À60 Zuber, M T., Solomon, S C., Phillips, R J., et al (15 authors) (2000) Internal structure and early thermal evolution of Mars from Mars Global Surveyor topography and gravity Science, 287, 1788À92 Zurek, R W., Barnes, J R., Haberle, R M., Pollack, J B., Tillman, J E & Leovy, C B (1992) Introduction to the Mars atmosphere In Mars ed H H Kieffer, B M Jakosky, C W Snyder and M S Matthews Tucson: University of Arizona Press, pp 799À817 Zurek, R W., et al (1992) Dynamics of the atmosphere of Mars In Mars, ed H H Kieffer, B M Jakosky, C W Snyder and M S Matthews Tucson: University of Arizona Press, pp 835À933 Some useful web sites http://www.msss.com http://photojournal.jpl.nasa.gov http://themis-data.asu.edu/ http://astrogeology.usgs.gov/mdim-bin/ dataListPage.pl?lat¼15N&lon¼113E http://valles.wr.usgs.gov/mcmolashaded/ http://marsrovers.jpl.nasa.gov/home/index.html http://marswatch.astro.cornell.edu/pancam_instrument/links.html http://pds.jpl.nasa.gov/ Index Accretion 277 Acheron Fossae 167 Acid fogs 237 Acidalia Planitia 116 part of low around Tharsis 85 Admittance 84 African Rift Valleys 95 Ages absolute 15, 23 Ages, relative, by remote sensing 14, 23 Alases 176 Alba Patera 2, 17, 48, 54–7, 92, 132, 136 low slopes 54 flank fractures 54 fracture ring 54 dikes 55 pit craters 55, 56, 88 sheet flows 55, 56 Tube-fed flows 55, 56 lava ridges 55 dilatational faults 55 channels 56, 57 pyroclastic deposits 56 graben 56, 84, 86 profile 54 Albedo 1, 9, 193 Albor Tholus 60 ALH84001 20, 21, 78, 267, 273–4, 277 Alpha Particle X-ray Spectrometer 232 Alpha Proton-ray Spectrometer 231 Alpheus Colles 160 AlQahira 122 Amazonian 277 Amazonis Planitia 45, 64, 161, 195 flows 66, 68 low slopes 67 extremely flat 161, 163 part of low around Tharsis 85 outflow channels 122–7 Amphitrites Patera 69, 73, 233 Antarctica 73 Aphelion 2, 16 Apollinaris Patera 67, 70, 232 Aquifer 117 Arabia 80, 174 anomalous crustal thickness 82 fretted terrain 82 sparsely dissected 132 Arabia Shoreline 165–8 Aram Chaos 117 Archean 268 fossils 269 Archean rocks 268 Areocentric longitude Sun 2, Ares Vallis 114, 116, 117, 231 Argyre 5, 27, 159, 160, 181 floor elevation 158 floor Hesperian in age 158 lake 156–8 Arsia Mons 46–9, 188 summit caldera 46 Dikes 47 magma supply rate 51 Arsinoes Chaos 115, 117 Ascreus Mons 46, 49, 51 summit caldera 49 flank vents 49 rounded terraces 50 Asteroids 24 Astronomical unit 1, Athabasca Vallis 59, 65, 122, 125, 126 Atlantis Chaos 151 Atmosphere collapse 262 Atmosphere, chemical composition 17 circulation convective boundary layer CO2 retention 260 early Mars 263, 271 eddies isotopic composition 17 mass 16 meridional flow pressure variations and range 5, 16 temperatures 6–8 scale height 5, 16 water content 11 column water abundance 174 collapse 262 Aureum Chaos 115, 117 Backstay rocks 242 Bacteria, smallest size 273 Bacterial spores 273 Bacterial-like objects 273 Banded Iron Formations 268 Barchanoid dunes 203, 231 Basaltic sands 201, 246 Basaltic volcanism 43–4 Basalts, Gusev 237 Base Surge 34 Basin and Range province 111 Basin circularity 139 concavity 139 divides 139 Becquerel 157 Index 298 Biblis Patera 57 Biologic fixation of carbon 268 Blue clearing Bodies of water 143 Bonneville crater 235, 240 Borealis basin 83 Boundary layer, turbulent 194 laminar 194 velocity profile 194 Breadbasket 240 Bromides 242 Burns Cliff 250, 251, 253 stratigraphic section 250, 251 Burns Formation 246, 248 bromine component 253 cemented basaltic mud 248 sulfates 248 lower unit 248 middle unit 248 upper unit 249 erosional contact 248 phosphates 248 sulfates moved up section 253 NaCl moved down section 248, 253 post-depositional alteration 252 Ca-Al rich inclusions 78 Calderas, terrestrial 43 Canadian shield 137, 149 Canals Candor Chasma 96, 97, 99, 105, 108, 119, 120 layered deposits 97, 107 moat 109 fault scarp 102 light-toned deposits 110 Canyon lakes drained to east 119 to north 119 volumes 121 Canyon wall rocks, layered 102, 111 Hesperian aged 102 Noachian aged 102 Canyon walls 102–3 ridge and gully topography 102 talus chutes 102 Canyons 279 formation 110–1 tension fractures 110 faulting 95, 110, 111 fault scarps 110 Hesperian in age 111 keystone failure 111 rifting 111 slow extension model 111 Canyons, oblique view 95 Cap seasonal 211 volumes 211 thickness 211 Capillary evaporation 249 Capri Chasma 100, 111 Carbon isotopes, Archean rocks 268 Carbonaceous chondrites 19, 258, 273, 277 Carbonates in meteorites 261 in atmospheric dust 261 below the surface 261 detected from orbit 261 dissolve in acid waters 261 form from CO2 during weathering 260 Cataracts in outflow channels 114 Cavernous weathering 238 Cavi Angusti 74, 224 Cavi Sisyphi 224, 225 Cement 252 Center of Mass/center of figure offset 5, 16, 80 Ceraunius Fossae 87 Ceraunius Tholus 46, 57, 58, 132, 136 radial channels 57 Cerberus 64–8 flows 67 Cerberus channels 126 start at graben 126 formed by faulting, groundwater eruption 126 deep aquifer 127 discharges 127 Cerberus Fossae 59, 64, 67, 87, 122 source of lava flows 66 source of water flows 66, 87, 119 Cerberus plains 65–7 young age 67 crater ages 67 pooling of water 127 Cerberus plains, young age 126 Cerberus-Amazonis platey flows 71 Chalcophile elements 20 Channeled Scablands 114 Channels, Chryse 114–21 Channels, median ridges 134 Chaotic terrain 114 merges with canyons 96, 100 Chasma Australe 212, 221, 223 Chasma Boreale 212, 215, 218, 220 Chassigny 20 Chlorides 239, 242 Chondrites 19, 44 Chondritic composition 77 Chryse 18, 82, 230 Chryse channels formed by groundwater eruption 117 draining of canyon lakes 119–21 glaciation 121 debris flows 121 channel ages 116 Chryse Planitia 71, 95, 100, 114–16, 161, 229 wrinkle ridges 89 part of low around Tharsis 85 Claritas Fossae 9, 92, 97 Clathrate 145 Climate history 280 post-Noachian 262–5 Climate, affected by large floods 114 Closed depressions 120, 137 Clouds water-ice white yellow Clovis 243 rocks oxidized 239 soft 239 Index extensively altered 240 CO2 clouds 259 scatter infrared radiation 259 CO2 losses by sputtering 261 CO2-H2O greenhouse 258–60 Columbia Hills 16, 155, 234–6, 238–44, 278 West Spur 238 Husband Hill 238 rocks Noachian in age 243 rocks not lacustrine 243 rocks altered 244 Comets 24 Compatible elements 20 Complex terrestrial craters 25 Compressional structures 89–90 Concentric crater fill 180, 181 Conglomerate 231 Coprates Chasma 88, 95, 96, 100, 103 flat floor, high walls 100 fault scarps 102 merge with other canyons 108 formed in Hesperian 111 Core liquid 277 convection in 77 radius 77 formation 77–8, 258, 277 time of formation 77, 78 Cosmic ray exposure ages 20 Crater central peak 25 Crater densities across dichotomy boundary 80 Crater diameter vs depth 29 Crater ejecta, morphology 23, 31–4 details preserved 36–41 ramparts 32–4 terminology 33 lobate patterns 23 indicator of ground ice 188 Crater formation 27–31 compression stage 27, 31 excavation stage 27 expansion stage 31 modification stage 27, 29 central peak formation 30 transient cavity formation 29 collapse 30 Crater modification 34–6 mounds 152 domes 72 scaling laws 38 cross-section 29 lakes 152, 153 Crater production function 39 Crater rim, height 25 inverted stratigraphy 25 breached by valleys 150 Crater size frequency distribution 23, 36–41 equilibrium distribution 39 Moon 41 Crater walls, slumping 25 terraced 25 Crater, explosion 29 Cratering record, lunar 15, 23, 38, 40, 42 299 terrestrial 23 Craters, cumulative numbers vs time 39 Craters, Lunae Planum 35 Craters, Mars 17 Moon 23, 34 Mercury 23 Craters, simple 24–5 complex 25–6, 28 simple to complex transition 25 complex to multi-ring transition 25–6 depth to diameter ratios 25 Craters, used to determine absolute ages 38–40 possible errors 40, 41, 216 Craters, Utopia 35 Creep 193 Cross bedded sandstone 248 Cross stratification 251 Crust 277 formation 78 composition 5, 277 density 82 Crustal thickness, changes across dichotomy boundary 80 bimodal 82 thin under large basins 27, 82 thin under northern plains 160 Crustal thinning under canyons 111 Cryosphere 13–14, 62, 73, 117, 131, 173, 262 fracturing 62 disrupted by dikes 62 recharged 258 Cryptoendoliths 273 Crystal molds 252, 253 Cumulative plots of craters 35 Dao Vallis 68, 129, 131, 146 Day, martian Debris aprons 180–4 richly textured 182 ages 182 role of ice 183 incorporate ground ice 183 glaciers 183 Debris flows 179, 182, 183 Decay of 182Hf 78 Deep-sea smokers 272 Deflation hollows 170 Delta 140, 141, 151, 154, 234, 258 Deuterium Deuteronilus shoreline 164–7 elevation 167 volume enclosed 167 Diapir 44, 88 Dichotomy boundary, morphologic attributes 82 Dichotomy, global Dike emplacement 72, 127 Dike swarms, magnetic anomalies 78 under canyons 111 Dikes 44, 47, 88 interaction with water and ice 63 affect groundwater circulation 47 injected into cryosphere 73 magma volumes 89 Dikes, terrestrial 89 Index 300 Dilatant faults 86, 88 Dislodgement 195 Disrupted terrain, dichotomy boundary 82 Dissected upland 134 dissected volcanoes 262 Dormancy 272 Dorsa Argentea Formation 74, 157, 222–5, 262 basal melting 225 peripheral channels 225 Drainage basins 137–9 shape 139 Drainage density 135 Drainage system less developed than Earth’s 137, 143 Drifts 197, 200, 229, 231 Drop Moraines 187, 189 Drumlins 184–5 Ductile layer 90 Dune field 255 Dune types 198–203 barchan 199 deposits 251 longitudinal 200 seif 200 star-shaped 200 terrestrial 199 transverse 199 Dunes 200, 207, 245, 248 polar 200, 212, 216, 218, 220 Dust devil 193, 195, 196, 236 Dust sink 197 Dust storms 1, 9, 193, 195–7, 216, 218 global 196 Dynamo 78 Eagle crater 246, 249 Eastern hemisphere Eccentricity, Earth Eccentricity, Mars 1–4, 16 Echus Chasma 96, 115, 121, 139, 144 side canyons 102–3 Ejecta, patterns 31–4 annulus 32 lobes 32, 33 curtain 29, 32 flow along the ground 33 rampart 34 platform 26, 33 Ejecta, fluidized 23, 26, 33 Elastic shells 84 Elevation difference, north-south 80 Elevation precision Elevation reference surface, Mariner-9 Mars Global Surveyor Elysium 5, 17, 18, 21, 59–64, 68, 70, 174, 279 dome 59 lava flows on east flank 64 fossae 59, 86 shorelines 165 Elysium index map 61 oblique view 62 Elysium Mons 59, 64 described 59 concentric and radial graben 59 channels 59, 128 channels emerge from graben 60, 62 summit caldera 62 radial dikes 65 Elysium outflow channels 122–9, 279 formation 127 Elysium Planitia 161 Endurance crater 201, 246, 249, 250 Eos Chasma 100 Ephrata fan 231 Episodic ocean hypothesis 263 Equilbrium distribution of craters 35, 37 Erosion rates 34, 137, 143, 258, 278 declined at end of Noachian 262, 278 Eruption cloud 46 Eruption quiescent periods 51 Eruption rates 44 Eruption styles 45 Escarpments, dichotomy boundary 82 Eskers 158, 160, 168, 224, 225 Etched uplands 204, 205, 207 Evaporite sand grains 248 reworked 249 Evaporites 149, 153, 246, 254 Meridiani Planum 113 Exhumed craters 246 Exosphere Exsolution of gases 45–59 Extensional structures 86–9 Fan deposits 140 Fault scarps 88, 96 Fault scarps, terrestrial 102 Faults, depths in canyons 111 Festoon cross bedding 252 geometry 250 Fissure eruptions 71 Floods 113, 160 effect on atmosphere 263, 264 Flow plains, mainly Amazonian in age 72 Flows, tube-fed 60, 72 sheet 60 Fossils 269 earliest 268 Fretted terrain 164, 167, 178–84, 280 debris aprons 181 viscous flow of surface materials 186 Fretted valleys 113, 178, 185–7 formed by enlargement of fluvial valleys 185 Frost heaving 176 Frost point, CO2 H2O 11, 174 Galaxia Fossae 59 Gale crater 153, 157 Gamma-ray Spectrometer 175 Ganges Chasma 100, 104, 105 layered deposits 100, 104, 107 drainage 121 light-toned deposits 110 Gas Chromatograph Mass Spectrometer 229 Gelifluction 176 Ghost craters 37, 151, 167, 168 Index Glacial deposits 188, 189 three facies 187 Glaciation 160, 265 Glaciers 48, 169, 184, 187–8, 280 cold based 187 temperate 187 carved outflow channels 187 in Argyre 187 in Hellas 187 on Arsia Mons 187, 189 on Tharsis volcanoes 187 on Olympus Mons 187, 190 young on Tharsis volcanoes 187 Global dichotomy 77–84, 160, 277 elevation profiles 80 expressed in three ways 78 formed by large impact 82 internal origin 84 plate tectonics 84 Global differentiation 77 Global groundwater circulation 143 Global hypsometry 79 Global temperatures, early Mars 259 Global topography 77 Goethite 239, 242 Graben 84 common around Tharsis 84 radial to Tharsis 92 Grain transport 194 Grand Canyon, Arizona 95 Granicus Vallis 65, 127, 128 Gravitational acceleration 16 Gravity 5, 77, 82, 160 Greenhouse 143 Greenhouse gases 258–61 Grjota Valles 65, 125, 127 Ground ice 173 abundance, high latitudes 175 low latitudes 175 inherited 175 Groundwater 14, 62, 173, 253 eruption 117 recharge 262 seepage 142, 257 Gullies 144–6, 280 on pole-facing slopes 145 on sand dunes 146 erosion by liquid water 144 groundwater seepage 145 mass wasting 145 melting of ice 145, 146 erosion by CO2 145 formed at high obliquities 145 Gusev 150, 151, 153, 232–4, 237 wrinkle ridges 90 regional context 232 ridged plains 234 etched floor 235 Gusev floor, complex origin 155 Gusev plains basalts 235, 239 mostly unaltered 235 alteration rinds 235, 237 fluted 238 301 Gusev plains 210 secondary craters 235 erosion rates 235 drifts 238 ripples 238 tails 238 dust devils 238 Gusev rocks 238 Adirondack class 239 Clovis class 239 Wishstone class 240 Peace class 241 Watchtower class 241 Backstay class 242 Gusev soils, composition 238 sulfate rich 238 Gypsum 211, 220 north pole 280 Habitability, post-Noachian Mars 271 Hadean era 268 Hadley cell Hadriaca Patera 68, 71, 72, 131 pyroclastic activity 69 nearby outflow channels 130 Harmakhis Vallis 129, 131 Hartmann’s isochrons 40, 41 Hawaii 43, 51 shield volcanoes 50–1 eruption type 45 eruption style Hazcams 231 Heat flow 84, 85 Heavy bombardment conditions 270 similar on Earth and Mars 270 Hebes Chasma 95, 96, 100, 116 layered deposits 99, 105 moat 109 Hebrus Vallis 127, 129, 130 Hecates Tholus 59, 63, 64, 129, 132, 136 channels 59 pyroclastic deposits 59 glaciers 188 Hellas 1, 5, 9, 17, 18, 27, 68–70, 80, 83, 158–9, 196 depth floor 130, 162 effects of formation 277 lake 156–8 layered sediments 159 lowest point on planet 158 pressure within basin thin crust 82 shorelines 161 Hematite 239, 240, 242, 244 Hematite concretions 248, 249 formed after deposition of host rock 253 Hephaestus Fossae 127, 129, 130 Hesperia Planum, wrinkle ridges 90 Hesperia, lobate scarps 90 Hesperian plains, dissected 262 Hesperian system 15 Hesperian valleys 262 Hesperian/Amazonian boundary age 41, 277 Index 302 High obliquity 263, 265 snow on volcanoes 264 Holden 151 Homopause Hrad Vallis 64, 127 Hubble Space Telescope 2, 196 Hybrid faults 86 Hydraotes Chaos 120 Hydrodynamic escape 258 Hydrogen content, soil 175 Hydrogen loss 258 Hydrologic cycle, caused by impacts 260 late Noachian 278 change at end of Noachian 144 Hydrosphere 14 Hydrostatic pressure 117, 119 Hydrothermal circulation 143, 263, 264, 272 Hydrous silicates 258, 262 Hyperthermophiles 272, 281 Iani Chaos 117 Icaria Fossae 84, 88 Ice ages 265 Ice deposits 146, 178, 182 flows 68 sheets 187 Ice stability 174–5 effect of obliquity 174–5 Ice veneer in alcoves 177 melting causes gullies 178 Ice-covered rivers 258 Iceland 73 Ice-rich veneer 177, 178, 280 Impact basins 277 buried 80 Impact erosion of atmosphere 142, 260 Impact rates, Moon and Mars compared 38 Impactors, size frequency distribution 24, 38 flux at Earth 24 Impacts enveloped Earth in rock vapor 270 Impacts, climatic effects 260, 263, 264, 270 Incremental plots of craters 37 Intercrater plains, wrinkle ridges 89 Interdune environment 249, 252 Isidis 18, 27, 76, 80, 82, 83, 86 thin crust 82 Isidis basin, depth 162 Isidis Planitia 9, 71, 72 volatile-rich floor materials 72 wrinkle ridges 90 Isotopes 77 Isotopic fractionation by sputtering 261 Ius chasma 97, 98 side canyons 1023 Jarosite 246, 253 Joăkulhlaups 130 Jovis Tholus 57, 59 Juventae chasma 96, 99, 101, 114, 115 layered deposits 99, 102, 107 sulfate-rich deposits 102 Kames 168 Karst 179 Kasei Vallis 113–15, 120, 121 discharge 117 origin 121 Katabatic winds 211 Kettles 105 Kilauea 51 Ladon Vallis 130, 156, 157 Lahars 60–4, 127 Lakes in the canyons 95, 112 drained to east 112 merge with outflow channels 107 supported by sulfates 107 melting of ice deposits 108 release of water by injection of dikes 108 Lakes in uplands 149–56 Landing sites, engineering constraints 232 Landslides 103–5 landslide scar 104 landslide debris aprons 104 young age 104 volatile content 105 longitudinal striae 105 runout length 105 subaqueous 105 water-logged sediments 105 Ganges Chasma 106 Melas Chasma 106 Latitudinally resolved climate models 259 Lava flows 44 tubes 60 channels 140 rafts 68 lakes 140, 151 effusion rates 51 Layered deposits 119, 120, 211, 280 in craters 151 Noachian terrain 278 Layered deposits in canyons 105–10, 112 Melas Chasma 108, 109 Candor Chasma 108, 109 fluted texture 106 remnants of country rock 107 younger than wall rock 107 sulfate rich 112 deposited in lakes 107–9 Layered deposits, Meridiani 244 age 245 sulfate rich 254 Layered deposits, north pole 212, 220 age 216 basal unit 218 composition, extent 212 marker beds 213 models for accumulation 218 persistence of layers 213 result from orbital and rotational motions 216, 218 shape of mound 217 unconformities 213 volume 212 Index Layered deposits, south pole 212, 221, 222 ages 221 central mound 221 higher then north 212 Levee 134 Life arose quickly on Earth 268 Life, Noachian Mars 274 Lineated valley fill 178, 184–5 forms in closed depressions 185 forms by merger of debris aprons 185 down-valley flow 185 Liquid CO2 145 Liquid water cut outflow channels 113 Liquid water stability 11–12 scarcity 271 pockets 271 Lithophile elements 20 Lithosphere flexure 46, 49, 51, 77, 84 under Tharsis 85, 92 model for Tharsis 86 Lithosphere thickness 84 thick under young volcanoes 84 thinner under older volcanoes 84 thin under Noachian terrains 84 Lobate flows 190 Lobate scarps 90 Loire Vallis 133, 150 Lunae Planum 18, 33, 71, 72, 116 wrinkle ridges 89, 90 wrinkle ridge spacing 90 vertical offset across wrinkle ridges 90 Lunar crater production function 38 Lunar highlands 23 maria 23, 71 rilles 62 South pole-Aitkin basin 82 Lyot 27, 30, 264 Ma’adim Vallis 113, 122, 134, 150, 151, 153, 154, 232, 233 formed by draining of Noachian lake 158, 232 delta 232, 243 Magma ocean 78, 84 Magma chamber 44, 51, 62 Magnetic anomalies 77, 78 absent around impact basins 78 Magnetic field 78 stripes 78, 84 Magnetite 239 Magnetofossils 273 Magnets 232 Maja Vallis 99, 101, 109, 115 Malea Planum 69, 71 wrinkle ridges 90 Mamers Vallis 178, 184 Mangala Vallis 122, 124, 126, 164 starts at graben 126 formed by faulting, groundwater eruption 126 Mantle, composition 44 depleted in siderophiles 77 upwelling 84, 85 Mare Cimmerium 137 Mare Serinum 137 303 Margaritifer Terra 95, 115 Margaritifer Vallis 130 Marine episodes 263 Mariner-4 Mariner-6 43, 211 Mariner-7 43, 211 Mariner-9 43, 113, 160, 267 Mars Orbiter Laser Altimeter Marte Vallis 64–7, 69, 125, 161, 164 Martian highlands 16–17 Martian meteorites 20–1, 77 Mass, Mars 16 Mass-wasting 95, 176 Mauna Loa 44 Mawrth Vallis 116 Medusae Fossae Formation 35, 68, 155, 193, 204, 206–8, 232, 233 Megaripples 200, 201 Melas Chasma 95–7, 120 merge with other canyon 108 enigmatic deposit 107 layers in wall 105 Memnonia Fossae 84, 88, 92 lobate scarps 90 Meridiani 18, 149, 152, 248 regional context 244 sediments 247 shoreline 167 Meridiani Planum 113, 193, 204, 244 widespread pavement 246 Mereo Patera 72 Mesopause 6, Meteor Crater, Arizona 25, 27 Meteorites 19–20 composition 77 differentiated 19 undifferentiated 19 infall 24 Meteors 24 Methane 274 Microbial life delivered to Mars 267 delivered to Earth 267 Microscopic imager 231 Mini-TES 231 Mississippi discharge 117 Missoula Flood discharge 117 Moat around canyon sediments 106 Molecular phylogeny 269 Moment of inertia 77 Montes Cordillera 27 Montes Rook 27 Moon, formation 277 Moraines 160, 187 Moăssbauer Spectrometer 232 Multi-ringed basins 26–7 Nakhla 20 Nanedi Vallis 133, 136, 142, 144, 262 Nanobacteria 273 Nanophase iron oxide 240 Navcams 231 Neukum crater size distribution curve 40, 41 Index 304 Neutral buoyancy 62, 88 Newton Crater 145 Niger Vallis 68, 129, 131, 136, 144 Nili Fossae 84 Nili Patera 72 Nilosyrtis 120 Nirgal Vallis 136, 137, 142, 144, 257, 262 Noachian 277 climate 257 craters with flat floors 151 hydrologic cycle 258 surface below northern plains 80 high impact rates 277 number of superposed craters 15 similar conditions on Earth and Mars 281 warm conditions 278 Noctis Labyrinthus 48, 92, 95–7 caused by extensional faulting 97 Nontronite 202 North polar basin 163 North pole 213 stratigraphy 218 basal unit 220 Northern Ocean, fate 168 ice cover 168 sublimation stage 160 Northern plains 149 contacts 164–7 depth to Noachian surface 162 regional slope 163 evidence for ice 168 formed by giant impact 160 multiple depressions 161 source of evaporites 254 Nue´es Ardentes 57 Obliquity 2, 4, 11, 16, 177, 272 variations 257 chaotic nature 4–5 affects poles 173 affects ice deposition 187 Ocean formation, climate effects 262 Ocean volumes 149, 167 Oceans in Noachian 143, 149, 278 post Noachian 149, 167 temporary 144 northern plains 160–71, 278 Oceans release CO2 262 Oceans, boiled away by large impacts 270 Olympia Planitia 212, 213, 218 Olympica Fossae 87, 121, 122 Olympus Mons 2, 17, 46, 48, 51–3, 84, 190, 279 pressure at summit summit elevation summit caldera 51, 53 cliff 51, 53 mesas 51 aureole 51–3, 67 outflow channels 122, 123 aureole 167 Ophir Chasma 88, 96, 97, 99 layered deposits 97, 105, 107, 108 moat 109 Opportunity 244–54 landing site 244, 247, 249 Opposition Orbit period 16 semimajor axis 16 Orbital and rotational motions, climate effects 264 Orbits, Earth and Mars Organic compounds, scarcity 271 Orientale basin 27 Outflow channel discharges 116 overestimated 116 Outflow channels 113–31, 279 Hesperian in age 111 merge with canyons 96, 100 formed by glaciers 114 lava erosion 114 debris flows 114 origin 117–21 start in rubble filled hollows 119 mostly post-Noachain 262 Chryse basin 115 Oxygen isotopes 20 Ozone Palagonite 202 Paleocrater lakes 152 Palos 150, 152 Pancam 231 Parana Chaos 151 Parana Vallis 133, 150, 155 Partial melting 44 Particulate transportation 194 Paterae 43 Pathfinder 21, 114, 205, 230, 231 Pavonis Mons 18, 46, 48, 50, 188 summit caldera 49 rifts on flanks 49 Peace rocks 241 clastic component 241 soft 241 lherzolite component 241 high sulfur content 241 MgÀCa-sulfate cement 241 Pedestal craters 35, 36, 204, 208, 244 confusion with volcanic craters 35 Pelean eruption 45 Perihelion 1–3, 16 Permafrost 175–7 active zone 176 Phase changes in mantle 85 Phase diagram, H2O and CO2 12 Phobos 35 Photosynthetic organisms 268 Phreatomagmatic eruption 63, 64 Phyllosilicates 143 Pillow lavas 73 Pineus Patera 69, 73 Pit caters 88 Plains 17, 70–2 Plate tectonics 18, 43 Platey flows, described 65–7 compared to terrestrial lava flows 66 ascribed to pack ice 67 Index Playa 254 deposits 248, 253 Plinian type eruptions 45, 46 Plucked zones in outflow channels 114 Plutonic rocks 44 Polar basin depth 161 Polar cap, residual H2O north 173, 216 residual CO2 south 173 Polar deposits 19, 204 Polar environment 211–12 Polar profiles 215 Polar recharge 142, 225 Polar terrains, description 212 Pollack crater 209 Polycyclic aromatic hydrocarbons 273 Polygonal ground 161, 176, 189–91 Post-Noachian climates 257 Precession 3–4 Precipitation 143, 258, 278 Proglacial lake 187 Prometheus 142, 212, 221 Pseudocraters 72 Pyroclastic flow 46 Pyroclasts 45 Quasi-circular depressions 27 Radii, equatorial and polar 1, 5, 16 Rahway Valles 66, 127 Rain, hot rock 270 Rainfall 140 caused by impacts 260 Rarefaction waves 29 Ravi Chasma 96 Chaos 115 Vallis 114, 118–20 Rays 24, 41 Recrystallization 249 Recycling of CO2 Reduced gases 258, 259 Residual north cap 211, 218 Residual south CO2 cap 217, 225, 227, 233, 280 underlying water-ice 226 dissipating 226 Retention of CO2 atmosphere 260 Returned samples 274 Reull Vallis 130, 131, 178 Ribosomal RNA 269, 270 Ridged plains 71–2, 162–4 mainly Hesperian in age 72 volcanic nature of 72 all around Tharsis 162 Ripples 198, 207, 250 Rock Abrasion Tool 232 Rock glaciers 176, 182, 189 Saltation 8, 193, 194, 198 Samara Vallis 133, 139 longitudinal profile 140 Sand grains 239 Sand sheets 248, 251 Sapping features 262 Schiaparelli 152 305 Seasons 2, 3, 16 Secondary caters 23, 27, 30 Sediment mounds 156, 244 Sedimentation 143 Sediments, marine 167–8 Serinum, lobate scarps 90 fossae 84, 88, 92 Shalbatana Vallis 114, 118, 120 Shear failure 86 Shergotty 20 Sherman landslide, Alaska 105 Shield volcanoes 43 Shock pressures 27 Shock waves 27, 31 Shorelines 164–8 Hellas 161 Siderophile elements 20, 77 Simud Vallis 111, 114, 115, 120 Sinai Planum Slope failure 64 Slope streaks 199 Snow at high obliquity 144 melting 262 deposition 265 Snowball Crater 25 SO2 in atmosphere 259 Softened terrain 181 Soils, basaltic 229 sulfur rich 229, 231 oxidants 229 Solar constant, mean Mars 16 Solar day 16 Solar Nebula 19 Solis Planum 93 vertical offset across wrinkle ridges 90 wrinkle ridge 89, 90 South pole 214, 217, 221–6 Spallation 20 Spatter ramparts 66 Spherules 246, 252 Spiral valleys 212 north pole 213 Spirit Rover 232–8 Spring, northern 2, Springs, groundwater 257 Star-shaped dunes 205 Sterilizing conditions, early Earth 270 Stony irons 19 Strahler stream order 134 Strandlines, Hellas 158, 160 volume enclosed 159 Stratigraphic systems 15 Stratocone 43 Stratosphere Stream profiles 139 Stress centers 92 change with time 92 Stresses, caused by Tharsis 84 Striae in outflow channels 114 Strike-slip fault 86 Stromatolites 269 Strombolian eruption 45 Sublimation hollows 191 Index 306 Sulfates 239, 242, 244 in canyons 119 in Gusev soils 238 in Columbia Hills rocks 238–44 in the Burns formation 246, 248 Sulfur in core 77 Summer, northern Summer, southern Sun luminosity 140, 258 Surface area, Mars 5, 16 Surface deformation 18 Surface markings Surface morphology, interpretation of 14 Surface Pressure Surface relief, range Surface runoff 131, 257, 258 Surficial, ice-rich deposits 177–8 stippled texture 177 pervasively pitted 177 ice-cemented dust 177 deposited at high obliquity 177 Survival of life 272–3 Swiss cheese terrain 226 Syria Planum 46, 48, 70 Syria-Thaumasia block 92, 93 Syrtis Major 1, 5, 75, 207 Planum 71, 72 Table mountains 73, 74 Tails 231 Tartarus Colles 64, 122 Teardrop islands 114, 116 Tempe Fossae 92 Tempe Terra 80 graben 84 Temperature vs depth below surface 11 Temperatures, surface 9–11, 259 polar needed for life 271 Tensile failure 86 Tension cracks 87 Terby 155 Terra Cimmeria, highly dissected 132 magnetic anomalies 78 Terra Meridiani, dissected by long valleys 132 Terra Serinum 150 magnetic anomalies 78 Terraces 150, 151 in crater 153 Terrain softening 179–80 Terrestrial life, common ancestor 269 Terrestrial life, range of condition it survives 272 Terrestrial rifts 111 Tharsis 17, 18, 21, 33, 43, 46–59, 70, 77, 84, 114, 174 formation 84–6 formed by accumulation of volcanics 85, 277 volcanic feed-back 82 impact induced thermal anomaly 85 load 85, 92 antipode 85 caused global flexure 85, 90–3, 277 already built in Noachian 85, 86 buries global dichotomy 79 no isostatic support 92 gravity low around 86 radial faults 18, 97, 277, 279 deformational features 91 Tharsis bulge 5, 18, 46, 68 summit 95, 96 Tharsis province 47, 48 Tharsis shields, small 57–9 partly buried 59 possibly built in Noachian 59 Tharsis Tholus 57 Tharsis trough 85 negative gravity anomaly 85 Tharsis volcanoes, preferred sites of ice deposition 187 THEMIS Type 1, Type surfaces 44 Thermal gradient 84, 85 Thermal inertia 9, 174 low regions as dust sinks 197 Thermal models 84 Thermokarst 176, 191 Thira 234 Threshold wind speeds for particle dislodgement 195 Thrust faults 90 Thumbprint terrain 168, 169 Time Stratigraphic Units 16 Tinjar Valles 65, 127, 128 Tinto Vallis 152 Tithonium Chasma 97 Tiu Vallis 111, 114, 115, 231 Topography, bimodal distribution 79 Transient brightenings Transverse dunes 204 Tropopause Troposphere Tuyas 73 Tyrrhena patera 69, 74 channels 69 mainly ash 69 Tyrrhena Planum 69 Ultramafic rocks 244 Ultraviolet photolysis 258 Uranius Patera 46, 57, 59 Uranius Tholus 57, 58 Utopia 27, 33, 83, 229, 230 basin 190 basin depth 161 Utopia valleys 127–9 formation of 127 UV flux 271 Uzboi Vallis 130, 157 Valles Marineris 18, 95–112 Valley cross-sections 135 Valley networks 257 decline in rate of formation 278 global distribution 132 Valleys described 132–7 origin 139–40 analogous to terrestrial valleys 131 cold-climate features 131 inner channels 133 ages 136 Index post-Noachian 144, 262 formation rate 137 Hesperian 279 on volcanoes 265 Vastitas Borealis Formation 72, 165, 167–70, 212 volume 168 textures 168 outer contact 168 Ventifacts 205 Viking-1 201, 230 Viking-2 230 landers 229, 267 landing sites 8, 9, 206 biology Experiment 229 Volatility of elements 19 Volcanic events, effect on climate 264 Volcanic mounds 46, 59 Volcanic plume 46 Volcanics, cumulative volume since Noachain 73 mostly basaltic 279 Volcanism, rates 18 effect of martian conditions 44–6 sub-ice 74 Volcanoes 17–8 dissected 132, 136 martian and terrestrial compared 43 around Hellas 69 Volcano-ice interactions 73–4 Vulcanian eruption 45 Warm climate episodes 131, 272 Warm conditions, Noachian 143 post-Noachian 144, 262 created by large impacts 144 Warrego Vallis 138 Watchtower rocks 241, 245, 246 components 241 stratified 241 impact ejecta 241 altered by hydrothermal fluids 242 307 Water vapor over north pole 212, 214 Water, distribution near-surface 13 Water, lost to space 168 in polar cap 171 in cryosphere 171 Water, role played in surface evolution 18–19 Water-ice below CO2 southern cap 212 Water-ice stability 12 effects of obliquity 13 Water-ice, ground content 12–13 Wave of darkening Weathering 260 removal of atmospheric CO2 260 Weathering rates 262 overestimated 260 West Spur 243 Western hemisphere White Rock 153, 209 Wind erosion 204–5 Wind streaks 197–8, 207 depositional 197, 198 erosional 197 frost 198 Wind-abraded rocks 210 Winds Wishstone rocks 240 ash-flow tuffs 240 formed during explosive event 241 minimally altered 241 Wrinkle ridges 71, 89, 90 circumferential to Tharsis 89, 92 height and spacing 167 Xe mass fractionated 258 Yardangs 208 Zodiacal light 24 Zunil 30 .. .The Surface of Mars Our knowledge of Mars has grown enormously over the last decade as a result of the Mars Global Surveyor, Mars Odyssey, Mars Express, and the two Mars Rover missions... summary of what we have learnt about the geological evolution of Mars as a result of these missions, and builds on the themes of the author’s previous book on this topic The surface of Mars has... denote time of year This is the equivalent of the Sun-centered angle between the position of Mars in its orbit and the position of the northern spring equinox At the start of northern spring