Dunes is the first book in over a decade to incorporate the latest research in this active and fast-developing field. It discusses the shapes, sizes, patterns, distribution, history and care of wind-blown dunes, and covers all aspects of dunes, terrestrial and in the Solar System. * The only book to cover all dunes, terrestrial and in the Solar System, in deserts, on coasts, and in the past * Represents the most current update on the research of dunes for over a decade * Incorporates the latest research to come out of China where the field is most rapidly expanding * Discusses the most recent range of skills and technology now focused on the study of dunes * Brings uptodate a rapidly expanding field

InhaltsangabeList of Figures xi Acknowledgements xv Introduction 1 Part One 1 Wind and Sand 7 Wind versus Bed 7 The Law of the Wall 8 Improving the wind/bed model 9 LiftOff 12 Holding down by gravity 12 Holding down by cohesion 12 Raising by lift 13 Raising by drag 13 Raising by bombardment 14 Thresholds 14 Grain size 16 The slope of the bed 17 The dynamics of water content 17 Crusts 19 Pellets 20 Sand in Motion 20 Saltation 20 Streamers and other medium-scale patterns of saltating sand 22Reptation 22 Creep 23 Other nearsurface activity 23 Suspension 24 The vertical distribution of load and grain size 24 The saturation length 24 The fetch effect 26 The response of a loose bed to erosion by the wind 27 The Transport Rate 27 Shapes, densities and mixtures of size 29 Hard surfaces 30 Rough surfaces 30 Moisture, temperature and humidity 31 Rain 31 References 31 2 Ripples 32 Subtypes 35 Models 36 Flow response 36 Gravity wave 36 Saltation length 37 Shadow zone 37 Mathematical 37 Pattern 38 3 The Form and Behaviour of Free Dunes 39 Definitions 39 Early Stages 39 Start 39 Minimum size 40 The Profile of a Fully Grown Dune 41 Toe 41 Windward slope (or 'stoss slope') 43 Crest 45 Lee slope 46 Movement 53 Turnover time, bulk transport 56 Size 56 Flowhierarchy models 57 Grainsize models 57 The time/supply model 58 References 58 Part Two 1000 to 10,000 m2; 100 to 1000 years 59 4 Pattern in Free Dunes 61 Definitions 61 WindDirectional Regimes 62 Global winds 62 Local wind systems 62 The Classification of Wind-Directional Regimes 65 WindDirectional Regimes and Dune Pattern 66 Transverse Dunes 66 Twodimensional pattern: vertical and downwind 67 Twodimensional pattern: horizontal and transverse to the wind 68 Selforganisation 69 Barchans 71 Quasitransverse patterns 75 Linear Dunes 80 Introduction 80 Models of formation 82 Sand Sheets 88 Dunes with Distinctive Sand 90 Gravel dunes 90 Zibars 91 Clay dunes 92 Lunettes 92 Gypsum dunes 93 Diatomite sands 93 Volcanic sands 93 Snow and ice dunes 94 Niveoaeolian deposits 94 References 94 5 Forced Dunes 96 Dunes Built around Bluff Obstacles 96 Climbing and echo dunes 96 Flanking and lee dunes 97 Clifftop and falling dunes 99 Dunes on Gently Sloping Terrain 99 Reference 99 6 Dunes and Plants 100 Wind, Sand and Plants 100 Rigid objects 100 Spatial pattern 101 Porosity 102 Flexibility 102 Plants as living things 103 The broader time/space framework 104 Dunes among Plants 104 Nebkhas 104 Blowouts 107 Parabolic dunes 109 References 111 7 Coastal Dunes 112 Coastal Dunes and Climate 112 The BeachDune System 114 Exclusively Coastal Dunes 117 Embryo dunes 117 Foredunes ('frontal dunes' or 'retention ridges') 118 Tsunamis 120 Coastal sand sheets 120 References 121 Part Three >0.3 mm; 8 Sand Seas 125 Terms 125 Large Sand Seas 127 Growth and Development 127 Sand Seas in Tectonic Basins 129 Topographically Unconfined Sand Seas 131 Transfer between Sand Seas 133 9 A History of Dune Sand 134 Provenance 134 Recycling 137 Maturation 139 Mineralogy 139 Size characteristics 141 Shape and surface texture 141 Redness 144 Relationships between Dune Fields and the Sources of Their Sand 145 Sourcebordering dune fields 145 Dune fields that have migrated away from their source 145 Sand seas that have taken sand from many local sources 146 The Australian sand seas and some aeolian sandstones 146 References 146 10 A History of Inland Dunes 147 Very Ancient Dunes: Siliceous Windblown Sandstones 147 The Emergence of Familiar Spatial and Dynamic Patterns 151 Dune Historiography 153 Dating 153 Dun

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