Iceland Within the Northern Atlantic, Volume 2 (eBook)

Brigitte Van Vliet-Lanoë is Emeritus Research Director at CNRS and is part of the Ocean Geosciences Laboratory at the University of Western Brittany, France. A surface geologist, she is a specialist in stratigraphy and the sedimentary formations of cold continental environments and their deformation by paleoseismicity.

List of Abbreviations ix

Preface xv
Brigitte VAN VLIET-LANOË and Françoise BERGERAT

Introduction xix
Brigitte VAN VLIET-LANOË and René MAURY

Chapter 1. Young Icelandic Volcanism and its Implications 1
René MAURY and Brigitte VAN VLIET-LANOË

1.1. Introduction 1

1.2. Icelandic magma series 3

1.2.1. Lava types 3

1.2.2. Geochemical diversity of young Icelandic basalts and their sources 8

1.2.3. Some geochemical constraints concerning the origin and geodynamic evolution of Iceland 13

1.3. Central volcanoes and active fissural systems 14

1.3.1. Central volcanoes 14

1.3.2. Fissural volcanism and subaerial lava flows 17

1.3.3. Hydromagmatism 26

1.4. Volcanic hazards in Iceland 31

1.4.1. Hazards related to lava flows 31

1.4.2. Hazards related to explosions and gas emissions 32

1.4.3. Jökulhlaups and associated hazards 37

1.4.4. Icelandic dust: a consequence of volcanism 44

1.5. References 51

Chapter 2. Volcanism and Glaciations: Forcings and Chronometers 57
Hervé GUILLOU, René MAURY and Brigitte VAN VLIET-LANOË

2.1. Subglacial volcanic landforms 57

2.1.1. Subglacial isolated volcanoes or tuyas 58

2.1.2. Hyaloclastite ridges or tindar 61

2.2. Volcanism, deglaciation and climate 65

2.2.1. General features: deglaciation, discharge and partial melting 65

2.2.2. Deglaciation and climate feedback 69

2.3. The hypothesis of a link between volcanism and climate and its test by dating 70

2.3.1. The K-Ar chronometer 71

2.3.2. The combination of K-Ar and 40Ar/39Ar methods for dating Icelandic volcanism 80

2.3.3. A link between volcanism and climate according to K-Ar ages? 86

2.3.4. A rhyolitic volcanism synchronous with deglaciations? 88

2.4. References 95

Chapter 3. Cenozoic Evolution of Iceland and the Cryosphere 103
Brigitte VAN VLIET-LANOË and Hervé GUILLOU

3.1. Ice ages and the opening of the Atlantic 103

3.1.1. The Middle and Final Miocene cooling 108

3.1.2. The acceleration of the Middle Pliocene 109

3.1.3. The Middle Pleistocene Transition 112

3.1.4. The initiation of thermohaline circulation 114

3.2. Iceland's Quaternary glaciations 116

3.2.1. Conditions for the development and functioning of ice caps 116

3.2.2. Glacio-isostasy 119

3.2.3. Icelandic data 123

3.2.4. The Icelandic record 126

3.3. The last glacial episode and its deglaciation 142

3.3.1. The Weichselian 142

3.3.2. The Last Glacial Maximum 144

3.3.3. Deglaciation and the Holocene 150

3.4. Iceland today, its climate and vegetation 161

3.4.1. The climate 161

3.4.2. Ocean circulation and climate 162

3.4.3. Soil, people and climate 167

3.4.4. Soils and erosion 173

3.5. References 179

Conclusion 193
Brigitte VAN VLIET-LANOË, René MAURY and Hervé GUILLOU

References 199

List of Authors 213

Index 215

Summary of Volume 1 221