Geodynamics of the Alps 1

Claudio L. Rosenberg, ISTeP, Sorbonne Université, France. Nicolas Bellahsen, ISTeP, Sorbonne Université, France.

Introduction xi
Nicolas BELLAHSEN and Claudio L. ROSENBERG

Part 1 Historical Introduction 1

Chapter 1 Alpine Sections Through Time: A Mirror of Evolving Observations and Thoughts on the Tectonics of the Alps 3
Claudio L. ROSENBERG

1.1 Introduction 3

1.2 Transition from landscape drawings to cross-sections: beginning of the 18th to the first half of the 19th century 5

1.3 Cross-sections between 1840 and 1880: first attempts toward interpretative sections 15

1.4 Cross-sections in the last two decades of the 19th century: the first kinematic interpretations 22

1.5 The beginning of the 20th century: first orogen-scale sections and the description of nappe piles 29

1.6 Argand and the invention of crustal plate tectonics (1916–1924) 42

1.7 Alpine cross-sections after Argand and before Plate Tectonics (1924–1960) 46

1.8 Alpine cross-sections after Plate Tectonics 49

1.8.1 Geophysical interpretations 49

1.8.2 Geological interpretations 53

1.9 Integrating deep geophysical imaging with surface structures (NFP20; Ecors-CROP) 58

1.10 Discussion and conclusion 59

1.10.1 Changing style of cross-sections as a function of changing interpretations of the Alps 59

1.10.2 Historical evolution of the nappe concept as shown by cross-sections 62

1.10.3 Plate Tectonics 65

1.11 References 66

Part 2 Recent and Present-Day Alpine Chain 77

Chapter 2 What We (Possibly) Know About the 3D Structure of Crust and Mantle Beneath the Alpine Chain 79
Anne PAUL

2.1 Introduction 79

2.2 Probing a very complex crust and crust-mantle boundary 83

2.2.1 A quick update on crustal exploration methods 83

2.2.2 Crustal tomography at the scale of the entire Alpine belt 85

2.2.3 Crustal structure imaged along seismic transects across the Alps 89

2.3 Probing subduction slabs and mantle fabrics 96

2.3.1 Subduction slabs 96

2.3.2 Mantle fabrics imaged by seismic anisotropy 103

2.4 Conclusion 106

2.5 Acknowledgments 107

2.6 References 107

Chapter 3 Topography and Landscape Evolution of the Alps 115
Gerit GRADWOHL, Kurt STÜWE, Jörg ROBL and Moritz LIEBL

3.1 Introduction 116

3.2 The Alps today 119

3.3 Deriving the history of topography 122

3.3.1 Morphometric analysis 123

3.3.2 Sediment budget 128

3.3.3 Thermochronometric data 131

3.3.4 Direct surface dating 133

3.4 Landscape evolution since the Eocene 136

3.5 Drivers of topography and landscape evolution 142

3.6 Conclusion 146

3.7 Acknowledgments 147

3.8 References 147

Chapter 4 Late-Orogenic Extension and Current Tectonics in the Western and Central Alps: A Review 161
Christian SUE

4.1 Introduction 162

4.2 Neogene brittle deformation: data analysis 164

4.2.1 Methodology, field strategy and data collection 164

4.2.2 Observations: some typical structures 167

4.2.3 Quantitative analysis of brittle deformation and kinematic synthesis 170

4.2.4 Brittle deformation dating and chronological considerations 174

4.3 From Neogene tectonics to current activity 178

4.3.1 Seismotectonic synthesis 181

4.3.2 Geodetic strain field 184

4.4 Interpretations and discussion: some insights on the alpine geodynamic processes 188

4.4.1 Miocene orogen-parallel extension 188

4.4.2 Plio-quaternary and current orogen-perpendicular extension 189

4.5 Concluding remarks 194

4.6 Acknowledgments 195

4.7 References 195

Part 3 Regional Alpine Studies from Extension to Collision 209

Chapter 5 Tectonic Evolution of the Eastern Alps 211
Walter KURZ, Harald FRITZ, Andreas WÖLFLER

5.1 Introduction 211

5.2 The Eastern Alps: Overview 212

5.3 Tectonic units of the Eastern Alps 218

5.3.1 Units derived from the (Mesozoic to Paleogene) European continent 218

5.3.2 Penninic nappes 221

5.3.3 Adriatic margin 223

5.3.4 Meliata unit 225

5.3.5 Eocene to Miocene magmatism 226

5.4 Distribution and timing of metamorphism within the Eastern Alps 226

5.4.1 Variscan collisional event (Late Devonian to Carboniferous) 226

5.4.2 Permian extensional event 227

5.4.3 Alpine subduction and collision (Late Jurassic to Neogene) (Eo-Alpine and Neo-Alpine event) 228

5.5 Austroalpine paleogeography and tectonics 230

5.5.1 Kinematics and timing of Austroalpine nappe stacking and extension 235

5.5.2 Post Eo-Alpine evolution 241

5.6 Cenozoic tectonics 243

5.6.1 Penninic and Sub-Penninic nappe tectonics 243

5.6.2 Lateral extrusion in the Eastern Alps 252

5.6.3 Constraints on vertical movements – late Alpine cooling 263

5.6.4 Deep structure of the Eastern Alps 264

5.7 Conclusion 266

5.8 References 267

Chapter 6 Alpine Corsica: From Tethys Subduction to Mediterranean Extension 293
Jacques MALAVIEILLE and Giancarlo MOLLI

6.1 Introduction 293

6.2 Overall architecture of Corsica 294

6.3 Corsica as part of the Alps or the Apennines? 296

6.4 Formation and exhumation of the high-pressure rocks in Corsica and the vergence of the subduction 297

6.5 Was there a micro-continent or an arc between Corsica and Adria and what is the origin of the “Nappe Supérieure”? 302

6.6 Age of subduction-related deformations 304

6.7 The role of Apenninic tectonics and the final shaping of Alpine Corsica 307

6.8 The geodynamic model for the Alpine Corsica: from Tethys subduction to Mediterranean extension 308

6.9 Acknowledgments 312

6.10 References 312

List of Authors 323

Index 325

Summaries of other volumes 327