Himalaya: Dynamics of a Giant, Geodynamic Setting of the Himalayan Range

Rodolphe Cattin is a professor at the University of Montpellier, France. His activities performed in the Himalaya are on crustal structure imaging from ground and satellite observations, river dynamics and stress transfer associated with seismic events and surface processes.Jean-Luc Epard obtained his PhD from the University of Lausanne, Switzerland (structural and Alpine geology) in 1990. He has been involved in 14 field expeditions in the Himalaya as participant or leader. His main area of expertise is the Mandi-Manali-Leh transect (India).

• Tributes xiEduardo GARZANTI, Vincent GODARD, Rodolphe CATTIN, György HETÉNYI, Jean-Luc EPARD and Martin ROBYRForeword xviiRodolphe CATTIN and Jean-Luc EPARDPreface From Research to Education: The Example of the Seismology at School in Nepal Program xixGyörgy HETÉNYI and Shiba SUBEDIPart 1 Tectonic Framework of the Himalaya and Tibet 1Chapter 1 Plate Reconstructions and Mantle Dynamics Leading to the India-Asia Collision 3Gweltaz MAHÉO and Guillaume DUPONT-NIVET1.1 Introduction 31.2 The India-Asia convergence and the age of the collision 61.2.1 The India-Asia convergence 61.2.2 The age of the India-Asia collision 71.3 Plate collision configurations 141.3.1 Reconstructing lost continental margins 141.3.2 Alternative collision configurations 161.4 Reconstruction of the Neotethys Ocean closure dynamic 171.4.1 Number of subduction accommodating the Neotethys closure 171.4.2 Location of the Intraoceanic subduction zone and associated arc 191.4.3 Driving forces of the India-Asia convergence during Neotethys closure 201.5 Conclusion 231.6 References 23Chapter 2 Building the Tibetan Plateau During the Collision Between the India and Asia Plates 33Anne REPLUMAZ, Cécile LASSERRE, Stéphane GUILLOT, Marie-Luce CHEVALIER, Fabio A CAPITANIO, Francesca FUNICIELLO, Fanny GOUSSIN and Shiguang WANG2.1 Introduction 332.2 Present-day Tibetan crustal deformation 362.2.1 GPS velocity field and focal mechanisms in Tibet 362.2.2 Surface motions and deformation due to Indian indentation 382.3 Tibetan lithospheric mantle subduction during collision 392.3.1 Imaging ongoing subduction beneath Tibet 392.3.2 Imaging subduction of lithospheric Tibetan mantle during the collision 412.3.3 Volcanism in Tibet showing the subduction of lithospheric Asian mantle during the early collision 432.4 Modeling the Tibetan plateau formation during the indentation of the Indian continent into Asia 452.4.1 Analogue modeling of the Tibetan lithosphere subduction during the indentation of India 462.4.2 Numerical modeling of Asian thickening and extrusion during the subduction of a continental-oceanic plate 492.5 Conclusion 512.6 References 52Chapter 3 The Major Thrust Faults and Shear Zones 57Djordje GRUJIC and Isabelle COUTAND3.1 Introduction 573.2 Some basic concepts 583.3 Main faults and shear zones 593.3.1 South Tibetan detachment system (STDS) 603.3.2 Main Central thrust (MCT) 673.3.3 Main Boundary thrust (MBT) 743.3.4 Main Frontal thrust (MFT) 773.3.5 Main Himalayan thrust (MHT), continental megathrust 813.4 Tectonic models 813.4.1 Fold-and-thrust belt versus channel flow 813.4.2 Coeval slip along the STDS and the MCT 843.5 Conclusion 873.6 References 87Part 2 Along Strike Variations 101Chapter 4 Seismological Imaging and Current Seismicity of the Himalayan Arc 103György HETÉNYI, Jérôme VERGNE, Laurent BOLLINGER, Shiba SUBEDI, Konstantinos MICHAILOS and Dowchu DRUKPA4.1 Introduction 1034.2 Imaging by elastic waves 1044.2.1 Active seismics 1054.2.2 Passive seismics 1054.2.3 Tomographic imaging for bulk properties 1064.2.4 Wave reflections and conversions for interfaces 1074.3 Exploring the Central Himalaya along cross-sections 1084.3.1 Field experiments 1084.3.2 Main interfaces 1094.3.3 Where do subducted plates go? 1154.4 Lateral variations 1164.4.1 Lateral ramps on the MHT, along-arc Moho variations 1164.4.2 Segmentation of the India plate lithosphere 1174.4.3 The western and eastern syntaxes 1194.5 Current seismicity of the Himalaya 1204.5.1 Earthquake detection, location and activity 1204.5.2 Seismicity of the Himalaya: an incomplete patchwork 1214.5.3 Seismicity of the Himalaya: main features 1234.6 Conclusion 1254.7 References 126Chapter 5 Gravity Observations and Models Along the Himalayan Arc 129Rodolphe CATTIN, György HETÉNYI, Théo BERTHET and Jamyang CHOPHEL5.1 Introduction 1295.2 Methods 1305.2.1 Measurements 1305.2.2 Corrections 1315.2.3 Anomalies 1335.3 Isostasy 1345.3.1 Local compensation 1345.3.2 Regional compensation 1365.3.3 Effective elastic thickness 1375.4 Flexure of the Indian plate 1385.4.1 Gravity anomaly across the Himalayan belt 1385.4.2 Along-strike variation between Nepal and Bhutan 1415.5 Satellite data contribution 1435.5.1 Gravity measurements from space 1435.5.2 Towards a three-dimensional image 1455.6 Conclusion 1475.7 References 148Chapter 6 Topographic and Thermochronologic Constraints on the Himalayan Décollement Geometry 151Peter A VAN DER BEEK, Rasmus C THIEDE, Vineet K GAHALAUT and Taylor F SCHILDGEN6.1 Introduction 1516.2 Methods 1566.2.1 Quantitative geomorphic analysis 1566.2.2 Measures of erosion at different timescales: cosmogenic nuclides and thermochronology 1586.2.3 From exhumation to kinematics: thermo-kinematic models 1626.3 Regional case studies 1636.3.1 Central Himalaya-Nepal 1636.4 Discussion 1766.4.1 Constraints on MHT geometry and kinematics at different timescales 1776.4.2 Nature and evolution of ramps on the MHT 1786.4.3 Evidence for out-of-sequence thrusting? 1796.4.4 Lateral segmentation of theMHT 1816.5 Conclusion 1826.6 References 183Part 3 Focus 195Chapter 7 Application of Near-surface Geophysical Methods for Imaging Active Faults in the Himalaya 197Dowchu DRUKPA, Stéphanie GAUTIER and Rodolphe CATTIN7.1 Introduction 1977.2 Near-surface geophysics 1987.2.1 Geophysical methods for fault mapping 2007.2.2 Case study data and inversion technique 2057.3 Geophysical results of case study from south Bhutan 2087.3.1 Electrical resistivity tomography 2087.3.2 Seismic tomography 2117.3.3 Micro-gravity 2137.4 Implications of near-surface geophysical findings 2157.4.1 Subsurface imaging 2157.4.2 Overthrusting slip rate assessment 2167.4.3 Deformation at the topographic front 2187.5 Conclusion 2187.6 References 219Chapter 8 Overview of Hydrothermal Systems in the Nepal Himalaya 225Frédéric GIRAULT, Christian FRANCE-LANORD, Lok Bijaya ADHIKARI, Bishal Nath UPRETI, Kabi Raj PAUDYAL, Ananta Prasad GAJUREL, Pierre AGRINIER, Rémi LOSNO, Sandeep THAPA, Shashi TAMANG, Sudhan Singh MAHAT, Mukunda BHATTARAI, Bharat Prasad KOIRALA, Ratna Mani GUPTA, Kapil MAHARJAN, Nabin Ghising TAMANG, Hélène BOUQUEREL, Jérôme GAILLARDET, Mathieu DELLINGER, François PREVOT, Carine CHADUTEAU, Thomas RIGAUDIER, Nelly ASSAYAG and Frédéric PERRIER8.1 Introduction 2258.2 Measurement methods 2288.2.1 Exploration approach 2288.2.2 Thermal spring water measurements 2298.2.3 CO2 flux and radon flux measurements 2308.2.4 Carbon content and isotopic composition measurements 2318.3 Summary of results at the hydrothermal sites in the Nepal Himalaya 2328.3.1 Overview of hydrothermal sites in Far-Western Nepal 2348.3.2 Overview of hydrothermal sites in Mid-Western Nepal 2358.3.3 Overview of hydrothermal sites in Western Nepal 2388.3.4 Overview of hydrothermal sites in Central Nepal 2408.3.5 Overview of hydrothermal sites in Eastern Nepal 2468.3.6 Overview of hydrothermal sites in the MFT zone 2468.4 Conclusion 2478.5 References 248Conclusion 255Rodolphe CATTIN and Jean-Luc EPARDList of Authors 257Index 263Summaries of other volumes 267