Plissements précurseurs et plissements tardifs des chaines de montagnes.

Discours d'ouverture de la 101° session de la société helvétique des Sciences Naturelles, prononcé le 30 aout 1920 à Neuchâtel .Proposition d'une théorie tectonique sur la formation des chaines de montagnes et particuliérement des Alpes

La tectonique de l'Asie. Conférence faite á Bruxelles, le 10 août 1922

International audienceExposé sur la tectonique de l'Asie , avec des coupes interprétatives nouvelles pour l'époque (1922)

About the lithospheric structure of central Tibet based on seismic data from the INDEPTH III profile

Signals from 11 shots and 8 earthquakes, and numerous teleseismic events were recorded along the 400-km seismic line INDEPTH III in central Tibet and interpreted together with previous seismic and tectonic data. The abnormal behavior of various mantle phases reveals a complex Moho-transition zone, especially in the northern part of the line, in the Changtang Block, where the lower crust and the mantle show unusually low velocities, a shingled appearance of Pn and no low-velocity layer in the upper crust. The strong east-west anisotropy in the Changtang Block is related to an easterly escape movement of the whole lithosphere, facilitated by the warm and weak layers in the lower crust and the upper mantle, bounded apparently by two prominent west-east running fault zones

Evolution and dynamics of a fold-thrust belt: The Sulaiman Range of Pakistan

We present observations and models of the Sulaiman Range of western Pakistan that shed new light on the evolution and deformation of fold-thrust belts. Earthquake source inversions show that the seismic deformation in the range is concentrated in the thick pile of sediments overlying the underthrusting lithosphere of the Indian subcontinent. The slip vectors of the earthquakes vary in strike around the margin of the range, in tandem with the shape of the topography, suggesting that gravitational driving forces arising from the topography play an important role in governing the deformation of the region. Numerical models suggest that the active deformation, and the extreme plan-view curvature of the range, are governed by the presence of weak sediments in a pre-existing basin on the underthrusting Indian Plate. These sediments affect the stress-state in the over-riding mountain range and allow for the rapid propagation of the nose of the range and the development of extreme curvature and laterally varying surface gradients.This study forms part of the NERC- and ESRC-funded project ‘Earthquakes Without Frontiers’. Our thanks go to Jerome Neufeld for many interesting coffee-time discussions, and James Jackson and Dan McKenzie, for comments on the manuscript. We thank Chris Morley and one anonymous reviewer for helpful comments on the manuscript.This article has been accepted for publication in in Geophysical Journal International ©: (2015) 201(2): 683-710, doi: 10.1093/gji/ggv005 , First published online March 9, 2015, Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved

Why ‘the uplift of the Tibetan Plateau’ is a myth?

The often-used phrase ‘the uplift of the Tibetan Plateau’ implies a flat-surfaced Tibet rose as a coherent entity, and that uplift was driven entirely by the collision and northward movement of India. Here, we argue that these are misconceptions derived in large part from simplistic geodynamic and climate modeling, as well as proxy misinterpretation. The growth of Tibet was a complex process involving mostly Mesozoic collisions of several Gondwanan terranes with Asia, thickening the crust and generating complex relief before the arrival of India. In this review, Earth system modeling, paleoaltimetry proxies and fossil finds contribute to a new synthetic view of the topographic evolution of Tibet. A notable feature overlooked in previous models of plateau formation was the persistence through much of the Cenozoic of a wide east–west orientated deep central valley, and the formation of a plateau occurred only in the late Neogene through compression and internal sedimentation

Back arc extension and collision : an experimental approach of the tectonics of Asia

International audienceThe deformation of the eastern Asian lithosphere during the first part of the India-Asia collision was dominated by subduction-related extension interacting with far effects of the collision. In order to investigate the role of large-scale extension in collision tectonics, we performed analogue experiments of indentation with a model of lithosphere subjected to extension. We used a three-layer rheological model of continental lithosphere resting upon an asthenosphere of low viscosity and strained along its southern boundary by a rigid indenter progressing northward. The lithosphere model was scaled to be gravitationally unstable and to spread under its ownweight, so that extension occurred in thewhole model. The eastern boundarywas free or weakly confined and always allowed eastward spreading of the model. We studied the pattern of deformation for different boundary conditions. The experimental pattern of deformation includes a thickened zone in front of the indenter, a major northeast-trending left-lateral shear zone starting from the northwest corner of the indenter, antithetic north-south right-lateral shear zones more or less developed to the east of the indenter, and a purely extensional domain in the southeastern part of the model. In this domain, graben opening is driven by gravitational spreading, whereas it is driven by gravitational spreading and indentation in the northeastern part where grabens opened along strike-slip faults. The results are compared with the Oligo- Miocene deformation pattern of Asia consecutive to the collision of India. Our experiments bring a physical basis to models which favour distributed deformation within a slowly extruded wide region extending from the Baikal Rift to the Okhotsk Sea and to southeast Asia and Indonesia. In this large domain, the opening of backarc basins (Japan Sea, Okinawa Trough, South China Sea) and continental grabens (North China grabens) have been associated with approximately north-south-trending right-lateral strike-slip faults, which accommodated the northward penetration of India into Eurasia