Skip to Main content Skip to Navigation
Conference papers

Switch from longitudinal to transverse drainage during mountain building: as case study from the Himalaya

Abstract : One of the greatest challenges in the study of the evolution of mountain ranges is determining the history of the development of longitudinal and transverse drainages. It has been proposed that the increase of the regional slope during mountain building primarily controls the evolution of the drainage pattern from longitudinal to transverse. Incipient crustal shortening in the upper crust is generally characterized by the detachment of the sedimentary cover from its basement resulting in folding and thrusting, and the undulation of Earth's surface. Folding and thrusting induce local slopes counter to the regional slope, which force the water path in the direction of the fold axes and thrust faults, that is, perpendicular to the regional slope. Enhanced regional slope and erosion in the upper crust, which removes the sedimentary cover during mountain building, result in the capture of the longitudinal rivers by the headward migration of the transverse rivers, and eventually by the progressive replacement of the whole longitudinal-dominated drainage by a transverse-dominated drainage. This evolution accounts for the common observation of the persistence of longitudinal drains where the sedimentary cover has been partly preserved, and for the dominance of transverse drains where the lower ductile crust has been exhumed. Based on a geomorphological analysis calibrated by published long-term (Apatite Fission Track) erosion rates and, new and published short-term (terrestrial cosmogenic nuclide) erosion rates it can be shown that the drainage of the NW Himalaya is evolving in a similar way. Long-term and short-term erosion rates show that the drainage divide between the transverse Beas river (NW India) and the longitudinal Chenab river, located farther in the hinterland, is migrating to the north at 1.5 ± 1.55 mm/yr and 1.7 ± 0.7 mm/yr, respectively. Divide migration to the North will eventually involve the capture of the upper reaches of the longitudinal Chenab river in ~2 ± 1 Ma. At the scale of the central and eastern Himalaya, this evolution from longitudinal-dominated to transverse-dominated drainage is enhanced by the strong difference in elevation of the efficient base level of the rivers on each side of the chain, which induces the inevitably northward migration of the main divide.
Document type :
Conference papers
Complete list of metadatas

https://hal-insu.archives-ouvertes.fr/insu-00948866
Contributor : Isabelle Dubigeon <>
Submitted on : Tuesday, February 18, 2014 - 4:35:11 PM
Last modification on : Friday, April 5, 2019 - 8:17:32 PM

Identifiers

  • HAL Id : insu-00948866, version 1

Collections

Citation

Julien Babault, A. Capo, Jean van den Driessche, L. Owen, M. Caffee. Switch from longitudinal to transverse drainage during mountain building: as case study from the Himalaya. AGU Fall Meeting 2013, Dec 2013, San Francisco, United States. pp.EP43E-05. ⟨insu-00948866⟩

Share

Metrics

Record views

138