The Interrelations of Post-Collision Tectonism and Sedimentation in Central Asia

  1. L. E. Frostick2 and
  2. R. J. Steel3
  1. M. E. Brookfield

Published Online: 16 APR 2009

DOI: 10.1002/9781444304053.ch2

Tectonic Controls and Signatures in Sedimentary Successions

Tectonic Controls and Signatures in Sedimentary Successions

How to Cite

Brookfield, M. E. (1994) The Interrelations of Post-Collision Tectonism and Sedimentation in Central Asia, in Tectonic Controls and Signatures in Sedimentary Successions (eds L. E. Frostick and R. J. Steel), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304053.ch2

Editor Information

  1. 2

    Reading, UK

  2. 3

    Bergen, Norway

Author Information

  1. Land Resource Science, Guelph University, Guelph, Ontario N1G 2W1, Canada

Publication History

  1. Published Online: 16 APR 2009
  2. Published Print: 28 FEB 1994

ISBN Information

Print ISBN: 9780632037452

Online ISBN: 9781444304053

SEARCH

Keywords:

  • sedimentary response to tectonic events;
  • post-collision tectonism and sedimentation in Central Asia;
  • early Miocene internal deformation of Tibetian and East Pamir plateau;
  • neotectonic evidence;
  • sediment budget studies;
  • river gradient studies;
  • radiometric and fission track dating;
  • basins and mountains;
  • southern foredeep

Summary

During the Late Tertiary the northwest Himalaya and adjacent ranges underwent progressively increasing uplift associated with crustal thickening and differential erosion. At the same time the adjacent Tarim and Tadjik basins and the Himalayan foredeeps subsided accumulating thick piles of clastic sediments. The ages of these accumulations have been used to infer contemporary tectonism in the mountains. Radiometric and fission track dating together with faunal and floral studies and sediment budget and river drainage studies allow gross rates of uplift and subsidence to be compared with net rates for different areas. These studies show that the bulk of the derived clastics were eroded from the fronts of the Karakorum, Himalayan and Pamir allochthons during progressively increasing rates of uplift and thrusting from Early Miocene times onwards. Nevertheless, cooling Cenozoic climates, partly driven by uplift, have also contributed to increasing physical erosion and coarsening of the deposited sediments through time. Furthermore, each range shows an independent history of uplift and erosion within the framework of generally increasing uplift and erosion in Late Tertiary times. Contemporary deposition in adjacent basins is partly dependent on the timing of adjacent uplifts. But uplift and deposition also depend on erosion and deposition along the courses of major rivers – which have not remained constant. The thickness of sediment accumulating in marginal basins and the isostatic uplift of ranges depend on when the river changed its course, on when and how much temporary storage occurred within intermontane basins, and the time at which the intermontane barriers were breached and their sediments eroded. In some cases, e.g. the Indus, Tsangpo, Salween and Mekong, the rivers have even switched into different major oceans or basins. Coarse clastic sediment pulses cannot be used to infer increased tectonism in adjacent ranges.