Petrology of Indus River sands: a key to interpret erosion history of the Western Himalayan Syntaxis

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

10

Scientific paper

The Indus River has been progressively transformed in the last decades into a tightly regulated system of dams and channels, to produce food and energy for the rapidly growing population of Pakistan. Nevertheless, Indus River sands as far as the delta largely retain their distinct feldspar- and amphibole-rich composition, which is unique with respect to all other major rivers draining the Alpine Himalayan belt except for the Brahmaputra. Both the Indus and Brahmaputra Rivers flow for half of their course along the India Asia suture zone, and receive major contributions from both Asian active-margin batholiths and upper-amphibolite-facies domes rapidly exhumed at the Western and Eastern Himalayan syntaxes. Composition of Indus sands changes repeatedly and markedly in Ladakh and Baltistan, indicating overwhelming sediment flux from each successive tributary as the syntaxis is approached. Provenance estimates based on our integrated petrographic mineralogical data set indicate that active-margin units (Karakorum and Transhimalayan arcs) provide ˜81% of the 250±50 106 t of sediments reaching the Tarbela reservoir each year. Partitioning of such flux among tributaries and among source units allows us to tentatively assess sediment yields from major subcatchments. Extreme yields and erosion rates are calculated for both the Karakorum Belt (up to 12,500±4700 t/km2 year and 4.5±1.7 mm/year for the Braldu catchment) and Nanga Parbat Massif (8100±3500 t/km2 year and 3.0±1.3 mm/year). These values approach denudation rates currently estimated for South Karakorum and Nanga Parbat crustal-scale antiforms, and highlight the major influence that rapid tectonic uplift and focused glacial and fluvial erosion of young metamorphic massifs around the Western Himalayan Syntaxis have on sediment budgets of the Indus system. Detailed information on bulk petrography and heavy minerals of modern Indus sands not only represents an effective independent method to constrain denudation rates obtained from temperature time histories of exposed bedrock, but also provides an actualistic reference for collision-orogen provenance, and gives us a key to interpreting provenance and paleodrainage changes recorded by clastic wedges deposited in the Himalayan foreland basin and Arabian Sea during the Cenozoic.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Petrology of Indus River sands: a key to interpret erosion history of the Western Himalayan Syntaxis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Petrology of Indus River sands: a key to interpret erosion history of the Western Himalayan Syntaxis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Petrology of Indus River sands: a key to interpret erosion history of the Western Himalayan Syntaxis will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-898226

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.