For the past 50 million years, India has been crashing into mainland Asia, creating the Himalayan range and uplifting Tibet, north of the mountains, to a current average height of 4500 meters above sea level.

But why is Tibet the one getting an uplift? Why isn't India, instead?

  • $\begingroup$ Well, for one, the Indian plate is under thrusting beneath the Eurasian plate. Also, the broadness of the Tibetan plateau is likely related to lower crustal processes. $\endgroup$ – stali Apr 24 '16 at 1:33
  • $\begingroup$ Could you clarify, please? $\endgroup$ – JohnWDailey Apr 24 '16 at 2:07
  • $\begingroup$ @gansub Why bring it up as though it were a big issue? $\endgroup$ – JohnWDailey Apr 25 '16 at 12:24

The simple answer is 'crustal thickness'. The two crustal plates of India and Eurasia are very different in character. The Indian plate is thin, the Eurasian plate is much thicker and more rigid. Both plates are so buoyant with respect to the underlying mantle that neither can subduct in the normal sense. But India is moving so fast that something has to give. The Indian plate is buckling a bit, but mostly being under=plated at low angle as the Eurasian plate rides over it - as it did is such spectacular fashion during last year's Nepalese earthquake.

PS the main continent-continent crunch occurred some 40 to 20 million years ago.

  • $\begingroup$ I don't understand the PS part. $\endgroup$ – JohnWDailey Apr 25 '16 at 22:56
  • $\begingroup$ John W.D. mentioned that India has been crashing into Asia for the last 50 million years, which is true in a way, but it's more complicated than that. Although the process still continues the main collision period was about 40 to 20 million years ago. See, for example, the tectonic section of my paper "A palaeo-hydrogeological model for arsenic contamination in southern and southeast Asia" Env. Geochemistry & Health. (2005) 27, 359-367. $\endgroup$ – Gordon Stanger Apr 26 '16 at 9:39
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    $\begingroup$ This answer would benefit from some references and/or links. $\endgroup$ – kwinkunks Apr 26 '16 at 14:02
  • $\begingroup$ That makes me curious what some of the larger earthquakes were like 20-40 million years ago. Nice, interesting answer. (not disagreeing with @kwinkunks on more links), but, I learned something reading that. $\endgroup$ – userLTK May 23 '16 at 4:16
  • $\begingroup$ Another good read is Kumar et al (2007). nature.com/nature/journal/v449/n7164/abs/nature06214.html $\endgroup$ – user2821 Jun 1 '16 at 9:04

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