Séminaire ISTeP - Julien Charreau

(CRPG , Université de Lorraine)

Unsteady topography in Central Asia due to imbalance between denudation and crustal thickening

The Tianshan mountains have complex and variable topography characterized by intermountain basins separated by individual ranges. Documenting the growth of this range is important for understanding both intracontinental mountain building. To this aim, we investigate whether the complex Tianshan topography is in equilibrium with crustal influx (thickening) and sediment outflux (denudation). Based on morphotectonic analyses, we estimate the total Pleistocene shortening accommodated across the eastern Tianshan. We also measured in-situ cosmogenic ¹⁰Be concentrations in modern and past river sands to constrain modern (0-2 ka) and Pleistocene basin-averaged denudation rates within the range and on its northern and southern flanks. These results show that crustal thickening and topographic growth outpaced denudation and sediment outflux by a factor of ~10. The origin of this disequilibrium will be discussed and the geometry of the Tianshan compared to other convergent mountain ranges around the world to better understand mechanisms of intracontinental mountain building.

Ce séminaire/webinaire se tiendra en présentiel en salle Fourcade (46-56, 5ème étage) ainsi qu'en ligne à partir de 12h30 via le lien Zoom ci-dessous.

Topic: Julien Charreau's seminar
Time: Jun 10, 2022 12:15 PM Paris
https://zoom.us/j/92499547021?pwd=L2kvWU5FY0J4UUVIMXJObFlLcmVyUT09
Meeting ID: 924 9954 7021
Passcode: Q0x1Jh