Liu S. Z., Xu X. W., Nocquet Jean-Mathieu, Chen G. H., Tan X. B., Jónsson S., Klinger Y. (2025). Lower crustal thickening drives active uplift in Northern Tibet. Earth and Planetary Science Letters, 655, p. 119245 [ p.]. ISSN 0012-821X.
Titre du document
Lower crustal thickening drives active uplift in Northern Tibet
Liu S. Z., Xu X. W., Nocquet Jean-Mathieu, Chen G. H., Tan X. B., Jónsson S., Klinger Y.
Source
Earth and Planetary Science Letters, 2025,
655, p. 119245 [ p.] ISSN 0012-821X
Mountains in collisional orogens generally grow as crustal rocks are advected over low-angle thrust faults, suggesting a close relationship between tectonic uplift and upper crustal shortening. For example, the Himalayas, hosting large-scale thrust fault systems, undergoes similar to 15-20 mm/year shortening and concomitant similar to 5 mm/year active uplift. However, geodetic observations reveal an active uplift of 1-2 mm/year across the East Kunlun Shan mountain range, the northern margin of the Tibetan Plateau, where no active thrust fault has been identified. This active uplift is too fast to be explained by the limited horizontal shortening of at most 1.0 +/- 0.2 mm/year. After quantifying and correcting for contributions arising from erosion, (de)glaciation, and recent earthquakes, the uplift rate across the East Kunlun Shan still amounts to 1.0 +/- 0.5 mm/year. Our simulations show that mantle processes cannot explain the GPS-observed uplift. We find that lower crustal thickening, rather than upper crustal shortening alone, drives the ongoing uplift across the East Kunlun Shan, hence challenging our current views on mountain range dynamics.
