1,2,1,2- 1Zhejiang Deep-time Digital Earth International Research Center, Hangzhou, China
- 2International Lithosphere Centre, Zealand, Denmark
- 3China Earthquake Administration, Beijing, China
- 4Yangtze University, Wuhan, China
The processes causing the uplift of the world’s highest continental plateaux in Tibet, the Andes and East Anatolia are enigmatic. A number of tectonomagmatic processes are proposed, and it is generally believed that the crustal structure is the key to explaining their high topography. Key factors affecting the crustal structure include the metamorphic formation of eclogitic rocks from lower crustal material, underplating and partial melting of the crust.
We show that the whole continental crust has low seismic velocity (<6.7 km/s) in the central Lhasa terrane of Tibet, which indicates that this thickest crust on Earth is felsic down to the Moho at 80 km depth. This formation of overthickened crust may have led to metamorphic formation of large amounts of dense, eclogitic lower crustal rocks immediately after formation with subsequent delamination, leaving behind a purely felsic crust with a thickness of up-to 80 km. This process has contributed significantly to the rise of this part of the Tibetan Plateau1.
Based on our new receiver function interpretation of the East Anatolian Plateau and the transition into the Arabian Shield, integrated with results from seismic tomography, MT and geochemical studies, we demonstrate the presence of an up-to 20 km thick underplated layer and a 10 km thick intra-crustal partially molten layer. The low density of these layers explains isostatically the high topography in eastern Anatolia2. The thicker crust in Tibet and the Andes show similar characteristics, and by a comparative study we show that the high topography of all three plateaux can be explained by isostatic uplift due the low density of these layers containing pockets of partially molten rocks.
1 Wang, G., Thybo, H. & Artemieva, I. M. No mafic layer in 80 km thick Tibetan crust. Nature Communications 12, 1069 (2021). https://doi.org/10.1038/s41467-021-21420-z
2 Zhou, Z., Thybo, H., Artemieva, I. M., Kusky, T. & Tang, C. C. Crustal melting and continent uplift by mafic underplating at convergent boundaries. Nat Commun 15, 9039 (2024). https://doi.org/10.1038/s41467-024-53435-7
How to cite: Thybo, H., Zhou, Z., Wang, G., and Artemieva, I.: Continental plateaux uplift by crustal melting, underplating and eclogitization, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10934, https://doi.org/10.5194/egusphere-egu26-10934, 2026.
