32-1 Crustal Thickness Restoration and Paleogeography of the Arabia-Eurasia Collision

Session: Latest Research Advances in Structural Geology and Tectonics (Posters)

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Recent advancements in plate reconstruction modelling techniques account for regions of distributed deformation and crustal thickness changes through time. However, these models can be limited in both detail and spatio-temporal coverage, hampering our ability to comprehensively model past topography and crustal thickness based on tectonic and geodynamic considerations. Using the Arabia-Eurasia collision as a case study, we develop a method to restore crustal thickness using the deformable tectonic reconstruction framework of GPlates software. During reconstruction, we also calculate the associated isostatic topography changes, which allows for the production of self-consistent paleogeography maps. The results can then be compared against other paleogeography and paleoaltimetry constraints as an independent test of the deforming reconstruction model.

Using our method, we develop a new tectonic reconstruction for the Arabia-Eurasia collision based on deforming regions and restoring the crust to a uniform initial thickness of 35 km. We show that our new reconstruction is more consistent with paleogeography constraints than the existing models. In our new reconstruction, the restored continental margins of Arabia and Eurasia overlap from 21-17 Ma, providing a constraint for the timing of hard continental collision. This collision timing is consistent with other evidence from the geological record as well as constraints from a new seismic tomography model that we have developed based on full waveform inversion. This case study demonstrates how our workflow can be used to assess and improve plate reconstructions over time and space (4D) and build self-consistent palaeogeography models. This approach is important for other settings and times throughout Earth history and provides a new, integrative perspective for a range of margin processes.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-5912

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