Fig. 2: Initial settings for the three-dimensional geodynamic model cases constrained by tectonic reconstructions.

a–e Digitalized plate reconstructions. The white dashed boxes show the extents of the geodynamic models. The thin black lines represent present-day coastlines. Abbreviations for the reconstructions were assigned on the basis of the first letter of the first author’s name and the year of paper publication, as follows: V14 is van Hinsbergen et al. ²⁰; V12 is Vergés and Fernàndez²¹; R22 is Romagny et al.¹⁷; S04 is Spakman and Wortel³³; and M23 is this study. Note that the main difference between M23 and S04 is in the weak zone, as indicated by the yellow area, which is behind the eastern Iberian margin. f–j Initial material, viscosity and temperature fields of the geodynamic model illustrated by Case 1-1, which is constrained by M23. f Initial material field and two sampling points, p1 and p2, which correspond to the positions of continental and oceanic lithospheres, respectively. These sampling points are indicated by the blue and red lines in (j). g, h Initial material field and viscosity field, respectively, represented by an arbitrary profile perpendicular to the trench. i Typical compositional columns for different tectonic units above a depth of 150 km. The AlKaPeCa Domain, a conceptual geological entity on the overriding plate that was later dismembered by subduction²⁰, has the same composition as the normal continental crust; however, its crust is highlighted in magenta for better visual identification. j Initial viscosity and temperature curves sampled vertically across the model from p1 and p2 in Case 1-1. The dashed lines represent temperature fields, whereas the solid lines represent viscosity fields. The blue lines correspond to p1, and the red lines correspond to p2. Abbreviations: L.T.O. = Liguro-Tethys Ocean.