Fig. 7: Digital elevation models and cross sections of the Greater Caucasus, Atlas, and Pyrenees.

The DEMs are from ETOPO22⁷⁰. In each DEM, the black line follows the drainage divide; the dashed lines are an offset of the black line. The dotted line in the Atlas delineates to first order the mountain belt orientation. a Cross-section through the Greater Caucasus is based on ref. ¹⁰, with deformation at depth > 25 km stipulated based on typical modelling results and inferred from refs. ^37,38. DEM-areas marked with `B' are potential pre-collisional rift basins connected by transfer zones ‘T’. b The cross-section through the Central High Atlas is based on ref. ⁸. WHA is short for Western High Atlas, CHA is Central High Atlas, EHA is Eastern High Atlas, MA is Middle Atlas. c The left cross-section through the Basque Pyrenees is based on ref. ⁴⁵; the middle section, ECORS-Arzacq, is based on ref. ⁷¹; the right section, ECORS-Pyrenees, is based on ref. ⁶. Labels on DEM show (1) the Labourd gravity anomaly, (2) the Bilbao gravity anomaly, (3) the transfer zone between the reconstructed Pyrenean and Basque-Cantabrian pre-collisional basins.