Cenozoic Suturing of Eurasia and Africa-Arabia
Crustal separation between Europe and North America-Greenland during the earliest Eocene, followed by the progressive opening of the Arctic-North Atlantic Ocean, was paralleled by collision of Africa-Arabia and Eurasia leading to their welding together along the Alpine megasuture.
This involved continued northward drift and also the counterclockwise rotation of Africa-Arabia relative to Eurasia in response to the progressive opening of the Central and South Atlantic and the Indian oceans (Hsu, 1982; Livermore and Smith, 1985;Savostinetal., 1986; Dercourtet al., 1986).
Sinistral differential movements between Africa-Arabia and Europe, which had decreased substantially during the latest Cretaceous and early Paleocene, ceased altogether during the latest Paleocene-earliest Eocene as a consequence of the onset of sea-floor spreading in the northern North Atlantic, the Norwegian-Greenland Sea, and the Eurasian Basin (Plate 17).
Africa-Arabia and Europe converged during the Eocene in an approximately north-south direction; during the Oligocene and early Miocene, their convergence direction changed, however, to a northwesterly dextral oblique one (Plate 18). This was the effect of differences in the rates of sea-floor spreading in the Central Atlantic and in the Arctic-North Atlantic. Magnetic seafloor anomalies indicate that sea-floor spreading slowed down in the Central Atlantic after anomaly 13 (± 37 Ma, Rupelian) whereas no corresponding change in spreading rates is evident in the North Atlantic until after anomaly 6 (Â± 20 Ma, Burdigalian) (Savostin et al, 1986). This would explain the dextral translation between Europe and Africa-Arabia that was superposed on their continued northward convergence. These plate motions governed the Main-Alpine orogenic phases