Fig. 1

a Palaeogeographic map during the late Eocene (37–34 Ma) modified from Popov et al. (2004); b Approximate position of the Alpine-Himalayan orogenic system, which is shown with a gray line from Europe to China, and of the Zagros Basin, which is shown with a red line in southwestern Iran (adapted and modified from World Map-A non-Frame.png on https://en.wikipedia.org/wiki/Alpide_belt)