Two types of mountain-forming systems exist on Earth — external orogens form during oceanic–continental plate collisions and internal orogens form where continental plates collide. Hafnium isotope data from orogens worldwide show that each has produced a distinctive signature over the past 550 Myr, reflecting the contrasting subduction geometry in each setting.
- William J. Collins
- Elena A. Belousova
- J. Brendan Murphy