Fig. 6: Plate reconstruction of de-anchoring between the Kerguelen plume and SE Indian Ridge.

The location of the Kerguelen plume is fixed to its present-day coordinates of 69° W, 50° S; plate boundaries and velocities were reconstructed at 20 Myr increments from 60 Ma to the present day²⁶ using GPlately⁴⁰. a The Kerguelen plume was centred on a triple junction separating Indian, Australian, and Antarctic plates as India is propelled towards Eurasia by double subduction¹². b Following plume–ridge de-anchoring, the SE Indian Ridge began to migrate northward at 2.7 cm/yr and spreading ceased along the India–Australia ridge. c Increased spreading rates along the SE Indian Ridge at 20 Ma translated to northward motion of the Australian plate at 7 cm/yr. d Present-day configuration of plate boundaries and the location of the Kerguelen plume.