The island of Réunion formed from two volcanoes, the active Piton de la Fournaise on the southern end of the island and Piton des Neiges, which is slightly taller and dormant. The Reunion hotspot that formed the Deccan Traps also produced the Chagos-Laccadive Ridge and the Mascarene Plateau and plays a role in the geology of Mauritius and Rodriguez Island. Isotopic dating in 1969 found that Réunion, Mauritius and Rodriguez all developed independently, but Réunion and Mauritius were much more closely related to the formation of the Mascarene Plateau.