These twin summits have been highly eroded over time. Piton de la Fournaise in full eruption. Over time there has been two catastrophic eruptions, the first resulting in a nested caldera. Dolomieu crater showing Aa lava. Today a twin volcano primarily built up of lava is located in the western portion of the caldera.
Many parasitic cones exist within the two calderas.
The summit of Piton de la Fouranaise in 1961 consisted of three craters Bory, Velain, and Dolomieu. As shown in the pictures above and below Dolomieu continued to be active in an August 1986 eruption. Dual vent eruption within Dolomieu and showing lava braiding down to the Indian Ocean. Dolomieu crater with Pahoehoe lava in foreground. More images of Reunion Island .