The Banda Arc (main arc, Inner, and Outer) is a dual chain of islands in eastern Indonesia that is around 2,300 km long. It is the result of the collision of a continent and an intra-oceanic island arc.
The presently active volcanic arc is mounted on stretched continental and oceanic crust whereas the associated subduction trench is underlain by continental crust, which has subducted deep enough to contaminate the volcanic arc with continental melts. The island of Timor is notable for the lack of volcanic activity. This is due to the island representing the zone of fore-arc and continental collision which prevents volcanic activity from occurring.
