インド・オーストラリアプレート
The Banda arc is famous for its 180° curvature and is, in Timor, generally agreed to be the product of collision between a volcanic arc and the Australian continental margin. The Banda Sea occupies the main portion of the Banda Sea Plate. The southern margin of the sea consists of island arcs above subduction zones. To the east of the Sunda Trench is the Timor Trough which lies south of Timor, the Tanimbar Trough south of the Tanimbar Islands and the Aru Trough east of the Aru Islands. These trenches are the subduction zone of the Indo-Australian plate beneath the Banda Sea Plate, where the Indo-Australian Plate moves northwards. Fore-arc sediments progressively carried northwards by the Indo-Australian Plate have been folded and faulted forming Timor island. To the northeast lies Seram Island which overlies the subduction of the Bird's Head Plate of West Papua. The deepest point of the sea, Weber Deep, is an exposed oceanic fault and the world's deepest forearc basin, with depth more than .