The Banda Sea: continental collision at the eastern end of Tethys

Author : John MilsomPublication : Bulletin of the Geological Society of MalaysiaVolume : 43Page : 41-47Year : 1999


Bulletin of the Geological Society of Malaysia, Volume 43, Dec. 1999, pp. 41 - 47


The Banda Sea: continental collision at the eastern end of Tethys


Department of Geological Sciences, University College London, London WC 1 E 6BT


Abstract: Continental collision in the Himalayan and Mediterranean segments of the Tethyan domain has produced regions of dramatic local extension within overall compressional environments. In the Mediterranean, deep basins have been created which are partly enclosed by orogenic belts forming arcs with total curvatures approaching 180°. These basins are floored either by attenuated continental crust (Alboran and Aegean seas) or by oceanic crust (parts of the Tyrrhenian Sea).

The eastern Indonesia (Banda Arc) segment of the Tethyan collision zone has not usually been considered in terms of continent-continent collision because attention has been focused on the present day impact of Australia. There is, however, much evidence for earlier collisions of fragments of the Australasian continent with this margin of Eurasia, and there are striking resemblances to the Mediterranean region. High standing ridges in the centre of the Banda Sea include continental material but water depths in excess of 5 km testify to the presence of oceanic crust in the North and South Banda basins. The 180° loop of the Banda Arc can be considered an end member in the spectrum of Tethyan collisional orogens, at the limit at which oceanic influences (in the form of the uncollided Indian Ocean west of Australia) remain important.