|
Alpine-Himalayan Orogens |
Department of Geology, Imperial College of Science and Technology, Prince Consort Road, London S.W.7
The Banda Arcs are the continuous, strongly recurved, links between two orogenic belts—the island arcs of the Greater Sunda orogen to the west and the Sulawesi archipelago region to the north. On their outer margin, the Banda Arcs parallel the margin of the adjacent continental shelf of Australia—West Irian on the south and south-east, whilst to the east they abut the Circum-Pacific orogenic region of West Irian. No ‘inner’ margin to the Banda orogen can be recognized: the Central Banda Basin has deep focus earthquakes, some vulcanism and seems to have been intimately associated with Tertiary orogenic behaviour. The width of the Banda orogen is thus problematical, but is between 530 and 320 km, probably averaging 400 km.
Segment: a central, NE-SW strip across both north and south arms of the Banda Arcs, and including the larger islands of Timor and Seram, has been selected for description (Fig. 1).
Zones: five zones are distinguished, largely on the basis of topography and bathymetry. Two form chains of islands—the Inner and Outer Banda Arcs—whilst the others (Central Banda Basin, Intra-Banda Arcs Trough, Foredeep) are submarine.
History: the oldest rocks known in the Banda Arcs have been affected by a pre-Permian(?) orogeny, which metamorphosed the original sedimentary and igneous rocks of the allochthonous Lolotoi Complex of Timor and folded them isoclinally. There was a phase of uplift and erosion during the L. Triassic which may have been accompanied by some folding, but evidence of such folding has not yet been demonstrated. Mesozoic-Tertiary orogenic
...
This 250-word extract was created in the absence of an abstract.
