Banda Arc
The Banda Arc (main arc, Inner, and Outer) is a set of island arcs that exist in Indonesia. The Banda arc of eastern Indonesia manifests the collision of a continent and an intra-oceanic island arc. The presently active arc is located on what appears to be oceanic crust whereas the associated subduction trench is underlain by continental crust.[1] The convergence of the Indo-Australian plates and Eurasia and resulted in the formation of the Sunda and Banda island arcs. The transitional zone between the arcs is located south of Flores Island and is characterized by the change in the tectonic regime along the boundary[2]
Terminology
Some academic literature refers to the arcs by location - so that main arc can be referred to as the 'southern',[3] the 'western' [4] Situated at the centre of three converging and colliding major tectonic plates, Indo-Australia, Eurasia, Pacific, the Banda arc comprises young oceanic crust enclosed by a volcanic inner arc, outer arc islands and a trough parallel to the Australian continental margin. It is a complex subduction setting (where one plate moves under another, sinking into the Earth's mantle), with possibly the largest fold on Earth, extending to a depth of about 650 km (404 mi), in a subducted plate.[5]
Inner/Outer
The Banda Arc is a double island arc formed by the collision of the Indo-Australian plate with the Eurasian plate. Principal islands include Timor, Flores, and Seram.
- The Inner Banda Arc consists of a string of recent and active volcanic islands from Komodo to Kekeh-besar of the Barat Daya Islands, including Flores, Solor, Alor, Wetar, and Damar.
- The Outer Banda Arc is older and non-volcanic. It overlies the margin of the Pre-Cambrian craton that makes up much of the continent of Australia. It stretches from Savu through Rote, Timor, Leti, Babar, Tanimbar, and the Kai Islands, before turning west to Seram, Ambon, and Buru. The outer arc is geologically associated with the Australian continent, though it is a more recent accretion than the neighbouring Aru Islands.
The feature they apparently formed is a 180-degree arc, which is more than 1,000 kilometres (620 miles) long. Geographically, it stretches across eastern Indonesia, and is delimited by an active inner volcanic arc. The outer arc contains numerous islands, and its internal structure contains young oceanic crust exclusively.[6]
See also
Notes
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
References
- Geological detail of Banda Arc is available in Wikibook: https://en.wikibooks.org/wiki/The_Geology_of_Indonesia/Banda_Arc
- MG Audley-Charles, 1986, "Timor–Tanimbar Trough: the foreland basin of the evolving Banda orogen", Spec. Publs int. Ass. Sediment, 8:91–102
Lua error in package.lua at line 80: module 'strict' not found.
