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Sunda‐Banda arc transition: Incipient continent‐island arc collision (northwest Australia)
Author(s) -
Shulgin A.,
Kopp H.,
Mueller C.,
Lueschen E.,
Planert L.,
Engels M.,
Flueh E. R.,
Krabbenhoeft A.,
Djajadihardja Y.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl037533
Subject(s) - geology , subduction , seismology , island arc , arc (geometry) , collision , collision zone , transition zone , ridge , basement , accretionary wedge , reflection (computer programming) , prism , paleontology , geophysics , geography , tectonics , geometry , physics , computer security , archaeology , optics , computer science , programming language , mathematics
The eastern Sunda arc represents one of the few regions globally where the early stages of continent‐arc collision can be studied. We studied along the western limit of the collision zone at the Sunda‐Banda arc transition, where the Australian margin collides with the Banda island arc, causing widespread back arc thrusting. We present integrated results of a refraction/wide‐angle reflection tomography, gravity modeling, and multichannel reflection seismic imaging using data acquired in 2006 southeast of Sumba Island. The composite structural model reveals the previously unresolved deep geometry of the collision zone. Changes in crustal structure encompass the 10–12 km thick Australian basement in the south and the 22–24 km thick Sumba ridge in the north, where backthrusting of the 130 km wide accretionary prism is documented. The structural diversity along this transect could be characteristic of young collisional systems at the transition from oceanic subduction to continent‐arc collision.