Revisiting the structure, age, and evolution of the Wharton Basin to better understand subduction under Indonesia.
IR@NIO: CSIR-National Institute Of Oceanography, Goa
View Archive Info| Field | Value | |
| Creator |
Jacob, J.
Dyment, J. Yatheesh, V. |
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| Date |
2014-04-07T08:58:02Z
2014-04-07T08:58:02Z 2014 |
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| Identifier |
Journal Of Geophysical Research: Solid Earth, vol.119; 2014; 169–190
http://drs.nio.org/drs/handle/2264/4502 |
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| Description |
Understanding the subduction processes along the Sunda Trench requires detailed constraints on the subducting lithosphere. We build a detailed tectonic map of the Wharton Basin based on reinterpretation of satellite-derived gravity anomalies and marine magnetic anomalies. TheWharton Basin is characterized by a fossil ridge, dated ~36.5Ma, offset by N-S fracture zones.Magnetic anomalies 18 to 34 (38–84 Ma) are identified on both flanks, although a large part of the basin has been subducted. We analyze the past plate kinematic evolution of the Wharton Basin by two-plate (India-Australia) and three-plate (India-Australia-Antarctica) reconstructions. Despite the diffuse plate boundaries within the Indo-Australian plate for the last 20 Ma, we obtain finite rotation parameters that we apply to reconstruct the subducted Wharton Basin and constrain the thickness, buoyancy, and rheology of the subducting plate. The lower subductability of younger lithosphere off Sumatra has important consequences on the morphology, with a shallower trench, forearc islands, and a significant inward deviation of the subduction system. This deviation decreases in the youngest area, where theWharton fossil spreading center enters subduction: The discontinuous magmatic crust and serpentinized upper mantle, consequences of the slow spreading rates at which this area was formed, weaken the mechanical resistance to subduction and facilitate the restoration of the accretionary prism. Deeper effects include the possible creation of asthenospheric windows beneath the Andaman Sea, in relation to the long-offset fracture zones, and east of 105°E, as a result of subduction of the spreading center.
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| Language |
en
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| Publisher |
American Geophysical Union
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| Rights |
An edited version of this paper was published by AGU. Copyright [2014] AGU. To view the published open abstract, go to http://dx.doi.org/10.1002/2013JB010285
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| Subject |
Plate tectonics
Subduction zone |
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| Title |
Revisiting the structure, age, and evolution of the Wharton Basin to better understand subduction under Indonesia.
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| Type |
Journal Article
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