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Evidence of micro-continent entrainment during crustal accretion


Pilia, S and Rawlinson, N and Cayley, RA and Bodin, T and Musgrave, R and Reading, AM and Direen, N and Young, MK, Evidence of micro-continent entrainment during crustal accretion, Scientific Reports, 5 Article 8218. ISSN 2045-2322 (2015) [Refereed Article]


Copyright Statement

Copyright 2015 The Authors Licensed under a Creative Commons Attribution-NonCommercial- NoDerivs 4.0 International License

DOI: doi:10.1038/srep08218


Simple models involving the gradual outboard accretion of material along curvilinear subduction zones are often inconsistent with field-based evidence. A recent study using 3-D geodynamic modelling has shown that the entrainment of an exotic continental fragment within a simple subduction system can result in a complex phase of growth. Although kinematic models based on structural mapping and high-resolution gravity and magnetic maps indicate that the pre-Carboniferous Tasmanides in southeastern Australia may have been subjected to this process, to date there has been little corroboration from crustal scale geophysical imaging. Here, we apply Bayesian transdimensional tomography to ambient noise data recorded by the WOMBAT transportable seismic array to constrain a detailed (20 km resolution in some areas) 3-D shear velocity model of the crust beneath southeast Australia. We find that many of the velocity variations that emerge from our inversion support the recently developed geodynamic and kinematic models. In particular, the full thickness of the exotic continental block, responsible for orocline formation and the tectonic escape of the back arc region, is imaged here for the first time. Our seismic results provide the first direct evidence that exotic continental fragments may profoundly affect the development of an accretionary orogen.

Item Details

Item Type:Refereed Article
Keywords:seismic tomography, Bass Strait, Tasmania, microcontinent
Research Division:Earth Sciences
Research Group:Geophysics
Research Field:Seismology and seismic exploration
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:Reading, AM (Professor Anya Reading)
UTAS Author:Direen, N (Dr Nicholas Direen)
ID Code:98163
Year Published:2015
Funding Support:Australian Research Council (LP110100256)
Web of Science® Times Cited:24
Deposited By:Earth Sciences
Deposited On:2015-02-04
Last Modified:2017-10-25
Downloads:331 View Download Statistics

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