Inherited crustal deformation along the East Gondwana margin revealed by seismic anisotropy tomography

S. Pilia*, P. Arroucau, N. Rawlinson, A. M. Reading, R. A. Cayley

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Citations (Scopus)
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Abstract

The mechanisms of continental growth are a crucial part of plate tectonic theory, yet a clear understanding of the processes involved remains elusive. Here we determine seismic Rayleigh wave phase anisotropy variations in the crust beneath the southern Tasmanides of Australia, a Paleozoic accretionary margin. Our results reveal a complex, thick-skinned pervasive deformation that was driven by the tectonic interaction between the proto-Pacific Ocean and the ancient eastern margin of Gondwana. Stress-induced effects triggered by the collision and entrainment of a microcontinent into the active subduction zone are evident in the anisotropy signature. The paleofracturing trend of failed rifting between Australia and Antarctica is also recorded in the anisotropy pattern as well as a tightly curved feature in central Tasmania. The observed patterns of anisotropy correlate well with recent geodynamic and kinematic models of the Tasmanides and provide a platform from which the spatial extent of deformational domains can be refined.

Original languageEnglish
Pages (from-to)12,082-12,090
Number of pages9
JournalGeophysical Research Letters
Volume43
Issue number23
Early online date15 Dec 2016
DOIs
Publication statusPublished - 16 Dec 2016

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Keywords

  • ambient noise tomography
  • continental accretion
  • crustal azimuthal anisotropy
  • East Gondwana
  • Tasmanides

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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