Chronological constraints on the Permian geodynamic evolution of eastern Australia

Li, Pengfei, Rosenbaum, Gideon and Vasconcelos, Paulo (2014) Chronological constraints on the Permian geodynamic evolution of eastern Australia. Tectonophysics, 617 20-30. doi:10.1016/j.tecto.2014.01.013

Author Li, Pengfei
Rosenbaum, Gideon
Vasconcelos, Paulo
Title Chronological constraints on the Permian geodynamic evolution of eastern Australia
Journal name Tectonophysics   Check publisher's open access policy
ISSN 0040-1951
Publication date 2014-03-17
Sub-type Article (original research)
DOI 10.1016/j.tecto.2014.01.013
Volume 617
Start page 20
End page 30
Total pages 11
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2015
Language eng
Formatted abstract
• The Texas beds in eastern Australia underwent a complex thermal history.
• The mafic volcanic rocks associated with slab breakoff were constrained at ~271-266 Ma.
• Volcanic rocks at ~271-266 Ma marked the end of rollback-assisted oroclinal bending.

The New England Orogen in eastern Australia developed as a subduction-related orogen in the Late Devonian to Carboniferous, and was modified in the Permian by deformation, magmatism and oroclinal bending. The geodynamics associated with the development of the New England oroclines and the exact timing of major tectonic events is still enigmatic. Here we present new 40Ar/39Ar results from metasedimentary and volcanic rocks from the southern New England Orogen. Eight grains from four metasedimentary samples (Texas beds) that originated in the Late Devonian to Carboniferous accretionary wedge yielded reproducible plateau ages of ~ 293, ~ 280, ~ 270 and ~ 260 Ma. These results suggest a complex thermal history associated with multiple thermal events, possibly due to the proximity to Permian intrusions. Two samples from mafic volcanic rocks in the southernmost New England Orogen (Alum Mountain Volcanics and Werrie Basalt) yielded eruption ages of 271.8 ± 1.8 and 266.4 ± 3.0 Ma. The origin of these rocks was previously attributed to slab breakoff, following a period of widespread extension in the early Permian. We suggest that this phase of volcanism marked the transition from backarc extension assisted by trench retreat to overriding-plate contraction. The main phase of oroclinal bending has likely occurred during backarc extension in the early Permian, and terminated at 271–266 Ma with the processes of slab segmentation and breakoff.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Earth Sciences Papers
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 8 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 7 times in Scopus Article | Citations
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Created: Wed, 12 Feb 2014, 21:44:27 EST by Dr Gideon Rosenbaum on behalf of School of Earth Sciences