Structural evolution of the early Permian Nambucca Block (New England Orogen, eastern Australia) and implications for oroclinal bending

Shaanan, Uri, Rosenbaum, Gideon, Li, Pengfei and Vasconcelos, Paulo (2014) Structural evolution of the early Permian Nambucca Block (New England Orogen, eastern Australia) and implications for oroclinal bending. Tectonics, 33 7: 1425-1443. doi:10.1002/2013TC003426

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
UQ332624_OA.pdf Full text (open access) application/pdf 23.64MB 0

Author Shaanan, Uri
Rosenbaum, Gideon
Li, Pengfei
Vasconcelos, Paulo
Title Structural evolution of the early Permian Nambucca Block (New England Orogen, eastern Australia) and implications for oroclinal bending
Journal name Tectonics   Check publisher's open access policy
ISSN 0278-7407
1944-9194
Publication date 2014-01-01
Year available 2014
Sub-type Article (original research)
DOI 10.1002/2013TC003426
Open Access Status File (Publisher version)
Volume 33
Issue 7
Start page 1425
End page 1443
Total pages 19
Place of publication Hoboken, NJ, United States
Publisher Wiley-Blackwell
Language eng
Abstract The Paleozoic to early Mesozoic southern New England Orogen of eastern Australia exhibits a remarkable ear-shaped curvature (orocline), but the geodynamic processes responsible for its formation are unclear. Oroclinal bending took place during the early Permian, simultaneously with the deposition of the rift-related Sydney, Gunnedah and Bowen basins, which bound the oroclines to the west. The Nambucca Block is another early Permian rift basin, but it is situated in the core of the oroclinal structure. Here we present new stratigraphic, structural, and geochronological data from the Nambucca Block in an attempt to better understand its tectonic history and relationships to the formation of the oroclines. We recognized four phases of folding and associated structural fabrics (S1-4), with the second phase (S2) dated at 275-265 Ma by 40Ar/39Ar geochronology of muscovite. This age overlaps with independent constraints on the timing of oroclinal bending, suggesting that the earlier two phases of deformation in the Nambucca Block (F1 and F2) were associated with orocline formation. We propose that oroclinal bending involved three major stages. The first stage (<300 Ma) was associated with variations in rates of trench rollback and formation of rift basins in a hot extensional backarc setting. This was followed by a second stage of oroclinal bending, possibly linked to dextral wrench faulting, which involved ~ N-S contraction (F1). Subsequent deformation at 275-265 Ma involved formation of nappe-style structures (F2). This phase of contractional deformation may have resulted from an increased plate coupling, that was possibly linked to flat-slab subduction.
Keyword Oroclinal bending
New England oroclines
Nambucca Block
40Ar/39Ar geochronology
Eastern Australia
Early Permian
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DP0986762
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Earth Sciences Publications
Official 2015 Collection
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 18 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 20 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Mon, 16 Jun 2014, 06:56:26 EST by Dr Gideon Rosenbaum on behalf of School of Earth Sciences