The contorted New England Orogen (eastern Australia): New evidence from U-Pb geochronology of early Permian granitoids

A series of sharp bends (oroclines) are recognized in the Paleozoic to early Mesozoic New England Orogen of eastern Australia. The exact geometry and origin of these bends is obscured by voluminous magmatism and is still debated. Here we present zircon U‐Pb ages that confirm the lateral continuation...

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Veröffentlicht in:Tectonics (Washington, D.C.) D.C.), 2012-02, Vol.31 (1), p.n/a
Hauptverfasser: Rosenbaum, Gideon, Li, Pengfei, Rubatto, Daniela
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Sprache:eng
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Zusammenfassung:A series of sharp bends (oroclines) are recognized in the Paleozoic to early Mesozoic New England Orogen of eastern Australia. The exact geometry and origin of these bends is obscured by voluminous magmatism and is still debated. Here we present zircon U‐Pb ages that confirm the lateral continuation of early Permian (296–288 Ma) granitoids and shed new light on the oroclinal structure. Orogenic curvature is defined by the alignment of early Permian granitoids parallel to the structural grain of the orogen, as well as the curved geometry of sub‐vertical deformation fabrics, forearc basin terranes, and serpentinite outcrops. Alternative geometrical interpretations may involve two bends (Texas and Coffs Harbour Oroclines), three bends (+Manning Orocline), or even four bends (+Nambucca Orocline). We argue that the model involving four bends is most consistent with available data, although further kinematic constraints are required to confirm the existence of the Manning and Nambucca Oroclines. A subsequent phase of younger magmatism (
ISSN:0278-7407
1944-9194
DOI:10.1029/2011TC002960