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

Rosenbaum, Gideon; Li, P-F.; Rubatto, Daniela

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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...[Show more]

dc.contributor.authorRosenbaum, Gideon
dc.contributor.authorLi, P-F.
dc.contributor.authorRubatto, Daniela
dc.date.accessioned2015-12-10T23:10:05Z
dc.identifier.issn0278-7407
dc.identifier.urihttp://hdl.handle.net/1885/63573
dc.description.abstractA 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 (<260 Ma) cuts across the curved structural grain, providing a minimum age constraint for orocline development. Assuming a structure of four oroclines, we suggest a tentative tectonic model that involves an early stage of subduction curvature during slab rollback at 300-285 Ma, followed by bending associated with dextral transpression. A final tightening of the curved structures was possibly obtained by E-W shortening during the late Permian to Triassic (265-230 Ma) Hunter-Bowen orogeny.
dc.publisherAmerican Geophysical Union
dc.rightsAuthor/s retain copyright
dc.sourceTectonics
dc.subjectKeywords: Age constraints; Curved structure; Eastern Australia; Exact geometry; Fore-arc basin; Geometrical interpretation; Granitoids; Kinematic constraints; Late Permian; Magmatisms; Mesozoic; New England; Orocline; Paleozoic; Permian; Serpentinite; Tectonic mode
dc.titleThe contorted New England Orogen (eastern Australia): New evidence from U-Pb geochronology of early Permian granitoids
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume31
dc.date.issued2012
local.identifier.absfor040303 - Geochronology
local.identifier.absfor040313 - Tectonics
local.identifier.ariespublicationf5625xPUB823
local.type.statusPublished Version
local.contributor.affiliationRosenbaum, Gideon, University of Queensland
local.contributor.affiliationLi, P-F., University of Queensland
local.contributor.affiliationRubatto, Daniela, College of Physical and Mathematical Sciences, ANU
local.bibliographicCitation.issue1
local.bibliographicCitation.startpage1
local.bibliographicCitation.lastpage14
local.identifier.doi10.1029/2011TC002960
local.identifier.absseo970104 - Expanding Knowledge in the Earth Sciences
dc.date.updated2016-02-24T09:40:51Z
local.identifier.scopusID2-s2.0-84856708481
local.identifier.thomsonID000300008400001
dcterms.accessRightsOpen Access
CollectionsANU Research Publications

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