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

摘要: [1] A series of sharp bends (oroclines) are recognized in the Paleozoic to early Mesozoic New England Orogen eastern Australia. The exact geometry and origin these is obscured by voluminous magmatism still debated. Here we present zircon U-Pb ages that confirm lateral continuation Permian (296–288 Ma) granitoids shed new light on oroclinal structure. Orogenic curvature defined alignment parallel structural grain orogen, as well curved sub-vertical deformation fabrics, forearc basin terranes, serpentinite outcrops. Alternative geometrical interpretations may involve two (Texas Coffs Harbour Oroclines), three (+Manning Orocline), or even four (+Nambucca Orocline). We argue model involving most consistent with available data, although further kinematic constraints required existence Manning Nambucca Oroclines. A subsequent phase younger (<260 cuts across grain, providing a minimum age constraint for orocline development. Assuming structure oroclines, suggest tentative tectonic involves an stage subduction during slab rollback at 300–285 Ma, followed bending associated dextral transpression. final tightening structures was possibly obtained E-W shortening late Triassic (265–230 Hunter-Bowen orogeny.