Paleomagnetic data from the New England Orogen (eastern Australia) and implications for oroclinal bending
MetadataShow full item record
© 2015 Elsevier B.V..Orogenic curvatures (oroclines) are common in modern and ancient orogens, but the geodynamic driving forces of many oroclines remain controversial. Here we focus on the New England oroclines of eastern Australia, the formation of which had been previously broadly constrained to the Early-Middle Permian. This time interval encompasses periods of both back-arc extension (at ~ 300-280 Ma) and subsequent contractional deformation (Hunter-Bowen Orogeny) that commenced at ~ 270 Ma along the paleo-Pacific and Gondwanan subduction plate boundary. We present new paleomagnetic data from volcanic rocks that were extruded during the transition from extension to contraction (at ~ 272 Ma), and we show that the oroclinal structure must have formed prior to the emplacement of the volcanic rocks. Our results thus indicate that oroclinal bending in the southernmost New England Orogen has been completed prior to the onset of Middle Permian contractional deformation. It is therefore concluded that the oroclines have likely formed during back-arc extension, and that a major contribution to the orogenic curvature was driven by trench retreat.
Showing items related by title, author, creator and subject.
Dating of lithospheric buckling: 40Ar/39Ar ages of syn-orocline strike-slip shear zones in northwestern IberiaGutiérrez-Alonso, G.; Collins, A.; Fernández-Suárez, J.; Pastor-Galán, D.; González-Clavijo, E.; Jourdan, Fred; Weil, A.; Johnston, S. (2015)Orogenic curvature is a ubiquitous feature of mountain belts, and the plate tectonic and geodynamic setting responsible for the development of curved orogens is a subject of debate. In order to distinguish between different ...
Unraveling the geometry of the New England oroclines (eastern Australia): Constraints from magnetic fabricsMochales, T.; Rosenbaum, G.; Speranza, F.; Pisarevskiy, Sergei (2014)The southern New England Orogen (NEO) in eastern Australia is characterized by tight curvatures(oroclines), but the exact geometry of the oroclines and their kinematic evolution are controversial. Here we present new data ...
Late paleozoic closure of the ob-zaisan ocean along the irtysh shear zone (NW China): Implications for arc amalgamation and oroclinal bending in the central Asian orogenic beltLi, P.; Sun, M.; Rosenbaum, G.; Jourdan, Fred; Li, S.; Cai, K. (2017)The largest accretionary orogen in the world, the Central Asian orogenic belt, has evolved through the assembly of various oceanic and continental blocks. Understanding the processes associated with the development of ...