Complex continental growth along the proto-Pacific margin of East Gondwana

摘要: We use ambient noise recordings from the largest transportable seismic array in Southern Hemisphere to image azimuthal variations Rayleigh wave phase anisotropy crust beneath southeast Australia. This region incorporates a transition Precambrian shield of Australia west younger Phanerozoic terranes east, which are thought have been formed by subduction-accretion processes. Our results, span shallow lower crust, show strong and consistent pattern that is oriented north-south, approximately parallel former margin East Gondwana. However, significant deviations this trend persist through period range 2.5 s \textgreater10 s. One most notable occurs along edge cratonic Australia, where Curnamona Province forms salient into accretionary terrane, here, fast axis follows boundary almost exactly, virtually coincident with magnetic lineations extracted aeromagnetic data. To east Lachlan orogen, masked Cenozoic Murray Basin, becomes strongly curved traces out semicircular radius 200-250 km. Farther returns dominantly north-south orientation. These new findings provide observational support recent geodynamic modeling results demonstrate how large-scale oroclinal structures can become embedded mountain belts. © 2014 Geological Society America.