New insight into Cainozoic sedimentary basins and Palaeozoic suture zones in southeast Australia from ambient noise surface wave tomography

[1] Detailed images of Rayleigh wave group velocity are derived from ambient seismic noise recorded by WOMBAT, a large rolling seismic array project in southeast Australia. Group velocity maps sensitive to crustal structure exhibit low velocity anomalies in the presence of sedimentary basins and recent hot-spot volcanism, and high velocities in regions of out-cropping metamorphic and igneous rocks. Distinct and well-constrained patches of low velocity within the Murray Basin provide new insight into the spatial extent and possible composition of pre-Tertiary infra-basins. In a broader tectonic context, our results show little evidence for the Palaeozoic building blocks of the southeast Australian continent that have been inferred from geological mapping and potential field data. This may mean that apparent changes in basement terrane near the surface are not associated with major changes in composition at depth.

[1]  M. H. Ritzwoller,et al.  Automated Detection, Extraction, and Measurement of Regional Surface Waves , 2001 .

[2]  Peter Gerstoft,et al.  Extracting time‐domain Green's function estimates from ambient seismic noise , 2005 .

[3]  B. Kennett,et al.  Lithospheric structure of Tasmania from a novel form of teleseismic tomography , 2006 .

[4]  S. Greenhalgh,et al.  Regional teleseismic tomography of the western Lachlan Orogen and the Newer Volcanic Province, southeast Australia , 2002 .

[5]  A. Dziewoński,et al.  A technique for the analysis of transient seismic signals , 1969 .

[6]  P. Clifford,et al.  3-D seismic tomography of the Adelaide fold belt , 2008 .

[7]  Yingjie Yang,et al.  Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements , 2007 .

[8]  R. Glen,et al.  The Tasmanides of eastern Australia , 2005, Geological Society, London, Special Publications.

[9]  S. Bryan,et al.  Early Cretaceous volcano-sedimentary successions along the eastern Australian continental margin: Implications for the break-up of eastern Gondwana , 1997 .

[10]  R. Cayley,et al.  Proterozoic – Early Palaeozoic rocks and the Tyennan Orogeny in central Victoria: The Selwyn Block and its tectonic implications , 2002 .

[11]  D. Gray,et al.  Lachlan Orogen subduction‐accretion systematics revisited , 2004 .

[12]  Erdinc Saygin,et al.  Ambient seismic noise tomography of Australian continent , 2010 .

[13]  N. Rawlinson,et al.  Insights into the structure of the upper mantle beneath the Murray basin from 3D teleseismic tomography , 2006 .

[14]  B. Kennett,et al.  Teleseismic tomography of the upper mantle beneath the southern Lachlan Orogen, Australia , 2008 .

[15]  Michael H. Ritzwoller,et al.  Ambient noise surface wave tomography of the Iberian Peninsula: Implications for shallow seismic structure , 2007 .

[16]  Michel Campillo,et al.  High-Resolution Surface-Wave Tomography from Ambient Seismic Noise , 2005, Science.

[17]  Nicholas Rawlinson,et al.  Simultaneous inversion of active and passive source datasets for 3‐D seismic structure with application to Tasmania , 2006 .

[18]  D. Gray,et al.  Evolution and Structure of the Lachlan Fold Belt (Orogen) of Eastern Australia , 2000 .

[19]  G. Panza,et al.  S-waves profiles from noise cross correlation at small scale , 2009 .

[20]  A. Vandenberg.  Timing of orogenic events in the Lachlan Orogen , 1999 .

[21]  Malcolm Sambridge,et al.  A dynamic objective function technique for generating multiple solution models in seismic tomography , 2008 .

[22]  C. M. Gray,et al.  Strontium isotopic and trace element heterogeneity in the plains basalts of the Newer Volcanic Province, Victoria, Australia , 1997 .

[23]  A. Crawford,et al.  The Tasman Line: Where is it, what is it, and is it Australia's Rodinian breakup boundary? , 2003 .

[24]  B. Kennett,et al.  Contrasts in mantle structure beneath Australia: Relation to Tasman Lines? , 2004 .