In 2008, as part of its Onshore Energy Security Program, Geoscience Australia and PIRSA acquired 262 km of vibroseis-source, deep seismic reflection data as a single north-south traverse (08GA-C1) in the Curnamona Province in South Australia. This line started in the south near outcrop of the Willyama Supergroup, ran to the east of Lake Frome along the Benagerie Ridge, and ended in the north to the northeast of the Mount Painter and Mount Babbage Inliers. Almost the entire route of the seismic traverse was over concealed bedrock, with only a few drillholes which could be used as control points. Overall, the crust imaged in the seismic section is relatively reflective, although the central part of the section contains an upper crust which has very low reflectivity. The lower two-thirds of the crust contain strong, subhorizontal reflections. The Moho is not sharply defined, but is interpreted to occur at the base of the reflective package at about 13 s two-way travel time (TWT), about 40 km depth. The highly reflective crust can be tracked, from the southern end of the seismic section, northwards for a distance of about 200 km. In the north, where rocks of the Mount Painter and Mount Babbage Inliers are exposed close to the section, the crust has a marked lower reflectivity, compared to the rest of the line. This contrast in crustal reflectivity suggests that the crust beneath the Mount Painter region is different to that beneath the Willyama Supergroup of the Curnamona Province in the south, raising the possibility of an ancient crustal boundary between the two regions.

Over the last decade there have been significant advances in our understanding of the: stratigraphy; magmatism; deformation; metamorphism; and timing of mineralisation, in the Eastern Goldfields Superterrane (EGST) of Yilgarn Craton, WA. The integration of these disciplines has enabled a holistic review of the tectonic history of the EGST, thereby providing a para-autochthonous geodynamic context for its mineralisation. A significant advance has been the recognition of a ~2.81 Ga rifting event off the eastern margin of the Youanmi Terrane which set up the north-northwest trending architecture of the EGST, as expressed in the Nd TDM map. Rifting was followed by the establishment of a convergent margin characterised by a west dipping subduction zone to the east of the EGST. Subduction resulted in the deposition of the 2.715-2.67 Ga volcanic stratigraphy and the emplacement of voluminous TTG magmatism, which resulted in magmatic thickening of the crust. Volcanism was terminated by a ~5 Ma pulse of east-northeast contraction which triggering lithospheric and lower crustal delamination associated with mid-orogenic extension. The lack of ultra-high pressure metamorphism and the presence of high geothermal gradients preclude this event from recording a continent-continent collision. Mid-orogenic extension initiated at 2.665 Ga resulted in the introduction of metasomatised mantle melts (Mafic-granites and Syenites), deposition of late-stage siliciclastic basins (which record anticlockwise PTt paths) and the start of significant economic gold mineralisation in the EGST. The delamination associated with this event resulted in significant heat input into the base of the crust, which eventually led to the emplacement of Low-Ca (crustal melt) granites and cratonisation of the EGST.

The Asia-Pacific Reference Frame (APREF) project is an initiative that recognizes the importance of improving the regional geodetic framework in the Asia-Pacific region. A substantial number of state-of-the-art GNSS networks, operated by national mapping agencies and private sector organizations, are available in the region. In the APREF initiative these networks are combined to realize a high-standard regional reference frame. The GNSS data of the network are processed by different Analysis Centres (ACs). The contributions of the different ACs are combined into a weekly solution by the APREF Central Bureau. This weekly solution is the core product of the APREF; it contains weekly estimates of the coordinates of the participating Asia-Pacific GNSS tracking stations and their covariance information. The APREF products, which have been available since the first quarter of 2010, gives a reliable time-series of a regional reference frame in the International Terrestrial Reference Frame and a quality assessment of the performance of the GNSS CORS stations included in the network. This contribution gives an overview of the current status of the APREF network and an analysis of the first APREF products.

A deep seismic reflection and magnetotelluric survey, conducted in 2007, established the architecture and geodynamic framework of north Queensland, Australia. Results based on the interpretation of the deep seismic data include the discovery of a major, west-dipping, Paleoproterozoic (or older) crustal boundary, interpreted the Gidyea Suture Zone, separating relatively nonreflective, thick crust of the Mount Isa Province from thinner, two layered crust to the east. East of the Mount Isa Province, the lower crust is highly reflective and is subdivided into three mappable seismic provinces (Numil, Abingdon and Agwamin) which are not exposed at the surface. To the west of Croydon, a second major crustal boundary also dips west or southwest, offsetting the Moho and extending below it. It is interpreted as the Rowe Fossil Subduction Zone. This marks the boundary between the Numil and Abingdon seismic provinces, and is overlain by the Etheridge Province. The previously unknown Millungera Basin was imaged below the Eromanga-Carpentaria basin system. In the east, the Greenvale and Charters Towers Provinces, part of the Thomson Orogen, have been mapped on the surface as two discrete provinces, but the seismic interpretation raises the possibility that these two provinces are continuous in the subsurface, and also extend northwards to beneath the Hodgkinson Province, originally forming part of an extensive Neoproterozoic-Cambrian passive margin. Continuation of this passive margin at depth beneath the Hodgkinson and Broken River Provinces suggests that these provinces (which formed in an oceanic environment, possibly as an accretionary wedge at a convergent margin) have been thrust westwards onto the older continental passive margin. The Tasman Line, originally defined to represent the eastern limit of Precambrian rocks in Australia, has a complicated geometry in three dimensions, which is related to regional deformational events during the Paleozoic.

The Tasman Orogen represents a long-lived accretionary orogen with numerous orogenic cycles of extension and subsequent orogeny. Although details of the orogen are controversial, it is evident that the present configuration represents the cumulate products of many orogenies including both accretion and significant rearrangement of terranes. As a result the Tasman Orogen plays host to a significant array of commodities within a myriad of deposit styles, related to a variety of tectonic regimes. It is also evident that many mineralisation styles are repeated through the different orogenic cycles, and commonly during the same parts of the orogenic cycle. For example, volcanic-hosted massive sulphide deposits form early in cycles, whereas lode gold deposits form during contractional orogenesis that terminates the cycle. The geological complexity is both an advantage and disadvantage. Although the complexity can hinder regional exploration, it offers significant potential for identifying regions where previously unrecognised mineralisation styles may be present, particularly under cover where the geology (and tectonic history) is less well constrained.

Interpretation of deep seismic reflection profiling coupled with forward modelling of gravity and aeromagnetic data, new zircon U-Pb age dating and the interpretation of the basement geology beneath the southern margin of the Eromanga Basin has provided insights into the southern part of the underlying Thomson Orogen and its relationship with the Lachlan Orogen to the south. Our interpretations of these data suggest that the northern Lachlan and southern Thomson orogens possessed a similar history from the mid-Late Silurian through to the Carboniferous. Major older differences, however, are suggested by the presence in the southern Thomson Orogen of relics of a possible Neoproterozoic arc, of Late Ordovician turbidites, by the geophysical evidence for crustal thickening caused by elevation of reflective lower crustal metavolcanic rocks high into the crust on a low-angle, north-dipping detachment thrust, and by old K-Ar age dates in southwestern Queensland. The seismically-imaged, north-dipping, crustal-scale Olepoloko Fault corresponds to the surface expression of Thomson-Lachlan boundary, and reflects the dip-slip and strike-slip partial reactivation and short-cutting of an older fault, which occurred in the Carboniferous, and probably also in the latest Silurian and Early Devonian.

The rifting history of the magma-poor conjugate margins of Australia (Great Australian Bight) and Antarctica (Terre Adélie) is still a controversial issue. In this paper, we present a model for lithosphere-scale rifting and deformation history from initial rifting to breakup, based on the interpretation of two regional conjugate seismic profiles of the margins, and the construction of a lithosphere-scale, balanced cross section, sequentially restored through time. The model scenario highlights the symmetric pattern of initial stretching resulting to pure shear at lithospheric-scale accompanied by the development of four conjugate detachments and crustal half-graben systems. This system progressively evolves to completely asymmetric shearing along a single south-dipping detachment at the scale of the lithosphere. The detachment accounts for the exhumation of the mantle part of the Australian lithosphere, and the isolation of a crustal klippe separated from the margin by a peridotite ridge. Antarctica plays the role of the upper plate with the formation of an external crustal high separated from the unstretched continental crust by a highly extended zone still active during the Australian exhumation phase. The total elongation amount of the Australian-Antarctic conjugate system reaches ~413km (61%). Elongation was partitioned through time: ~189km and ~224km during symmetric and asymmetric stages, respectively. During symmetric stage, both margins suffered relatively the same elongation accommodated by crustal stretching (~105km (45%) and ~84km (38%) for Australia and Antarctica, respectively). Again, both margins accommodated relatively the same elongation during the asymmetric stage: the Antarctic upper plate records an elongation amount of ~225km (40%) as crustal tectonic stretching, above the inferred low-angle south dipping detachment zone, whereas the Australian lower plate suffered ~206km (61%) of elongation through mantle exhumation.

This report presents the results of a geodynamic synthesis of South Australia, focusing predominantly on the Archean to Mesoproterozoic of the Gawler Craton and Curnamona Province in terms of geodynamic setting, architecture, and age, using results of a geological synthesis, seismic interpretation, sequence stratigraphy, geochronology and geochemistry. This was undertaken with the dual aims: 1. To better understand the tectonic and geodynamic setting of the Gawler Craton and Curnamona Province 2. To accompany the interpretation of recently-acquired seismic reflection transects (see related product below), and to highlight new geochemical and geochronological data collected from South Australia.

This Resource Package contains two major products: GA Record 2009/41 and two full-colour, A0-sized map sheets (containing maps at 1:5 million, 1:6 million, and 1:3 million scales) that show the continental extent and age relationships of Archean mafic and ultramafic rocks and associated mineral deposits throughout Australia. These rocks have been assigned to twenty-six Archean Magmatic Events (AME) ranging in age from the Eoarchean ~3730 Ma (AME 1) to the late Neoarchean ~2520 Ma (AME 26). The temporal and spatial relationships of these Magmatic Events in the Pilbara Craton, Hamersley Basin, Sylvania Inlier, Yilgarn Craton, and Gawler Craton are represented on a Time-Space-Event Chart on Sheet 1. An enlarged inset map on this sheet provides in more detail the polygon and line data of the events in the Pilbara Craton, Hamersley Basin, and Sylvania Inlier. Sheet 2 shows the interpreted distribution and characterisation of Archean mafic-ultramafic magmatic rocks in the Yilgarn Craton. In particular, potential new areas of komatiitic rocks under cover that elsewhere in the craton host significant resources of nickel, copper, and platinum-group elements, are highlighted. Other maps on Sheet 2 summarise the nickel resource endowment and crustal neodymium model ages of various geological provinces in the Yilgarn Craton. These map sheets, when used in association with another recently produced map 'Australian Proterozoic Mafic-Ultramafic Magmatic Events (GeoCat 66114; published in 2008)', summarise the temporal and spatial evolution of Precambrian mafic-ultramafic magmatism in Australia. Record 2009/41 (Geocat 69935) is a user guide for the `Australian Archean Mafic-Ultramafic Magmatic Events' map (Geocat 69347). It compiles all the geological and geochronological data that underpins the information portrayed on the map. The Resource Package also contains in addition to the maps and record, a spreadsheet of data that support the maps and a time-series animation summarising all the Archean Mafic-Ultramafic Magmatic Events. <h3>Related products:</h3><a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=69935">Guide to using the Australian Archean Mafic-Ultramafic Magmatic Events Map</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=70461">Proterozoic Mafic-Ultramafic Magmatic Events Resource Package</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=66114">Australian Proterozoic Mafic-Ultramafic Magmatic Events: Map Sheets 1 and 2</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=66624">Guide to Using the Australian Proterozoic Mafic-Ultramafic Magmatic Events Map</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=69213">Proterozoic Large Igneous Provinces: Map Sheets 1 and 2</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=70008">Guide to using the Map of Australian Proterozoic Large Igneous Provinces</a>

Deep seismic reflection profiles have been acquired and interpreted to better understand the crustal architecture and geodynamic evolution of Australia's geological provinces. Here, we examine some of these profiles to better understand how the Australian continent formed in the Archean and Proterozoic. The 2007 deep seismic reflection survey in North Queensland imaged a major, west-dipping, Paleoproterozoic (or older) crustal boundary, which we interpret as a suture, separating relatively nonreflective, thick crust of the Mount Isa Province in the west from thinner, two layered crust to the east. This boundary is also imaged by magnetotelluric data and 3D inversions of aeromagnetic and gravity data. Farther to the northeast, a second major boundary dips west or southwest, offsetting the Moho and extending below it. It is interpreted as a fossil subduction zone, and is overlain by supracrustal rocks of the Etheridge Province, with ages of ~1720 Ma, which is interpreted as the minimum age of the suture. Seismic profiles in southeast Australia, collected between 1996 and 2009, were combined to provide a cross section of the crust across the Archean-Mesoproterozoic Gawler Craton, Neoproterozoic-Paleozoic Adelaide Rift System, Mesoproterozoic Curnamona Province, Neoproterozoic-Paleozoic Koonenberry Belt and Silurian-Devonian Darling Basin. The transect imaged at least four discrete seismic provinces in the middle to lower crust, all bounded by east-dipping, crustal-penetrating fault zones which extend to the Moho. As the seismic provinces have not been traced to the surface, age control is poor, but they are inferred to be older that the upper crustal rocks above them, most of which are Archean to Mesoproterozoic in age.