Interpretation of the 2006 deep seismic reflection data across the western Lachlan Orogen of southeast Australia have provided important insights into crustal-scale fluid pathways and possible source rocks in the Victorian orogenic gold province. The seismic profiles span three of the most productive structural zones in Victoria: the Stawell, Bendigo and Melbourne zones. Variations in the age and style of gold deposits across the structural zones are reflected by changes in crustal structure and composition, as revealed by the seismic data.

Geological regions with abnormally high endowment in metals appear to have resulted from the fortunate juxtaposition in space and time of numerous, possibly exceptional, processes. The Archean eastern Yilgarn Craton, Western Australia is such a region. The approach taken in this Special Issue is to consider the gold mineral system in the eastern Yilgarn Craton in terms of a series of integrated components, referred to by Price and Stoker (2002) and Barnicoat (2007) as the Five Questions: 1. What are the geodynamic and P-T histories of the system? 2. What is the architecture of the system? 3. What are the fluid reservoirs? 4. What are the fluid flow drivers and pathways? 5. What are the metal and sulphur transport and depositional processes? In order to better understand these components and the geological processes which define them, a range of scales needs to be considered. At each scale, however, the relative benefits of considering any one of the five components are varied. For example at the terrane scale, an analysis of the geodynamics and architecture provides most insight, whereas an analysis of deposition mechanisms is best conducted at a deposit scale. This Special Issue focuses specifically on the first two questions, in order to provide a greater understanding of the geodynamic and architectural processes which have contributed to the elevated endowment of gold in the eastern Yilgarn Craton. The papers in this Special Issue reports some of the results produced by the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC, www.pmdcrc.com.au), a research centre funded for seven years by the Australian Government, universities and mineral exploration industry partners.

Over the last fifteen years, Geoscience Australia, through its Onshore Energy Security Program, in conjunction with Primary Industries and Resources South Australia (PIRSA), the Geological Survey of New South Wales (Industry & Investment NSW), the Australian Geodynamics Cooperative Research Centre, and the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC), has acquired several deep seismic reflection profiles, which, when combined, form an east-west transect about 870 km long in southeastern Australia. The seismic data vary from low-fold, dynamite-source to higher-fold, vibroseis-source data. The combined seismic profiles, from the western Eyre Peninsula to the Darling Basin, provide a near complete cross-section of the crust across the Gawler Craton, Adelaide Rift System, Curnamona Province, Koonenberry Belt and Darling Basin. The entire region is dominated by east-dipping faults, some of which originated as basin-bounding extensional faults, but most appear also to have a thrust sense of movement overprinting the extension. In the Gawler Craton, an inferred shallow, thin-skinned thrust belt occurs to the west of an inferred thick-skinned thrust belt. The boundary between the two thrust belts, the Kalinjala Mylonite Zone, was active at least during the Kimban Orogeny, with possible extensional movement at that time. The thrust movement possibly occurred during the ~1600 Ma Olarian Orogeny.

In 2009, as part of its Onshore Energy Security Program, Geoscience Australia, in conjunction with the Northern Territory Geological Survey, acquired 373 km of vibroseis-source, deep seismic reflection, magnetotelluric and gravity data along a single north-south traverse from the Todd River in the south to nearly 30 km north of the Sandover Highway in the north. This traverse, 09GA-GA1, is referred to as the Georgina-Arunta seismic line, extends from the northeastern Amadeus Basin, across the Casey Inlier, Irindina and Aileron provinces of the Arunta Region and Georgina Basin to the southernmost Davenport Province. Here, we report the results of an initial geological interpretation of the seismic and magnetotelluric data, and discuss some preliminary geodynamic implications.

The Archean Yilgarn Craton of Western Australia, is not only one of the largest extant fragments of Archean crust in the world, but is also one of the most richly-mineralised regions in the world. Understanding the evolution of the craton is important, therefore, for constraining Archean geodynamics, and the influence of such on Archean mineral systems. The Yilgarn Craton is dominated by felsic intrusive rocks - over 70% of the rock types. As such these rocks hold a significant part of the key to understanding the four-dimensional evolution of the craton, providing constraints on the nature and timing of crustal growth, the role of the mantle, and also the timing of important switches in crustal growth geodynamics. The granites also provide constraints on the nature and age of the crustal domains within the craton. Importantly, this crustal pre-history appears to have exerted a significant, but poorly understood, spatial control on the distribution of mineral systems, such as gold, komatiite-associated nickel sulphide and volcanic-hosted massive sulphide (VHMS) base metal systems

As part of initiatives by the Australian and Queensland Governments, four new seismic reflection lines and three corresponding magnetotelluric lines were acquired in 2007 over the Mt Isa, Georgetown and Charters Towers regions. These data, combined with existing multidisciplinary data, have provided new insights into the 3D architecture, geodynamics and economic potential of the North Queensland region.

The New England Orogen (NEO) forms the easternmost part of continental Australia, being one of a number of identified orogenic belts within the Tasman Orogenic Zone of eastern Australia. The NEO borders parts of the Lachlan, Thomson and North Queensland Orogens (see Fig. 1), though actual contacts are largely obscured by the Sydney-Gunnedah-Bowen basin system and other cover rocks. The NEO consists of a collage of terranes and has a complex history that stretches from the Neoproterozoic to the Late Mesozoic, although most of the exposed geology is Devonian and younger. A major characteristic of the NEO in this convergent margin setting is the voluminous Carboniferous to Triassic magmatism, which forms a major component of the orogen. Importantly, this magmatism is not confined to the NEO. Carboniferous to mid Triassic felsic magmatism (ca. 350-220 Ma) (Post-Kanimblan Orogeny to Hunter-Bowen Orogeny) forms a major part of the Tasman Orogenic Zone, extending in a wide belt from central New South Wales (the Bathurst region) to islands within the Torres Straits, straddling the Lachlan, Thomson, New England and North Queensland Orogens (Fig. 1), as well as extending into the Proterozoic basement west of the Tasman Orogenic Zone in northern Queensland (Fig. 1). As such, the geochemical and isotopic characteristics of these magmatic rocks, and their regional variations, have the potential to provide significant information regarding the nature and age of the crust in these orogens, as well as to provide constraints on the relationship of the development of the NEO to the neighbouring orogens.

The Australian continent is actively deforming in response to far-field stresses generated by plate boundary interactions and buoyancy forces associated with mantle dynamics. On the largest scale (several 103 km), the submergence of the northern continental shelf is driven by dynamic topography caused by mantle downwelling along the Indo-Pacific subduction system and accentuated by a regionally elevated geoid. The emergence of the southern shelf is attributed to the progressive movement of Australia away from a dynamic topography low. On the intermediate scale (several 102 km), low-amplitude (c. 100–200 m) long-wavelength (c. 100–300 km) topographic undulations are driven by (1) anomalous, smaller-scale upper mantle convection, and/or (2) lithospheric-scale buckling associated with plate boundary tectonic forcing. On the smallest scale (101 km), fault-related deformation driven by partitioning of far-field stresses has modified surface topography at rates of up to c. 170 m Ma-1, generated more than 30–50% of the contemporary topographic relief between some of Australia’s highlands and adjacent piedmonts, and exerted a first-order control on long-term (104–106 a) bedrock erosion. Although Australia is often regarded as tectonically and geomorphologically quiescent, Neogene to Recent tectonically induced landscape evolution has occurred across the continent, with geomorphological expressions ranging from mild to dramatic.

One of the main outputs of the Earthquake Hazard project at Geoscience Australia is the national earthquake hazard map. The map is one of the key components of Australias earthquake loading standard, AS1170.4. One of the important inputs to the map is the rate at which earthquakes occur in various parts of the continent.

The Australian Proterozoic Large Igneous Provinces GIS Dataset is designed for display at a nominal 1:5 000 000 scale, showing the time-space distribution of Proterozoic Large Igneous Provinces (LIPs) in Australia. Large Igneous Provinces are relatively rare magmatic events distinguished by exceptionally large volumes of mafic dominated magma emplaced over short geological periods of a few millions years or less. Five major LIPs have been recognised, or proposed, so far in Australia, beginning with the ~1780 Ma Hart LIP, followed by the ~1210 Ma Marnda Moorn LIP, the ~1070 Ma Warakurna LIP, the ~825 Ma Gairdner LIP, and the ~510 Ma Kalkarindji LIP. The early Cambrian Kalkarindji LIP is included in this Proterozoic compilation because of its size and importance. Only the youngest two of these LIPs (Gairdner and Kalkarindji) are established as comagmatic provinces based on both time correlation and geochemical equivalence. The other proposed LIPs (Hart, Marnda Moorn and Warakurna) are based on time equivalence alone. For further information on the five proposed Proterozoic LIPs refer to the guide to using the map of Australian Proterozoic Large Igneous Provinces (Geoscience Australia Record 2009/44). Earlier released extracts include two pdf maps of Australian Proterozoic Large Igneous Provinces and an accompanying Geoscience Australia Record. This release presents the Australian Proterozoic Large Igneous Provinces as a GIS dataset and it should be used in conjunction with the Australian Mafic Ultramafic Magmatic Events GIS Dataset released by Geoscience Australia in 2014 (<a href="https://pid.geoscience.gov.au/dataset/ga/82166">link</a>). This file geodatabase that contains points, lines and polygons representing mafic and ultramafic rocks in Australia which have been placed in a magmatic event framework in time and space, primarily based on geochronological data. Together, these datasets provide comprehensive information on the evolution of mafic-ultramafic magmatism associated with the Australian continent, and will be of interest to explorers in the search of magmatic ore deposits of nickel, platinum-group elements, chromium, titanium, and vanadium.