This map is part of a series which comprises 50 maps which covers the whole of Australia at a scale of 1:1 000 000 (1cm on a map represents 10km on the ground). Each standard map covers an area of 6 degrees longitude by 4 degrees latitude or about 590 kilometres east to west and about 440 kilometres from north to south. These maps depict natural and constructed features including transport infrastructure (roads, railway airports), hydrography, contours, hypsometric and bathymetric layers, localities and some administrative boundaries, making this a useful general reference map.

Mineral deposits are a product of the coincidence of favourable geological conditions within a given spatial and temporal setting. Collectively, these key geological elements may be considered as aspects of a mineral system. Mineral system-based investigations of the potential for a range of uranium systems have recently been undertaken in northern Queensland, east-central South Australia and the southern Northern Territory. Building on the methodology employed in northern Queensland, the mineral system assessment in South Australia and the Northern Territory consists of four key system components: (1) sources of metals and fluids, (2) drivers of fluid flow, (3) fluid pathways and architecture, and (4) depositional sites and mechanisms. Favourable geological criteria are developed from these four components, which are in turn translated into mappable geological proxies. Thus, the mineral systems framework drives the collection and synthesis of geoscientific data. This approach minimises the influence of localised geological controls, which may only be significant at the mine scale, and allows the system to be mapped on a broad scale, maximising the 'footprint' of mineralisation. Locations of known mineralisation are not considered in the assessment but are used to verify results. By employing a systems-based approach, the potential of relatively unexplored areas may be assessed objectively, transparently and systematically. Significantly, the approach used here is able to predict the potential for unrecognised mineralisation beneath cover. The assessments undertaken for uranium potential successfully reproduce the location of known uranium deposits and, importantly, delineate several areas where uranium mineralisation is currently unknown.

Building a continental-scale land cover monitoring framework for Australia

Despite the extensive resources, ongoing mining activity and economic importance of iron-ore in Australia, the genesis of iron-ore and particularly its timing, remains relatively poorly understood. Most iron-ore in Australia is interpreted to originate as Banded Iron Formation (BIF) that has subsequently experienced one or more fluid leaching events in which silica is removed, leaving the residual rock highly enriched in iron (Morris and Kneeshaw, 2011). While this general model appears relatively well established, questions remain regarding whether iron-enrichment typically occurs over one or more events, the timing of such events, and the controls on fluid movement leading to iron enrichment. Here we report textural observations and U-Pb isotopic results from zircon extracted from hematite ore from the Iron Knob mine in the Middleback Range, South Australia. The U-Pb ages have yielded unexpected results that are interpreted to indicate at least some fluid interaction and iron enrichment in the Middleback Range occurred in multiple stages through the Paleozoic and Mesozoic. Such timing is unexpected given the local geological context, but may in part be explained by early Paleozoic tectonic events in the Adelaide Fold Belt (Delamerian Orogeny), ~100 km to the east, having played a role in mobilising supergene fluids within the adjacent margin of the Gawler Craton.

Since the Indonesian islands of Sumatra and Java lie adjacent to an active subduction zone and include some of the world's most densely populated areas, the reduction of potential earthquake fatalities through improved building codes and seismic hazard assessments is a high priority. One of the most critical parts of an earthquake hazard assessment is a quantitative description of the level of ground motion generated by an earthquake, also known as Ground Motion Prediction Equations (GMPEs). We have developed a strong ground motion database for of Sumatra and Java. This catalog includes: best-available earthquake catalogue parameters; a compilation of site response information using various techniques; and ground motion parameters commonly used in seismology and engineering applications, such as response spectra. We will show how the database can be used for investigating which published Ground Motion Prediction Equation (GMPE) are appropriate to use for Indonesian earthquake hazard assessment.

For well over a decade GPS time series have been used as an effective way of densifying a reference frame. During this period numerous advances have been made in the analysis and modelling techniques applied to GPS observations. This has seen GPS time series improve by almost an order of magnitude in accuracy, and has allowed even more challenging applications of GPS time series analysis to be investigated such as glacial isostasy, elastic deformation of the earth's crust due to atmospheric loading and atmospheric tomography. Despite numerous improvements in the GPS analysis technique to handle different error sources there still remains significant long term site-specific biases. The biases are often caused by local multi-path effects and/or near-field antenna phenomena and have an adverse impact on the signal being analysed. Typically the largest effect is seen in the height component or the scale of the reference frame determined by the GPS network. Correction of these site-specific systematic errors can not only remove biases, but will also reduce the phase residual noise level, thus providing a better resolution to distinguish the signal of interest. We will present a technique to detect, and model for long term systematic errors by using one-way phase residuals obtained from a post-processed GPS network. We will then assess the impact of applying these derived individual site models into a re-processed solution for the purposes of reference frame determination at the Regional and Global level. We will also asses the performance of these derived site-specific models for real-time solutions.

Aerial photography for mapping

Wibble

1m contours were generated for the Christmas Island urban area from the August 2011 LiDAR digital elevation model.

Understanding of the depth of cover is poor across large areas of Australia. The spectral method is an efficient method of producing reliable depth to magnetic basement estimates across large regions of the continent. A semi-automated work-flow has been created that enables the generation of depth to magnetic source estimates from windowed magnetic data using the Spector and Grant method. The work-flow allows for the correction of the power spectra prior to the picking of straight-line segments to account for the fractal distribution of magnetic sources. The fractal parameter (ß) varies with depth and was determined by picking multiple depth estimates in regions of outcropping magnetic basement which have been upward continued to different levels in order to simulate different amounts of burial beneath non-magnetic sediments. A power law function best approximates the decay of ß with depth. An iterative schema has been incorporated into the workflow which is used to determine the optimum ß where the depths of magnetic sources are unknown. Preliminary testing in a region of known magnetic basement depth has produced encouraging results, although further testing is required. The decrease of ß with increasing depth suggests that the fractal distribution of magnetisation becomes more correlated over larger volumes of observation.