Typological analysis of Australian coastal aquifers

Occurring in the southwest of Western Australia, the 1968 Meckering earthquake (MS 6.8) resulted in the formation of an extensive surface rupture complex comprising faults with a range of orientations and demonstrating reverse and dextral lateral offsets. The rupture extended for approximately 37 km and scarps were as high as 2.5 m high near to the centre of the complex. Modeling of the seismological characteristics of the source show reverse failure occurred on a north-south striking, east-dipping, surface, but how this is related to the local Precambrian bedrock geology is not clear.Interpretation of new aeromagnetic data, together with subsequent ground-truthing, has allowed concealed bedrock lithology and structure to be mapped in previously unachievable detail. These data show that the surface faulting correlates closely with linear magnetic anomalies, interpreted as dykes/faults and lithological contacts. The apparent arcuate form of the fault complex is explained in terms of the reactivation of northeasterly (dykes and faults) and northwesterly (stratigraphic) trending features in a stress regime with an east-west oriented maximum principal stress. Space problems created where these two trends converge led to the creation/reactivation of a linking north-south trending thrust fault which accommodated the greatest displacements recorded for the 1968 event. This interpretation is consistent with previous research on the source parameters of Meckering event, which invoked one or more easterly dipping failure surfaces and reverse slip.

22-1/F50-12/6 Vertical scale: 750

D53/B1-122 Vertical scale: 200

F54/B1-135 Vertical scale: 1000

Large areas of prospective North and North-East Queensland have been surveyed by airborne hyperspectral sensor, HyMap, and airborne geophysics as part of the 'Smart' exploration initiative by the Geological Survey of Queensland. In particular, 25000 km2 of hyperspectral mineral and compositional map products, at 4.5 m spatial resolution, have been generated and made available via the internet. In addition, more than 130 ASTER scenes were processed and merged to produce broad scale mapping of mineral groups (Thomas et al, 2008). Province-scale, accurate maps of mineral abundances and minerals chemistries were generated for North Queensland as a result of a 2 year project starting in July 2006 which involved CSIRO Exploration and Mining, the Geological Survey of Queensland (GSQ), Geoscience Australia, James Cook University, and Curtin University. Airborne radiometric data acquired over the same North Queensland Mt Isa - Cloncurry areas as the hyperspectral surveys, had been acquired at flight line spacing of 200 metre. Such geophysical radiometric data provides a useful opportunity to compare the mineral mapping potential of both techniques, for a wide range of geological and vegetated environments. In this study, examples are described of soil mapping within the Tick Hill area, and geological / exploration mapping within the Mt Henry and Suicide Ridge prospects of North Queensland.

At the request of Prime Minister and Cabinet (PM&C), Geoscience Australia (GA) prepared this report for the purposes of informing a National Security paper that highlights potential national security issues associated with climate change.

Modelling the effects of granitic intrusions in the EGST: Magmatic volatiles, contact metamorphism and mechanical effects

Uraninite dating of the Kintyre deposit and Rossing South prospect using electron probe chemical U-Th-Pb technique.

A key component of Geoscience Australia's marine program involves developing products that contain spatial information about the seabed for Australia's marine jurisdiction. This spatial information is derived from sparse or unevenly distributed samples collected over a number of years using many different sampling methods. Spatial interpolation methods are used for generating spatially continuous information from the point samples. These methods are, however, often data- or even variable- specific and it is difficult to select an appropriate method for any given dataset. Machine learning methods, like random forest (RF) and support vector machine (SVM), have proven to be among the most accurate methods in disciplines such as bioinformatics and terrestrial ecology. However, they have been rarely previously applied to the spatial interpolation of environmental variables using point samples. To improve the accuracy of spatial interpolations to better represent the seabed environment for a variety of applications, including prediction of biodiversity and surrogacy research, Geoscience Australia has conducted two simulation experiments to compare the performance of 14 mathematical and statistical methods to predict seabed mud content for three regions (i.e., Southwest, North, Northeast) of Australia's marine jurisdiction Since 2008. This study confirms the effectiveness of applying machine learning methods to spatial data interpolation, especially in combination with OK or IDS, and also confirms the effectiveness of averaging the predictions of these combined methods. Moreover, an alternative source of methods for spatial interpolation of both marine and terrestrial environmental properties using point survey samples has been identified, with associated improvements in accuracy over commonly used methods.