An interpretation of SIMS O isotope analysis and LA-MC-ICP-MS Lu-Hf analyses of zircons from the Rum Jungle Complex, northern Australia

22-1/F50-16/7 Vertical scale: 100

Groundwater dependent ecosystems (GDEs) are an important feature of the Australia landscape and as need to be incorporated into water management to maintain their persistence. However the first step to ensuring sustainable management of GDEs is the identification of such communities. With recent technological advances in remote sensing, identification of GDEs is becoming more commonly achieved through temporal analysis of biophysical properties detected from satellite imagery, for example as used in the National Atlas of Groundwater Dependent Ecosystems. However, many of these remote sensing studies only concentrate on surface processes and fail to integrate the spatial and temporal dynamics of these communities with subsurface processes such as depth to watertable, groundwater quality, groundwater flow paths and recharge zones. In this study, LiDAR canopy digital elevation model and foliage projected cover data were combined with Landsat imagery in order to characterise the spatial and temporal behaviour of woody vegetation in the Lower Darling Floodplain, New South Wales. This multi-temporal data was then combined with hydrogeological, hydrogeochemical and hydrogeophysical data to assess the relative importance of hydrological processes and groundwater characteristics. Central to the approach was the use of airborne electromagnetics which provided a 3-dimensional context to otherwise point-based borehole data. Through these multiple lines of evidence, two types of groundwater dependent vegetation communities were identified. In both classes vegetation was concluded to be utilising groundwater within the shallow unconfined aquifer, however the distinction was the degree of connectivity with underlying aquifers through either an absence of the regional aquitard or connection via faults. This study highlights the importance of integrating remote sensing with both surface and subsurface data to gain an improved understanding of vegetation dynamics and groundwater dependency. These findings are being used to assess the suitability of proposed groundwater-development options in the study area, and have implications for riparian vegetation management more broadly.

22-1/F53-2/4 Vertical scale: 400

22-1/F51-14/6 Vertical scale: 500

22-1/H53-1/4 Vertical scale: 400

In the literature of remote sensing image analysis, an endmember is defined as a pixel containing only one land cover substance. However, with the varying resolutions of available sensors, in most cases a single pixel in a satellite image contains more than one type of land cover substance. One challenge is to decompose a pixel with mixed spectral readings into a set of endmembers, and estimate the corresponding abundance fractions. The linear spectral unmixing model assumes that spectral reading of a single pixel is a linear combination of spectral readings from a set of endmembers. Most linear spectral unmixing algorithms rely on spectral signatures from endmembers in pre-defined libraries obtained from previous on-ground studies. Therefore, the applications of these algorithms are restricted to images whose extent and acquisition time coincide with those of the endmember library. We propose a linear spectral unmixing algorithm which is able to identify a set of endmembers from the actual image of the studied area. Existing spectral libraries are used as training sets to infer a model which determines the class labels of the derived image based endmembers. The advantage of such approach is that it is capable of performing consistent spectral unmixing in areas with no established endmember libraries. Testing has been conducted on a Landsat7 ETM+ image subset of the Gwydir region acquired on Jun 22, 2008. Three types of land cover classes: bare soil, green vegetation and non-photosynthetic are specified for this test. A set consisting of 150 endmember samples and a number of ground abundance observations were obtained from a corresponding field trip. The study successfully identified an endmember set from the image for the specified land cover classes. For most test points, the spectral unmixing and estimation of the corresponding abundance are consistent with the ground validation data.

The Olympic Cu-Au Province, of the eastern Gawler Craton, lies beneath the sedimentary sequences of the Stuart Shelf. Rocks of the basement are Late Archean metamorphics, and the Proterozoic Donington Suite, Hutchison Group, Wallaroo Group, Hiltaba Suite granitoids and mafic intrusives, and the Gawler Range Volcanics. Except for parts of the Gawler Range Volcanics, none of the basement crops out and is covered by sequences exceeding 3 km thickness, in places. Interpretation of units and structures was via gravity and airborne magnetic data. Some geological calibration was done by checking exploration drill logs or by examining the core. When core was examined, petrophysical properties were measured and used to constrain the interpretation. This map has been produced as a GeoPDF, which is an extension to the standard PDF file format viewed using Adobe Acrobat Reader. Layers can be turned off and on to customise the view of the data, similar to using Geographic Information System tools. In addition, GeoPDF maps are georeferenced to be compatible with other coordinated geographic data. Coordinate locations and distances can be retrieved automatically. A plug-in to view GeoPDF using Adobe Acrobat Reader is available as a free download ( http://terragotech.com/solutions/map2pdf_reader.php ).

No abstract available

The Moonta Subdomain forms the southern part of the Olympic Cu-Au province on the eastern margin of the Gawler Craton, and underlies most of the Yorke Peninsula and Spencer Gulf. The domain basement comprises metasediments and metavolcanics of the Palaeoproterozoic Wallaroo Group (~1760-1740 Ma) which were deformed and metamorphosed to upper greenschist-amphibolite facies during the Kimban Orogeny (~1720 Ma). These rocks were further deformed and intruded by granitoids and minor mafic intrusions of the Hiltaba Suite between about 1600 Ma and 1575 Ma. The Moonta Subdomain basement is highly prospective for iron oxide-Cu-Au mineralisation associated with the Hiltaba magmatic event. However outcrop of these basement rocks is limited almost entirely to narrow coastal exposures. The majority of the prospective basement is concealed by up to 100 metres of Neoproterozoic to Quaternary sediments, and geological mapping of the basement is largely limited to interpretation of geophysics (airborne magnetics, gravity, AEM) and drilling. This map has been produced as a GeoPDF, which is an extension to the standard PDF file format viewed using Adobe Acrobat Reader. Layers can be turned off and on to customise the view of the data, similar to using Geographic Information System tools. In addition, GeoPDF maps are georeferenced to be compatible with other coordinated geographic data. Coordinate locations and distances can be retrieved automatically. A plug-in to view GeoPDF using Adobe Acrobat Reader is available as a free download ( http://terragotech.com/solutions/map2pdf_reader.php ).