Demonstrates the application of modelling gamma-ray spectrometry and DEM for mapping regolith materials and in predicting salt stores.

3-6 July, 2001, Townsville, Qld.

No abstract available

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Mineralizing events in the North Pilbara Terrain of Western Australia occurred between 3490 Ma and 2700 Ma and include the oldest examples in the world of many ore deposit types. The mineralizing events were pulsed and associated with major volcano-plutonic (volcanic-hosted massive sulfide [VHMS], porphyry Cu, Sn-Ta pegmatite, mafic-ultramafic-hosted Ni-Cu-PGE, Cr and V, and epithermal deposits) and deformation events (lode Au?Sb deposits). In many cases, the mineralizing events are associated with extension, either in rifts, pull-apart basins or back-arc basins. Although mineralizing events occurred throughout the evolution of the North Pilbara Terrain, the most significant deposits are related to the development of the Central Pilbara Tectonic Zone (CPTZ). The CPTZ is sandwiched between the older East and West Pilbara Granite-Greenstone Terranes. Four significant volcano-plutonic and three significant deformation events occurred in and around the CPTZ between 2950 and 2840 Ma, a relatively short period in the evolution of the North Pilbara Terrain. Mineralization in the East and West Pilbara Granite-Greenstone Terranes was less intense and occurred over a much longer period. Compared to other Archean granite-greenstone terranes, the North Pilbara Terrain is poorly endowed: the only known world-class deposit in this region is the Wodgina Ta-Sn deposit. This lack of major mineral deposits may relate to the low rate of crustal growth of the North Pilbara Terrain. If such is the case, then the long history of crustal development and extensive recycling in the Pilbara is responsible for both the diversity of mineral deposits therein and, partly, the apparent poor endowment of the North Pilbara Terrain.

This map is part of the series that covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 513 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and 110 kilometres from north to south. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. The topographic map and data index shows coverage of the sheets. Product Specifications Coverage: The series covers the whole of Australia with 513 maps. Currency: Ranges from 1995 to 2009. 95% of maps have a reliability date of 1994 or later. Coordinates: Geographical and either AMG or MGA (post-1993) Datum: AGD66, GDA94, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Paper, flat and folded copies.

The Great Australian Bight airborne laser fluorosensor (ALF) MkII survey was flown in 1989 by BP. The MkII system used a 308nm laser wavelength, longer than the 266nm used in the later MkIII system. The Raman peak wavelength is 344nm and the fluorescence region is 370nm to 580nm. This report is a reinterpretation of the original BP data using ALF_Explorer software. Survey lines were numbered from 1 to 281 but many lines had several segments. A total of 520 line segments were detected in this survey using a line break distance of 100m. Lines 201 and 203 had 92 and 71 segments respectively. A noisy navigation system may have produced apparent breaks on these lines. If the extra segments on these lines are excluded, the survey contains 359 segments. The lines were acquired at approximately 3,000m spacing in a NS orientation and a flying height of 100m. A total of 33,154,869 spectra were processed at an average spacing of 15m to 22m. Each recorded spectrum is the average of ten detected spectra. The averaging was done to reduce the data recording rate, which was limited by the available hardware. The fluorescence response was very weak for the Great Australian Bight ALF survey, requiring a very sensitive detection method. The 3km line spacing is not sufficiently close to detect most fluor clusters. The Great Australian Bight ALF MkII data is probably not suitable for identifying the isolated, low intensity fluors.

The Perth Basin airborne laser fluorosensor (ALF) MkII survey was flown in 1989 by BP. The survey was designed to detect natural oil seepage over a large region of the Perth Basin, Western Australia, in an effort to refine the petroleum prospectivity assessment. An area of about 80km by 400km was surveyed at 5km line spacing. A total of 510,500 fluorosensor spectra were recorded. This report is a re-interpretation of the BP data by Signalworks Pty Ltd using the ALF Explorer software. A total of 1,355 fluors were picked out of the 510,500 recorded spectra in the final interpretation. This is an average fluor density of 2.65 fluors per thousand spectra. The fluorescence response over most of the survey area consisted mainly of relatively low confidence fluors (compared to the more reliable MkIII survey data). High intensity fluors are located in several zones in the middle of the survey, probably over small islands, being caused by the exposed island material fluorescing. While fluor density variations can be seen on the fluor map the geological implications are not clear. Because of its susceptibility to noise, the MkII ALF system produces less confident fluor maps than the MkIII system. Some mapped fluor density variations may be influenced by sea state or water property variations

This map is part of the series that covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 513 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and 110 kilometres from north to south. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. The topographic map and data index shows coverage of the sheets. Product Specifications Coverage: The series covers the whole of Australia with 513 maps. Currency: Ranges from 1995 to 2009. 95% of maps have a reliability date of 1994 or later. Coordinates: Geographical and either AMG or MGA (post-1993) Datum: AGD66, GDA94, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Paper, flat and folded copies.