The Southern Thomson Orogen VTEM-plus® Airborne Electromagnetic Survey was conducted by Geoscience Australia as part of a collaborative project with its partners the Geological Survey of New South Wales and the Geological Survey of Queensland. The Survey contributes to the Australian Academy of Science's UNCOVER Initiative and Geoscience Australia's response to this as part of the National Mineral Exploration Strategy.

Geoscience Australia contracted Geotech Airborne Ltd to acquire VTEM-plus® airborne electromagnetic (AEM) data over part of the Southern Thomson Orogen in Queensland and New South Wales in April and May 2014. The data were also processed by Geotech Airborne Ltd using its FullWaveForm® processing techniques.

The survey is designed to assess the under-cover geology and prospectivity of the Southern Thomson Orogen around Hungerford and Eulo and straddles the New South Wales-Queensland border. The survey comprises two parts:

1. A regular regional survey on 5000 m spaced East-West lines totalling 3352 line km and covering an area of 16 261 km2.

2. Two regional traverses adjacent various roads totalling 915 line km.

The Southern Thomson Orogen is a priority area for mineral systems research. Much of the area lies underneath cover of sedimentary basins and is a poorly-understood element of Australia's geology. The Orogen contains Cambro-Ordovician rocks that have potential for Iron Oxide Copper-Gold (IOCG) resources, porphyry copper-gold and Volcanic-Hosted Massive Sulphide (VHMS) deposits. Survey data will add to knowledge of cover thickness and character and will inform future geological mapping in the region.

The Southern Thomson Orogen VTEM-plus® AEM Survey data release includes the final contractor supplied (Phase 1) datasets AEM survey. The data will be available from Geoscience Australia's web site free of charge:

http://www.ga.gov.au/about/what-we-do/projects/minerals/current/continental-geophysics/airborne-electromagnetics

The data release package includes:

1. Point-located electromagnetic dB/dt and derived B-field data with associated position, altimeter, orientation, magnetic gradiometer, and derived ground elevation data. These data are in ASCII column format with associated README and ASEG-GDF2 header files. The dataset consists of a separate download file for the:

a. Main survey block Part 1 (flight lines 1000-1171)

b. Main survey block Part 2 (flight lines 1180-1360)

c. Traverse lines (flight lines 3000-3006 and 4000-4007)

d. Repeat lines

e. High altitude lines.

2. Waveform files for every flight containing the 192 kHz sampling of the transmitter current and receiver waveforms.

3. Point-located conductivity estimates derived using the EM Flow® conductivity depth imaging (CDI) algorithm with associated position, altimeter, orientation, magnetic gradiometer, and derived ground elevation data. Data include the conductivity estimate for each 5 m interval and selected depth slices. These data are in ASCII column format with associated README and ASEG-GDF2 header files. All regular survey, traverses and repeat lines are included in a single download file.

4. Gridded data, at 1 km cell size in, for the conductivity depth slices derived from the EM Flow® CDI data, magnetics and elevation data in ER Mapper® binary raster grid format with associated header files.

5. Graphical multiplots, in PDF format, for each flight line showing EM Flow® CDI sections and profiles of Z-component dB/dt data, magnetics, powerline monitor, height and orientation data.

6. Operations Report.

7. ESRI shapefiles and KML files of flight lines.

8. Metadata and License files.