Airborne Electromagnetics

Southern Thomson Orogen VTEMplus® AEM survey

A map describing the flight lines for the Southern Thomson Orogen VTEMplus® AEM Survey

Southern Thomson Orogen VTEMplus® AEM survey

The Southern Thomson Orogen VTEMplus® AEM 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 VTEMplus® 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:

  • A regular regional survey on 5000 m spaced East-West lines totalling 3352 line km and covering an area of 16 261 km2.
  • 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 VTEMplus® AEM Survey data release includes the final contractor supplied (Phase 1) datasets AEM survey. The data is available from Geoscience Australia's website free of charge.

The data release package includes:

  • 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:
    • Main survey block Part 1 (flight lines 1000-1171)
    • Main survey block Part 2 (flight lines 1180-1360)
    • Traverse lines (flight lines 3000-3006 and 4000-4007)
    • Repeat lines
    • High altitude lines.
  • Waveform files for every flight containing the 192 kHz sampling of the transmitter current and receiver waveforms.
  • 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.
  • 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.
  • 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.
  • Operations Report.
  • ESRI shapefiles and KML files of flight lines.
  • Metadata and License files.

Available data

AEM data collected from the survey and models resulting from them can be downloaded using the links in the table below.

Southern Thomson Orogen VTEMplus® AEM Survey details
Survey Name State Sub
regions
Area
(km2)
Line
km
Survey
completed
AEM
system
Release of Geoscience
Australia-funded data
only - Contractor
supplied data
Complete final data
release - Contractor
supplied data and
Geoscience Australia
inversion products
Southern Thomson Orogen VTEMplus® AEM Survey
 (1267)
NSW-QLD Thomson Orogen 16,261 4267 5 May 2014 Geotech VTEMplus® Southern Thomson Orogen VTEMplus® AEM survey
(18 August 2014)

TBA

Capricorn 2013 AEM TEMPEST® survey

A map showing the location of flights lines for the Capricorn 2013 AEM TEMPEST Survey. The background to the map consists of geological polygons of the Geoscience Australia 1:1 million scale Geological Map of Australia. 1:250,000 scale map sheet boundaries and names are also included.

Capricorn 2013 AEM TEMPEST® survey flight lines

The Capricorn 2013 AEM TEMPEST® survey, conducted as part of the Western Australia Exploration Incentive Scheme and managed by Geoscience Australia on behalf of the Geological Survey of Western Australia (GSWA), is a $2.5 million contribution to the Distal Footprints of Giant Ore Systems: UNCOVER Australia project. The Capricorn 2013 AEM TEMPEST® survey is the largest AEM survey by area flown in Australia to date at 146 300 km2 (this is larger than the country of Greece).

The Capricorn 2013 AEM survey is Stage 1 of the WA Reconnaissance Airborne Electromagnetic Survey (WARAEM) 2013-20 National Geoscience Agreement project, designed to provide broad-acre, wide line-spacing, airborne electromagnetic (AEM) data over the approximately 70% of the area of Western Australia that is underlain by Precambrian rocks that occur at or within about 300 m of the surface.

The Capricorn Orogen is a geologically complex area, the surface expression of which has a surface extent of approximately 240 000 km2 (approximately 9% of the area of the State). It is prospective for potentially large discoveries of gold, copper, and other base metals.

The Capricorn 2013 AEM TEMPEST data release includes the final contractor supplied (Phase 1) datasets from the TEMPEST® time domain AEM survey as well as a set of GSWA-produced imagery made from the data.

The data release package includes:

  • Point-located, computed B-field EM time-series channel data in ASEG-GDF2 (ASCII) format (also TMI and terrain data)
  • Point-located computed conductivity and terrain data in ASCII format
  • Data multiplots (EM X- and Z-component time series, CDI sections, TMI, altimeter and monitor channels) in PDF format
  • CDI stacked sections in PDF format
  • Gridded data: EM time constant (X- and Z-components); selected conductivity-depth slices (in ER Mapper format, 1 km cell size)
  • Geo-referenced images of gridded EM data in JP2 format
  • Geo-referenced images of gridded TMI, Ternary Radiometrics, Bouger Gravity and DEM data in JP2 format
  • Flight path map in ESRI shapefile format
  • Survey operations report in PDF format
  • Metadata and License files

Available data

AEM data collected from the surveys and models resulting from them can be downloaded using the links in the table below.

Capricorn survey details
Survey Name State Sub
regions
Area
(km2)
Line
km
Survey
completed
AEM
system
Release of Geoscience
Australia-funded data
only - Contractor
supplied data
Complete final data
release - Contractor
supplied data and
Geoscience Australia
inversion products
Capricorn 2013 AEM TEMPEST®
(1265)
WA Capricorn Orogen 146 300 30 123 10 January 2014 GCG TEMPEST® Capricorn 2013 AEM TEMPEST survey
(19 June 2014)

TBA

2006-2011 Onshore Energy Security Program

Under Geoscience Australia's Onshore Energy Security Program (OESP), Airborne Electromagnetic (AEM) data was acquired in areas considered prospective for unconformity-related and palaeochannel-hosted uranium deposits. The program was aimed at reducing exploration risk and promoting exploration activity.

The surveys were designed to reveal new information about regions by acquiring the AEM data at line spacings of between one to six kilometres over relatively large areas. The improved understanding of the regional geology resulting from the surveys is of considerable benefit to mining and exploration companies, many of which were co-contributors to the cost of acquisition.

As well as enhancing the search for uranium and other energy sources, the survey results are directly relevant in exploration for a variety of commodities and other resources, including groundwater. The three priority projects chosen for the OESP AEM data acquisition, decided through mineral systems analysis and discussions with the Western Australia, South Australian and Northern Territory Geological Surveys are:

  1. Paterson Province (Western Australia)
  2. Pine Creek (Northern Territory)
  3. Frome Embayment (South Australia)

Project 1 - Paterson Province, Western Australia

Paterson project, WA

Paterson project, WA

Paterson project, WA

Paterson project, WA

The Paterson project area is centred on the Kintyre uranium deposit and provides AEM data coverage over those areas where Paleoproterozoic Era Rudall Complex and Neoproterozoic Era sediments of the Yeneena Basin either outcrop or are expected to lie beneath less than 500 metres of cover. The area also includes the Telfer gold deposit, the Nifty copper deposit, the Woodie Woodie manganese deposit and others.

Objectives

  • To map unconformities and paleochannels which may be prospective hosts for uranium mineralisation
  • To support geological mapping of lithologies and structures in the subsurface
  • To improve depth to basement estimates
  • To map alteration, mineralisation or host horizons for other commodities including gold, copper and manganese.

Other products

In addition to the AEM data and inversion products linked in the OESP table below, several additional products are available for the Paterson area. These include:

Project 2 - Pine Creek, Northern Territory

The goal of the Pine Creek AEM survey is to characterise the electromagnetic response of Paleoproterozoic rocks, particularly graphitic units adjacent to Archean granite domes, and map these units in regions of extensive cover, such as the Woolner Granite, and Daly River Basin areas. The project will also attempt to map key sub-surface unconformities and structures which may have units in regions of extensive cover, such as the Woolner Granite, and Daly River Basin areas. The project will also attempt to map key sub-surface unconformities and structures which may have influenced mineralising fluids.

Pine Creek project, NT

Pine Creek project, NT

Objectives

  • To map unconformity and palaeochannel uranium host rocks
  • To map the thickness of Kombolgie Subgroup rocks (depth to prospective interface)
  • To map graphitic basement conductors
  • To map the thickness of regolith cover.

Progress update: November 2011

  • Contractor supplied data has been released online
  • Integrated geological and geophysical interpretation will be completed late 2011
  • Interpretation record released November 2011.

Other products

In addition to the AEM data and inversion products linked in the OESP table below, several additional products are available for the Pine Creek area. These include:

Project 3 - Frome Embayment-Murray Basin, South Australia

Frome Embayment project, SA

Frome Embayment project, SA

The Frome Embayment-Murray Basin project will provide regional AEM data over a 95 000 square kilometre area between the Flinders Ranges and the State border in South Australia. Extensive Mesozoic to Cenozoic cover blankets the highly prospective area, which hosts major palaeochannel-type uranium deposits at Beverley, Four Mile, Honeymoon and Goulds Dam.

Objectives

  • To map palaeochannels which may host uranium deposits
  • To map Beverley Sands/Alpha Mudstone
  • To map thick channels of the Eyre Formation
  • To map faults and fault blocks
  • To map depth to cratonic basement, especially over the Benagerie ridge southeast of Lake Frome
  • To map alteration or mineralisation involving other commodities including gold, copper, lead and zinc
  • To map Murray Basin strand lines.

Progress update: November 2010

  • Survey flown between May 2010 and October 2010
  • Phase 1 (contractor-supplied) data released March 2011.

Other products

In addition to the AEM data and inversion products linked in the OESP table below, several additional products are available for the Frome Embayment-Murray Basin area. These include:

Available data

AEM data collected from the surveys and models resulting from them can be downloaded using the links in the table below.

OESP Airborne Electromagnetic Programs and downloadable data
Survey Name State Sub
regions
Area
(km2)
Line
km
Survey
completed
AEM
system
Release of Geoscience
Australia-funded data
only - Contractor
supplied data
Complete final data
release - Contractor
supplied data and
Geoscience Australia
inversion products
Paterson WA Paterson South 11 800 9200 28 November 2007 TEMPEST Paterson South TEMPEST AEM Survey, WA, 2008 Final Data (P1168)
(4 March 2009)
Paterson TEMPEST AEM Survey, Western Australia, 2010 Complete Final Data
(30 April 2010) 
 
Paterson TEMPEST AEM Survey, Western Australia, 2010 Final Inversion Data and Conductivity Models
(30 April 2010) 
Paterson North 35 400 19 400 28 October 2008 TEMPEST Paterson North TEMPEST AEM Survey, WA, 2008 Final Data (P1168)
(17 Apri l 2009)
Pine Creek NT Woolner 8300 6900 5 December 2008 TEMPEST Pine Creek - Woolner Granite Area TEMPEST AEM Survey, NT, 2009 Final Data (P11 96 - part 1 of 2)
(10 July 2009)
Pine Creek TEMPEST AEM Survey, Northern Territory, 2010 Final Inversion Data and Conductivity Models
(30 June 2010)
Rum Jungle 34 900 14 200 24 May 2009 TEMPEST Pine Creek - Rum Jungle TEMPEST AEM Survey, NT, 2009 Final Data (P1196 - part 2 of 2)
(30 September 2009)
Phase-1 and Phase-2 data release for area infill area RJ7 within the Rum Jungle AEM survey, 2010
(14 Dec 2010)
Woolner-
Rum Jungle

4194 17 674
TEMPEST Phase-1 Data release for infill areas within Woolner Granite-Rum Jungle Surveys 2010
(11 April 2011)

Kombolgie 30 500 8800 27 April 2009 VTEM Pine Creek - Kombolgie VTEM AEM Survey, NT, 2009 Final Data (P1195)
(4 December 2009)
Pine Creek - Kombolgie VTEM AEM Survey, NT, 2010 Final Data including infill areas: K1, K2 and K3. (P1195)
(20 Dec 2010)
Pine Creek - Kombolgie VTEM (TM) AEM Survey, NT: Revised EMFlow Conductivity Estimates to 2 km Depth
(20 Dec 2010)
Kombolgie VTEM AEM Survey, Northern Territory, 2011 Inversion Report and Data Package (P1195)
(7 July)
Frome Embayment SA Cariewerloo N/A 600 6 September 2010 TEMPEST Available from PIRSA (26 November 2010) Available from PIRSA (26 November 2010)
Frome 95 000 32 000 2 November 2010 TEMPEST Frome Embayment TEMPEST AEM Survey, South Australia, 2010 Final Data (P1231)
(31 March 2011)
Frome Embayment TEMPEST AEM Survey: Inversion Report and Data Package
(4 July 2011)
C1 subscription infill SA Frome 5000 1100 2 November 2010 TEMPEST Frome Embayment AEM Phase-1 and Phase-2 data for the Callabonna Uranium infill area, South Australia
(16 April 2012)
Frome Embayment AEM Phase-1 and Phase-2 data for the Callabonna Uranium infill area, South Australia
(16 April 2012)
Frome GA-LEI (200m) SA Frome 95 450 32 317 2 November 2010 TEMPEST

Frome Embayment TEMPEST AEM Survey, South Australia, 2010 Final Data (P1231)
(31 March 2011)

Frome Embayment TEMPEST AEM Survey: Inversion Report and Data Package (200m)
(15 June 2012)

The Geoscience Australia data releases include the contractor supplied data and EM Flow conductivity depth image (CDI) sections for only the lines funded by Geoscience Australia. The complete final data releases make available both the contractor supplied data and Layered Earth Inversions (LEI) sections, grids and interpretive products for all Geoscience Australia and infill company flight lines.

Contractor supplied data includes:

  • AEM ASCII data
  • AEM Gridded data
  • AEM multiplots with EM Flow CDI sections
  • Logistics report.

Geoscience Australia inversion products include:

  • AEM ASCII LEI models
  • AEM ASCII elevation slices
  • AEM multiplots with LEI sections
  • Grids and georeferenced images of cross sections, total conductance, elevation slices and depth slices
  • AEM Go Map showing depth of investigation
  • Report.