ModelVision software, Research and Services
Tensor Research Newsletter
August 2025
See us in Perth at AEGC Booth 92
​We will be in Perth to enjoy the AEGC conference hosted by ASEG, PESA and AIG. We welcome the opportunity to talk with you about magnetic and gravity applications and the many different ways to get more value from your data. Come and chat with us about the latest ModelVision 18.0 release, RPD Mapping or just to say hi.
Dave Pratt is also presenting two papers (#81Aliasing estimation for TMI and FTMG survey design and #87 Large scale magnetic gradient tensor surveys from TMI data) as part of the Tuesday Potential Fields sessions. The first paper shows how to create large scale magnetic tensor survey line data from tensor-ready magnetic surveys and legacy datasets. He will illustrate the process with surveys from the Agnew-Wiluna Nickel Belt and Gawler Craton.
The second paper demystifies the estimation of aliasing in magnetic surveys by presenting a new way for direct estimation of the errors in grid data derived from total field and full tensor magnetic gradient (FTMG) surveys. The technique allows us to evaluate different gridding methods as well as survey design for specific target geology characteristics.
Release of ModelVision 18
Release 18 of ModelVision was made available in early April and we are pleased with how quickly most of our users have updated to the latest release. The complete replacement of the Help system, documentation and online context sensitive searching was a much larger project than we had anticipated. For the documentation, every image is a mini project and many were replaced with images captured from realistic geological investigations.
RockMod used to subset bodies created from a RPD Mapping project in the Cloncurry district of QLD. The RockMod chart by Clark shows that the selected range is in the skarn region and consistent with an intersection of specific units with the granite carapace. The upper map shows only bodies highlighted by RockMod, while the lower image shows the original points coloured by susceptibility and labelled with the depth below ground estimates.
The AnswerGenius AI Assistant has been further improved since the release with much more focussed responses than we achieved during the early trials. The normal context sensitive help (F1 key) or full text search is still the best place to get to the right place in the documentation, but if you are not sure where to start, the AnswerGenius may get you there faster. Here is a common example: We often get asked the question about activating remanence in models because it is turned off by default. You can also activate remanence on individual bodies which is important for reducing the number of degrees of freedom during inversion and avoids decreasing the inversion focus.
Magnetic Mentor ASEG Preview Series
Dave has started writing a series of short Preview articles called the Magnetic Mentor on applied magnetic interpretation for mineral exploration students and early career graduates. Many don’t have access to a mentor and the pressure of a new job leaves little time for research on how best to prepare, present, analyse and interpret magnetic data. ​
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The articles are organised as a natural progression from the fundamentals of high dynamic range TMI data through to understanding limitations and how to visualise and extract the underlying geological information, spatial properties, depth and rock properties. Wherever possible, Dave provides links to relevant chapters in the new CSIRO book Exploration Magnetics Theory and Practice where a concept is expanded to cover more detail and additional examples.
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And there is something in there for everyone who wants to see if they can squeeze that little bit extra out of their processes. This image shows a comparison using a popular hue saturation and luminance (HSL) colour model (a) with a modified CET-R4 colour lookup table image (b). Apart from the image colour, all other image settings are the same and the linear colour perception model (CET) enhances more geological features.
Comparison of -Bzz tensor grid data derived from the South Australian Gawler Craton magnetic survey comparing the HSL (a) and CET-R4 (b) colour LUTs
The data, background information and supporting files such as colour lookup tables are available from the Magnetic Mentor series data link. The series data and Preview publications are freely available for download as a tutorial source. Public domain data has acknowledgements of the data sources and citation information is provided should you wish to publish the data.
Exploration Magnetics Theory and Practice
A must have new book from CSIRO Publishing edited by: Phil Schmidt, James Austin, David Clark, Keith Leslie, Mark Lackie, Clive Foss. An essential resource for geophysicists, geoscientists and geological mapping agencies.
Exploration Magnetics provides a comprehensive review of the application of magnetisation and magnetic field studies to mineral exploration. It investigates how subsurface models of magnetisation properties and distribution can be derived from magnetic field data. The book also covers geological controls on magnetisation, including linkage between magnetisation and mineralisation, illustrates the magnetic field expression of those magnetisations and explains how to recognise them.
Next Generation Explorers Award - NGEA
Tasman Gillfeather-Clark (DMPE) and Rebecca (Becki) Montsion (CSIRO) are organising a forum session for undergraduate and post-graduate students during the AEGC Conference. There will be presentations on the goals of the NGEA award and a panel discussion, along with benefits for student and university participation. Both Tasman and Becki have participated in past contests and have very personal experience with the opportunities it created for them to pursue their career passions. If you know any students who would be interested in finding out more about the award, make sure they take a close look at the program.
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Dave Pratt has been part of the international committee for the NGEA when it was first known as the Frank Arnott Award to honour Frank’s contribution to data integration and visualisation of geoscience data. Dave is working with Tasman and Becki towards an Australian version of the Award which we have called NGEAOZ. Winning teams will be encouraged to enter their projects in the international competition where the top six teams compete during the annual PDAC event in Toronto. Congratulations to the Magnetic Misfits team from the University of Adelaide for taking out the top prize in 2025.
The participating teams now form an alumni with many taking advantage of the industry exposure and mentoring processes opened up to them. Teams from South America, Southern Africa and Europe have been regular participants in the NGEA in addition to regular contributions from Canada and Australia.
RPD Mapping
Our RPD Mapping (rock property and depth mapping) research has driven a lot of improvements in ModelVision:
• visualisation of point datasets
• improved numerical annotation with 1 to 8 per point
• new geological symbol subset
• large scale model import with remanence and additional body types
• model subsetting
• RockMod for rock property analysis.
Example full text search to find a list of FFT filters where references to line and grid filters were returned.
A subset of existing and new symbols have been grouped under Structural symbols to shorten the selection process. More will be added in the future, but this new set is very useful for attributing RPD Mapping point sets. We use the azimuth for the tensor-derived strike directions, quality to modulate symbol size and colour for a range of parameters such as depth below ground surface, constrained inversion magnetic susceptibilities, apparent resultant magnetisation rotation angle (ARRA), dimensionality and structural indexes for geological shape identification. The upper two maps show bodies highlighted by RockMod with strike direction arrows overlays on the left map. The filled circle is coloured by inverted magnetic susceptibility, size modulated by one of the quality measures and annotated with depths below ground.
Over the last three years, we have had the opportunity to apply RPD Mapping to a broad range of geological settings with detailed analysis of quantitative results demonstrating the value of full magnetic gradient tensor data. Some highlights from the projects include:
• Reduction of the essential quantitative data to a point set for mapping applications
• Confidence estimates are vital for interpretation procedures and data visualisation
• Continuous depth estimation along magnetic features is important for geological interpretation
• Compact rock properties derived from high resolution tensor data adds significant value
• Direct conversion of point sets to models, making target validation much easier
• Agreement with independent geophysical depth investigations
• Magnetic noise contains useful geological information in special cases
• High resolution magnetic depths are useful for water resource development
• Geological shape factors highlight small and relevant features that may go unnoticed
• The importance of the real impact of line spacing on exploration outcomes
• The importance of quality sensor elevation and ground clearance.
David Pratt
Manager Research and Development David.Pratt@tensor-research.com.au
PO Box 5189, Greenwich NSW 2065 Australia
