PROJECT
A radiometric renaissance: making better use of an under-utilised geophysical-geochemical dataset
Exploring for new mineral responses using natural radioactivity from the rocks
There is evidence that with better understanding of the variations in radioelement (K, Th,U) content in mineralised environments and a better capability to model these responses, radiometric data could play a much greater role in exploration.
Opportunities exist to work with geochemical and radiometric datasets from a wide range of deposit types to understand their radiometric signatures. The proposed research will comprise two basic approaches both of which will be tested using a new modelling method:
(i) A radioelement (K, Th, U) based classification of rocks will be created. Radioelement concentrations are known to be correlated with concentrations of some major elements (Dickson and Scott, 1997), but no systematic study has been described. Establishing the relationships between ‘radiometric-based’ geology and geochemical rock classifications is key to better utilisation of radiometrics in a mapping role during exploration.
(ii) There are periodic reports of detectable radiometric responses from hydrothermal alteration from various individual deposits of various types, e.g. VMS, orogenic gold and epithermal precious metals (Shrive et al., 1997). However, responses are inconsistent and often examples do not unequivocally demonstrate that alteration zones are the dominant causes of responses.
We propose to use a compilation of published descriptions of geochemical variations within alteration zones establish systematic relationships to better understand enhancement/depletion of the radioelements in alteration zones.
Key to understanding radiometric responses from both alteration and different rock types is modelling of expected responses. Radiometric data are the only kind of geophysical data that are not routinely ‘modelled’. A unique radiometric forward modelling software package has been created by Dr Brian Minty and is available for this project. This software can be used to model radiometric responses of mineral system components, systematically exploring the effects of varying radioelement contents (for example in alteration zones), accounting for variable exposure, size and shape of the components and also topography.
The integration of these different lines of research has the potential to improve greatly our ability to extract geological information from radiometric datasets for exploration purposes.
For more background information, see the suggested readings below.
- Suggested readings
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- Dentith and Mudge, 2014. Geophysics for the Mineral Exploration Geoscientist. Cambridge University Press.
- Dickson and Scott, 1997. Interpretation of aerial gamma-ray surveys - adding the geochemical factors. AGSO Journal Australian Geology & Geophysics, 17, 187-200.
- Shives et al., 1997. The detection of potassic alteration by gamma-ray spectrometry – recognition of alteration related to mineralisation. Proceedings of Exploration ’97. Prospectors and Developers Association of Canada, 741-752.
As part of this PhD the applicant will:
- Compile and analyse geochemical and radiometric data from mineralised environments from Australia and elsewhere in the world.
Research team leader: Professor Mike Dentith
I am a Professor of Geophysics at UWA and senior researcher within the Centre for Exploration Targeting (CET). I have supervised more than 40 PhD projects undertaken by students from all over the world. My research interests are in applied geophysics as used in exploration for natural resources. Research will be co-supervised with geologists and geochemist in the CET and Dr Brian Minty.
Collaborations
External collaborators:
- Geological Survey of Western Australia
- Various mining companies
- Individuals and companies interested in collaborating with this research should contact the research leader Professor Mike Dentith.
How to apply
Interested in becoming part of this project? Complete the following steps to submit your expression of interest:
Step 1 - Check criteria
General UWA PhD entrance requirements can be found on the Future Students website.
Requirements specific to this project:
- There are mainly opportunities for students with backgrounds in geophysics, geochemistry and geology, but also mathematics, computer sciences, data analytics, physics and engineering.
Step 2 - Submit enquiry to research team leader
Step 3 - Lodge application
After you have discussed your project with the research team leader, you should be in a position to proceed to the next step of the UWA application process: Lodge an application. Different application procedures apply to domestic and international students.
Scholarships
- Domestic students
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All domestic students may apply for Research Training Program and University Postgraduate Awards (UPA) scholarships
- International students
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A range of scholarships are available from international organisations and governments. The full list, organised by country, is available on the Future Students website.
In addition, all international students may apply for International Research Training Program scholarships.
- Indigenous students
- Indigenous students are encouraged to apply for Indigenous Postgraduate Research Supplementary Scholarships.
- Forrest Foundation scholarships
- All international and Australian students who wish to study towards the degree of Doctor of Philosophy (PhD) at The University of Western Australia may apply for Forrest Scholarships.
