Aberdeen-Curtin Alliance PhD Scholarship
Funded PhD scholarship, jointly supported via Curtin University (Western Australia) and University of Aberdeen (UK).
Project title: Listening through rock salt: Quantifying petrofabrics and seismic velocity anisotropy of evaporites to improve seismic imaging
Principal supervisor: Nick Timms (Curtin University, Perth, Western Australia),
Co-supervisors: Dave Healy (University of Aberdeen, UK), Enrique Gomez-Rivas (University of Aberdeen, UK)
Application deadline: 13th December 2016
Our ability to interpret seismic reflection data depends on the quality of the velocity model used in the seismic processing. Natural salt deposits are preserved in many sedimentary basins worldwide and are often conspicuously present on seismic reflection surveys. In order to ‘listen through’ thick evaporite deposits to interpret the pre-salt structures at depth, we need to be confident in our seismic images and seismic velocity models. However, published velocity data for evaporites is rare and often confined to simple end member minerals (halite, gypsum, anhydrite). In addition, due to their low strength, natural ductile flow of many of these rocks results in strong petrofabrics that influence seismic velocity anisotropy. Real evaporitic deposits are polymineralic and their petrofabrics are relatively poorly studied, and consequently P- and S-wave velocity anisotropies not well constrained. Recent preliminary work at Aberdeen and Curtin has shown how simple combinations of evaporitic minerals and their crystallographic orientation can produce surprising seismic velocity anisotropy in rock salt (Vargas-Meleza et al., 2015, Journal of Structural Geology). However, the influences of mineralogy, phase distribution, grain size, shape, and crystallographic orientation on the velocity characteristics of natural rock salt are yet to be fully explored.
Aims and objectives
The main aims of the project are to quantify petrofabrics in polyminerallic evaporates and their measure effects on velocity anisotropy. In this project the student will collect natural polymineralic rock salt samples from selected outcrop analogues (and core wherever possible), and measure their P- and S-wave velocities as a function of confining pressure (up to 250 MPa), temperature (up to 200 °C), and axial stress (up to 100% of yield stress) at the University of Aberdeen. The student will use optical petrography and quantitative characterisation of phase, grain and crystallographic orientation properties via scanning electron microscopy and electron backscatter diffraction analysis at Curtin University to characterise and quantify the mineral assemblages and textures, and then relate the measured velocities to these mineralogical and textural variations.
Scholarship description and project logistics
This project is supported by the Aberdeen-Curtin Alliance, and comprises a stipend (living allowance), AU$2,500 travel funds between the two institutions and project funding. The PhD candidate will be enrolled in both institutions simultaneously, and spend two years at Curtin University (home institution) and one year at University of Aberdeen (visiting institution). The total duration of the project is three years. The stipend will be paid by the local institution in local currency for the duration of the stay. The stipend at Aberdeen will be at RCUK rates (UK£14,296 per annum equivalent), and at Curtin at APA rates (AU$26,288 tax-free per annum equivalent). The vacancy is open to applications from international and Australian national applicants.
Visit the Research Scholarships page for information about tuition fees at Curtin. A tuition scholarship (fee waiver) is available for international applicants. The student is responsible for acquiring and paying for entry visas for both countries.
Candidate selection criteria
We are looking for a highly motivated candidate who must have the flexibility in their personal lives to fulfil the travel arrangement. Must have a minimum Bachelor Honours degree in geology or geophysics at 2.1 class. Good writing and speaking skills in English (see ‘postgraduate higher’ minimum IELTS, etc., requirements for the Aberdeen College of Physical Sciences), a good background in geosciences (geology and/or geophysics and mechanics), and proficiency in high school-level mathematics and physics are essential.
Highly desirable skills/experience include geometry (e.g., structural geology, geological mapping), mineralogy, and an understanding of rock microstructures.
Please send the following documents as attachments via email to Nick Timms by the application deadline.
- Cover letter: In your letter, please summarise your suitability for the PhD project.
- Curriculum vitae (CV)/Resume: Please include your nationality, academic qualifications, any relevant experience that address the selection criteria (detailed above) and names and contact details of two referees.
- Evidence of qualifications: Please provide a copy of your degree certificate(s) (in original language and officially translated into English where relevant), and a transcript of your undergraduate degree results (in original language and officially translated into English where relevant). For non-native English speaking applicants, please provide evidence of English proficiency (IELTS Academic/TOEFL iBT/PTE Academic/Cambridge English Advanced & Proficiency scores).
- Presentation: Shortlisted candidates will be requested to prepare give a short presentation.