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This project is eligible for support from Cardiff Universtiy through the School of Earth & Ocean Sciences.

To apply, please visit the Cardiff University Postgraduate Research portal: http://www.cardiff.ac.uk/for/prospective/postgraduate/applying.html

 Description

The Bushveld Complex of South Africa is the world’s largest layered igneous intrusion and greatest storehouse of Cr, V and platinum-group elements (PGE). From base to top the complex is divided into five zones: Marginal, Lower, Critical, Main and Upper. The boundaries between them are often characterised by geochemical shifts related to major injections of new magma (e.g. Kruger 2005). Spatially, the Bushveld Complex comprises five lobes (Far Western, Western, Eastern, Southern and Northern).  Many Bushveld models assume that all lobes were connected, and development of Cr, PGE and V mineralization was contemporaneous in the different parts of the intrusion (e.g. Kruger 2005). However the major stratigraphic marker horizons found in the other lobes are either absent in the Northern lobe or their proposed correlation is controversial (Roelofse and Ashwal 2012). In particular, the Northern Main Zone contains a thick zone of unusual Mg olivine-rich cumulates (troctolites and harzburgites) that have no direct equivalent in the other lobes

The aim of the project is to determine the origin of the olivine-rich unit; whether it is new magma influx, a lateral equivalent of the Pyroxenite Marker known from the other lobes, or a raft of Critical Zone rocks suspended in the Main Zone. The unit has potential economic significance as the only other place where similar olivine-rich cumulates occur they host high grade PGE mineralization.  This research will be carried out in partnership with Bushveld Minerals, an AIM-listed mining company.

Fig 1

Figure 1: (A) troctolites in drillcore at Waterberg; (B) troctolite with hazrburgite “xenoliths” on surface; (C) Cu-rich sulphides in Main Zone peridotites at Aurora

Training

Fieldwork (surface mapping and logging of drill core) with Bushveld Minerals in South Africa

Mineralogical analysis (SEM and LA-ICP-MS)

Whole rock geochemistry (ICP-OES, ICP-MS) including fire assay for PGEs

Sulphur, oxygen and strontium isotope analysis (SUERC)

In addition to project-specific training, the student will have access to the DTP training courses. The student is also expected to present project results to national and international conferences. Combined, the training package of the project will give the student an array of skills suitable for a career in academia or industry

Background Reading

Kruger (2005) Mineralium Deposita, v. 40, p.451-472. Roelofse and Ashwal (2012) Journal of Petrology, v. 53, p.1449-1476.

Contact Details

Dr Iain McDonald - mcdonaldi1@cardiff.ac.uk