Return to page

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

A meteorite fragment intersected by a borehole through the 870 m thick Morokweng impact melt sheet in South Africa is the only known preserved clast of a large asteroid impacting on Earth 144 Ma ago. The meteorite is of an unusual composition. It contains no Fe-Ni metal, is relatively PGE depleted, but enriched in sulfide. Preliminary studies indicate the presence of a suite of unusual contact minerals. The aim of the project is to determine the composition of the meteorite and thereby constrain the nature of the asteroidal parent body and the interaction of the meteorite with the melt sheet. Analytical techniques include mineral analysis by SEM and LA-ICPMS and dating of phosphates to identify potentially older impact events on the Morokweng parent body. High-resolution X-ray computed tomography scans will unravel the 3D internal characteristics of the meteorite and statistically assess the dimensions of the phases identified. X-ray fluorescence mapping using the Australian synchrotron will generate compositional maps for a full range of elements at a micron-scale resolution.

F1

Fig 1. Morokweng meteorite, as intersected in drill core.

Training

Through interaction with the supervisors, the PhD student will be trained in research methodology and a variety of petrological, analytical and modelling techniques (Petrographic microscope, FESEM, Laser ICP-MS, X-Ray tomography). He/she will spend 5% of his/her time demonstrating in the School and thereby gain teaching experience, which is essential when planning an academic career. Further training will be provided through attendance of international conferences, e.g. the annual meetings of the Meteoritical Scoety. The PhD student will also spend three weeks in Perth learning the application of HRXCT in petrological studies. In addition, several BSc students will be involved in minor aspects of the project, e.g. meteorite and melt sheet petrography.

Background Reading

Maier, W.D., et al. (2006). Discovery of a 25 cm asteroid clast in the giant Morokweng impact crater, South Africa. Nature, 441, 203-206.

McDonald, I., et al. (2001). Platinum-group elements in the Morokweng impact structure, South Africa: evidence for the impact of a large ordinary (L) chondrite projectile at the Jurassic-Cretaceous boundary, Geochim. Cosmochim. Acta 65, 113-123.

Contact Details

Professor Wolfgang Maier – maierw@cardiff.ac.uk