School of Earth & Ocean Sciences

A native of Glasgow, Iain McDonald took his undergraduate degree at the University of Glasgow. In addition to the obvious subject specific skills, the BSc Chemistry & Geology course in the late 1980's provided invaluable "hands-on" training in the kinds of applied analytical chemistry, instrument development and inspired bodging that has long since disappeared from most undergraduate courses. In 1990, Iain moved to South Africa to begin a PhD on PGE geochemistry with Maarten de Wit at the University of Cape Town. Unfortunately the laboratory where most of the work was to be carried out was 700 miles away in Johannesburg so Iain moved north to the City of Gold. He found a lab and a long term home among the various geologists, nuclear and solid state physicists, chemists and engineers in the Schonland Research Centre for Nuclear Sciences (now iThemba Labs) at the University of the Witwatersrand. Over the course of his PhD, Iain developed improved fire-assay methods for PGE analysis, was involved in the characterisation of a new low-level PGE standard reference material and showed in a series of experiments that the presence of carbon, and particularly carbon monoxide, in melts could lead to volatilisation of all the PGE

Spherules of impact melt from the late Archaean Jeerinah impact layer, Hamersley Basin, Western Australia (courtesy, B. Simonson)

In 1993, Iain returned to the UK to a postdoc at Manchester University working with David Vaughan and Grenville Turner. The project formed part of a larger EU funded project to evaluate new types of Pt and Pd mineralisation in Madagascar and Albania. After three years in Manchester, Iain took up a lectureship in Geochemistry at the University of Greenwich in 1996. Over the next five years he set up a laboratory for routine PGE analysis and began a sustained programme of research into PGE geochemistry at impact craters collaborating with colleagues in Austria, Denmark, South Africa and America. These studies involved searching for extraterrestrial PGE in impact melt sheets and breccias at Morokweng (South Africa), Ries (Germany), Chesapeake Bay (America) and Zhamanshin (Russia) and for traces of the Late Heavy Bombardment recorded in metasediments at Isua in Greenland.

Since moving to Cardiff in 2001, Iain played a major role in the design and commissioning of the Elemental Analysis Laboratory in 2002 and manages the facility with support from Maira Hernandez Guzmann. During 2002, Iain built up another PGE lab in Cardiff - the only one in the UK to focus on impact crater research - and expanded his research to cover meteorites as well as craters. The highlight of this research has been the discovery of a boulder sized fragment of the asteroid that formed the 144 million year old Morokweng impact crater in South Africa. The results of this work (Maier et al. 2006) were published in Nature in May 2006 and represent the first discovery of fossil meteorites at a large impact crater.

Exploration drilling of the Platreef on the farm Zwartfontein (courtesy, D. Holwell)

The other major area of research that Iain has led since moving to Cardiff is a re-evaluation of the PGE mineralization in the northern limb of the Bushveld Complex in South Africa. This limb hosts the enigmatic Platreef Ni-Cu-PGE deposit and its relationships with the rest of the Bushveld Complex are not clear. In conjunction with PhD students David Holwell and Paul Armitage, this research has revolutionised ideas about the Platreef, its relationship with the Merensky Reef, and the manner in which magmas were intruded into the northern limb. This has led to completely new genetic models for this style of deposit (McDonald et al. 2005, Holwell et al. 2005; Holwell and McDonald 2007).

Current Research Interests

• Development of ICP-MS and LA-ICP-MS techniques
• PGE mineralization in the northern limb of the Bushveld Complex, South Africa
• PGE in mantle xenoliths and kimberlites
• PGE in meteorites, impact melts and impact ejecta deposits

Recent Grants

• 2002-2004: 24 month Leverhulme Trust Grant award (Grant F/00 407/K) on impact signatures at the J/K boundary. £57,300.
• 2003-2006: NERC Industrial CASE studentship award NER/S/C/2003/11952 in conjunction with Anglo American plc for support of PhD student David Holwell.
• 2004-2005: NERC Isotope Geoscience Facilities Steering Committee award (IP/839/11-04) to support in-situ sulphur isotope work by at the SUERC. £17,600 in kind award.
• 2006-2008: NERC Isotope Geoscience Facilities Steering Committee award (IP/909/0506) to support in-situ sulphur isotope work by at the SUERC. £20,650 in kind award.