Messengers from the Mantle exhibition coming to the University of Johannesburg for GeoCongress week, 13 to 21 July 2018

Opening on 13 July and continuing through the GeoCongress meeting, the University of Johannesburg’s Kingsway Campus Main Library in Auckland Park will host the exhibition Messengers from the Mantle: Diamonds and Craton Roots. Rather than focusing specifically on the beauty and monetary value of diamonds, the exhibition highlights the scientific knowledge of the Earth’s interior gained over the past fifty years through the study of kimberlites and the “messengers” they have brought up from the Earths’ mantle, such as xenoliths and inclusion-bearing diamonds. The exhibition was mainly developed from 2014 to 2016 by a team led by UCT Emeritus Professor and famed exploration geologist John Gurney and was first put on display at the International Geological Congress in Cape Town in August 2016, to widespread acclaim. Since then, it has been displayed at other venues, such as the 11th International Kimberlite Conference in Gaborone, Botswana.

The exhibition highlights the symbiotic relationship between diamond exploration/mining and research into the Earth’s mantle. It is widely known that diamond mining has yielded rare and scientifically valuable deep Earth materials for study, but it is less appreciated that scientific analysis of these materials has generated information that has proved crucial in the exploration for diamonds. John Gurney was a key figure in the discovery and early evaluation of many diamond-bearing kimberlites in Canada, and over the past fifty years he and his students and collaborators have assembled a research collection exceeding 14,000 specimens of kimberlites, mantle rocks and related materials. It is this collection, housed at UCT in a space informally known as “the Mantle Room” (now officially the John J. Gurney Upper Mantle Research Collection), that was the source for the materials showcased in the Messengers from the Mantle exhibition.

The exhibition is aimed at a geologically interested audience, but no prior knowledge of the mantle or kimberlites is assumed. Messengers from the Mantle: Diamonds and Craton Roots consists of 13 sections covering the Structure of the Earth, Kimberlites, Peridotites, Eclogites, Metasomatism, Megacrysts, Diamonds, Exploration, Alluvial Diamonds, Marine Diamonds, History of Diamond Mining, History of the Mantle Room and Unsolved Mysteries. The Exhibition contains ten exhibit cases, each containing backlit large format thin sections of specimens on display, allowing the unusual colours and textures of these unique rock specimens to be shown clearly. There are also a large number of touchable specimens and specimens of heavy mineral concentrate from different southern African kimberlites that can be examined closely.

The Exhibition will be on display from 13 to 21 July 2018 on the 5th floor foyer of the University of Johannesburg’s Kingsway Campus Main Library in Auckland Park. It will be accessible free of charge to GeoCongress delegates, as well as the public, during this time.