Igneous and Metamorphic Studies Group (IMSG) Annual Meeting 2012

 

The 4^th Annual Meeting of the Igneous and Metamorphic Studies Group was held from the 15^th to the 18^th of January 2012, at the University of the Witwatersrand, Johannesburg.

This year saw an unprecedented turnout, with a total of 75 people attending, 36 of these being students, mostly of postgraduate level. The academic institutions represented this year include Wits University, University of Stellenbosch, University of Pretoria, University of Johannesburg, North-West University, University of KwaZulu-Natal, University of Cape Town, Rhodes University and the University of the Free State.

The meeting started with an evening of drinks and snacks in the Geology building, which saw the reuniting of many old acquaintances as well as the establishing of new ones.

Then followed two days of talks, covering a wide range of subjects such as the early oxygenation of the mantle, the origin of I-type granites, metamorphism-related tremors at the subduction interface, unusually low δ¹⁸O magmas in Namaqualand, resorption of diamonds in kimberlite magmas, water-present melting involved in early crust formation and establishing metamorphic grades in coal, to name but a few. These were accompanied by much healthy debate, both in the lecture theatre and over drinks in various Melville bars.

The IMSG meeting offers a great opportunity for students to get experience in presenting and prizes are awarded for the best postgraduate student talks. This year the prizes went to Khensani Mavikane of the University of Pretoria for the Best M.Sc. Student Presentation (“Polymetamorphic Evolution of Schistose Rocks from the Giyani Greenstone Belt: Evidence from Microstructural Analysis”), and Natalie Deseta of Wits University for the Best Ph.D. Student Presentation (“Intermediate-Depth Earthquake Generation: What Hydrous Minerals Can Tell Us”). The M.Sc. prize was a closely fought battle and the judges also commended runner-up Carly Faber for her excellent presentation (“Melt Migration along Axial Planar Leucosome, Damara Belt, Namibia”).

On Tuesday evening we enjoyed a sumptuous buffet dinner at Hofmeyr House. The merriment continued late into the night and several people had to be coaxed out...

On Wednesday, we took a bus to the south of Joburg to the Ventersdorp Supergroup lavas. First stop, the enigmatic ocelli and basalt layering in the Meredale Member at Eagle Brick Quarry. Immiscibility or magma mixing? Going down or going up? Pre-eruption or post-eruption? Perhaps a few papers will result...

Next stop was the lithic tuff at the base of the Ventersdorp, in contact with the Wits – one of the few sites where this contact may still be seen.

We had lunch sitting on the amygdaloidal lavas of the Alberton Formation, at Klipriviersberg Nature Reserve. Here there is a sequence of exceptionally well-preserved lava flows, complete with 2.7 billion year old chill margins and flow-foliated amygdaloidal tops and bottoms. Also to be seen were a few blesbok, springbok and zebra, no-doubt intrigued by the gaggle of humans traipsing up the hill, noses to the ground.

Grant Bybee pointing out the preserved toe of a lava flow to Sharad Master, at Klipriviersberg Nature Reserve. John Bussio is in the foreground.

The full programme and abstract booklet is available. Thank you to everyone who attended.

For more information on the IMSG meeting, please contact Trishya Owen-Smith (trishya.owen-smith@students.wits.ac.za).

Local organising committee:

• Lew Ashwal
• Grant Cawthorn
• Trishya Owen-Smith
• Natalie Deseta
• Grant Bybee

Sponsors:

• Geological Society of South Africa
• Red Dog Scientific Services
• Mineralogical Association of South Africa
• Wits School of Geosciences