Assoc Prof. Andy Tomkins - Honours Projects

Variation in gold content of arsenopyrite at the Fosterville gold deposit, Victoria

Supervisors: Andy Tomkins, Chris Voisey, Joel Brugger
Field of study: Economic Geology
Preferred Program: Honours

Much of the gold at Victoria’s largest currently operating gold mine occurs in arsenopyrite. Interestingly, the mineralization style in this deposit varies considerably with depth: in the upper part gold is mainly hosted in arsenopyrite, then deeper down stibnite appears and there is some visible gold, then below that there is very high-grade visible gold and less stibnite. Gold occurs in arsenopyrite through the full depth range. Mining is now starting to expand into the nearby Robin’s Hill deposit and there is not much known about gold in arsenopyrite there. This project will conduct a detailed program of sample collection, petrographic evaluation and laser ablation ICP-MS analysis of arsenopyrite through the full depth range of the Fosterville deposit and compare with the arsenopyrite at Robin’s Hill in order to better predict the distribution of gold in both deposits.

Determining the age of undated impact structures in Australia

Supervisors: Andy Tomkins
Field of study: Planetary Science
Preferred Program: Honours

There are five meteorite impact craters in Australia that are undated but could plausibly have been generated in the mid-Ordovician period. The mid-Ordovician was a time characterised by unusually high meteorite impact rates, a unique period in at least the last 550 million years and probably much more. This project will visit one or more of these five Australian impact craters to collect samples for geochronology. The samples will be characterised prior to mineral separation work and then geochronology will be conducted on mineral separates. This work will help determine whether Australia bears several scars from the Ordovician impact spike (one is known already).

For further information, contact Andy Tomkins