In the days prior to the Goldschmidt Conference a group of twenty six conference delegates from nine countries participated in a four day journey to explore some of the geological highlights of western Victoria-a broad area extending west from Melbourne for over 400kms close to the border with South Australia.
Geologically speaking the western districts of Victoria form the southernmost part of the Lachlan Fold Belt and are well known for their rich goldmines, tektite strewnfields and for the extensive province of Cenozoic basaltic volcanism returning a varied suite of mantle xenoliths to the Earth's surface.
The trip commenced in Melbourne and headed out along the Great Ocean Road, a magnificent stretch of open road running several hundred kilometres west and bordering the wild Southern Ocean. On the way we visited some of the remnant Gondwana rainforest at Maits Rest and inspected the spectacular ‘twelve apostles', a series of impressive sea stacks which dominate this part of the so-called ‘shipwreck coast'. With the backdrop of a wonderful sunset against the apostles, participants were then treated to a close up encounter with a pod of Southern Right whales on their annual migration.
The next day concentrated on volcanic activity, visiting the famous Lake Bullenmerri maar structure, the volcanic cinder cone of Mt. Noorat, lava tubes at Byaduk, and hunting for mantle xenoliths at Mortlake down inside Mt Shadwell volcano (in a quarry!).
The third day took us inside the Tower Hill maar structure. Along the way we saw emus, koalas and kangaroos....this was rapidly becoming a ‘wildlife tour of western Victoria'! We then headed north to examine aboriginal rock art in the Grampians National Park and, to finish the day, we enjoyed a magnificent dinner at the Royal Mail hotel in Dunkeld at the foot of the Grampians ranges.
Granites and gold were the themes for the next day. Initially, we inspected the unusual sodium rich granites of the Victoria Valley complex. This was a unique time to visit an area which had been devastated by bushfires covering over 130,000 hectares 6 months previously. However, it is a testament to the resilience of the Australian bush that most of the native trees were displaying a flush of new growth, providing an eerie contrast against their blackened limbs. Heading out of the Grampians from Halls Gap we made for the Victorian goldfields.
Gold was first discovered in Victoria in the 1850's and the ensuing gold rush fuelled the rapid development of the city of Melbourne which quickly became the nations largest city, and also led to the establishment of the Geological Survey of Victoria. The next 60 years saw production of ~ 80 million ounces of gold and, today, total Victorian gold production represents some 2% of all gold mined in the world.
After a visit to the working Wonga Mine (and a local winery!) we finished off the day in Bendigo with a memorable dinner deep underground in the workings of the Central Deborah mine after a brief tour and some hands on experience with several generations of drill rigs.
Returning to Melbourne the next day we were all feeling relaxed, refreshed and ready for the conference to begin...
Jon Woodhead, Janet Hergt, Roland Maas, Trip Leaders