The 2020 Howitt Lecture
A Joint Presentation with the Geological Society of Australia (Victoria Division)
Victoria’s foundation rocks are largely formed from sediments deposited in the sea over a period of some 100 million years. But because these rock strata have been extensively folded and faulted, there is no obvious way of determining the ages of their exposures at particular locations.
Since the earliest days of geological investigation, the primary method of determining these ages has been the analysis of fossils. In much of Victoria, the most critical fossils are no more than tiny marks on the rocks—the remains of extinct animals called graptolites. The name means “writing on stone,” and that is how many of them look.
Join distinguished geologist Alfons VandenBerg, who will explain what these curious creatures were, and when and how they lived. Are they extinct, as was long believed? Given that we can’t access their DNA, how can we determine their relationships? Are they useful for geological mapping? How did they protect themselves? Fons will demonstrate a variety of these ‘marks’ magnified, displaying an amazing diversity of characteristics. Most importantly, it will show how a close examination reveals the remarkably rapid evolution of those characteristics, making them a key tool in unravelling the sequence of events that made the foundation rocks of eastern Australia.
For details, registration and further information…read more.