Our showcase series highlights the various research and teaching activities that take place within the School of Geosciences. It's an opportunity for you to discover what it's like to be a practising Geologist or Geographer and what activities, as a student within the School, you do to become one.
Have you ever been curious about what it's like to work in Antarctica? Want to see what our students experience on our annual South-East Asia / Pacific Fieldschool? Over the coming months our showcase series will focus on these and other activities. We hope you enjoy!
Our current showcase: An Antarctic Expedition
The theory of plate tectonics is an important part of current geological thinking. It describes the large scale motion of the Earth’s crust. The crust is broken up into sections, known as tectonic plates, and these have been moving slowly over millions of years.
At the places where plates meet lots of interesting things happen. Earthquakes, volcanoes, the creation of ocean trenches and mountains all occur at these plate boundaries. The Himalayas mountain range for example is the result of two large plates pushing, or converging, into each other.
Events like the formation of the Himalayas are useful for geologists who are interested in understanding the forces behind plate tectonics. Unfortunately, this kind of evidence only helps us understand what happens at the upper part of the Earth’s crust. Geologists who want to know what happens in the lower part of the crust have to find other evidence. For the School’s Associate Professor Geoff Clarke that meant a two-month visit to Antarctica.
In late 2002, Geoff Clarke and two of the School’s postgraduate students, Jacqueline Halpin and Florien Schröter, travelled to Antarctica with Richard White of the University of Melbourne. Their research centred on the coastline between the Oygarden Group and Stillwell Hills. The rocks in this region were part of the lower crust roughly 1000 million years ago but now rest at the Earth’s surface. Studying these rocks gives geologists a fantastic opportunity to learn more about the forces acting in the lower crust.
The geologists’ trip to Antarctica began in Sydney, from where they flew to Cape Town in South Africa to board the Russian Ice Breaker Kapitan Khlebnikov. The ship took them to Antarctica through some pretty spectacular pack ice on its way to Mawson base, the longest-running Australian Antarctic station. From there the team began their field trip, travelling on quad bikes and towing all the equipment they would need for the next six weeks.
The team’s journey involved a round-trip from Mawson to Alphard Island, some 300 kilometres away, with stopovers at Colbeck Hut and the Stillwell Hills. The stopovers gave Geoff, Jacqueline, Richard and Florian the opportunity to eat and rest, undertake their field work, perform emergency training exercises and conduct any necessary repairs to their equipment.
As it turns out repairs were definitely necessary. Difficulties with one of their quad bikes made for slow going early into their trip. Failures with their communication and dirty fuel for their cooking stoves also provided extra challenges to the team. All this in addition to constantly keeping an eye out for dangerous conditions throughout their trip.
Whilst the travel wasn’t always easy, it certainly was beautiful. The Antarctic landscape is not simply fields of white snow and ice. It is full of life and amazing geological features. The team met Emperor penguins on their travels, one even seemingly offering advice on how to repair their quad bike. The team also had the chance to get up close to a rare Antarctic sight: a jade berg.
Jade bergs are icebergs with a distinctive green tinge. No one knows for sure how they are formed, but one theory suggests that they are formed on the bottom of the ice shelf where fresh water with algae in it has gathered.
For Geoff, Jacqueline, Florian and Richard however, the jade berg was simply an object of beauty and fascination. Their field work focused on mapping and sampling the rock formations they encountered during their journey. And the team’s research along the Antarctic coast was extremely fruitful. Jacqueline and Florian used the data they collected to complete their PhD theses and along with Geoff published several academic articles. Their research provided greater insight into the processes that shaped the Earth’s crust many millions of years ago. This knowledge, in turn, helps geologists better understand better the geological processes that take place today.
- Halpin, J.A., Gerakiteys, C.L, Clarke, G.L., Belousova, E.A. and Griffin, W.L., "In-situ U-Pb geochronology and Hf isotope analyses of the Rayner Complex, east Antarctica", Contributions to Mineralogy & Petrology, 2005, 148, 689-706.
- Halpin, J.A., White, R.W., Clarke, G.L. and Kelsey, D.E., "The Proterozoic P-T-t evolution of the Kemp Land coast, east Antarctica; constraints from Si-saturated and Si-undersaturated metapelites", Journal of Petrology, in press (2006).
- Halpin, J.A., White, R.W., Clarke, G.L. and Kelsey, D.E., "Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica", Journal of Metamorphic Geology, in press (2007)