Andreas Läufer: Studying Antarctica’s Geological History
Geologist Dr. Andreas Läufer and his colleagues from the German Federal Institute for Geosciences and Natural Resources (BGR) have just finished their second season at PEA. This year, they used helicopters to get around in the field and did some research in conjunction with the Alfred Wegener Institute for Marine and Polar Research (AWI).
What were your research objectives this season?
We had two main objectives this year. First of all, we've been trying to reconstruct part of the geological history of the Gondwana Supercontinent, which formed between 650 and 500 million years ago and broke up about 180 million years ago. Secondly, we've been looking at the long-term evolution of the landscape after the Gondwana supercontinent broke apart.
We're particularly interested in learning more about how quickly the orogeny that formed Gondwana took place, how the modern Sør Rondane Mountains formed, how quickly uplift and erosion has taken place since Gondwana break-up, and so on. Initial results from our research so far indicate that the Sør Rondane Mountains might be located at the southeastern end of the orogen that was created some 500 million years ago when the Gondwana supercontinent was forming. The northern end of this ancient orogen or mountain range is next to the German Neumayer III Station in the western part of Dronning Maud Land.
Why do you need to use helicopters for your research this year?
The helicopters are much more time effective and time-saving than the skidoos. Skidoos are difficult to use when you're trying to get around mountainous areas like in the Sør Rondane. The kind of rock samples we need lie in rocky outcrops that jut out of the ice. A lot of the samples we were taking were high up in mountainous areas. We're not mountain climbers like Alain is, so having helicopters to get us directly to the places we want to survey saved us a lot of time.
And having the helicopters allowed us to do sampling in three or four different spots in a single day, and allowed us to travel further in one day than by skidoo. By helicopter, you can get all the way to the easternmost part of the Sør Rondane Mountains from PEA in only 60 minutes.
What exactly do you look at in the rock samples you bring back to Germany?
We look at two things. Firstly, we look at the magnetic signatures. Such things may be used, for instance, to indicate where the piece of rock was on the planet when it formed due to the way the ferromagnetic materials in the rock were aligned with the Earth's magnetic field at the time. However, in cooperation with the aerogeophysics group of AWI, we use these signatures to tell something about the type of rocks or structures that are hidden beneath the ice. This is an area of expertise that geophysicists have, which is why we've got one on our team.
Secondly, we do a geochemical analysis to determine the composition of the rocks – what kind of minerals they are made of, what kind of temperatures and pressures the rocks were exposed to. There's also lot of geochronology dating techniques we'll use on the rock samples to determine how old the rocks are. And last-not-least, we use structural geology to tell us something about the orogenic, or mountain-building, forces that acted in the Sør Rondane.
You had some new members of the team with you this year, including some students.
This year we had four senior scientists (including myself) and two students with us. One of the students form the University of Bremen is working on the investigation into the long-term landscape evolution of the region, and the other is a structural geologist who is investigating the formation of the Gondwana supercontinent.
How were the two students on the team able to adapt to Antarctica? Was this their first time there?
This was indeed their first time in Antarctica, and they had no problems adapting. After a brief introduction, the students were able to do field work on their own.
Were you able to accomplish everything you planned to do this year?
We were able to accomplish pretty much everything we set out to accomplish. We're very content with how things went. Now we're looking forward to getting the samples we've taken this year back to Germany to be analyzed starting in late March or early April.
This is the second year we've been working on this project in the Sør Rondane, and so far we've been happy with the results we've been able to get.
You collaborated with the Alfred Wegener Institute (AWI) this year…
Yes. AWI has been working on a collaborative aerogeophysical programme in parallel with our geology programme, which was designed by our two institutes. They were using their new Polar-6 plane to survey the Sør Rondane Mountains, looking at the magnetic signatures of the rocks, measuring the ice thickness on top of the mountains, and also the gravity.
The data the Polar-6 collected will provide a more detailed picture about the geological structures underneath the ice. So we'll be able to get the same kind of information about the rocks underneath the ice that we've been getting form sampling the parts of the rocks that are exposed at the top. It's been a very challenging yet very interesting part of the project.
Now that your field work in Antarctica has finished for the season, what's left to do?
A team is staying behind at Novolazarevskaya Station to do some field research there for one week. It's a place where no real geological research has ever been done.
A meteorite survey team collected meteorites in that area two or three years ago and they collected rocks from the moraines, and we found certain kinds of rocks which nobody thought existed in that area. So we thought it might be a good idea to send a helicopter team down there to sample some of the rocks.
How many more seasons will you need to go back to this part of Antarctica in order to finish this research project?
That's a rather difficult question to answer. We'll need at least one more season in the Sør Rondane region of Antarctica. However next season we're planning to go to the other side of Antarctica by the Ross Sea on the Pacific side and do a big expedition there next year.
But we'll need to do some more aerogeophysics work in Sør Rondane eventually, and of course BGR will send a geologist to do some field work in parallel. We'll know more once we get some results from the samples we've taken. But I'm quite sure we'll come back. We had such great hospitality at PEA and they were so helpful with the logistics!
Picture: Dr. Andreas Läufer - © International Polar Foundation