Monday, January 27th
Today, Eugene Domack led our group of students on a field trip. The sun was shining and it was a perfect day to get out of the city for a bit. To reach our destination, our group rented a van and drove north and west to reach Mt. Field National Park. The geology of the park is striking and is quite relevant to our upcoming area of study. Geologically speaking, Tasmania is more similar to Antarctica than it is to Australia. Thus it is a great way to get warmed up to the geology of Antarctica before departing. Gene explained these similarities to us over the course of the day at various important sites.
One of our first points of interest was located at Russell Falls. The rocks exposed at the picturesque waterfalls are sedimentary, and are a part of the Parmeener Supergroup. The stratigraphy of Antarctica shows a corresponding grouping of sedimentary layers called the Beacon Supergroup. The falls are not only beautiful but are an example of the similarities between Tasmania and Antarctica. The succession of sedimentary layers contains the Permian/Triassic contact, which is a sharp angular contact separating the Permian period from the Triassic period. This contact will help us to put a relative date on the sediments from Antarctica, and also gives insight into the ancient climate of the supercontinent, Gondwana. Russell Falls was an important stop in helping our student group understand the climate history of the region.
From Russell Falls, we moved on to Lake Dobson. The lake and many lakes in the surrounding region were created in pockets where ancient glacial ice collected, creating tarns. These characteristics show that historically, the region was glaciated and experienced much lower temperatures than today’s climate. Peat bogs also exist near Lake Dobson, another climate marker that only exist within a narrow temperature range. Geologically speaking, the region is unique. Large tabular dolerite intrusions create a flat topography in certain areas. The intrusions also give insight into the breakup of Gondwana, the supercontinent consisting of Antarctica, Australia, Africa and South America. The tabular intrusions are interpreted as a release of heat from the underlying mantle. This is thought to be the process that split the supercontinent into the multiple continents that we see today.
Mikhaila Redovian and Kara Vadman, Colgate University