Mound springs, garnet sands and tektites
Thursday May 2nd 2024 at 7 pm
Mawson Lecture Theatre,
Department of Earth Sciences, University of Adelaide
Forum presented by University of Adelaide PhD students
Fletcher Nixon, Sharmaine Verhaert and Jake Jolly
Department of Earth Sciences, University of Adelaide
The student forum has become a regular feature of our programme, giving graduate students from the Department of Earth Sciences an opportunity to tell the FGC about the exciting work that they are doing, and for the FGC to learn how these young and enthusiastic researchers are chipping away at the frontiers of earth science. The forum will take the form of a 15-minute presentation by each of the students followed by discussion with the audience. They will love to have your feedback, and to answer your questions.
Mound Springs: Arid Australia’s Palaeothermometers
Fletcher Nixon
Quantitative records of past temperature variability in arid environments are crucial in understanding the full range of the Earth’s climatic regions. However, temperature reconstructions are rare for arid and semi-arid environments, particularly in the Southern Hemisphere, including Australia. This talk will cover how the novel ‘clumped isotope’ technique can be used for carbonates from the iconic central Australian mound springs to reconstruct past temperature changes during the last ~300,000 years. I’ll also share some of the preliminary findings from my PhD, as well as their implications for past climates in Australia’s continental interior.
Garnet sands in South Australia uncover an ancient mountain range in East Antarctica
Sharmaine Verhaert
The Fleurieu and Yorke Peninsula coasts host a number of garnet-bearing beach sand patches which were winnowed from nearby Permo-Carboniferous glacial sediments of the Cape Jervis Formation and afterwards concentrated on the beach by wave action. Over 500 of these garnet grains were dated using a new technique which was developed at the University of Adelaide, and were found to have ages ranging between 620 and 580 million years (Ediacaran). However, these ages cannot be linked to any garnet-grade metamorphic rocks in southern Australia., My research suggests that these garnets were instead eroded from an ancient mountain range in East Antarctica, which is now almost completely hidden underneath a thick ice sheet.
Tektites: from impact to glass
Jake Jolly
Tektites are fragments of the upper crust that are ejected into the atmosphere during high energy meteorite impacts. While the details of tektite formation are still largely unclear, they are commonly assumed to be homogeneous. Examination of these tektites has revealed intricate structures on a micron scale that hold unique information linked to the behaviour of elements at very high temperatures. My research aims to explore the shaping and early development of tektites to better understand their formation, composition, and behaviour of elements under high temperatures.
Members and visitors are warmly invited to attend. No booking requirement.
University policy is to close doors at 7.00 pm, so be sure to arrive punctually! The door will however be checked briefly for late arrivals immediately before the main lecture starts (around 7.10 to 7.15 pm). The FGC doorbell will no longer be available.
Refreshments will be served in the tea room following the meeting.
The meeting will be zoomed. The link will be distributed to members by email a day or two before the meeting.
Please be warned that there is no wheelchair access to the lecture theatre.
