Dr. Agathe Lisé-Pronovost
School of Geography, Earth and Atmospheric Sciences
The University of Melbourne
Paleomagnetic records from stalagmites and lake sediments and applications for Australia’s cultural and natural history
In this lecture, I will present the latest Holocene paleomagnetic records from Australian stalagmites, lake sediments and lava flow and discuss their incorporation into geomagnetic field models. There is a long-standing imbalance in the global distributionof high resolution paleomagnetic data, with the southern hemisphere critically under-documented relative to the northern hemisphere. Australia is one region lacking high quality data. Here, paleomagnetic results from three Australian sites are presented. The first site is Webbs Cave on the Nullarbor Plains (southern Australia). It is the first Holocene paleomagnetic record from stalagmite in Australia and reaches decadal scale resolution over the last 4.2 ka. The second site includes the Crater lakes Keilambete and Gnotuk (southeast Australia) reaching centennial-scale resolution over the last 10 ka. Those lake sediments, first studied by Charlie Barton in the 1970s, are to my knowledge the only Australian sediment paleomagnetic record sometimes included inglobal databases and models. The lakes were cored again in January 2023, with the goal to revisit the pioneer records with modern state-of-the-art paleomagnetic techniques. The third site is the Budj Bim cultural volcanic landscape (southeast Australia). Now listed as a UNESCO World Heritage site, the 36.6 ka (Ar/Ar) lava flow was engineered by Indigenous people over millennia into a complex eel aquaculture system. We will present an archaeomagnetic investigation into Indigenous fire technology and draw onthis case study to highlight exciting applications for developing regional paleomagnetic dating in Australia.