Dr. Malcolm McMillan1, Dr. Samuel Boone1,2, Associate Professor Stijn Glorie3, Dr. Angus Nixon3, Associate Professor Martin Danišík4, Dr. Renjie Zhou5, Professor Barry Kohn1, Ferdinand Mayer-Ullmann3, Dr. Romain Beucher6, Moritz Theile6, Dr. Fabian Kohlmann6, Professor Brent McInnes4, Dr. Bryant Ware4
1The University of Melbourne, Melbourne, Australia, 2The University of Sydney, Sydney, Australia, 3The University of Adelaide, Adelaide, Australia, 4Curtin University, Perth, Australia, 5The University of Queensland, Brisbane, Australia, 6Lithodat Pty. Ltd., Melbourne, Australia
Biography:
Dr. Malcolm McMillan is a thermochronologist working at the University of Melbourne studying the denudation response following continental rifting in eastern Africa and Australia. Malcolm is also interested in investigating the influence of climate and bushfire frequency on low temperature thermochronology. Malcolm is part of the AuScope Geochemistry Network (AGN) working as a data scientist in areas of fission-track and (U-Th)/He thermochronology.
Abstract:
Low-temperature thermochronology is a temperature-sensitive dating technique used to constrain the evolution of Earth’s crust over geologic time. Researchers commonly combine thermochronology with numerical modelling to quantify thermal histories. These models generate best-fit paths in time-temperature space that are used to better understand Earth processes such as basin deposition, mountain formation and surface erosion. In particular, thermochronology has been widely utilised to model the patterns of uplift and erosion following large-scale continental break-up. However, interpreting continental break-up thermal history models is complex as rock samples have experienced significant geographic movement through time that is often difficult to reconcile in their present-day context.
Here we present a powerful new tool for geospatially visualising thermal history models in 4D, developed as an extension to the open-access AusGeochem platform. The significant advancement is the ability to roll back geologic time and display time-sliced thermal history data, which also influences the paleogeographic location of the sample using AusGeochem’s paleo-reconstruction tool powered by pyGPlates. Essentially, this utility allows researchers, for the first time, the ability to observe rate of cooling (denudation) for all samples in a study area at a specific slice in geologic time as the movement and break-up of continents proceed.
To demonstrate the utility of this tool, we present a comprehensive dataset of >5000 low-temperature thermochronology data points and associated thermal history models from across Central Gondwana, modern-day southern Africa, and document the continental-scale upper crustal thermal evolution since the Jurassic.