We are pleased to announce a School Seminar by Dr Tobermory Mackay-Champion on the topic of: The Origin of Earth's First Continents and the implications for Mars and Venus.
Abstract
The emergence of stable continental crust marks a defining stage in planetary evolution, yet the mechanisms that enabled Earth's earliest continents to form remain debated. These first continents are dominated by tonalite–trondhjemite–granodiorite (TTG) suites, whose origin provides a key record of the conditions under which continental crust first developed. Using Finland's exceptionally well-preserved Lake Inari terrane, we combine phase-equilibrium modelling with Bayesian statistics to derive the first sample-specific preßssure–temperature constraints on Archaean TTG magmatism. Integrating these results with a global TTG dataset reveals that TTGs are the geochemical manifestation of a narrow, volatile-regulated pressure-temperature window within which melt generation, segregation, and preservation of buoyant felsic continental crust are simultaneously achieved. Our results show that continent formation predictably emerges when fundamental planetary properties, such as bulk composition and thermal structure, permit intersection of this window. I will conclude by exploring the implications of this framework for the formation of continental crust on Mars and Venus. This work was done in collaboration with Prof Chris Hawkesworth (University of Bristol) and Dr Jaana Halla (Finnish Museum of Natural History).
Bio
I am a seismologist with research interests in petrology, tectonics, and planetary science. I completed an undergraduate master's degree and DPhil at the University of Oxford, where I investigated the tectonic setting of sediment-hosted copper deposits in Africa using passive seismology, petrology, and structural analysis. After a postdoctoral position at the University of Oxford applying passive seismology to geothermal and mineral exploration, I joined Dr James Verdon's research group at the University of Bristol. My current research investigates how passive seismology and distributed acoustic sensing (DAS) can be used to characterise and monitor carbon capture and storage (CCS) sites.