2022DP220103027 to Chris Clark, Martin Hand & Naomi Tucker

What goes on inside subduction zones? This project aims to decipher how rocks behave inside subduction zones. Subduction is a central tenant of plate tectonic theory and the project will test the hypothesis rocks can become trapped within giant long-lived eddies that circulate material within subduction zones. This international collaborative project will generate new knowledge regarding the time scales rocks can remain trapped inside subduction zones using pressure–temperature–age constraints from subducted rocks. We will use this information as a framework for numerical simulations of subduction zone behaviour. The project will provide significant benefits in training a new generation of Earth scientists, and in broadening public awareness of fundamental Earth science.

2020DP200101104 to Tim Johnson & Chris Clark

Deciphering the tectonic record of the early Earth. This project aims to decipher how and why plate tectonics emerged, and how any precursor tectonic system modulated planetary heat loss. The project expects to generate new knowledge regarding the tectonic record of the early Earth using pressure–temperature–age constraints from truly ancient (2.8–4.0 billion year old) metamorphosed rocks worldwide. Expected outcomes of this collaborative international project include the development of a conceptual geodynamic model for the early Earth. This should provide significant benefits in permitting a better understanding of the where and why of Australia’s natural resources, in training a new generation of Earth system scientists, and in broadening public awareness of fundamental Earth science.

2019 – DP190103849 to Pete Kinny, Alex Nemchin and Aaron Cavosie

Hidden geochemical treasure: Reading the Earth’s history recorded in apatite inclusions in zirconThis project aims to undertake high precision measurements of the isotopic composition of tiny apatite inclusions in the mineral zircon. This will create an entirely new isotopic data set to combine with age and isotope data for the host zircons, to study the formation and evolution of the Earth’s crust. Primary apatite inclusions represent a hitherto untapped treasury of pristine geochemical information made accessible by the latest advances in microanalytical and imaging technology. This information will be used to test models for the timing of formation of the first continents, to map continental growth over time and to evaluate the origins of the Earth’s oldest rocks and minerals and the environmental conditions on the early Earth.

2016DP160104637 to Martin Hand, Chris Clark et al.

Rehydration of the lower crust, fluid sources and geophysical expression. This project aims to explore a long-standing mystery: the origin of deep crustal electrical conductors detected by magnetotelluric imaging of tectonically stable crust. These features occur in cratons of all ages, and commonly cross cut structures and lithologies. This project aims to investigate the hypothesis that such features are the record of ancient deep crustal fluid flow, which modified the rock electrical properties. Using an exceptionally exposed natural laboratory preserving large-scale rehydration of anhydrous lower crust, the project plans to determine the source of fluids and the compositional changes they induced. It then plans to experimentally determine changes in resistivity induced by fluid flow and use that data to model the magnetotelluric response at crustal scale.

2015DP150102773 to Ian Fitzimons and Chris Clark

Migmatites, charnockites and crustal fluid flux during orogenesis. Migration of volatile fluid and molten rock controls many Earth processes including rock deformation and the formation of mineral and energy deposits. Deep crustal fluids are hard to study directly, and their characteristics are usually inferred from lower crustal rock brought to the surface by erosion. For over 30 years one such rock called charnockite has been used to argue that lower crust is dehydrated by influx of carbon dioxide-rich fluid, while other evidence supports dehydration by water extraction in silicate melt. This project aims to use the shape, distribution and chemistry of mineral grains to trace the passage of volatiles and melt through charnockite, constrain the nature of lower crustal fluids and resolve a long-standing controversy.

2012DE120103067 to Chris Clark

How does the continental crust get so hot? This project is aimed at constraining the tectonic drivers of high geothermal gradient crustal regimes. The key outcomes of this project are better constraints on the tectonic drivers of high geothermal gradient metamorphism and the development of quantitative tools to assess the evolution of heat within areas of mountain building.