Craton margins play a crucial role in mineral exploration as they host faults, fractures, and shear zones that facilitate hydrothermal fluid movement, transporting and depositing dissolved metals into valuable mineral deposits. We use the high-resolution full-waveform seismic inversion model REVEAL to extract horizontal shear wave velocity (VSH), vertical shear wave velocity (VSV), and isotropic P-wave velocity (VP) across depth slices from 150 to 200 km, a range that captures most cratonic lithosphere based on tectonic age and lithospheric thickness analyses. Machine learning, applied through clustered maps, demonstrates that VSH effectively delineates craton boundaries, aligning with target mineral deposits, including iron oxide copper–gold (IOCG) and sediment-hosted lead, zinc, and copper deposits. These boundaries are characterized by high horizontal shear velocities (4.58–4.68 km/s), and trace the edges of cratons, accreted passive margins, orogens, and thick volcanic arcs. Using published thermal and lithospheric thickness models, we distinguish cratons from other thick lithospheric features and identify their edges and associated deposits. Our results show that ∼85 % of the total metal content (Cu + Pb + Zn) in target deposits lies within ∼120 km of high-velocity cluster boundaries identified as craton edges. Near-craton deposits reveal ∼80 % of the total metal content within ∼90 km of craton boundaries. The weighted cumulative distribution function shows a steeper gradient in metal content closer to craton boundaries, indicating higher concentrations near these tectonic features. Focusing on just 16 % of Earth’s continental areas can reveal over 80 % of known target deposits, highlighting the significance of craton boundaries quantitatively mapped in this study.
Curious about Australian cratons? Read the full story in Precompetitive Review.
- The search space for sediment-hosted and IOCG deposits has been drastically reduced by remarkable new mapping of craton boundaries by a University of Sydney PhD candidate. Exciting work led by Hojat Shirmardgouravan has newly mapped the world’s craton boundaries with a novel combination of global seismic tomography, machine learning and other techniques. The new paper then takes a further step by showing 80% of the total metal content of the world’sPb-Zn-Cu sediment-hosted deposits lies within a 90-km wide corridor, and about 90% within 110 km.
- Testing by CSIRO and the Geological Survey of WA of a new generation of satellite-borne hyperspectral sensors suggests they could be genuine game-changers for exploration for a wide variety of metals. They found the new, free satellite systems are almost as good as airborne data that explorers pay to collect. When data of that quality is being scooped up over entire regions, it becomes a very powerful reconnaissance tool for mapping alteration related to orebodies or even directly detecting mineralisation.
- A new study by the Geological Survey of South Australia of the under-explored Nuyts Domain of the Gawler Craton has provided constraints on a complex package of sediments and intrusives and raised the prospectivity for Ni-Cu.
