Why Gold and Chromium Coexist Beneath Heathcote: A Geological Deep Dive

The rocks beneath Heathcote, Victoria hold a rare geological marriage: chromium and gold occurring in close proximity, a combination that puzzles and fascinates geologists alike. This blog explores the tectonic and magmatic history behind this pairing, tracing it back to ancient ultramafic intrusions and greenstone belts that form part of Victoria’s Paleozoic accretionary complex. Chromium, hosted primarily in spinel-rich serpentinites and chromitites, was emplaced during deep mantle upwelling, while hydrothermal fluids later introduced gold into nearby fracture systems—often along shear zones or faulted contact zones between mafic and ultramafic rocks. The result is a geochemical and structural overlap where two vastly different ore types were concentrated by overlapping geological processes. Heathcote isn’t just a goldfield—it's a cross-section of Earth’s deeper plumbing.