Heather’s expertise is in low-temperature geochemistry and biogeochemistry with a focus on weathering and mineral nutrient cycling using a critical zone science approach. Within this context, she studies the relationships between mineralogy and soil nutrients, mineralogy and phosphate fluxes in aquifers, microbe-mineral interactions in soils, and microbe-mineral interactions in the deep subsurface in the context of energy exploitation. Future global challenges to environmental sustainability and food security urgently require the ability to accurately “earthcast” changes in the critical zone (Earth’s “skin”), but that will not be possible until we can untangle the highly interconnected processes involved. Heather utilises a range of techniques at multiple spatial and temporal scales to examine these interconnected processes, including microscopy and spectroscopy (e.g. SEM, electron microprobe, synchrotron-based techniques), wet chemistry, reactive transport modelling, and microbiology.