I am interested in how the Earth works. I’ve always followed my curiosity, and at different times have looked at movement of water between ocean basins, recolonisation of the tops of marine avalanches by microorganisms, how petrifying springs work, cleaning up hyperalkaline pollution, rainfall changes in northern Africa and the Mediterranean, icebergs in the North Pacific and the carbon flow between bedrock and surface water. Surprisingly, I’ve been using the same tools in all these studies, through investigating the chemistry of sediment, especially limestone and similar carbonate bodies. Carbonate makes up the shells of microorganisms I use to study changes in the ocean, are the major mineral forming in freshwater springs, rivers and lakes, forms a sink for hyperalkaline pollution and carries most of the inorganic carbon in the Earths crust. Carbonate geochemistry is a really diverse area to work in, and there are always surprising new things to learn!