The interaction of water with the geosphere is a fundamental earth process, and underpins society from the basics of water supply, through the generation of the mineral resources needed for future low carbon development, to the ultimate lifetime and fate of the metals we use in the environment. Minerals and the structures within them preserve a record of these processes. Understanding of these processes is linked to finding environmentally acceptable resources for the future. This lecture will discuss the role of water in geological processes, examine how hydrothermal and weathering solutions can form the resources needed for new clean energy technology, and look at how biogeochemical processes can lead to the final release of metals to the environment. The geological sites involved in these investigations will range from the Arctic Circle, China and Madagascar, to the mud in Shoreham Harbour!