The CMWS Early Science Project at P65 aims to unravel the formation of economic metal deposits in the Earth’s crust by hydrothermal supercritical hydrous fluids using in-situ X-ray Absorption and Fluorescence spectroscopy. The talk will focus on the scientific motivation and the hydrothermal autoclave used for the in-situ experiments. I will also briefly discuss first results and present our near-future plans.