This special issue was initiated during the research workshop on Magma and Fluids, scheduled from 4 to 6 July 2022 at Orléans. This workshop was also an occasion to celebrate the prolific career of Michel Pichavant.

Magma and fluids play a crucial role in the Earth's dynamics by ruling mass and heat transfer from the innermost to the outermost regions of our planet. Capturing the ability of magma to convey heat requires its petrology to be tightly defined on the one hand and the mechanics of multiphase systems to be quantitatively addressed on the other hand. This approach can link intrusive to extrusive processes and is central to capturing the processes conducive to ore deposits. Magma is connected to fluids as it degases not only during volcanic processes but also during deep intrusions, as deep crystallization produces abundant fluids that can interact with the solids and mix with other fluids, building peri-magmatic hydrothermal systems and ore deposits.

In this special issue, we welcome contributions to the petrology, the transport properties, the geochemistry, and the mechanics of magma and fluids, as well as any studies connecting these two realms, using experimental, numerical, and field approaches to bridge the gap in knowledge on magma and fluids. We also welcome studies of high-temperature fluid–rock interactions.