Nitrogen is an important volatile element when it comes to habitability because of its omnipresence both in our atmosphere and in the molecules that form the basis of life. Today, studies are multiplying, whether to trace the origin of terrestrial nitrogen, as well as how it is stored on the Earth's surface and at depth, or how it is exchanged between the different reservoirs. Our work seeks to address these last two points, we seek to understand and characterise nitrogen in silicate melts under magmatic conditions (i.e. quantification and speciation), but also the exchange with a fluid phase at equilibrium via degassing/solubilisation phenomena.

The two main parameters highlighted by most studies as having an impact on nitrogen solubilisation in silicates melts are oxygen and nitrogen fugacity (fO2, fN2). Three main nitrogen species have been described in silicate melts: N3- and NH3 dominant under reduced conditions (i.e.