CC BY 4.0 UnportedTitarenko, A.Recio-Blanco, A.de Laverny, P.Hayden, M.Guiglion, G.2023-04-192023-04-192019https://oa.tib.eu/renate/handle/123456789/12027http://dx.doi.org/10.34657/11060Chemical abundance dating methods open new paths for temporal evolution studies of the Milky Way stellar populations. In this paper, we use a high spectral resolution database of turn-off stars in the solar neighbourhood to study the age dependence of the [Y/Mg] chemical abundance ratio. Our analysis reveals a clear correlation between [Y/Mg] and age for thin disc stars of different metallicities, in synergy with previous studies of solar-type stars. In addition, no metallicity dependence with stellar age is detected, allowing us to use the [Y/Mg] ratio as a reliable age proxy. Finally, the [Y/Mg]-age relation presents a discontinuity between thin and thick disc stars around 9-10 Gyr. For thick disc stars, the correlation has a different zero point and probably a steeper trend with age, reflecting the different chemical evolution histories of the two disc components.enghttps://creativecommons.org/licenses/by/4.0520Galaxy: abundancesGalaxy: diskGalaxy: stellar contentGalaxy: structureArticle