Weathering enables element cycling making life possible on the earth surface and is the long-term feedback mechanism to regulate the Earth’s climate. It is controlled by the complex interaction of geochemical, geomorphological, hydrological and biological processes and effected by human activities. This includes deep weathering in bedrock, soil formation, the release of elements and their fate in ground and surface water, plant-soil interaction and the input of pollution elements in dust, soil and water. The application of multiple isotope systems including traditional stable (e.g. C, H, O, S) and radiogenic (e.g. Nb, Sr, Pb) isotope systems, cosmogenic nuclides (e.g. 10Be, 26Al), fallout radionuclides (e.g. 137Cs, 239/240Pu) and metal stable isotopes (e.g. Li, Mg, Si, Ca, Fe, Cr, Cu, Zn) together with other tracers enabled us to decipher linkages and mechanisms of weathering processes and to quantify fluxes in the critical zone across varying lithologies, tectonic settings, climatic conditions and anthropogenic influences – we call this initiative CZ-Tope. The goal is to constrain weathering processes from the mineral scale to the catchment size to elucidate global biogeochemical cycles. This session invites contributions encompassing field studies, laboratory experiments, exploring the analytical frontiers of measuring isotope proxies and modelling approaches to understand the processes driving Earth’s surface development. As the earth surface system itself is multidisciplinary, we encourage submissions focusing on physical, chemical, and biological processes.