Nickel isotope fractionation during continental weathering

The phenomena we report and discuss here may long have been the dominant controls on the distribution of Ni isotopes in Earth's near-surface, terrestrial environment, at least since oxygenation of the atmosphere. Due to lack of abundant oxygen in air and water earlier in Earth history, the biogeochemical cycle of Ni isotopes was almost certainly rather different, such that riverine dissolved Ni was not necessarily enriched in heavy isotopes relative to continental crust, and the oceans may not have been so highly enriched in heavy isotopes of Ni as they are presently.