In the diagram above, lithium sinks are described in concentrations (ppm) and displayed as boxes.[1] Fluxes are shown as arrows and are in units of moles per year.[2] Continental rocks containing lithium are dissolved, transferring lithium to rivers or secondary minerals.[2] Dissolved lithium in run-off travels to the ocean.[2] Fluid release from hydrothermal vents contributes to oceanic lithium reserves while lithium is removed from the ocean by secondary mineral formation.[2]
Rivers eventually feed into the ocean, providing approximately 50% of marine inputs.[2] The remainder of lithium inputs come from hydrothermal venting at mid-ocean ridges, where lithium is released from the mantle.[1] Secondary clay formation removes dissolved lithium from seawater to the authigenic clays[3] and to the altered oceanic crust.[1]
Lithium isotopes have potential as viable geochemical tracers for processes such as silicate rock weathering and crust/mantle recycling due to significant lithium isotope fractionation during these processes.[2]