Abstract:
A unique feature of the Re-Os isotope system is its ability to provide precise and accurate depositional ages from organic-rich sedimentary rocks. Applications include geologic timescale calibration, stratigraphic correlation, and dating key events such as biological innovations, mass extinctions, carbon cycle perturbations, Snowball Earth glaciations, and atmospheric oxygenation. Multiple sediment types reveal temporal variations in the osmium isotope composition of seawater, driven by changes in osmium inputs from continental weathering, seafloor hydrothermal systems, and extraterrestrial material. These variations provide valuable information on climate–tectonic interactions, glacial–interglacial cycles, large igneous province magmatism, bolide impacts, and crustal evolution. Continental processes can be inferred from lake sediment records. These diverse applications highlight the central role of the Re-Os isotope pair in understanding Earth’s evolution.