Stable Uranium Isotope Geochemistry and its Application in Tracing Earth's Oxygenation History

Key Points

• To explore the mechanisms of uranium isotope fractionation and its implications for tracing Earth's oxygenation.
• Review of uranium isotopes and their fractionation mechanisms in geochemical reactions.
• Analysis of uranium cycling in weathering, river transport, and marine processes.
• Discussion of the global uniformity of uranium isotopes in non-sulfidic regions.
• Uranium oxidation is highly sensitive to oxygen levels and significantly affects isotope composition.
• The composition of dissolved uranium isotopes is mainly controlled by regional hypoxic sulfide marine areas.
• Carbonate minerals record uranium isotopes, aiding in quantitative reconstruction of oceanic hypoxic areas.

Abstract