A 3-Billion-Year Lithium Isotope Record from Marine Dolostones

I am extending the seawater lithium isotope record beyond the Neoproterozoic back toward 3 billion years (Ga) using more than 500 marine dolostones. Dolostones show non-linear δ⁷Li evolution and heavier values compared to shallow-water carbonates (Kalderon-Asael et al., 2021). The seawater δ⁷Li curve from dolostones overlaps with δ⁷Li trends from foraminifera, brachiopods, and corals over the Mesozoic and Cenozoic, and with fluid inclusions in halites over the Phanerozoic.

Dolostones suggest modest non-linear changes in seawater δ⁷Li over the past 3 Ga, with minima during the Cretaceous, Cambrian, and Archean and maxima during the Tonian, Permian, and Quaternary Periods (Weldeghebriel et al., 2025, Goldschmidt Conference).

Lithium isotopesDolostonesPrecambrianArchean

Lithium isotope systematics of carbonate archives — δ⁷Li values of primary and altered bulk shallow-water carbonate sediments formed under various diagenetic conditions from modern carbonate platforms in the Bahamas and South China Sea (modified from Wei et al., 2024). Also shown for comparison are δ⁷Li of marine clays and bulk sediments (Chan et al., 2006), continental clays (Chan et al., 2006), and upper continental crust (Teng et al., 2004).

Sequential leaching and column chemistry workflow for dolostone lithium isotope analysis — Sequential leaching workflow for δ⁷Li analysis in bulk carbonates and dolomites (modified from Cao et al., 2023).

Related publications

This is an ongoing project.