Paleontology and Stratigraphy of Fossils

Ancient ocean chemistry left chemical fingerprints in marine sediments that researchers can now read using trace metals like molybdenum and vanadium, along with isotope ratios of elements such as uranium and sulfur. By interpreting these signals, geochemists reconstruct how oxygen levels in seawater and the atmosphere changed across hundreds of millions of years, shedding light on catastrophic episodes known as oceanic anoxic events, when widespread oxygen depletion coincided with mass extinctions and rapid climate shifts. A central challenge is disentangling the local redox conditions of a particular sedimentary basin from global ocean signals, since the same chemical proxy can reflect very different environmental histories depending on where and how sediments were deposited. Active work focuses on refining the calibration of these proxies in modern settings and on integrating biogeochemical models with isotope records to better constrain the pace and triggers of major oxygenation events throughout Earth's history.

Works

168,950

Total citations

1,757,730

Keywords

PaleoredoxPaleoproductivityTrace MetalsOceanic Anoxic EventsAtmospheric OxygenationBiogeochemical Cycling