Paleontology and Stratigraphy of Fossils

Researchers reconstruct the chemical state of ancient oceans by analyzing trace metals, stable isotopes, and other geochemical signatures preserved in marine sediments, using these proxies to determine when and where seawater became depleted in oxygen and how productive surface waters were at specific moments in Earth's past. These reconstructions are central to understanding oceanic anoxic events—episodes when oxygen-poor conditions spread across large swaths of the seafloor—and to tracing the long-term oxygenation of the atmosphere over billions of years. Both processes are tightly coupled to biogeochemical cycles involving elements like carbon, sulfur, and molybdenum, whose isotopic records encode information about microbial activity, weathering, and volcanic input that would otherwise be invisible. Active work is focused on sharpening the fidelity of individual proxies, disentangling local basin effects from global signals, and clarifying the causal links between redox change, nutrient availability, and the mass extinctions that punctuate the Phanerozoic record.

Works

170,167

Total citations

1,770,803

Keywords

PaleoredoxPaleoproductivityTrace MetalsOceanic Anoxic EventsAtmospheric OxygenationBiogeochemical Cycling