This review focuses on the rapidly growing field of natural 238U/235U variability, largely
driven by the technical advances in the measurement of U isotope ratios by mass …

The emergence and diversification of early animals is commonly thought to have coincided
with atmosphere and ocean oxygenation across the terminal Neoproterozoic and early …

Delayed Earth system recovery following the end-Permian mass extinction is often attributed
to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains …

The terminal Ediacaran Period witnessed the decline of the Ediacara biota (which may have
included many stem-group animals). To test whether oceanic anoxia might have played a …

Piecing together the history of carbon (C) perturbation events throughout Earth's history has
provided key insights into how the Earth system responds to abrupt warming. Previous …

Widespread marine anoxia is hypothesized as the trigger for the second pulse of the Late
Ordovician (Hirnantian) mass extinction based on lithologic and geochemical proxies that …

The protracted oxygenation of the ocean-atmosphere system is one of the most fundamental
changes to the Earth system through its history. The uranium isotopic composition (238 …

Oceanic Anoxic Event 2 (OAE 2), occurring∼ 94 million years ago, was one of the most
extreme carbon cycle and climatic perturbations of the Phanerozoic Eon. It was typified by a …

Metal and metal isotope records in carbonates have the potential to provide novel insights
into ancient ocean–atmosphere redox conditions, paleoenvironmental conditions, and …

Uranium isotope variations (δ 238 U) recorded in sedimentary carbonate rocks are a
promising new proxy for the extent of oceanic anoxia through geological time. However, the …