[HTML][HTML] Environmental controls on very high δ238U values in reducing sediments: Implications for Neoproterozoic seawater records

MO Clarkson, TC Sweere, CF Chiu, R Hennekam… - Earth-Science …, 2023 - Elsevier
Uranium isotopes (δ 238 U) are a widely applied tool for tracing global changes in oceanic
anoxia. Interpretation of seawater values and trends, often reconstructed from carbonates …

Sea level controls on Ediacaran-Cambrian animal radiations

FT Bowyer, RA Wood, M Yilales - Science Advances, 2024 - science.org
The drivers of Ediacaran-Cambrian metazoan radiations remain unclear, as does the fidelity
of the record. We use a global age framework [580–510 million years (Ma) ago] to estimate …

Electron flux is a key determinant of uranium isotope fractionation during bacterial reduction

AR Brown, M Molinas, Y Roebbert, A Sato… - … Earth & Environment, 2023 - nature.com
Uranium isotopic signatures in the rock record are utilized as a proxy for past redox
conditions on Earth. However, these signatures display significant variability that …

A diverse Ediacara assemblage survived under low-oxygen conditions

LB Cherry, GJ Gilleaudeau, DV Grazhdankin… - Nature …, 2022 - nature.com
The Ediacaran biota were soft-bodied organisms, many with enigmatic phylogenetic
placement and ecology, living in marine environments between 574 and 539 million years …

Carbonate uranium isotopes record global expansion of marine anoxia during the Toarcian Oceanic Anoxic Event

MN Remírez, GJ Gilleaudeau, T Gan, MA Kipp… - Proceedings of the …, 2024 - pnas.org
The Toarcian Oceanic Anoxic Event (T-OAE;~ 183 Mya) was a globally significant carbon-
cycle perturbation linked to widespread deposition of organic-rich sediments, massive …

Uranium and molybdenum isotope evidence for globally extensive marine euxinia on continental margins and in epicontinental seas during the Devonian …

S Yang, X Lu, X Chen, W Zheng, JD Owens… - … et Cosmochimica Acta, 2023 - Elsevier
Abstract The end-Devonian Hangenberg Crisis was one of the biggest Phanerozoic mass
extinctions. However, the mechanism (s) that triggered this event is still debated. In this …

UID: The uranium isotope database

H Li, FLH Tissot - Chemical Geology, 2023 - Elsevier
As the parent element in the U-Pb and Pb-Pb radiochronometers, uranium (U) was one of
the first heavy elements whose isotopic composition was carefully determined. Thought to …

Exploring uranium isotopes in shark teeth as a paleo-redox proxy

H Li, MA Kipp, SL Kim, ER Kast, JJ Eberle… - … et Cosmochimica Acta, 2024 - Elsevier
The uranium isotope composition (δ 238 U) of seawater is a powerful proxy for the extent of
marine anoxia. For paleoredox reconstructions, carbonates are the most popular U isotope …

Carbonate uranium isotopes across Cretaceous OAE 2 in southern Mexico: New constraints on the global spread of marine anoxia and organic carbon burial

JT Kulenguski, GJ Gilleaudeau, AJ Kaufman… - Palaeogeography …, 2023 - Elsevier
Oceanic anoxic events (OAEs) represent discrete intervals of decreased marine oxygen
concentrations often associated with volcanism, enhanced organic carbon burial coupled …

Productivity and organic carbon loading control uranium isotope behavior in ancient reducing settings: Implications for the paleoredox proxy

RL Rutledge, GJ Gilleaudeau, MN Remírez… - … et Cosmochimica Acta, 2024 - Elsevier
Uranium isotopes in ancient sedimentary rocks have emerged as a powerful proxy for the
oxygenation history of Earth surface environments. Proper quantitative interpretation of δ …