[HTML][HTML] Uranium in natural waters and the environment: Distribution, speciation and impact

PL Smedley, DG Kinniburgh - Applied Geochemistry, 2023 - Elsevier
The concentrations of U in natural waters are usually low, being typically less than 4 μg/L in
river water, around 3.3 μg/L in open seawater, and usually less than 5 μg/L in groundwater …

Metal stable isotope signatures as tracers in environmental geochemistry

JG Wiederhold - Environmental science & technology, 2015 - ACS Publications
The biogeochemical cycling of metals in natural systems is often accompanied by stable
isotope fractionation which can now be measured due to recent analytical advances. In …

Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry

H Cheng, RL Edwards, CC Shen, VJ Polyak… - Earth and Planetary …, 2013 - Elsevier
We have developed techniques for measuring 234U and 230Th on Faraday cups with
precisions of 1–3 epsilon units (1 ε-unit= 1 part in 104) using multi-collector inductively …

238U/235U Systematics in Terrestrial Uranium-Bearing Minerals

J Hiess, DJ Condon, N McLean, SR Noble - Science, 2012 - science.org
The present-day 238U/235U ratio has fundamental implications for uranium-lead
geochronology and cosmochronology. A value of 137.88 has previously been considered …

[HTML][HTML] Metrology and traceability of U–Pb isotope dilution geochronology (EARTHTIME Tracer Calibration Part I)

DJ Condon, B Schoene, NM McLean… - … et Cosmochimica Acta, 2015 - Elsevier
Abstract Mixed 235 U–233 U–205 Pb (–202 Pb) tracers for U–Pb isotope-dilution isotope
ratio mass spectrometry have been prepared under the auspices of the EARTHTIME …

[HTML][HTML] Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago

P Deschamps, N Durand, E Bard, B Hamelin… - Nature, 2012 - nature.com
Past sea-level records provide invaluable information about the response of ice sheets to
climate forcing. Some such records suggest that the last deglaciation was punctuated by a …

Marine anoxia and delayed Earth system recovery after the end-Permian extinction

KV Lau, K Maher, D Altiner, BM Kelley… - Proceedings of the …, 2016 - National Acad Sciences
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 …

Extensive marine anoxia during the terminal Ediacaran Period

F Zhang, S Xiao, B Kendall, SJ Romaniello, H Cui… - Science …, 2018 - science.org
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 …

High-precision and high-resolution carbonate 230Th dating by MC-ICP-MS with SEM protocols

CC Shen, CC Wu, H Cheng, RL Edwards… - … et Cosmochimica Acta, 2012 - Elsevier
To facilitate the measurement of U–Th isotopic compositions suitable for high-precision and
high-resolution 230Th dating of coral and speleothem carbonates, secondary electron …

Uranium and molybdenum isotope evidence for an episode of widespread ocean oxygenation during the late Ediacaran Period

B Kendall, T Komiya, TW Lyons, SM Bates… - … et Cosmochimica Acta, 2015 - Elsevier
To improve estimates of the extent of ocean oxygenation during the late Ediacaran Period,
we measured the U and Mo isotope compositions of euxinic (anoxic and sulfidic) organic …