Uranium Redox State in Cretaceous Marine Shales of Australia

Geochemical analysis characterizes uranium oxidation states in 11 sediment samples from the Cretaceous Toolebuc Formation. Research employed high-energy resolution fluorescence detection x-ray absorption spectroscopy and nanoscale secondary ion mass spectrometry. Findings indicate 20 to 30% of uranium exists as U(VI) in organic-rich shales.

Use Cases

• Analyze uranium oxidation state (U(VI) proportion) correlation with total organic carbon (TOC) content across shale and coquinite samples.
• Model uranium distribution patterns at mm to nanoscale using NanoSIMS data on associations with organic matter or sulphide minerals.
• Compare uranium speciation results from HERFD spectroscopy with depositional environment classifications (anoxic vs. dysoxic).
• Investigate the variation in estimated oxidation state within individual samples, reported as a range of ~20% of U(VI).

Strengths

• Data derived from advanced analytical techniques including HERFD x-ray absorption spectroscopy and NanoSIMS.
• Includes 11 characterized samples with total organic carbon (TOC) content ranging from 0.3 to 13.4 wt%.
• Findings on U(VI) proportion (20-30%) are quantified and supported by spot analysis variation ranges.

Limitations

• Small sample size of 11 specimens limits statistical generalizability.
• Data presentation is in HTML format, not a structured, machine-readable table.
• Spatial coverage is restricted to one formation in the Eromanga Basin, Australia.

Provenance

Source

Geoscience Australia Data

Collection Method

High-energy resolution fluorescence detection (HERFD) x-ray absorption spectroscopy and nanoscale secondary ion mass spectrometry (NanoSIMS) on collected sediment samples.

Time Range

Cretaceous period (specifically the Toolebuc Formation).

Freshness

null

Geography

Eromanga Basin, Australia.