Unlocking Uranium ore origins: An REE and multivariate statistical approach.

Area of Science:

• Geochemistry
• Nuclear Forensics
• Analytical Chemistry

Background:

• Differentiating uranium ore sources is crucial for nuclear forensics and counter-proliferation.
• Rare earth element (REE) signatures offer potential geochemical fingerprints for ore provenance.
• Tanzania hosts geologically distinct uranium deposits requiring source differentiation.

Purpose of the Study:

• To develop and validate a robust methodology for differentiating uranium ore sources using REE signatures.
• To establish unique geochemical fingerprints for Tanzanian uranium deposits (Mkuju, Manyoni, Bahi).
• To assess the utility of REE analysis combined with multivariate statistics for nuclear forensics applications.

Main Methods:

• Analysis of 45 uranium ore-bearing soil samples from three Tanzanian localities.
• Acid digestion followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for REE determination.
• Chondrite normalization and multivariate statistical analyses (PCA, HCA) using XLSTAT.

Main Results:

• Distinct REE geochemical fingerprints were identified for Mkuju, Manyoni, and Bahi deposits.
• Mkuju samples show high REE concentrations, positive Eu anomaly, and two HCA clusters (roll-front model).
• Manyoni samples exhibit a single dominant PCA factor, positive Ce anomaly, negative Eu anomaly, and two HCA clusters (bimodal roll-front model).
• Bahi samples display a complex origin with supergene processes, negative Eu and Ce anomalies, and three HCA clusters (multiple sources/overprinting).

Conclusions:

• Chondrite-normalized REE patterns coupled with multivariate statistics provide a reliable tool for uranium ore soil provenance.
• The established geochemical fingerprints significantly enhance capabilities in nuclear forensics.
• This methodology contributes to strengthening global nuclear security through improved source attribution.