Fayek,M., Horita,J. and Ripley,E.M.(2011): The oxygen isotopic composition of uranium minerals: A review. Ore Geology Reviews, 41, 1-21.


 Uranium ore is an essential material in the preparation of nuclear fuel for civilian as well as military uses. Uranium is first extracted from uranium-bearing minerals using a variety of reagents, and is precipitated from solutions as yellow cake prior to isotope enrichment processes. The disintegration of the former Eastern Bloc in the 1990s and frequent unrest in the Middle East have underscored the need for better characteriziing source uranium ores for forensic and attribution purposes.
 The world's major deposits of U occur in several distinctly different geological environments. Fourteen principal types of U deposits and rocks with elevated uranium contents are recognized with more than 40 subtypes. Combining our own analysis and literature data, we have amassed over 250 oxygen isotope data from 13 major U-producing countries, which vary widely from -32 to +11‰. However, interpreting the oxygen isotopic composition of uraninite in terms of the composition of the fluid from which it precipitated, or interacted with, requires knowledge of the fractionation factor and temperature of interactions, which are not always available. Since each deposit type occurs within a unique geologic setting and is generally formed from chemically distinct fluids, the chemical compositions of the uranium ores are also distinct: uranium deposits that form in igneous rocks have higher trace element compositions relative to sandstone-hosted deposits. Our data shows that one of the most useful techniques for distinguishing between uranium ore is to use a combination of δ18O values and rare-earth elements (e.g., La/Yb ratios). These methods may allow investigators to trace uranium ore back to the source.

Keywords: Uranium ore; Oxygen isotope; Global distribution; Rare earth element; Forensic and attribution』

1. Introduction
2. Uranium deposits
 2.1. Uranium geochemistry and mineralogy
  2.1.1. Uranium geochemistry
  2.1.2. Uranium mineralogy
 2.2. Classification of uranium deposits in the world
3. The isotopic composition of fluids and isotope fractionation factors
 3.1. Potential sources of fluids involved in he formation of uranium deposits
 3.2. Isotopic fractionation factors for the assessment of fluids involved in the formation of uranium-rich ore deposits
4. Methods of isotopic analysis
 4.1. Conventional BrF5 analysis
 4.2. SIMS analysis
 4.3. TIMS
5. Distribution of oxygen isotopes of uranium ores
 5.1. Geographical location
 5.2. Deposit type
 5.3. Uranium minerals
6. Nuclear forensics and uranium deposits: oxygen isotopes and trace elements
7. Conclusions