Rare earth element signature in uranium oxides and associated minerals in uranium deposits: in-situ quantitative measurements by ablation laser ICP-MS and geochronic studies
Creators
- Lach, Philippe
- Universite de Lorraine, Ecole doctorale RP2E - Ressources, Produits, Procedes et Environnements, Collegium Sciences et technologies, UMR G2R 7566, Faculte des Scineces, Vandoeuvre les Nancy (France)
- G2R, Universite de Lorraine, CNRS, Cregu, Boulevard des Aiguillettes B.P. 70239, F-54506, Vandoeuvre-les-Nancy (France)
Description
The ore deposits often display complex stages of formation leading to multiphase mineral crystallizations. The study of these minerals needs to use a sensitive and localized analytical method. Laser ablation coupled to ICP-MS is a good tool for in situ measurements of low element concentrations (<10 ppm) at a small scale in minerals (around 10 μm diameter). Two major objectives concerning the use of LAICP- MS have been carried out in this thesis. First part is focused on the determination of the best analytical conditions for rare earth element (REE) quantification with LA-ICP-MS in uranium oxides and associated minerals (carbonate, fluorite). This approach has been coupled to isotopic analysis using ionic microprobe. The second part is dedicated to the application of the methodology on 21 uranium ore bodies typical of four different types of deposits. The uranium oxides from unconformity-related uranium deposits (Athabasca Basin) show typical REE signature whatever their age and location. Data on End Grid U mineralization (Thelon basin) suggest similar conditions of formation and ages as in Athabasca unconformity-related uranium deposits. High temperature during magmatic uraninite formation induced strong incorporation of REE in their structures. REE signatures of uranium oxides related to vein type deposits suggest a control of the host rocks. Finally, the different REE signatures obtained on uranium oxides from breccia pipe-related deposit show a strong variation in the conditions of formation in these supposed similar deposits. (author)
Abstract (French)
Le caractere souvent polyphase de la formation des mineralisations uraniferes exige de disposer d'une methode analytique localisee et sensible a de faibles concentrations. L'ablation laser coupIee a un systeme d'analyse par ICP-MS est un instrument de choix permettant l'analyse in-situ de concentrations elementaires inferieures a 10 ppm, a l'echelle de la dizaine de micrometres. Un double objectif concernant l'utilisation d'un systeme LA-ICP-MS est presente dans cette these. Un developpement methodologique permettant l'analyse localisee des elements de terres rares (ETR) par LA-ICP-MS aussi bien dans les oxydes d'uranium que dans d'autres matrices minerales associees aux depots, couple a des datations isotopiques par microsonde ionique fait l'objet d'une premiere partie de ce travail. L'application de la methode sur 21 cibles naturelles representatives de 4 types de gisement d'uranium est presentee dans une seconde partie. Ainsi, les oxydes d'uranium des gisements associes aux discordances du bassin Athabasca montrent des signatures en ETR caracteristiques quelles que soient leur age et leurs localisations. Des analyses similaires de la zone d'End Grid (bassin du Thelon) permettent de supposer des conditions et des ages de formations similaires aux gisements de type discordance. La teneur en ETR des uraninites magmatiques s'explique par la temperature elevee de leur incorporation. Les signatures des oxydes d'uranium des gisements de type filonien montrent un equilibrage entre les fluides mineralisateurs et certains mineraux porteurs d'ETR des roches encaissantes. Enfin, les differentes signatures en ETR des oxydes d'uranium des gisements de type Breccia pipe refletent des fortes variations dans les conditions de depot dans ces gisements a priori genetiquement semblables. (auteur)Files
51079043.pdf
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Additional details
Additional titles
- Original title (French)
- Signature geochimique des elements des terres rares dans les oxydes d'uranium et mineraux associes dans les gisements d'uranium: analyse par ablation laser couplee a l'ICP-MS et etude geochronologique
Publishing Information
- Imprint Pagination
- 319 p.
- Report number
- FRNC-TH--10987
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 51079043
- Subject category
- S11: NUCLEAR FUEL CYCLE AND FUEL MATERIALS; S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; S58: GEOSCIENCES;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ABLATION; ATHABASCA DEPOSIT; CARBONATES; ELECTRON MICROPROBE ANALYSIS; ELECTRON MICROSCOPY; ICP MASS SPECTROSCOPY; INCLUSIONS; ION MICROPROBE ANALYSIS; ISOTOPE DATING; PETROGRAPHY; QUANTITATIVE CHEMICAL ANALYSIS; RARE EARTHS; TRACE AMOUNTS; URANINITES; URANIUM DEPOSITS; URANIUM ORES; URANIUM OXIDES
- Descriptors DEC
- ACTINIDE COMPOUNDS; AGE ESTIMATION; CARBON COMPOUNDS; CHALCOGENIDES; CHEMICAL ANALYSIS; ELEMENTS; GEOLOGIC DEPOSITS; GEOLOGY; MASS SPECTROSCOPY; MATERIALS; METALS; MICROANALYSIS; MICROSCOPY; MINERAL RESOURCES; MINERALS; NONDESTRUCTIVE ANALYSIS; OIL SAND DEPOSITS; ORES; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; RADIOACTIVE MATERIALS; RADIOACTIVE MINERALS; RESOURCES; SPECTROSCOPY; URANIUM COMPOUNDS; URANIUM MINERALS
Optional Information
- Notes
- 242 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses