Rare earth element (REE) concentrations and zoning in individual mineral grains
The abundances of all the REE, down to the ppm level, in 5 to 20 ..mu..m spots of meteoritic and terrestrial grains, were determined with a CAMECA IMS-3F ion probe. Moderate energy filtering (approx. 75V) was used to eliminate complex matrix interferences and the mass spectrum, from atomic masses 133 to 191, was deconvoluted into the elemental and monoxide components. Measurement precision of the REE abundances is generally better than 10%. As an example, REE patterns in calcium phosphate from mesosiderites are presented in this paper. Although secondary ion yields are known to vary with the matrix composition, relative ion yields among REE were found to be constant in the minerals analyzed so far (phosphates and oxides). REE zoning was observed in 10..mu..m grains of meteoritic perovskite. The method is presently being extended to the analysis of silicates. The LREE, which are the easiest to analyze because of the lack of oxide interferences, can be measured down to the level of approx. 50 ppb. The relative abundances of selected major and trace elements are also routinely monitored.
- Research Organization:
- Washington Univ., St. Louis, MO (USA)
- OSTI ID:
- 6611005
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
- Country of Publication:
- United States
- Language:
- English
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