Lunar prospector measurements of the distribution of incompatible elements gadolinium, samarium and thorium
- Los Alamos National Lab., NM (United States)
- Observatoire Midi-Pyrenees, Toulouse (France)
- Lunar Research Inst., Gilroy, CA (United States)
- Univ. of Hawaii, Manoa, HI (United States). Hawaii Inst. of Geophysics and Planetology
Lunar Prospector neutron spectrometer (NS) and gamma ray spectrometer (GRS) observations have been used to map out the distribution of incompatible elements on the lunar surface. Specifically, the GRS data provide maps of the distribution of thorium and potassium while the NS data provide information on the distribution of iron and titanium, and the rare earth elements gadolinium and samarium. Using results of analysis of Celementine spectral reflectance (CSR) data, the Fe- and Ti-contributions to the NS data can be removed, leaving primarily rare earth element contributions from Gd and Sm. The Th and K maps correlate with the inferred Gd and Sm maps (r {approximately} 0.93), but there are regions of significant disagreement. One of these is in the KREEP-rich circum-Imbrium ring. No clear explanation has emerged for this disagreement, though Th, K, Gd and Sm have differing degrees of incompatibility. These results clearly are important to discussions of the geochemistry of the Procellarum-Imbrium Th-rich Terrane and the South-Pole-Aitken Terrane.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 334321
- Report Number(s):
- LA-UR-99-521; CONF-990303-; ON: DE99002217; TRN: AHC29914%%125
- Resource Relation:
- Conference: Lunar and planetary science conference, Houston, TX (United States), 15-19 Mar 1999; Other Information: PBD: [1999]
- Country of Publication:
- United States
- Language:
- English
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