X-RAY DIGITAL IMAGING PETROGRAPHY OF LUNAR MARE SOILS - MODAL ANALYSES OF MINERALS AND GLASSES

Citation
La. Taylor et al., X-RAY DIGITAL IMAGING PETROGRAPHY OF LUNAR MARE SOILS - MODAL ANALYSES OF MINERALS AND GLASSES, Icarus, 124(2), 1996, pp. 500-512
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Astronomy & Astrophysics
Journal title
IcarusACNP
ISSN journal
0019-1035
Volume
124
Issue
2
Year of publication
1996
Pages
500 - 512
Database
ISI
SICI code
0019-1035(1996)124:2<500:XDIPOL>2.0.ZU;2-H
Abstract
It is essential that accurate modal (i.e., volume) percentages of the various mineral and glass phases in lunar soils be used for addressing and resolving the effects of space weathering upon reflectance spectr a, as well as for their calibration such data are also required for ev aluating the resource potential of lunar minerals far use at a lunar b ase. However, these data are largely tacking. Particle-counting inform ation for lunar soils, originally obtained to study formational proces ses, does not provide these necessary data, including the percentages of minerals locked in multi-phase lithic fragments and fused-soil part icles, such as agglutinates. We have developed a technique for modal a nalyses, sensu stricto, of lunar soils, using digital imaging of X-ray maps obtained with an energy-dispersive spectrometer mounted on an el ectron microprobe. A suite of nine soils (90 to 150 mu m size fraction ) from the Apollo 11, 12, 15, and 17 mare sites was used for this stud y. This is the first collection of such modal data on soils from all A pollo mare sites. The abundances of free-mineral fragments in the mare soils are greater for immature and submature soils than for mature so ils, largely because of the formation of agglutinitic glass as maturit y progresses. In considerations of resource utilization at a lunar bas e, the best; lunar soils to use for mineral benefication (i.e., most f ree-mineral fragments) have maturities near the immature/submature bou ndary (I-s/FeO congruent to 30), not the mature soils with their compl ications due to extensive agglutination. The particle data obtained fr om the nine mare sons confirm the generalizations for lunar soils pred icted by L. A. Taylor and D. S. McKay. (C) 1996 Academic Press, Inc.