A comparative study of iron abundance estimation methods: Application to the western nearside of the Moon

作者：Bhatt Megha^*; Mall Urs; Woehler Christian; Grumpe Arne; Bugiolacchi Roberto

来源：Icarus, 2015, 248: 72-88.

DOI：10.1016/j.icarus.2014.10.023

• Moon
• Spectroscopy
• Mineralogy

The FeO weight percentage (wt.%) abundance of the Moon's western nearside (55 degrees S-55 degrees N and 5 degrees E-40 degrees W) is estimated using data from the InfraRed Spectrometer-2 (SIR-2) and the Moon Mineralogy Mapper (M-3). In this study, we modified an FeO abundance estimation algorithm (Bhatt, M., Mall, U., Bugiolacchi, R., McKenna-Lawlor, S., Banaszkiewicz, M., Nathues, A., Ullaland, K. [2012]. Icarus 220, 51-64) which relies exclusively on the 2-mu m absorption band parameters. The modified FeO abundance estimation algorithm and the regression-based elemental abundance estimation algorithm (Miller, C., Grumpe, A., Berezhnoy, A., Bhatt, M.U., Mall, U. [2014]. Icarus 235, 86-122) which is based on the 1-mu m and 2-mu m absorption band parameters is applied to the M3 data. We have compared results obtained from these two modified algorithms with a previously published Clementine's FeO wt.% map (Lucey, P.G., Blewett, D.T., Jolliff, B.L. [2000]. J. Geophys. Res. 105, 20297-20306). The effects of topography and space weathering on FeO wt.% estimates have been successfully minimized using the modified algorithm based on the 2-gm absorption band parameters. Thus, this algorithm can be successfully applied at middle to high latitudes. Furthermore, a correction for TiO2 is applied to the FeO abundance estimation algorithm based on the 2-mu m absorption band parameters using the M3 data. Our comparative study shows a good correspondence between the three algorithms discussed. There are two locations: the crater Tycho and the region around Rima Bode which show major discrepancies. Our modified algorithm based on the 2-gm absorption parameters predicts 3-4 wt.% less FeO for the ray system of Tycho than for the surrounding region. The average iron abundance for the lunar highlands is about 6 wt.% and for the mare regions is about 16 wt.% using the regression-based elemental abundance estimation algorithm and the algorithm based on the 2-mu m absorption parameters. This result is consistent with the previous analysis using Lunar Prospector Gamma-Ray Spectrometer data sets. The FeO wt.% is in the range 20-24 wt.% for the high-Ti basalts using both the modified iron abundance estimation and the regression-based elemental abundance estimation algorithms.

• 出版日期2015-3-1