¹Satoru Yamamoto,¹Moe Matsuoka,²Hiroshi Nagaoka,³Makiko Ohtake,¹Ayame Ikeda
Journal of Geophysical Research (Planets) (in Press) Link to Artice [https://doi.org/10.1029/2024JE008663]
¹Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
²Earth and Space Exploration Center, Ritsumeikan University, Kusatsu Shiga, Japan
³School of Computer Science and Engineering, The University of Aizu, Aizuwakamatsu, Japan
Published by arrangement with John Wiley & Sons

We studied the global distribution and geological features of lunar surface sites whose spectra indicate an ilmenite-rich composition. Hyperspectral data obtained by the Kaguya Spectral Profiler were used for data mining to identify diagnostic features of a 1- and 2-μ
m spectral reflectance of ilmenite, revealing the global distribution of sites showing ilmenite-rich spectra. The results show that regions with ilmenite-rich spectra are concentrated at the margins of impact basins on the lunar nearside, whereas no such regions are identified in the Feldspathic Highland Terrain or the South Pole-Aitken basin. Using multiband images and a digital terrain model obtained by the Kaguya Multiband Imager and Terrain Camera, we examined the geological features of each site showing ilmenite-rich spectra and found that most of the sites are distributed on pyroclastic deposits overlying highland materials. Spectra interpreted as glass-rich material are prevalent in and around areas having ilmenite-rich spectra. However, sites showing ilmenite-rich spectra do not correspond to mare regions with
-rich basalts. These results may indicate that the concentration of ilmenite in pyroclastic deposits is high enough to exhibit diagnostic features of 1- and 2-μ
m spectral reflectance of ilmenite, whereas the concentration in mare regions with
-rich basalt is not. Since pyroclastic deposits are expected to be extensive, deep unconsolidated deposits of relatively block-free debris, resulting in high processing efficiency in the hydrogen reduction processes, our data may be useful for developing an efficient exploration strategy for ilmenite as a lunar resource.