@article{oai:repo.qst.go.jp:00047009, author = {Yamashita, N. and Gasnault, O. and Forni, O. and d'Uston, C. and Reedy, R.C. and Karouji, Y. and Kobayashi, S. and Hareyama, M. and Nagaoka, H. and Hasebe, N. and Kim, K.J. and 小林 進悟}, journal = {Earth and Planetary Science Letters}, month = {Nov}, note = {The first unambiguous global distribution of Ca on the Moon has been revealed by the Kaguya Gamma-Ray Spectrometer. The observation of the 3737 keV gamma rays from 40Ca with a high energy resolution Ge detector, corrected for fast neutrons, improved greatly our confidence in these remote sensing data. While the derived Ca abundance generally confirms the mare-highland dichotomy, we found that the eastern mare regions such as Crisium, Nectaris, and Fecunditatis exhibit unexpected high Ca abundances. This may be explained by regional concentrations of high-Ca clinopyroxene. Our Ca map also shows that the lowest CaO abundance found in the returned samples (∼8 wt%) may actually be common in Oceanus Procellarum, suggesting the possible sampling bias of Apollo and Luna missions. These observational results on Ca serve as a complementary criterion for better characterization of mare regions on the Moon.}, pages = {93--98}, title = {The global distribution of calcium on the Moon: Implications for high-Ca pyroxene in the eastern mare region}, volume = {353/354}, year = {2012} }