Potassium and Thorium Abundances at the South Pole-Aitken Basin Obtained by the Kaguya Gamma-Ray Spectrometer
In this study, we present detailed K and Th distribution maps of the South Pole-Aitken (SPA) basin with a (100-km)2 resolution for the compositional and evolutional studies. These maps have been constructed for the first time from the Kaguya gamma-ray spectrometer (KGRS) data sets acquired during SE...
| Published in: | Journal of Geophysical Research: Planets |
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| Main Authors: | , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
John Wiley & Sons
2019
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| Subjects: | |
| Online Access: | https://repo.qst.go.jp/?action=repository_uri&item_id=77182 http://id.nii.ac.jp/1657/00077164/ |
| Summary: | In this study, we present detailed K and Th distribution maps of the South Pole-Aitken (SPA) basin with a (100-km)2 resolution for the compositional and evolutional studies. These maps have been constructed for the first time from the Kaguya gamma-ray spectrometer (KGRS) data sets acquired during SELENE (Kaguya) low-altitude observations at 50 km. The K and Th distribution maps are compared with those obtained by KGRS high-altitude observation and Lunar Prospector GRS high- and low-altitude observations. The use of KGRS low-altitude data sets with high energy resolution enable to obtain unambiguous counts of individual gamma-ray lines, leading precise elemental maps of K and Th comparing to previous studies. K and Th abundances at the areas of some large impact craters infilled with mare deposits are lower than that in surrounding regions. Geologic maps of the SPA region obtained by the Kaguya Multiband Imager are assimilated and confirmed based on the K and Th distributions. The evolution hypothesis of the SPA region based on the SPA giant impact event suggested by some previous model studies is also confirmed. |
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