10.1029-2018JE005826Figure211460001.pptx

The (a) topographic, (b) crustal thickness, and thorium distribution of the Moon show a dichotomy between the nearside and farside. Data are presented in Mollweide equal-area projection centered at 90°W longitude, with nearside on the right of center and farside on the left of center. The star on the nearside represents the center of the proposed Procellarum basin (Wilhelms, 1987); the red dashed line and white solid line represent the boundary of transient crater with a radius of 850 km and final basin with a radius of 1,600 km of the proposed Procellarum basin, respectively (Wilhelms, 1987). The thin black line on the nearside of the Moon represents the Procellarum KREEP Terrane boundary. The black dashed lines represent the boundary of Imbrium (Im), Orientale (Or), and Apollo (Ap) basin, respectively. The topographic and crustal thickness distributiona are derived from the Lunar Orbiter Laser Altimeter (Smith et al., 2010) and Gravity Recovery and Interior Laboratory (GRAIL) observations (Wieczorek et al., 2013), respectively; the thorium distribution is from the observations of Lunar Prospector gamma ray spectrometer (Prettyman et al., 2006).