Lunar Tectonics

Despite numerous random features on the lunar surface tied to irregular impact processes, there is evidence of regular wave-borne structures of various scales. The most important among them is the largest, covered with dark basalts, depression known as the Procellarum Basin. It is a characteristic feature of the lunar nearside clearly visible during the Full Moon (Fig. 1). Recently, this large feature was considered as a typical impact. Systematic gravity surveys, however, established that the Procellarum Basin is a tectonic formation of deep origin (Andrews-Hanna et al. 2014). The antipodal farside is composed mainly of “continental” highland formations. The dichotomous opposition of the highland and lowland hemispheres, which is typically observed in the structures of planetary bodies of various classes, sizes, and compositions, is a characteristic phenomenon of wave origin. The most fundamental wave mode divides a globe into two hemispheres: uplifted and subsided ones. The Moon is...