Role of Earth-Moon rotational dynamics in the shaping of the surface of our planet

Abstract

ABSTRACT The age of the Moon (1.55–1.78 b.y. old) as calculated from its regression as a function of geological time is much younger than the currently accepted age (ca. 4.52 Ga) determined by radiometric dating of lunar samples collected by Apollo astronauts. This discrepancy has posed a serious challenge for planetary scientists to account satisfactorily for the formation and subsequent breakup of Pangea. Conventional orbital models of the Earth-Moon system cannot explain why Pangea formed on only one hemisphere of Earth, whereas this study’s proposed two-stage rotation model can provide a plausible explanation. Calculations and a plot of the Earth-Moon separation distance against geologic age suggest that, during their first ~3.0 b.y., Earth and the Moon were mutually tidally locked, rotating as an integrated unit about a barycenter (designated as stage I rotation). Beginning 1.55 Ga, however, Earth disengaged from its tidal lock with the Moon and entered its current orbital mode (designated as stage II rotation). The dynamics associated with the two rotational modes of the Earth-Moon system throughout Earth’s history are hypothesized to constitute the driving forces for the migration and coalescence of landmasses during stage I rotation to create Pangea, and its ultimate breakup and drifting during stage II rotation.