Periodic Signals of the Milky Way Concealed in Terrestrial Sedimentary Basin Fills and in Planetary Magmatism?

Abstract

Long periodic geodynamic processes with durations between 150 and 600 Million years appear to be in phase with similar galactic cycles, caused by the path of the solar system through the spiral arms of the Milky Way. This path is assumed by some authors to cause climate change due to cosmic ray fluctuations, affecting the cloud formation and the related albedo of the Earth, which periodically lead to glaciations every 150 Ma. With the glaciations, the sea level fluctuates accordingly. Subsequently, the varying sizes of shallow seas are causing periodic changes of the Moon’s tidal dissipation, which affects presumably other geodynamic processes on the Earth. The Moon may therefore synchronize directly or indirectly long periodic Phanerozoic cycles (sea level, orogeny, magmatism, sedimentation, etc.) with the Milky Way. As sea level fluctuations, orogeny, sedimentation and magmatism can be described as members of a geodynamic feedback system; no apparent reasons appear to be required to assign a cause of the cyclicity to agents outside of the galactic-climatically synchronized Earth-Moon system. However, recent observations of young volcanism on the near Earth terrestrial planets may require a new understanding. Magmatic/volcanic episodes on Venus, Mars and Mercury as well as on the Earth’s Moon are apparently contemporaneous thermal events accompanying increased magmatic/volcanic activities on the Earth, following a 300 myr cycle. Therefore, a collateral galactic thermal source within the Milky Way appears to be needed that only affects the interior of the planets without any recognizable direct effect on life and geology on the Earth. The search for such a source may lead to astrophysical questions, related to a spiral arm affected distribution of dark energy, dark matter or even specific neutrino sources. However, all possible astrophysical answers are outside of the author’s competence.