Are cratering and probably related geological records periodic?

✍ Scribed by S. Yabushita

• Book ID: 104627451
• Publisher: Springer Netherlands
• Year: 1996
• Tongue: English
• Weight: 825 KB
• Volume: 72
• Category: Article
• ISSN: 1573-0794
• DOI: 10.1007/bf00117540

✦ Synopsis

The controversial topic of periodicity in geological records in relation to astronomical modeling is reviewed. Although impact cratering, frequency distribution of geomagnetic reversals, and mass extinction of fauna yield periods when certain tests are apphed, none of them can be regarded significant in the sense of mathematical statistics. The first two records yield periods of 30 Myr, while the faunal-extinction record yields a period of N 26 -27 Myr. It seems that although catastrophes in the form of large impacts trigger mass extinctions, certain geophysical or geological conditions need be satisfied for mass extinctions to be realized. One should not expect to find an indisputable periodicity in cratering record because random impacts by asteroids are dominant. Thus, the earthcrossing cometary flux modulated by the galactic tidal force appears consistent with the weak detected periodicity.