Of Cosmic Catastrophes: How A Stone-a...: The Cycle

The authors highlight several geological markers to support their theory:

The Cycle of Cosmic Catastrophes: How a Stone-Age Comet Changed the Course of World Culture The Cycle of Cosmic Catastrophes: How a Stone-A...

: Discoveries of radioactive mammoth bones and magnetic microspherules in specific sediment layers. The authors highlight several geological markers to support

: A massive comet or fleet of comets struck or exploded over North America around 12,900 years ago, an occurrence the authors simply call "the Event". 900 years ago