[Rockhounds] How Tiny Plants Changed the Planet, 488 Million Years Ago

[Alan Silverstein]

https://www.caltech.edu/about/news/clear-as-mud-how-tiny-plants-changed-the-planet-488-million-years-ago

Recent, relatively brief article from Caltech, starts thus:

> Nearly 500 million years ago, Earth's lowland landscapes were
> dominated by vast sandy, gritty plains.  They then underwent a major,
> irreversible change, after which these landscapes became dominated by
> thick layers of mud...

In short, tiny early plants => trace organic chemicals in water =>
flocculation of clay particles.