Cyclic Regularity of extinction events & other disasters ¶¶¶

Cyclic Regularity of extinction events & other disasters.

Hi,
Does anyone know of any good sites showing the
Cyclic Regularity of extinction events, volcanic &
weather disasters, disease outbreaks etc ?
Saw a great site about 4 years ago but
can't find where I saved the URL.

Thanks in advance if you can help  :-)
Regards.
amazure