[ClearCase_guy]

Very interesting book about the time period, and the possible causes of the Dark Ages. Volcano - Weather - Famine - Plague. All basically inter-linked, but basically starting with a volcano.

[colorado tanker]

Very interesting book. Just read some of it on Amazon. Definitely fits with the catastrophism theme.

Interesting that he links population loss in the Arabian Peninsula with the rise of Islam. Quite some catastrophe there.