At http://arxiv.org/abs/physics/9908052v2 … this is a pre-publication review of a paper co-authored by Douglas Keenan. The title is, 'The Three Century climatic upheaval at c2000BC, and regressed radiocarbon disparities' … which may set the cat among the pigeons (over C14 dates) and shine a light on an interesting episode in history.
This period is notorious for its C14 plateau and in recent years the 2300 date seems to have migrated back to 2500 (for reasons of convenience for somebody). SIS Review published a series of articles by Moe Mandelkehr that brought together evidence for a world wide event at 2300BC – which led to disruption and upheaval for the next two or three centuries (which is where the 2000BC number comes from). Thereafter, Marie Agnes Courtey, in France, has also found evidence of a cosmic event (atmospheric fireball) at the time of the Akkadian Empire collapse (around 2150BC) which explains why a period of 300 years was involved (the plateau event). Keenan is not the only person to notice the plateau as Mike Baillie, the Belfast dendrochronologist, locates a low growth tree ring event at 2345BC. The suspicion therefore is that the 2500 date is based on uncertain science and possibly a desire not to connect the dots. If the data is spread over a wide plateau rather than in a narrow crook it makes the idea of catastrophism less credible and more easily refuted. Hopefully, Keenan will burst open the goody bag and show some unwelcome truths – but don't hold your breath. He is a lone voice in a consensus wilderness.
Keenan is not into a global catastrophic event and is only concerned with the mainstream explanation for the upheaval, but he has detected C14 oddities which can only benefit a scenario such as that of Mandelkehr. The abstract claims the event was caused by a colossal volcanic blast – which probably means ice cores and tree ring data is involved. It would have had to be truly colossal to account for the global upheaval and subsequent migrations it provoked. We may take the volcano as a diversionary tactic by mainstream in order to stop people looking at the data too closely. Keenan will keep the pot boiling as he will also look at changes in the monsoon track and ocean circulation patterns that are blamed on the said volcano. You may note that Mandelkehr's scenario also involved volcanoes – and many other things. The real question should be what was the vector, the driver of the volcanoes, earthquakes, ocean circulation and monsoon changes, and mass migrations of tribes over long distances. What was the driving force that got all this in momentum. Focussing on a theoretical volcano (of larger than life power) is simply avoiding the issue head-on. How does a volcano affect the atmosphere for 300 years?
This paper does not appear at Keenan's web site, www.informath.org … so it may never have been published.