At www.physorg.com/print204991757.html (and variously at www.sciencedaily.com and http://geology.com ) at first reflection we seem to have another example of scientists rejecting a new theory without investigating the claims. A paper in October’s Current Anthropology by two archaeologists says, ‘.. in so far as concerns the archaeological record, an extraterrestrial impact is an unneccessary solution for an archaeological problem that does not exist’. This is in stark contrast to what the likes of Firestone and Kennet have alleged. They say that very few Clovis sites show evidence of human occupation after the Clovis period. At the few sites that are reoccupied Clovis and post-Clovis artefacts are separated by archaeologically sterile layers of sediments which they claim indicates a gap, or dark age – in time. Comet advocates actually argue there was a dead zone in the archaeological record of North America – which lasted some 500 years.
Note … now, we appear to have some old horse chestnuts being thrown about and it seems to me that the archaeologists may have a point. For example, i) why should all evidence of human activity have disappeared for 500 years as an impact would not have affected every corner of North America, and ii) the actual dating of anything by C14 methodology would be hampered by an intrusion of cosmic material creating a C14 plateau. This is the more likely explanation for the missing 500 years and therefore arguments based on dates may be unreliable, and iii) we have the problem that the comet advocates are going along with the geological argument that the sediments concerned were laid down over a long period of time. This might not be the case and may go some way to explaining why the Younger Dryas event is assigned such a long period of time when in effect those sediments may have been laid down catastrophically and therefore fairly quickly. Finally, the idea that the YD boundary event involved an impact and widespread destruction is taken as read by the two archaeologists when perhaps the YD boundary event does not require such an interpretation. After all, no actual crater has been found as yet. The event may have been fairly similar to what happened in 2300BC – but on a larger scale perhaps. As Moe Mandelkehr has shown in his various papers published by SIS journals the 2300BC event involved long distance folk movements and it seems likely that something similar could have happened as a result of the YD boundary event – particularly if it suddenly became very cold in the far north. In other words, migrants from Siberia that may have established themselves in what is now Canada may have shifted location, reoccupying the zone formerly inhabited by the Clovis people. There was a void, or niche in the landscape, and just as catastrophes encourage biological niches to be filled by novel species so too might the Palaeo-Indian phase of the Early Holocene represent a re-colonisation of not just North America but a very rapid expansion all the way down into central and south America which is an unarguable fact of archaeology. Therefore this paper does not really represent a negative for the comet advocates – it could be used constructively. Bearing this in mind it might be useful to visit http://wattsupwiththat.com/2010/09/30/no-evidence-for-clovis-comet-catastrophe-archaeologists-say/ which is basically a repeat of the Physorg abstract – with comments. Anthony Watts is introducing new subjects onto his blog as AGW is becoming a little weaker and is not the jolly giant on a perch anymore. The two archaeologists, it seems, actually argue that a lack of human occupation is no reason to assume a population collapse. I suppose this is because they have had to deal with dark ages elsewhere – almost always associated with C14 plateau events. They even say the sediment issue may be explained by local geological processes – as if they acknowledge local catastrophe rather than continent wide catastrophe. They also say something much less likely – the disappearance of Clovis points might have been as a result of choice.
In contrast, Terry Jones of the California Polytechnic State University (link provided by one of the commenters) made an argument last year that from the perspective of Californian archaeology, there is a distinct gap in occupation – and this is precisely the gap of the comet advocates, between 12,900 and 12,200 years ago (700 years rather than 500). He adds to this by saying there are very few sites C14 dated between 12,200 and 10,500 years ago – which would require some kind of explanation. A phase of reduced human activity in the very early part of the Holocene is a phenomenon not just of North America but of many other regions of the world. In Britain it is assumed the return of cold weather during the Younger Dryas caused the Late Pleistocene population to migrate southwards (and perhaps they did) with just a trickle coming back into Britain after the YD came to an end. However, what if a large number of them died as a result of the YD boundary event – the survivors, just a few perhaps finding refuge in caves or whatever, would have taken quite some time to re-establish themselves in significant numbers so that they were archaeologically visible. You can look at the archaeology in a number of ways – it is so ephemeral no conclusive interpretation is practical.