Radiation event confirmed at Clovis disappearance

Radioactive carbon-14 levels 3 to 4 times higher than normal

4 Oct 10 – Reader agrees / disagrees with me


Robert,

I enjoy your site and generally tend to really appreciate the diversity and alternative views that you offer.  Concerning Clovis I think you may be somewhat mislead by popular archaeological literature.

First, I do think that there really was a truly remarkable “radiation event” that coincides with the onset of the Younger Dryas.  That event, whatever it was created not only the “nanodiamond” layer, but a tremendous radiocarbon anomaly that distorts C-14 dating for about 2,000 years.

Note from Robert.

Not only did radioactive carbon-14 levels measure 3 to 4 times normal, radioactive beryllium-10 levels measured 2 to 3 times normal. Similar wild jumps in carbon-14 and beryllium-10 levels occurred 23,000 years ago at the Mono Lake magnetic excursion, 33,500 years ago at the Lake Mungo magnetic excursion, and still earlier at the Lachamps magnetic excursion.

I discuss these anomalies in “Magnetic Reversals and Evolutionary Leaps.”

I heard Firestone present his ideas at the Southeast Paleoindian Conference in Columbia, S.C., some years ago.  At that time they had not yet identified the “nanodiamond” horizon and he was leaning toward a comet strike in the Hudson Bay region.  The problem was, and I asked him about this at the time, you cannot generate a significant amount (if any) of C-14 from a comet strike.  C-14 is generated by cosmic ray bombardment of a nitrogen isotope within our atmosphere.  It is so short-lived that no significant amount could arrive from an interstellar source.  The trip would simply be too long for the isotope to survive.  So a comet, unless it was a nuclear bomb comet, was right out.

However, turning to Clovis, you need to remember first that like paleontology, archaeology consists of a dreadfully scant number of facts strung together with a cob web of pet ideas. There are a number of different elements that mark Clovis, but the one that is popularly noted most often is “fluting” of the base of the projectile point.  That simply means that the maker set up a percussion on point on the base, and removed a broad flake from one face extending up the point’s length from the base toward the tip.  He then repeated the process on the opposite face.  This creates a “bi-concave” cross section that apparently was popular for around 500 to 1,000 years during the terminal Pleistocene.

Popular literature tends to portray Clovis as a fine-art high point because of the beauty and character of the best of the specimens.  Professional literature on the other hand sees many more shades of grey.  Fluting occupies an extreme end of a gradient of “basally-thinned” spear and dart points, and possibly knives.  Absolutely ALL it does is offer a hafting point for the shaft or hilt.  We today might find the pieces artistic and beautiful, but the Clovis hunter spread adhesive in that flute and attached his shaft there.

The Clovis point was a practical, pragmatic solution to a problem.  In fact there are other fluted points such as Folsom and Cumberland, which appear toward the end of the Younger Dryas.  They are fluted but the makers have invented new methods of producing the “flute.”  Where Clovis points were fluted with a percussion (hammer blow) method, Cumberland and Folsom were evidently pressure flaked to produce the flute.

Well-made Folsom points are even more impressive than Clovis, though they aren’t as large; they may have a maximum thickness of five millimeters near the edges, and a minimum thickness – along the flute axis – of 2 or 3 mm.

There is no archaeological evidence of a hiatus of human presence in the Americas during the YD.  There _may_ have been population fluctuations, but the most parsimonious interpretation of the available data seems to indicate that humanity in the Americas survived the Younger Dryas onset, duration and ending.  Fluting appears to have died out simply because other hafting methods worked just as well or better.

As I mentioned above though.  C-14 dating during the YD is very problematic because of the C-14 anomaly that collapses a couple of millennia into an apparent 500 year span.  Thus if there was a hiatus we might not be able to discern it.

Another issue that I noted was the idea that places occupied by Clovis were abandoned and were not reoccupied.  This is simply not correct.  First, there are very few Clovis primary encampments known.  Of those few, there are sites such as Gault site in Texas, and the Borax Lake and Sky Rocket sites in California, where the archaeological records extend through numerous cultures and thousands of years.  Sky Rocket for instance was more or less continuously occupied for at least 10,000 C-14 years.  Gault may have a span that even includes pre-Clovis occupation.

There are plenty of interesting debates that circle around Clovis because it is the earliest recognizable human culture in the Americas, but as I mentioned, it is American itself, so there MUST be earlier people here than Clovis.

So far there is precious little “pre-Clovis” that is unequivocal – Monte Verde in Chile and more debated, Meadowcroft, in Pennsylvania.  The archaeological debates can get fairly bitter and loud.

In any case, thanks for the site and keep up the good work.

J. W. Dougherty

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John Dougherty is a professional archaeologist by profession and works primarily in the far west.  

 


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