Sunday 27 January 2013

A Black Spot on Palaeolithic Archaeology: The Two Bitumen-Splattered Mousterian Artifacts from Umm el Tlal, Syria.

I very much hope that my absence from your 'puter or mobile from time to time means that my unconscious is cooking something up of which I'm not aware until it pops into my head. O' course, I've pretty much covered everything at least once by now. Maybe I should hang up my spurs. Seriously. Who wants to hear the same blah, blah, blah every time they pop their head in? Let me see... *scratches head* Oh! Thanks, unconscious! Here's something.
     Somehow or other this baby snuck past me back in '96. Hmmm. 8-month-old baby. Fieldwork. More fieldwork. Job hunt. Baby. I'm gonna cut myself a little slack for missing it. Besides, I've said plenty about similar somethings in the past. Surely I've covered this. *searches the SA for keyword Umm el Tlel* Nothing. Hmmm. Guess I have some work to do. *rubs hands together with obvious glee*
     OK. Straight face. Published in Nature 380, 336--338, "Bitumen as hafting material on Middle Palaeolithic artifacts," by Eric Boëda et al. [I should mention that I'm acquainted with two of the co-authors---Hélène Valladas and Norbert Mercier. We met while I was working at Kebara Cave in 1989. Everyone treated me well that summer. But Hélène and Norbert were extra kind. I even shared a room with Norbert for a week or so while we were staying at a hotel at Zikhron Ya'aqov toward the end of the season. Which reminds me. Contemporary PhD students Michael Spiers, Steve Churchill, Dan Lieberman, Ann Délange, and Erella Hovers were also there that summer. Small world. Sort of.]
     Anyway. Bitumen. Hafting. I've previously handled several insupportable claims for Middle Palaeolithic hafting---here, here, here and here, to name but a few... One more won't hurt.
From Boëda et al., 1996.

    According to the map Umm el Tlal is near the present-day village of El Kowm. It looks to be about 50 km from Bichri Djebel, in what's now Syria. In the uppermost Mousterian level the team found two lithic artifacts that are stained with bitumen. I have no argument with the chemists on this one. I'm willing to give them that much. These two [count 'em. Two!] bits of rock---one a convergent side-scraper [in the old Bordesian typology; one a 4-cm quadrangular flake---bear traces of bitumen in places where the authors want us to believe that bitumen would preserve if they'd been hafted to sticks. Have a look below. The solid black portions depicted in a are representations of traces of bitumen. As are the similarly solid black portions of the little flake shown in c, further down[I have to say that the black bits on the smaller flake are kind of lost in amongst the very dark lines indicating the Hertzian ripples. Thus, it's difficult, really, to know what's bitumen and what isn't were c is concerned.]
     I find it fascinating that, on the evidence, Nature even bothered to send this paper to referees. And the referees ought to be put in the stocks.

From Boëda et al., 1996.
With regard to the convergent side-scraper the bitumen remnant is interpreted thusly:
The trace of bitumen is present on both faces of the side-scraper and, except at the point, it follows the curve of the right side of the tool, 1 cm below its edge. The left side and the proximal end of the tool were set into a handle. 
So, lemme get this straight. We have an intermittent streak of bitumen on the dorsal surface. No bitumen present on the proximal surface. No bitumen visible on the entire left side of the artifact. Yet, we're expected to believe the interpretation given in b, that almost the entire surface was buried in the haft. I think we must presume that the bitumen on the side not shown is less suggestive than what we can see in this diagram. Otherwise, why leave it a mystery. Regardless, I think it's a real stretch [based on the illustration, mind you] to infer, first of all, that the bitumen had once coated a substantially greater area. It's also difficult for me to accept that the mere presence of bitumen can be taken as prima facie evidence that this artifact was hafted.
     Consider the distribution of the bitumen. I don't know much, if anything, about bitumen taphonomy, but if some bitumen is still adhering to this artifact, where did the rest go? Sure, the two linear patches near the distal end roughly parallel the retouched right margin. And it's true, the distal-most 0.5 cm of the longer patch appears to roughtly parallel the same margin. But the remainder of the larger 'stain' wanders away from the right margin, up to, but not across the medial ridge of a flake scar on the left half, and then turns abruptly back toward the right margin, but extends to the right margin---not stopping 1 cm from it, which is how the atuhors interpret the distal-most 1.5 cm of the bitumen stain. How are we supposed to know, from the distribution, that the stick wasn't hafted along the right margin and proximal end?
     If the bitumen had originally coated the lefterly portion of the flake such that it cemented a haft to the majority of the artifact, why has it remained in certain places, but not others? And are we to believe that the tool-maker fashioned a haft to fit the side-scraper, then only smeared bitumen along the haft-flake boundary? I couldn't imagine that. Could you? Moreover, it seems to me that, if the authors can completely ignore the absence of bitumen elsewhere on the artifact, implying to me that there has been a random loss of bitumen over the ages, I'm feel that I'm well within my rights to suggest that the bitumen was never there in the first place!
     As for the conclusion that the presence of bitumen can be straightforwardly inferred to mean that it was being used as hafting cement, I have to say that I find it implausible. I can say that unflinchingly, if only because the little 4-cm flakoid shown below would prob'ly be the last bit of rock that a sentient being would want to haft to make a handled tool. Were there no Levallois flakes to be hafted? There were some Levallois remains at Umm el Tlal. But, no Levallois points, either? No Levallois blades? Surely those late Neanderthals weren't so desperate to use this tiny, nearly useless piece of rock that they hafted it so they could get a grip! [So is the idea that anyone would haft over a perfectly good edge (i.e. the left margin of the convergent scraper). Likewise, who'd haft a side scraper lengthwise? Wouldn't it make more sense to haft it perpendicular to the long axis?]
     I think it's the authors who should get a grip! It's, it's, scandalous to think that they could have gotten away with this! I'm completely flummoxed. Hey, maybe that's why Nature published it. Maybe they got confused, and were so embarrassed that the editor and the referees all let it pass. Yeah. That's it. That's the ticket!
From Boëda et al., 1996.
Geez, Dr. Science, how did the bitumen get there in the first place, if it wasn't put there by a Neanderthal? Hmmm. Let's see. I can think of half a dozen possibilities, none of which depend on a source of bitumen close to the Umm el Tlal. The authors point out that Bichri Djebel is the nearest known source of naturally occurring bitumen. However, the chemical signature of the Umm el Tlal bitumen isn't chemically identical with that of the nearby Bichri Djebel site, nor of the Hit site downstream. Not that it matters to me that we don't know the source of the bitumen. What difference could it possibly make?
     The authors finish with the finding that the bitumen was heated to a high temperature before its putative use as a hafting cement. Hmm. Naturally occurring bitumen, meet naturally occurring fire.  
     Unknown source. Unknown process by which bitumen came to be adhering to two small lumps of rock. Not much to hang an argument on [I wouldn't have thought].
     It should be fairly clear that this article, which claims to present evidence of an activity previously unknown among the Neanderthals, might just as well have claimed those same Ns were building rockets to the moon. There's just about an equal amount of support for that conclusion in the evidence from Umm el Tlal.

My Gawd. Will it never stop???

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