Driven By Drink, And An Ode To Fridays!

While still a Ph.D. student at UC Berkeley, I had several conversations with Mickey Dietler about drinking, agriculture, and the rise of socioeconomic inequality. His dissertation ended up titled 'Driven by Drink.' It was, if I recall, a treatment of the Roman trade in wine up and down the great rivers of France in the Iron age. At the time I was thinking a lot about how foragers (nimrods, piscators, pluckers and planters) gave up their strong proscriptions against self-aggrandizement and hoarding for the ownership and circumscription of land that followed in places where agriculture was a viable practice. As an undergraduate I'd had many long chats with Brian Hayden regarding the processes responsible, which for him turns on the inflationary economy of competitive feasting (e.g. the Potlatches on the Northwest Coast). I can't remember if it was he or I  who suggested that booze might have figured in the whole process, and that it could easily explain why grains became domesticated long before there's any evidence of substantial storage facilities, grain economies, and so forth. So, I have to say that I'm genuinely pleased to see that Brian has published on the idea that it was (essentially) beer production that spurred the intensification of agriculture that we see in the early Neolithic of the Near East and elsewhere.

So, since it's Friday, and I'm takin' it easy after a rigorous week telling it like it was. Raise your glasses and let's all drink to Brian Hayden's health and sensible, human level theories about the development of socioeconomic inequality. The 1% need not attend.

Next Up: Asses Wild

I'm very close to posting a ... how shall I put it? ... foreclosure on the whole idea that hafting occurred in the MP.
     Clock's ticking.     

Wherein I Get The Last Word on Campitello Quarry's Birch Tar

[Please note: after I posted this Dr. Langbroek commented further, proving to me that, once again, I was unsuccessful in painting a clear enough picture of what I think explains the extraordinary archaeological occurrences at Campitello Quarry. I've tried to indicate, using yellow typeface, the location of my most recent additions to the text, which includes a new, more helpful diagram.]

I prolly shouldn't be doing this. My mum used to say, 'Robbie [she called me Robbie]. Have the courage of your convictions.' I found out years later that it didn't matter what I thought. All that matters is that you get other people to listen to you and think you're right!

Marco Langbroek has delivered another comment, which on the surface would be a very damaging rejoinder to my recent critique of the Campitello Quarry birch-tar hafted lithic implement. I'm crestfallen, since I thought I'd put it very succinctly. My apologies, Marco. Nevertheless, it's apparent that I may not have written it so as to avoid being misunderstood. Apparently he thinks that I've misinterpreted what Mazza et al. have written about the sedimentary context of the find. 
     For that reason [and because I respect Dr. Langbroek for taking the time to provide the contra side in this discussion] I think it's really important that I disabuse my opponent of any false interpretations of the pro side. So, I'm going to begin by quoting the pertinent passages of Mazza et al.'s geomorphological description in their entirety. I'm hoping this'll help to make crystal clear what they (and not just my interpretations of what they) thought were the depositional circumstances of the artifacts and faunal remains. Afterward I'll be in a better position to tackle Marco's rejoinder and clarify what I think most likley explains the presence of the archaeological traces recovered at Campitello Quarry.
     Nota bene: I want you to keep uppermost in your mind that Mazza et al. are, almost exclusively, describing the generalized stratigraphic succession for the entire Upper Valdarno Basin, and not, directly or otherwise, the actual sedimentary context of the excavation. I'm gonna suggest that Mazza et al. relied either on their own, or a geologist's, stratigraphic correlations across the entire basin, for the inference that the sands they were excavating were the undisturbed sands of the sabble di Levane [see their generalized stratigraphic column below for the location of these named units]. Indeed, one wonders at the absence of what would normally be the obligatory stratigraphic profile of the excavation. I'm left to speculate that there was no such profile to draw, and that the excavation took place after the 15 or so meters of overburden had been removed by quarry workers, leaving only what the excavators interpreted as the undisturbed sands of the upper sabble di Levane.

Here is what Mazza et al. have to say [and remember that these are all of what they've published pertaining to the sediments containing the artifacts and animal remains].

Five fluvial cycles were recognized at Campitello quarry. The three lower ... consist of horizontal to planar, cross-stratified, coarse-grained gravel [labelled ciottolami di Laterina in the illustration above]. They are overlain by the trough to plane, cross-laminated and epsilon cross-stratified sand of the two upper cycles [labelled sabble di Lavane in the illustration above]. Individual cycles are some 2-6 m thick and are separated by sharp, generally planar and sometimes erosive bounding surfaces. The fining-upward trend attests to a change from braided and/or lowly sinuous to meandering river deposition.

The archaeological and palaeontological items were buried in 0.30-0.40 m of massive, grey-green sand of the uppermost fluvial cycle [i.e. the sabble di Lavane]. The latter consists of 5-6 m tabular, laterally persistent, sand with minor intercalations of silty clay and fine gravel intersects. Lateral accretionary bedding (epsilon cross bedding...) is the dominant sedimentary structure which indicates point-bar deposition in a wide, highly sinuous, meandering fluvial channel [emphasis added here]. ... This cycle grades up into over 15 m of prevalently massive, bioturbated and deeply pedogenized silty clay with abundant root traces, local peaty horizons, and lenticular to tabular sand interbeds [labelled limi di Latereto in the illustration above]. These lithofacies [i.e. the silty clays comprising the limi di Latereto] indicate a flood plain mostly filled with fine-grained overbank sediments and with crevasse splay deposits [emphasis added here].

The stratigraphic indication yielded by [the] few small mammal remains is indirectly confirmed by other six isolated cheek teeth of Arvicola  found in thinly laminated silty clay, about 5 m above the elephant bed.

Numerous rodent remains were found ... in a layer of fine sand, silty clay and thin laminae of organic debris, that coated the sand bed which contained the stone implements and the elephant skeleton. 

To summarize, the artifacts and faunal remains were recovered from the upper 30-40 cm portion of the sabble di Levane sands, which were deposited in the time-transgressive context of a point bar.* After the putative deposition of the archaeological traces, the river apparently went on to deposit 30 to 40 cm of additional point-bar sands in the same place, a process that takes considerable energy and is unlikely therefore to result in any depth of finer sediments.
     Yet, according to the excavators, in that accumulating point-bar deposit they found a 'capping' layer of fine sand, silty clay, and thin layers of organic debris. Given that it was some considerable time before the meandering stream and its point-bar deposit was very gradually replaced by a lower-gradient hydrological regime dominated by over-bank deposits and crevasse splays comprising fine sands, silts and clays.
     I'm hoping that by clarifying what the report says and what it implies, I can persuade my detractor that I haven't distorted the published record. Here is what the comment states... 

...it is very clear from the Mazza et al. paper that the laminated fine sands and silty clays (including the microfauna) that cap the artifact-containing deposits represent the place where point-bar deposits change into distal floodplain as the river is changing course and incising deeper.

[I beg to differ. A river that's incising is not given to serious over-bank events. Those are much more likely to happen, and are much more frequent and severe as the stream gradient approaches horizontal through a process of deposition and aggradation in its bed. Having just read what Mazza et al. really said about the changing hydrological regime in the Valdorno Basin, the reader will quickly see that my detractor is the one misreading the published account. The transition to a floodplain occurred long after deposition of the sands in which the archaeological traces were found.] 
     I wondered how any artifact that had been deposited in a point bar would develop a patina. My detractor goes on to say 

Patination does not exclusively occur when artifacts spend long times on the surface, as you suggest. ... Moreover, ... patinated artifacts are typically older than the Holocene. 

However much I desire to debate the former of these two points, and call him on the latter statement, I will say only this. I never suggested that the artifacts are, necessarily, Holocene (although I believe that they most probably are).      
     The next, and last paragraph in my reader's comment demonstrates that my original words truly failed to make the sense that I'd hoped they would.  

You fail to explain how bones of one single Pleistocene elephant came to be "reworked" as a homogeneous ensemble together with "Holocene" artifacts. The description and mapping of how these remains of one single Pleistocene elephant, including elements of clearly different size and weight, were found over a small area, clearly indicates that the elephant was encountered in situ, not in secondary deposition as you claim. In a hydraulic jumble you'd expect more heterogeneous remains, and definitely not a preserved association of bones of differing size/weight of one single carcass: the smaller ribs for example would not be found together with the more massive limb elements and mandible in the latter situation. And the artifact with the tar lump, was excavated from *below* one of the elephant ribs, i.e. are definitely part of the same deposits. To me, the evidence for in situ preservation of this Pleistocene elephant carcass combined with the fact that the artifacts were found among these bones during a controlled excavation, clearly attest against your hypothesis that the artifacts are intrusive Holocene artifacts. In that sense, the situation is wholly different from your Old Crow River analogue.  [emphasis added]

So you do not convince me, as your argument does not make sense, taphonomically.    

In the first place I never said that the archaeological traces were part of a 'hydraulic jumble.' In fact, quite the opposite. I maintain that they never saw the Middle Pleistocene river water that deposited the sands in which they were found. They most likely came together from different layers higher up in the sequence either in one of the erosion gulleys visible in their cross-section, or did so during quarrying. The circumstances that I'm describing would be of the kind I've tried to illustrate in my usual inimitable style [i.e. not very good] in the diagram below. 

The lefterly part illustrates the erosion and secondary deposition of the materials from different ages dropping into their mixed secondary context. At the top, very near or at the surface is the birch-tarred flake's original locatation. Lower down (approximately 5 m above the archaeological accumulation) is the place where the excavators noticed a primary context for microtine teeth. The archaeological circumstances are equivocal as to the likely temporal relationship between the microtine and the elephant remains. I've depicted the original location of the Elephas bones lowest in the sequence, but there's no reason to think the animal remains couldn't have been penecontemporaneous, or in fact younger than the microtines. It's also possible that Marco is correct, and that the elephant bones are in their primary context. A lot of possibilities. The righterly part of the diagram simply shows the approximate location of the excavated materials in the stratigraphic column, as inferred by Mazza et al.

The upper layers, being primarily fines, have formed a cap on the predominantly sand middle layer at the top of which the artifacts were found. Such sediments normally retain a good deal of structural integrity as they erode, leaving a sub-vertical to vertical face that protects the layers beneath it from the worst ravages of erosion. As sure as shootin' an erosion gulley in the Valdarno Basin will incise the upper terrace and when it cuts deep enough to expose the sand, it will allow material from younger sedimentary contexts to drop vertically from the face and be incorporated in the exposed sediments at the bottom of the erosional feature. 
     If the elephant remains were in close association in the intact flood-plain sediments they would, when eroded out, logically form a secondary deposit that resembles, to a degree, the spatial distribution of the primary deposit higher up in the profile. This kind of depositional environment very easily explains both the accumulation of objects of different ages in one place, and makes the circumstances at Campitello Quarry analogous to those at Old Crow Flats.

    Thus, if I'm correct, whether or not the birch tar was found beneath a mammoth rib is of no relevance whatsoever. It's 'provenience,' regardless of the care taken during its excavation, wouldn't mean bugger all if the sediments were disturbed. Begging the question again!
     Can I go NOW?

* (i.e. what accumulates on the inside bend of a meandering river, and which aggrades toward the far bank as the water flowing past the outer bank causes cut-bank erosion and the bend gradually becomes more acute until, during a high-water phase the swollen river cuts across the narrow finger of land in the elbow of the bend, leaving the point-bar sediments to become encased in sediments deposited at some later time by whatever process is then in play at that location.)

So Much To Say; So Little Time To Say It!

Here it is: Thursday again. 
     And I'm not ready for Thursday this week. 
     I feel a bit like Arthur Dent felt in Douglas Adams's The Hitchhiker's Guide to the Galaxy when he famously stated 

'This must be Thursday.
I never could get the hang of Thursdays.'

And, wouldn't you know it, about twenty minutes later the Earth is demolished to make way for a new hyperspace by-pass! You see? Thursdays are inherently bad! And on this Thursday, February 9, 2012, I've too much to say about more pressing matters to leave me time to present a touchstone.
     Therefore, I'm officially cancelling Thursday this week, to make way for a) a crafty deflection of what I think is b) a set of misguided statements about c) my earlier statements about d) the sedimentary context of Campitello Quarry's birch tar, and what it may or may not say about e) the possibility of early Middle Palaeolithic chemical engineering. In so doing, I'm hoping to forestall an Adams-like demolition of the Subversive Archaeologist in the process of making way for the Neaderthals R Us crew to keep their juggernaut from getting caught in traffic. As it were.
     So, please be patient, and forgive me the time that I'm having to spend on these matters. I believe that they're of crucial importance to subversive archaeologists of every stripe--NOT just those of you in the 'What were the Neanderthals?' arm of our business. 

Haft-Way There!

I don't recall why I would have 'unpublished' this. Nevertheless, it's back now. Published on February 8, 2012.

Of late you've seen two really good examples of how archaeologists can 'get it wrong.' One was Pawlik and Thissen's claim from Inden-Altdorf, in Germany, in which I questioned their empirical observations and conclusions. The other you saw just yesterday, in which it appears that a tar-encased flake was very probably recovered in (at best) a mixed depositional context, which would lead to an overestimate of its age. Let's see... as I understand it, there were four articles crucial to the claim that the Neanderthals engineered birch tar as a hafting mastic--no small feat, even for people like you and me. [Thanks again to Marco Langbroek and Iain Davidson for bringing me up to date on that literature, albeit for different reasons.] 
     That leaves only two. One is a real beauty: an argument, wrapped in a mystery, inside an enigma. 

This tiny flake fragment (proximal-distal length a mere 14 mm) is interpreted as part of 'A Levallois point embedded in the vertebra of a wild ass (Equus africanus): hafting, projectiles and Mousterian hunting weapons,' by Boëda, Geneste and Griggo (Antiquity 73:394-402, 1999).

The other is (near enough) what naughty kids get for Christmas. It's two small lumps of birch tar from a lignite quarry near Königsaue, Landkreis Aschersleben-Staßurt (Germany).

A lump of birch tar (27 x 20 mm). From 'High-Tech in the Middle Palaeolithic: Neandertal-Manufactured Pitch Identified, by Koller, Baumer and Mania (European Journal of Archaeology 4:385-397, 2001).

As I've said in the recent past, this stuff really hurts my brain. So it means I might not show up here for a day or two. But, Arnold-like, I'll be back. Count on it.

Of Birch-Tar Hafts and Caribou-Tibia Fleshers: Campitello Quarry and Old Crow Flats

All would-be subversives take note, regardless of your area or epoch of specialization. This article is about sedimentary context--association--and only nominally about the Middle Palaeolithic. Even if you're not someone who gets a kick out of interpreting site sediments, and prefers to leave that to the 'experts,' you'd be far better off sticking with this post because one day, sure as shootin', you'll need to have these skills under your belt lest you fall for the oldest geomorphological trick in Mother Nature's book.

     In 2001 Mazza et al. (2004) discovered some very interesting lithic artifacts in a galaxy far, far away the Campitello sand and gravel quarry, near Bucine, in Italy. One was half encased in birch tar, and bore the unmistakable negative impressions of the haft. Cool enough, you might say. Trouble is, the claim is that it's Middle to early-Late Pleistocene in age. More Neanderthal chemical engineering? Wait and see. 

[May I say that Marco Langbroek has been very kind in directing my attention to this find. The trouble with my having been inactive for so many years is that I've been unable to keep up with the primary literature. It means, simply, that I am reliant on my friends and friendly acquaintances to bring such material to my attention. In this case, Marco has set me something of a challenge, and has goaded me into trying to, as he puts it, 'explain this one away.' All I can say in response is, 'With pleasure!']

A tip of the hat to Marco Langbroek for making this image available to us.

Thus, the gauntlet is thrown down (a lot like the gloves in a hockey game, in actual fact, which is, as you know, the national sport of my home and native land, but which I never played). This'll be most difficult trial in the short tenure of the Subversive Archaeologist. 

     After sowing the seeds of doubt with respect to claims of Middle- to Late-Pleistocene birch tar from Inden-Altdorf, Germany (Pawlik and Thissen 2011), I should say at the outset that I've no quarrel whatsoever with the chemical characterization of the Campitello Quarry mastic as being that of birch tar. Mostly it's because the same chemist that organized the real chemical characterization of birch tar is a co-author on the Campitello Quarry paper. So, where does that leave the subversive? If ya can't fault the evidence, you might be able ta find fault with the context.

[In fact, the contrast between this claim from Italy and the one from Inden-Altdorf has made me realize that there are really only two primary ways that archaeologists can 'get it wrong.' First is in the interpretation of their observations, as I've argued was the case at Inden-Altdorf. The other is the context of the evidence. In the Campitello case, it's the context--the association of the artifacts with the surrounding sediments--with which I have a problem.] 

     I think the Italians were expecting a little flak on the matter of context. In the following quote from their introduction, you'll notice that they are quick to point out their biostratigraphic evidence, which they aver will corroborate the putative age of these objects.  

Elephant and rodent remains were exposed in November 2001 in a clay pit, Campitello Quarry, in the outskirts of Bucine, a small village in the southern part of the Upper Valdarno basin, on the left hydrographic side of the Arno River. … The bones were entombed in fluvial gravels and sands stratigraphically dated to the Middle Pleistocene. A more clear-cut chronological indication is given by the rodents which prove that the finds date back to a moment of the late Middle Pleistocene [emphasis added].

As I was reading along, as I'm sure you will, too, I noticed that the artifacts and Elephas remains were found in sediments first described as a 'clay pit,' then as 'fluvial gravels and sands,' and finally as the fluviatile, 'massive, grey-green sand' of the latest stratigraphic unit, the Monticello Succession of the Valdarno Basin. Here's a schematic cross-section of the Arno River Valley from the article.

I want to go here. Look at the name of the mountain range in the south!

This sedimentary context is one in which chronostratigraphic 'mixing' is not just possible, but likely. In this case, the most recent sediments are identified as 'flood-plain' and these form a terrace, capping the older sediments in a recently formed, deeply dissected valley system. These recent erosional features are illustrated by the narrow U-shaped voids that have exposed the stratigraphic sequence to varying depths across the Valdarno Basin.

     Such erosional gulleys and valleys are notorious in  archaeological lore because they're places where younger clasts can easily be introduced into older sediments, and be unrecognized as such by the excavators. In this case, the excavators arrived after some of the Elephas bones were discovered (presumably by workers quarrying for sand and gravel--a common enough occurrence in such geological formations), which means that, at least for those objects discovered during quarrying, ALL of the overburden had already been removed. The authors do not say whether or not the portion they actually excavated was taken from beneath 15 or so metres of more recent sediments. But you'd think they might have mentioned it if they did. 

     So, there's at least a possibility that the sand in which they excavated was not the sand that had lain undisturbed for upwards of several hundreds of thousands of years. Take a closer look at the Valdarno cross-section, which I've pumped up in the illustration below. Here you can see these U-shaped erosional gulleys, and you don't need much of an imagination to see how it's possible for items of any age to be introduced into what are much older sediments as these features evolve. Couple that possibility with the absence of any real contextual evidence (or published description) for what lay stratigraphically superior to the bone and stone remains, and you have a recipe for, at a minimum, serious questions about their true provenience(s).

By the way. The notation with respect to the Acheulean is only meant to convey the presumed age of the oldest artifacts found terrace-top. Everything up to and including yesterday is up there, too. 

     Luckily for us, the Mazza et al. article provides several clues that the bones and lithics were indeed introduced from younger sediments. The first of these is the grain size of the enclosing sediments, which is described as fluviatile sand in a point bar context. Any stream that is depositing nothing but sand at some point in its journey has long since lost the energy to transport larger and heavier clasts, such as Elephas bones and the relatively massive lumps of stone and tar. That said, a river laying down sand at a point bar still has considerable speed and transport capacity, even if it's bedload is well-sorted sand, which leads me to the second observation.

     The second clue that the tar-wrapped artifact may have been introduced from more-recent times involves its   preservation condition. According to Mazza et al. the bones and stones do not appear to have been entrained for long (i.e. no signs of rounding that would rapidly occur in an ongoing point bar context). How is it possible, then, that they were buried without any signs of having been entrained in such a fluvial context? Not very possible is the definitive answer. [I would hasten to add that it's just possible that they were purposefully buried in a river point bar by some obsessive-compulsive Mid- to Late-Pleistocene hominid. But I doubt it.]

     The third clue given in Mazza et al. is that the lithic artifacts are patinated. This implies a considerable time spent in the open (ask anyone). Again, this isn't what you'd expect on a point bar.

     The fourth clue that all is not as it should be is the context of the microtine fauna, described in this way.

[the microfauna were found] in a layer of fine sand, silty clay and thin laminae of organic debris, that coated the sand bed which contained the stone implements and the elephant skeleton [emphasis added].

Such sediments could NOT have been deposited in a point bar. Full stop. Unless, that is, the river suddenly turned into a basin in which water stood still long enough for the fines (i.e. clay and silt-sized particles) to settle out. Something just isn't right about the archaeologists' interpretation of the sedimentary context of these objects. There can be no doubt of that.

     Notwithstanding the fine work done by the faunal specialists in identifying the Mid-Pleistocene microfauna, or the chemical characterization of the birch tar, or the taphonomic study of the Elephas bones, there is nothing coherent about the archaeological context of these finds. Every aspect of the archaeologists' description contributes to the strong suspicion that the substantive finds are not all from the same time.

     To give you an example of how easy it is to get fooled by the complex depositional processes in geomorphic contexts like the Valdarno Basin, one need only recall the famous 'Old Crow Flats caribou flesher' that caused a big stir amongst Paleo-Indian archaeologists in North America and abroad in the late 1960s and on into the 80s. Discovered in a point bar of the Old Crow River, this caribou bone artifact was found associated with 25,000 year old animal bones. 

The same type of caribou tibia artifact as that found at Old Crow Flats (Illustration credit).

The following is a snippet of a synopsis of North American archaeology that appeared in Archaeology magazine in 1999.

In the summer of 1966, a paleontologist collecting fossils from along the Old Crow River in arctic Canada found amidst a jumble of bones from now-extinct Pleistocene animals a caribou tibia, its end carved into a toothed spatula. The mammoth remains found with the flesher appeared to have been flaked and fractured, like artifacts. The specimens were more than 25,000 years old, far older than anything then known from the western hemisphere. ...redated in the 1980s the caribou tibia flesher proved to be only 1,350 years old.

from David J. Meltzer, 'North America's Vast Legacy,' Archaeology 52(1), January/February 1999.

Those with long enough memories will bear me out on this matter.

     In closing, I'd like to offer a challenge of my own: that Mazza et al. subject a minute sample of the birch tar for radiometric dating--specifically radiocarbon. I'll bet my well-worn Marshalltown that it doesn't exceed the limit of radiocarbon dating, which, as most of you know, is (at the extreme end of extreme) not above 75,000 years, and is normally cited as give or take 50,000. Definitely not Middle Pleistocene, but could be Late. My guess is that it's no more than terminal Pleistocene or Holocene in age.

     *puff of smoke*

Wait For It...

What I'm working on at the moment will be less a discussion of Neanderthal capabilities than it will be one of distinguishing between sense and nonsense in an archaeological arugument. After pointing out some empirical shortcomings of the Pawlik and Thissen article on Middle Palaeolithic production and use of birch tar as a hafting mastic I've been asked [in a way] to have a look at another paper that makes a similar claim. I have grave reservations about it's conclusion as well, but from an entirely different point of view. In this case, I'm quite happy to accept the interpretation that it was birch tar, and that the lithic fragments had at one time been hafted to something. My reluctance to accept the argument has to do instead with the sedimentary context, and the real likelihood that these artifacts have been ascribed to the wrong time period, which is something that all archaeologists can appreciate, regardless of their area and period of specialization. [Students of the North America Archaic will recognize the problems that I think inhere in the Mazza et al. paper. So, wait for it... 

Tip o' the hat to Marco Langbroek for passing along this image of the Campitello Quarry birch-tar hafting mastic adhering to a couple of what look like exhausted bifaces.

     Unfortunately this stuff doesn't write itself, and no critique is possible without some background research and a close reading of the data presentation. All I can do is beg your forbearance, and thank you for your patience. 
     The article in question is another one suggested by Marco Langbroek, Mazza et al.'s 2006 'A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed,' Journal of Archaeological Science 33:1310-1318.
     Stay tuned. And fear not. The Subversive Archaeologist is on the job! [I can't help feeling a little like Sherlock Holmes at times. You wish, Rob!]

Dirty Deeds, Done Dirt Cheap

I was one for a couple of years in the 90s. I know that some of you are. Many of you know one. Nevertheless, I wonder if the majority of you have ever seen one. Itinerant archaeologist would be the polite term for them. Their business cards would read 'Have Shovel, Will Travel' if they could afford business cards. Or, better still, 'Dirty Deeds Done Dirt Cheap.' Most are just a phone number on the front page of someone's excavation log book. Some might get a mention in a report. Collectively you can call them by their usual tag: Shovel Bums.
     They love archaeology, the outdoors, interesting companions, the side trips to sample local colour (to say nothing of the local micro-brewery), and most of them wish that they had some job security. Compared to the Project Archaeologists, they're paid like the extras in a movie. And you could probably justify their pay grade if they were university kids trying to make a buck in the summer. That hardly describes the ones who've done this year in and year out. They're sought out by the Project Archaeologists because of two qualities they possess: they'll give you a good day's work, and they've probably worked on most of the earlier projects in your vicinity. Sure, they've worked ALL over the state, and maybe shouldn't know anything about your site or its neighbours. But they've been all over the state, over and over again. They've covered it like white on rice. And their knowledge is deep.
     Did I say state? I misspoke. Borders mean little to them. Nevada? Sure. Big project in Oregon? Put me down. Some would say that they're happy as long as they can keep themselves in beer and cigarettes. Maybe so. Such moralizing does violence to their dedication to Archaeology. And besides, you could say the same about a lot of academics! 
     There are a few job 'clearing houses' on the web, and it's probably a good thing that many public libraries have internet access for those unfortunate enough not to have a computer at home, or a home, for that matter. The oldest, so far as I know, is shovelbums.org. 
     Next time you meet one, you might offer to buy them a beer. Believe me, you'll learn more about your craft than you ever thought was possible. And you'll laugh until you cry. There's little diplomatic reverence for the 'field director' in their stories, and a healthy dose of self-deprecation that might just explain why they're at the bottom, rather than the top, of their profession. Fellow members of the SDC will know what I mean. [I sincerely wish that I could give a golden Marshalltown to anyone who knows what the acronym SDC stands for. They would honestly deserve it.] Raise your glasses.

You Hafta Be Kidding!

It's the weekend, and I've had a hard week, what with trying to deal with the Subversive Archaeologist's very first academic detractor. I prolly screwed up by engaging him publicly. Live and learn. Still, my new colleague from the Netherlands, Dr. Marco Langbroek, has given me the chance to say something juicy about the latest claim for Neanderthal smarts. In that respect it wasn't such a bad week after all! 
     I know! I know! It's another Middle Palaeolithic post. But, WAIT! This post is more about the argument than the Big Questions that interest the archaeologists of modern human origins. As such, it should interest most of you, since no period is free of inferential missteps such as the one I'm about to discuss.


I should begin by asking you to remember that any--ANY--archaeological inference is an argument from evidence. Even the recognition of a piece of lithic debitage is heavily theorized from background knowledge, and is implicitly argued into existence every time you say, 'I found a flake.' In today's case, the archaeological interpretation stands or falls on the conjunction of a) empirical observation and b) the arguments linking those observations to well-understood processes that are uniquely capable of producing the phenomenon for which an explanation is sought. In other words, the inference in question is an argument within an argument based on some observations that the archaeologists think can help to explain the phenomenon. Mull that over for a moment. 
     The take-home message is that it's not enough to have some empirical observations--those observations must be evidently pertinent to the overall argument. In this case, the observations themselves don't stand on their own. Instead of being as straightforward as deciding whether one is observing a 1 or a 2, the authors must rely on argument to the effect that it's a 2 because it's probably something like the material that those other 2s are made of. 
     Thus, today's archaeological inference is based on an empirical observation that's argued to be evidence of a phenomenon that the authors argue is the same material that they're familiar with from another archaeological context in which similar arguments were made about similar stuff. *out of breath* Confusing? Try being a referee for this stuff. It's hurts my brain, and perhaps more than anything explains why some stuff gets published that should probably never have seen the light of day. Never mind. On with the show!


Pawlik and Thissen (2011) claim to have evidence that the mid-to-late Pleistocene inhabitants of Germany used a very sophisticated, dry-distillation process to make a tar from the bark of birch trees, which they used as a mastic to haft stone to some other material, in this case, presumably, wood, bone, or antler. This is a technology not seen again until it's development by the much-later Mesolithic and Neolithic inhabitants of Europe, as well as the inhabitants of the vast birch forests of ancient North America (think Hiawatha). If Pawlik and Thissen's claim were to stand, it would be a HUGE boost for the Neanderthals R Us crowd. Not only would it imply that our congeneric relatives were making what are called 'composite tools,' but also that they were waaayyyy ahead of their time. Kudos to Pawlik and Thissen! Huzzah for the Neanderthals! Uh. Not so fast. Unfortunately for the authors, the evidence presented is insufficient to support their rather extraordinary claim. Have a look at some of the artifacts. 

Pay particular attention to the lump at the bottom. Does it look to you as if it was almost covered, on both faces, by whatever substance it is that the authors claim to have identified. (From Pawlik and Thissen 2011) 

Pawlik and Thissen have identified the residue on these artifacts to be that of birch tar. If you put a bunch of birch bark in a sealed container and subject it to high heat for a good, long time, the bark will be reduced to a tar (a process called dry distillation). Birch tar is compounded of guaiacol, phenols, cresol, xylenol, and creosol. These are aromatic organic compounds comprised primarily of Carbon (C), Oxygen (O), and Hydrogen (H).
    Pawlik and Thissen argue that the dark material coating some of the artifacts from Inden-Altdorf (in Germany, near Bonn) base their interpretation on the following data. First, they looked at the residue under a stereo microscope. They report observing a 

'dried dark brownish black viscous liquid with micro-hairline cracks in the surface can be seen. It possesses a strong similarity to the birch pitch residues identified on Neolithic tools from the lake dwelling site Burgäschisee-Süd, Switzerland and implements from the Mesolithic sites of Henauhof-Nord, Germany'. 

So, under a stereo microscope it's VISUALLY similar. See for yourself what they saw under low-power magnification.

 Most archaeologists worth their salt would instantly recognize this as some kind of organic patina or residue. (From Pawlik and Thissen 2011.) 

Then the samples were examined using a scanning electron microscope (SEM): 

'SEM showed layers of molten plant tissue frazzles and fibres in an amorphous matrix of solidified pitch, thus indicating the vegetable origin of the residues [emphasis added].

So, with no other empirical evidence presented, it's gone from 'looks like it' to 'Hey, it's pitch.' On to the Electron Dispersive X-ray (EDX) examination. The data are reproduced below.

From Pawlik and Thissen (2011).

The spectra from Inden-Altdorf are d and e. Those from the later Stone Age of Europe are given in f and g. An experiment to make birch tar produced spectrum h. In support of their extraordinary claim, Pawlik and Thissen say only the following by way of interpretation.

'The spectrum of elements acquired from several residue samples shows a significant peak for carbon, verifying the organic nature of the samples.' 

So, it's organic. Any archaeologist would have suspected as much at the outset. There's also a lot of oxygen. Same result. Where's the hydrogen? It's too light to disperse the X-rays, so it doesn't show up on the spectrum. But, believe me, it's there. They go on to say only this: 

'More significant is the presence of Ca, K and S. Their traces are shown in considerable quantities as well in the EDX histograms of birch pitch [sic] found on artefacts from the Neolithic site Burgäschisee-Süd and the Mesolithic site of Henauhof-Nord II... .' 

End of story. Not quite. I didn't see much in the way of a pattern match across the four spectra shown in d through g. 
     I thought I might be confused by the different size of the X-axis scales. So, I've aligned the four spectra and adjusted the image sizes so that the scales are all the same on the x-axis. Have a look now.

The spectrographic evidence. Click to enlarge. Key to elements observer: Carbon (C), oxygen (O), Silicon (Si), calcium (Ca), Manganese (Mn), Magnesium (M), Sulphur (S), Iron (Fe), Potassium (K), Sodium (Na) (after Pawlik and Thissen 2011).

All four have, to varying degrees, big C and O peaks. That's a no-brainer, since we're dealing with organic compounds. Because of the ubiquity of C and O in organic compounds of all kinds, you can effectively ignore those two elements in your search for a signature for birch tar. That leaves us with the rest. Looking at the rest, we see peaks of Si in all four. Over 90% of the Earth's crust is composed of silicate minerals, making silicon the second most abundant element in the earth's crust (about 28% by mass) after oxygen. Thus, I would expect to see a peak of Si in any sample taken from the earth's crust, whether it included organic molecules or not. I think you can see where I'm going with this. The authors mention, especially, the co-occurrence of calcium, sulphur and potassium in the Inden-Altdorf spectra, and say that they are in that respect similar to the later examples (f and g). But they ignore manganese, which occurs in the Inden-Altdorf samples, but not in the spectra from later times. 

     So, the question becomes 'Which elements are indicative of birch tar, and which aren't?' The authors are silent on that matter, and thus we are faced with taking their word for it that the four spectra are evidence of the same material. I find that a bit hard to swallow. Call me a skeptic. Call me a pedant. But don't call me a fool. Each of the four chemical signatures are unique, and contain unique occurrences of elements not shared with the other three. To me that means they're similar, but not identical. And we're no closer to understanding their similarities and differences than we were when we were looking at the artifacts macroscopically.
     To me, this doesn't look like conclusive proof of anything other than that these four samples are organic in nature, and derive from the lithosphere. If these were fingerprints, they wouldn't hold up in court. If they were DNA comparisons, OJ goes free again! 
     I wonder why the archaeologists didn't, at that point, proceed to a true chemical characterization of the substance, rather than relying on the results of a minimal spectroscopic study. Only they know the reason. But there are ways to chemically characterize such substances in a more thorough manner--one that might be considered more conclusive. And whaddayaknow. Someone recently characterized birch tar. From a 2011 article in Journal of Analytical and Applied Pyrolysis comes 'Analytical pyrolysis with in situ thermally assisted derivatisation, Py(HMDS)-GC/MS, for the chemical characterization of archaeological birch bark tar,' by Ribechini, Bacchiocchi, Deviese, and Colombini. 
      They report on birch tar produced for a comparison with material from ancient Greece and Rome. Their chemical characterization of birch tar was (ow to poot eet?) a smidgeon more specific than that presented by Pawlik and Thissen. For example, instead of finding the elemental constituents of carbon and oxygen, Ribechini et al were able to identify the very organic molecules that comprise birch tar. See for yourself. This is a list of the compounds they identified.

From Ribechini et al. 2011

Fairly specific, you'd have to say. And not an inorganic molecule among 'em. Moreover, not a single K, Ca, Mn, Mg, or S, if I'm not mistaken.
     Next, the relative proportions of those 70 compounds. First, the reference birch tar. Below that, the chemical characterizations from ancient Greece and Rome. In this illustration, once again, I've compiled two figures and changed the relative sizes, so as to line up the X-axis at the same scale.

From Ribechini et al. 2011

The upper part is the reference sample; the lower, double graph, is the story from the ancient Mediterranean. I see a very strong similarity. And the similarity is borne out after closer scrutiny. Relative abundance of inorganic elements, which is the basis of Pawlik and Thissen's thesis, pales by comparison with a real chemical analysis. Perhaps we'll see such an analysis in the near future. But I doubt it. P and T got their thesis published, and now they can hang back and watch the Neanderthals R Us crowd adore them for it.
     I'm not a chemist. But I see a far better match among Ribechini et al.'s three chemical characterizations than the four EDX spectra that Pawlik and Thissen provide as the basis for their conclusions. At least Ribechini et al. are comparing the reference sample with the subject samples in a more refined manner than Pawlik and Thissen employed. Am I wrong in being skeptical of Pawlik's conclusions? If I am, I should get out of the science business, 'cause Pawlik and Thissen's article sure doesn't look like science to me. More like wishful thinking on their part. 

Working.....

Even though I'm not finished with Neanderthal DNA and interbreeding, I thought I'd spread myself even thinner by looking into the claims for hafting using Birch tar in the Middle Palaeolithic. At the moment it's not looking good for the very recent claims coming from Inden-Altorf in Germany. Those from Campitello Quarry in Italy and Konigsau in Germany will be next on the list. 

     You see, I can't help being just as skeptical of the idea that Neanderthals were capable of dry-distilling birch bark as I ever was about purposeful burial, and twice as skeptical that they were hafting their lithic artifacts as I have always been that they would not be the sort of individuals you or I would want to date. 

I'm also working on a paean to the shovel-bum, the heart and sole of CRM in North America.

Hoping to roll them out in the next few days. It might require silent running for a day or so. Don't worry! I'll let you know when I return.

I've, sadly, had to shelve the Neanderthal face for the time being. I'm having trouble getting the information that I need to advance my thesis.

Finally, I have plans for another word painting. Here's a hint. What do Merritt Lake (near Elkhorn Slough on Monterey Bay), relic shellcrust sequences from eastern Australia, and California archaeology have in common? Definitely a golden Marshalltown if you can figure that one out! [Spawn of Endra is disqualified from this competition]

Thanks for dropping in. Don't forget. Penny in a mug! 

Touchstone Thursday: Horace Miner's Body Ritual among the Nacirema

American Anthropologist 58:503-507, June 1956

As many of you are aware, the majority of academic archaeologists in North America receive training in three other fields of knowledge, the anthropologies--sociocultural, linguistic, and physical (or biological). It's a sad truth that most who become archaeologists (and physical anthropologists), while cognizant of the necessity of the culture concept to what we do, are equally aware that there is in some university departments little love lost between the sociocultural anthropologists and us archaeologists.

     When I took my first course in cultural anthropology, I was just out of high school, and, growing up, the closest I'd come to anthropology was the National Geographic and Social Studies classes. I remember being taken aback when the scope of anthropology was revealed to me for the first time. One of the facets of our discipline that fascinated me early on was ethnography, which in those days still meant tales of exotic people doing all sorts of things that seemed strange to a young man from the suburbs of Vancouver. 

     I also remember, vividly, learning the concept of ethnocentrism, and how un-anthropological it was to practice that particular 'ism', regardless of how bizarre the behaviour of people in other cultures may have seemed to me. Today's touchstone drove home the point in a very memorable way. Horace Miner's 'Body Ritual Among the Nacirema', while essentially a summary of extensive participant observation on Miner's part, conveys some of the mystery and 'otherness' that it is (or was) anthropology's stock in trade.

     If you haven't encountered it before now, I suggest you read it to your children, rather than closeting yourself in your study. It's a fascinating narrative dealing with an even more fascinating subject.

Frustrated? Me, Too!

In February 2012 I violated the 'if it ain't broke don't fix it' law. I installed what I thought was going to be a superior commenting system to take the place of the one that was integrated with blogger, the 'engine' I use to create the Subversive Archaeologist. Unfortunately it didn't work very well. So, I tried going back to the original system, and I failed miserably. 
    Here, I reproduce those comments that were lost in the shuffle, in hope that it'll in some way make up for the screw-up. In reverse chronological order.

My response to Stan would be...they look like cores on elongated, tabular raw material. Best to let the authors do the talking, illustratively speaking. I know I'm not a flint-knapper. But jeebuz criminy, if these are prepared blade cores, I'm ... well... I'm a dirty rascal!

They call this a blade core. Hmmm. 

If you or any other rock-knockers can see any way that this is evidence for a blade-production industry, I'm gonna give up my Ph.D.!