The Acheulean in Arizona: More Bizarre News From the Dark Side of Archaeology

It really doesn’t get any better than this. And mind, I wouldn’t normally expend much energy dispelling incipient myths like this one, were it not that in this case there’s a real danger of it sprouting legs and moving under its own power thanks to a daft academic archaeologist in Boston.

We won’t be so crass as to point out the misspellings, 
erroneous capitalization and poor punctuation. Will we?

My dad used to say ‘A little knowledge is a dangerous thing.’ The only serious danger in the field of archaeology [aside from liver disease and arthritic knees] is that a patently false claim–however well-intentioned–becomes received knowledge. In other words, an erroneous claim that becomes an archaeological myth. In this instance, the danger to archaeology is being multiplied by a gullible Phoenix media hungry for an interesting story and, in an unusual turn of events, a truly credulous and misinformed ‘professional’ archaeologist, Curtis Runnells, from Boston University.

A putative Acheulean site in Pheonix, Arizona (Photo credit)

      The story goes like this. Mr. Ken Stanton, Amateur Archaeologist, thinks he’s found an Acheulean archaeological site. The Acheulean, previously known only from Europe, Africa and southern Asia began about 1.5 Ma. This isn’t the first time that such objects have come to light in the southwestern United States. Indeed, the Arizona story is virtually identical to that of the Calico Hills site, famed for having fooled Louis B. Leakey into thinking that Homo erectus had somehow made it to the Americas in the Early to Middle Pleistocene. His attention was drawn to the site  in the late 1950s after broken rocks similar to those Mr. Stanton has lately found compelled archaeologist Ruth DeEtte Simpson to announce her interpretation–that the site contained very old, very crude, stone tools like those that had been known in Europe and Africa for nearly a century. The Calico Hills’ proponents are still making those same claims fifty years on, even though they’ve been thoroughly and rigorously refuted by archaeologists who know a great deal about the geological processes and their expectable outcomes in the production of a desert alluvial fan–C. Vance Haynes, for one.

Ruth ‘Dee’ Simpson and L.S.B. Leakey at the Calico Hills Early Man site.
(Photo credit)

     But what are the claims, Rob? We wanna see!
Behold and be dismayed. First, photos of Stanton’s finds and a cross-section of the sedimentary context, all kindly provided by Mr. Stanton, himself.

An amorphous lump of 
angular vein quartz
A pointy lump of angular vein quartz.

A tiny piece of angular quartz

As one can plainly see from these illustrations, this is vein quartz, which while being very hard, is also quite brittle. And, while some forms of quartz fracture conchoidally, this type does not. Its material nature aside, the geological context is most important in this instance. That these artifacts are found in a desert alluvial fan should be a red flag for any archaeologist, especially one who’s geomorphologically aware or is in fact a geoarchaeologist. Alluvial fans develops as a result of the intense, but infrequent, rainstorms that are characteristic of desert climates. The rain falls upslope and quickly entrains every loose bit of rock and dirt that has, through colluvial action, come to rest in the dry course of the newly active ephemeral stream since its last activation. Depending on the energy level of the flow and the nature of the rock being carried along, the overall result is what you see in the profile below.

A cut through the alluvial fan, with quartz geofact visible in the centre.

This high-energy alluvial phenomenon is more appropriately called a debris flow, rather than an ephemeral stream, because the water represents just one component of the stream, the majority consists of sedimentary clasts of various sizes that collide forcefully with one another to produce what in some cases may be seen to resemble chipped stone artifacts that humans or human ancestors have made. This kind of object is called a geofact because it was created by geological processes, but nonetheless fools a naive observer because they appear to have been chipped in a manner that broadly resembles early hominin stone technology. And Rule #1 states that if something that you think is made by people, but that could just as well be made by other natural processes, you can not give priority to people, but must instead show cause as to why we should think anything other than that these are geofacts! 

     The kind of deposit shown in the profile is a diamicton–comprising an unsorted (or at best poorly sorted) mélange of newly angular bits of rock as well as sand, silt and clay, not all of which are clast supported. Such deposits are very UNlike the ones that a permanent stream produces in its path. In the Arizona case the quartz stands out from the rest of the material in the fan because it happens to be of a type that’s analogous to that of the finer-grained rock that makes good stone artifacts. I wonder how many bits of vein quartz Mr Stanton passed up because they didn’t look like ‘good’ artifacts!
     Aside from the attention that Stanton’s claims received in the Phoenix media, news of his ‘discovery’ reached an academic archaeologist who is, unfortunately, credulous and is giving these naturally broken rocks more attention than they warrant. The following three passages are messages that archaeologist Dr. Curtis Runnels of Boston University has sent to Mr. Stanton, which have given the Arizona man no reason to suspect that his claims are theoretically unsound.

 These are extremely interesting artifacts and the context is very interesting too. I am not an expert in Arizona desert geology, but the the [sic] deposit looks like a cemented debris flow or perhaps a lake-margin deposit. It could very well be Pleistocene in age. It should certainly be possible to date that context if you can get a knowledgeable regional geologist to look it over; for instance by a technique like Infrared Stimulated Optical Luminescence on the sand grains I can see in the surround [sic] matrix.

We can only guess about the nature of Pleistocene humans: our own species, Homo sapiens, is dated securely at sites like Herto (Ethiopia) to 200,000 years ago and would certainly be a candidate, as well as Homo heidelbergensis (a hominin grade that dates to ca. 400,000 years ago). Without fossils there is no way to tell because these kinds of tools were probably made by more than one hominin grade, perhaps by as many as four or five! 

My summary is that you have early looking artifacts in a definite geologic context that might help pin down their age.


Dear KC,

Thank you for showing me the photographs of the lithic artifacts and their findspot from the site that you have discovered near Phoenix.

My specialty is the Palaeolithic of the Old World in the eastern Mediterranean and SE Europe, and not the American SW, but the artifacts that you have shown me would be considered as Lower or Middle Palaeolithic if they were foud [sic] in my area.

They are definitely artifacts [emphasis added], and the typological and technical characteristics that I see in the photographs are consistent with their identification with Pleistocene industries (modes or technocomplexes).  Similar artifacts are widely distributed in the Old World, and have been reported also in the United States over the past century or so. Unfortunately they are rather hard to date: in the Old World such industries have a wide chronological span, ranging from 1.6 myr to ca. 0.175 myr (and some similar forms occur in the Middle Palaeolithic or Middle Stone Age in Europe and Africa much later, down to ca. 50 kyr). Therefore, it is of particular importance that your finds appear to be in a datable geologic context. The photographs you showed me appear to show artifacts in situ (geologically speaking) in a cemented breccia or debris flow. This suggests two things to my mind. The original sites, in the sense of living floors or occupation areas, have no doubt been destroyed by erosion and the artifacts have been redeposited downslope.  Dating the breccia/debris flow would, therefore, give a minimum age for the artifacts, but that would be an important start. My geological training is in the Mediterranean in regions (e.g. Greece, Albania, and Turkey) with similar arid conditions to the American SW, and from what I can see in your photographs I would consider the artifact-bearing deposit to have considerable age, probably Pleistocene.

A more precise estimate In short, I would accept as a working hypothesis to be tested by further research in the field that these artifacts are of Pleistocene age and likely to pre-date, perhaps by a considerable margin, the earliest accepted industries such as Clovis and Folsom in the SWof their age or the affinities with other industries would not be possible at this stage of research.

Good luck! Sincerely yours, Curtis

Curtis Runnels, MA, PhD, FSA, Professor of Archaeology, Archaeology Department, Boston University, 675 Commonwealth Avenue, Boston MA 02215

Editor, Journal of Field Archaeology

and later on

Here is a longer message than I could manage yesterday on my phone in the train. No need to send me the Washington Artifacts; let’s not risk getting them lost in the mail. I want to concentrate on the Arizona stuff for the moment. My plan is to discuss the artifacts you already sent me with a geoarchaeologist who is familiar with Arizona geology and get his opinion on the context.

My other plan is to write an essay in the Journal of Field Archaeology as Editor-in-Chief (co authored with my contributing editor Professor Norman Hammond, who is also the Archaeology Correspondent for theTimes of London and the editor of the Times Literary Supplement). He is a New World specialist and we have already talked about how the Pre-Clovis picture is becoming clearer. We will call for a total reexamination of the old sites (e.g., George Carter’s Texas Street Site and Calico among others) and a new open minded approach to the Pre-Clovis question and invite contributions of manuscripts on the subject for publication. I think the timing is right. The Stanford and Bradley book, Across Atlantic Ice, will be published in January and in it they make their case for the movement of Solutrean people by boat across the Atlantic in the Palaeolithic to the east coast. If one group of Palaeoliths could make the trip, then anything is possible and a complete restudy of the archaeological record is warranted.

All this takes time and don’t worry about your priority (i.e. credit for your discovery). I have the evidence before me that you found this stuff first and am willing to say so whenever and wherever necessary.

Best wishes,


I ask you, ‘How lame can this guy Runnels be?’ He recognizes that this is a debris flow, but somehow fails to make the connection between the nature of an active debris flow and the concomitant and expectable damage to, in this case, vein quartz. I will be very surprised if, when Runnels approaches the ‘geoarchaeologist who is familiar with Arizona geology’ he is told anything other than that these are perfectly good geofacts and not, as Runnels proclaims, ‘definitely artifacts.’ [By the way, I’m guessing that the above-mentioned geoarchaeologist is none other than Paul Goldberg, whose academic appointment is also at BU. Paulie, you still haven’t responded to my Wonderwerk Cave take-down. Clock’s ticking…]
     Nitey, nite!

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Prometheus Unfounded: Contradictions and Conundrums at Wonderwerk Cave

Wonderwerk Cave profile (Photo by M. Chazan)

I’ve previously opined on aspects of the claim for very early fire use at Wonderwerk Cave, South Africa here, here, here, and here. In brief, it’s Swiss cheese. Today I’m beginning to look at Peter Beaumont’s 2011 synthesis of the ‘evidence’ for hearths in the cave, published in Current Anthropology. Forgive me if this comes across as unusually pedantic–I find the author’s descriptions to be less-than rigorously scientific, and thus less-than helpful if one’s hoping to cast a critical eye on what amounts to his life’s work. I’ve found it all very difficult to wrap my brain around. See what you think.   
     Beaumont begins his discussion of what he calls ‘hearths’ by mentioning that in places he observed ‘poorly defined ash lenses’ and in other places ‘ash-rich’ deposits, which he thought had been ‘single hearths … largely destroyed (perhaps by trampling).’ It’s unfortunate that there could be so much ambiguity entailed in such a short paragraph.
     First of all, what really is the difference between a ‘poorly defined lens’ and an ‘ash-rich deposit’? Aren’t they both ‘ash rich’ if you can recognize the ash in profile? And what about the other sequelae of burning, charcoal and the reddened substrate. I would have expected any fire that could turn plant fuel to ash would have been sufficiently hot and of such a duration that it would also have reddened the sediments beneath the fire. Moreover, in many cases where reddened sediments and ash are visible in a stratigraphic sequence there is a higher than average chance that there will be a layer of charcoal-enriched or blackened sediment between the reddened substrate and the ash. Trampled or not, Beaumont’s inference that these ash lenses were hearths is hardly to be believed on the face of it.
     Presumably Beaumont wants us to believe that, in the case of the ‘ash-rich’ places, any vertical distinction that at one time would have been evident between the ash and the reddened sediments had been obliterated by treadage. Yet, if that were the case, how is it that he’s able to discern anything that might be called discrete (albeit poorly defined) ash lenses? For Beaumont to be able to observe ‘lenses’ comprising ash, those lenses must have escaped, in large part, the destructive results of trampling. And surely, if the ash ‘lenses’ had escaped the ravages of time and trampling such that they were visible in profile, the underlying reddened sediments would also have retained enough integrity to be visible, too! Yet, the author mentions nothing about the substrate, reddened or otherwise. Odd. On the other hand, one has to agree that in all likelihood it was trampling that transformed what had once been intact ash deposits elsewhere in the cave into something the author calls (merely) ‘ash-rich.’

[My recognizing problems with Beaumont’s after-the-fact verbal descriptions doesn’t ensure that the his inferences are incorrect. However, one does have to wonder. Doesn’t one? One would have thought that a perspicacious referee or editor would have noticed these vague and incongruous descriptions. Wouldn’t one?] 

     Alas, the abovementioned ‘hearths’ aren’t the only curiosities to be found in Beaumont’s treatment of putative fire use at 1+ Ma. In another example he describes stratum MU2, in excavation 5, where as much as 45 cm (!) of the stratigraphic column ‘is very largely composed of white ash with many burned bones and fire-damaged Middle Stone Age artifacts.’ This ash apparently ‘accumulated slowly’ and continuously between about 1,155,000 and about 70,000 years ago. [Get out your calculators!] 
     Depending on what Beaumont means by ‘very largely composed of’ [and it’s not at all clear], it sounds as if he’s suggesting that for 1,085,000 years a very wide area of the cave received little other sedimentary input than that of completely combusted plant material. That’s a prodigiously long time for a single depositional process to have endured, and a phenomenally long time for a large surface comprising a substance as mobile as ash to have survived without either blowing away or being adulterated by larger [especially inorganic], autochthonous clastic input. 
     Even more mysterious: Beaumont claims that the ash was the result of thousands of fires fueled by above 15 tons of fuel. It’s really hard for me to imagine that such a focus of hominid activity could have escaped the inevitable, and destructive, treadage that would have accompanied that use of that part of the cave for what amounts to a single activity–that of making and keeping fire–over such a vast expanse of time. I suppose it’s not impossible. But, probable? I really don’t think so. Plausible? Barely.
     Beaumont’s description of MU 2 in excavation 5 just makes no sense. If his account of its clastic composition is accurate, nothing but a long-lived colony of fire-loving faeries could have produced it! There must be alternative explanations. And, indeed there are, provided by an unlikely source–the latter-day excavators of Wonderwerk Cave, the very ones who have recently reprised Beaumont’s long-standing claim of fire use by Acheulean hominids.
     Here’s what Matmon, Chazan, Porat and Horwitz conclude in ‘Reconstructing the history of sediment deposition in caves: A case study from Wonderwerk Cave, South Africa‘ published in the Geological Society of America Bulletin (First published online October 14, 2011, doi: 10.1130/​B30410.1).

The cave sediments comprise a sequence of fine sands and silts that were transported naturally by wind to the environs of the cave and later into the cave by water. Transport within the cave occurred by low-energy water sheetflow, which distributed and deposited the sediment in its final location. Field observations and grain-size distribution analysis of the sediments inside and outside of the cave imply the following sediment transport scenario: eolian transport of Kalahari sand to the Kuruman Hills, slope wash of the eolian sediment into the intermontane valleys, fluvial transport of the sediment from the intermontane valleys to the entrance of the cave, and final deposition of the sediment inside the cave by low-energy water action.

 These are the verbatim conclusions. Unfortunately for the authors, this sequence of transport processes leading to the input of allochthonous sands and silts at Wonderwerk Cave can equally explain the presence of anything that would be as easily transported as sands and silts. Indeed, anything lighter than fine sand–if it shows up at the doorstep–would have been subsequently transported into the cave by sheetwash. Sheesh! They’ve done my work for me! 
     Their conclusions also solve a riddle that I found while wandering through the images from Wonderwerk. This one shows non-conformable and curiously wavy strata. I’ve drawn yellow rectangles where I see evidence of what appear to be erosional events overlain by non-conformable strata. These observations support the conclusions of Matmon et al. It appears that there have been numerous erosional episodes during the build-up of sediments in Wonderwerk Cave. The wavy contacts suggest an agent even more energetic than sheetwash. If these observations are borne out it’s clear that at times the input of material and liquid from outside the cave was considerable.     

After Berna et al. 2011

Make of it what you will. 
     Beaumont describes ‘grass mats’ in various stages of combustion that occur here and there in the cave. Regardless of how they arrived at the cave’s doorstep, in they went–wind-whipped dry grass, partly combusted grass, grass ash [try saying that five times really fast without saying something unfit for polite company], small bits of burned bone made as light as fine sand by partial combustion. You name it! Matmon et al.’s conclusion opens the door to serious questioning of Wonderwerk’s depositional history. How can they claim, unequivocally, that any wind-transportable allochthonous sediments came to rest in the cave by the hands of hominids?
     Seriously! They are way past the bounds of logical inference when they claim that any of the tiny particles that Berna et al. describe in exquisite micromorphological detail were left there as a result of hominid behaviour. Somebody’s gotta tell them. I’m trying me best. But they appear not to be listening.
     So, get out there to the meetings and to your classrooms and call out the litany of overwrought inferences of hominid behaviour that keep emanating from Wonderwerk Cave!     

One thing’s for sure: the excavations at Wonderwerk Cave are looking more and more like job security for this Subversive Archaeologist.

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