[Aztlan] Plaster & "Progress"

[Bradley Russell]

To return to the original post in this discussion:
Bruce Dahlin and I recently published an article entitled Traditional Burnt-Lime Production at Mayapan, Mexico in the Winter 2007 (Vol. 32, Number 4) issue of Journal of Field Archaeology which contains much information related to the questions asked in this post.  We undertook a study of lime production after I documented seven large lime burn sites outside of the city wall on the west side of the city.  More information on that discovery can be found in my recently completed doctoral dissertation which can be downloaded from http://mayapanperiphery.net/.
 
Sadly, the lack of burn sites thus far recorded has left this important industry largely overlooked in favor of other productive activities with a more obvious archaeological signature.
 
We conducted an experimental lime kiln (calera) burn at Mayapan several years ago to determine the material investments, labor investments and likely archaeological signature for ancient lime production.  The calera was constructed in the traditional manner by three local informants with experience in the techniques that were used very commonly before the advent of modern industrial production.  The numbers derived were then compared to estimated lime usage at Mayapan, population 17,000 at its peak, to determine how large the industry and its environmental impact would have been.  
 
In summary, we found that Mayapan would have been using 2184 cu m of lime for both construction and maize soaking in an average year.  This amounts to 78,624 person hours of labor a year or the input of more than 200 people eight hours a day every day of the year.  It is likely that lime production was seasonal, taking place during the rainy season when water used in slaking the quicklime would have been readily available.  Thus more than 400 people would have been involved full time for roughly half of the year.  
 
In terms of raw materials utilized in its production we found the amount of wood needed to be "high but sustainable".  Based on our data, Mayapan's residents would have been burning roughly 4 sq km of wood for lime production in an average year.  Assuming that wood resources would have been relatively scarce inside the city itself, lime production would have been largely restricted to peripheral locations (IMO the main reason that burn sites have been extremely under-documented and the industry poorly understood).  
 
While 4 sq km seems like a very large amount, you must consider the the type of wood being used.  We found that secondary growth woods roughly (25 years old) were preferred based on their diameter and burn characteristics.  This links lime production strongly with the practice of slash and burn agriculture as the rotatation of fields likely would have provided much of the wood being burned.  So, assuming a 25 year fallow period for any area yielding fuel, some 100 sq km of area would have been in some phase of the cleared/regrowing cycle.  Some 4 km of that being used in any given year and most in various stages of regrowth.  
 
That being the case the area within 5 km of the site limits would have been able to provide a sustainable harvesting area.  Rather than a situation where 4 sq km was added to the denuded landscape every year in a cumulative process that would eventually strip available fuel entirely overtime in an expanding radius, the needed wood would have been found in a restricted area that did not continue to grow with each passing year.  Of course the area involved would vary from site to site depending on population and intensity of use of the material.  
 
In short, unless the practice so depleted the soils of nutrients that these numbers would change over time, I do not believe that lime production at the site would have caused the kind of denuding of the forests that would prompt site abandonment.
 
Much more work on the nature of the lime industry is badly needed if we are going to fully understand its economic and environmental significance.  More peripheral survey work at major sites would almost certainly turn up many more burn sites than have been documented to date.  
 
BTW - Having worked at Mayapan with Marilyn Masson since 2001, I am in complete agreement with Sabloff and Rathje on this issue.  The Postclassic has been badly misunderstood for decades. Fortunately, that is finally beginning to change.
 
Thanks for the question Sam.  My apologies for not responding sooner. I have been in the field and out of touch with my e-mail.
 
Bradley Russell
SUNY - Albany
 > Date: Mon, 18 Aug 2008 14:59:42 -0400> To: aztlan at lists.famsi.org> From: Samuel.Y.Edgerton at williams.edu> Subject: [Aztlan] Plaster & "Progress"> > Listeros: I have just read an article by Jeremy Sabloff (in cooperation > with William L. Rathje) published a year ago in the Proceedings of the > American Philosophical Society, Philadelphia (151.1, March 2007, pp. 11-27) > which, in spite of its unwieldy title ("It Depends on How We Look at > Things: New Perspectives on the Post-Classic Period in the Northern Maya > Lowlands"), has provoked me to ask some questions about plaster - that most > common-place and taken-for-granted bonding material used everywhere in > ancient Mexico and Central America by Maya builders and sculptors.> Actually, the gist of Sabloff's piece has to do with his and Rathje's > argument that traditional assessment of Post-Classic Maya society as > "decadent" is wrong; that in fact Post-Classic society, especially in the > northern lowlands, was even more prosperous materially than the Classic. > The difference should rather be understood as a contrast between a society > dependent on religious ideology for its well-being, and a society more > dependent on secular economics. While Classic peoples spent more time > propitiating the spiritual forces with elegantly decorated temples, > Post-Classic folks were less attentive to art and architecture while more > concerned with the mundane business of trade and commerce.> The author's prime example is Mayapan, the powerful political hub of Post > Classic Yucatan, but at the same time artistically impoverished. Many of > its buildings are poorly constructed with mis-matched stonework masked by a > veneer of smoothing plaster. Indeed, plaster seems to have been similarly > employed in other Post-Classic sites like Tulum and Dzibalchaltun. This > "decadent" practice is excused, however, by an interesting comparison to > modern building methods in the technically progressive US where cheap > concrete is likewise used to put a smooth face on skeletal internal > construction - suggesting that the Post-Classic Maya were resorting to the > same labor-saving technique signifying their increased attention to > material prosperity.> Nevertheless, even the Classic Maya were massive users of plaster, > particularly for paving their extensive public plazas. The site of Cuello > in Belize for instance boasted a plaster covered plaza more than a meter > thick, indicating that it was paved and repaved continually for > centuries. Eliot Abrams in a paper on "architectural energetics" delivered > during the 1994 DO Conference, estimated that 90% of all Maya structural > labor was spent of preparing and applying plaster.> Might one dare assume therefore that plaster work was not only the major > non-agricultural occupation of the Maya laboring classes, but plaster > itself was the major manufactured product of the entire Maya economy?> Furthermore, wasn't plaster even more important than stone to the Maya > sculptor's art? Indigenous artists learned early how to mold plaster to > stone armatures, permitting them to realize extraordinary imagery, in both > high and low relief, on architectural surfaces, indeed to cover entire > temples in plaster relief like the Rosalila in Copan. Merle Greene > Robertson discovered that the once colored plaster figures in relief on the > Palenque Temple of Inscriptions were painted not only on the visible > outside but also fully on the inner surface, the side buried in the temple > wall never to seen by living human eyes.> Does this not imply that humble plaster (as we consider it today) had for > the Maya a much higher, even sacred quality - like jade when worked into > attractive forms - and was so appreciated by the gods?> And finally, did not this endless obsession for plaster bear some of the > blame for the so-called Maya collapse? Would not the constant need for > firewood with which to burn limestone have eventually denuded the forests > surrounding Maya ceremonial centers, thus giving the inhabitants good > reason to abandon these sites for new places with a greater supply of > near-by firewood?> Sam Edgerton > > _______________________________________________> Aztlan mailing list> http://www.famsi.org/mailman/listinfo/aztlan> Click here to post a message Aztlan at lists.famsi.org> Click to view Calendar of Events http://research.famsi.org/events/events.php> > 
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