Science in Archaeology: a Review Author(S): Patrick E

Home , Achziv, Aerial archaeology, Archaeometallurgy, Ein Karem, Natural (archaeology), Willem van Zeist

Science in Archaeology: A Review Author(s): Patrick E. McGovern, Thomas L. Sever, J. Wilson Myers, Eleanor Emlen Myers, Bruce Bevan, Naomi F. Miller, S. Bottema, Hitomi Hongo, Richard H. Meadow, Peter Ian Kuniholm, S. G. E. Bowman, M. N. Leese, R. E. M. Hedges, Frederick R. Matson, Ian C. Freestone, Sarah J. Vaughan, Julian Henderson, Pamela B. Vandiver, Charles S. Tumosa, Curt W. Beck, Patricia Smith, A. M. Child, A. M. Pollard, Ingolf Thuesen, Catherine Sease Source: American Journal of Archaeology, Vol. 99, No. 1 (Jan., 1995), pp. 79-142 Published by: Archaeological Institute of America Stable URL: http://www.jstor.org/stable/506880 Accessed: 16/07/2009 14:57

Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use.

Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=aia.

Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission.

JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected].

Archaeological Institute of America is collaborating with JSTOR to digitize, preserve and extend access to American Journal of Archaeology.

http://www.jstor.org Science in Archaeology: A Review PATRICK E. McGOVERN

The inaugural appearance of yet another "news- ometry" had no precise definition (it has yet to be letter" of recent archaeological discoveries, reflect- made an entry in Webster's or the Oxford unabridged ing AJA's historic and ongoing commitment to such dictionary), and that it was too narrowly focused on reviews, is both auspicious and somewhat daunting.' the physical sciences and connoted too great a con- Late 20th-century science-here viewed in its more cern for precise measurements ("-metry"). Archae- narrow sense as the natural sciences-is now mak- ologists might justifiably claim that their measure- ing its share of discoveries in Old World archaeol- ments, if not so precise, are at least better suited to ogy, a field that some consider a rather esoteric pur- cultural interpretation and broader issues of why suit, divorced from the modern world. A review of things developed the way they did, how these devel- this kind might then simply be seen as a long-overdue opments are expressed in the modern world, and response to our headlong plunge into a technolog- whether any predictive value can be attached to such ical present and future. Computers and other "black findings. boxes" are no longer just the province of a few sci- The phrase "archaeological science" has fared entific wizards, but are now part of everyone's life, somewhat better,4 but raises the hackles of both including the archaeologist's, whether we like it or archaeologists (archaeology itself being viewed by not and whether it produces worthwhile results in many as a social science) and natural scientists, who our research or not. Since there is no turning back, do not view this as a well-developed discipline. Since we all need advice on how best to cope with this revo- "Science and Archaeology" is a similarly infelicitous lution and perhaps even come to enjoy it a little more. juxtaposition, I have settled on "Science in Archaeol- Such a review can be as daunting to its author as ogy" as the title for this review. This phrase implies to its readers. How does one launch an endeavor that that science of whatever variety (social, biological, has few if any precedents,2 and which even its prac- physical, etc.) has found its way into archaeology, and titioners cannot decide among themselves what to it is for us to decide whether it is producing worth- call? A roundtable discussion on "Future Directions while results. in Archaeometry,"3 held in conjunction with the This review is not intended, however, to cover every 1981 Archaeometry symposium at Brookhaven Na- scientific approach or application in archaeology, tional Laboratory, highlighted the fact that "archae- but rather, to present a selected range of viewpoints

1 Publication of this review has been made possible in of some of the latest developments is the "Archaeometric part by a generous subvention from the Frederick R. and Clearinghouse"inJFA. C.W. Beck, who assiduously saw this B. Margaret Matson Fund, established specifically to en- review through 26 installments, retired last year, and the courage publication of technological studies in AJA.Fred S. editorial reins have now been passed to J. Henderson of Kleiner and Frederick R. Matson are to be especially Sheffield University.More specialized newslettersare also thanked for first proposing the idea of such a review to published on a regular basis-e.g., La Tinaja,which deals and me, then helping to make it a reality by their sugges- with archaeoceramics and is edited by J.E. Corbin (Box tions, moral support, and, in the case of Fred Matson, con- 13047, SFAStation, Nacogdoches, Texas 75962-3047), and an of his own on tributing essay ceramic ecology. Tracey the series of reviews on archaeometallurgy in the Journal Cullen also provided very thoughtful and practical advice ofMetals, edited by V.C.Pigott (MASCA,University Museum, on and contributors. goals possible University of Pennsylvania, Philadelphia, Pennsylvania For a brief of history archaeological newslettersin AJA, 19104). Rather than duplicate what can already be found see ES.Kleiner, 'Archaeology in Asia Minor/Anatolia,1955- in these and other more eclectic newsletters,this overview 98 1993," AJA (1994) 1-3. attempts to take stock of the "field"and develop guidelines 2 In the United the for States, Society Archaeological for effective researchand discussion among archaeologists Sciences publishes the SASBulletin, which is a very useful and natural scientists. "newsletter"that provides up-to-date information on ad- 3J.S. Olin ed., FutureDirections in Archaeometry:A Round vances in the field, meetings, publications, and funding Table(Washington, D.C. 1982). A series of textbooks on the 4 opportunities. archaeological L. van Zeist,"Archaeometry: The Perspective of an Ad- sciences is also currently being prepared by members of ministrator,"in R.L.Bishop and EW.Lange eds., TheCeramic this in society collaboration with Plenum Press, New York. Legacyof Anna 0 Shepard(Niwot, Colo. 1991) 346-57. Another newsletter that has kept archaeologists abreast

79 American Journal of Archaeology 99 (1995) 79-142 80 PATRICK E. McGOVERN [AJA 99 and examples of how natural science functions within is difficult to obtain, because such research is too an archaeological framework. Future reviews, assum- "interdisciplinary"-it does not fit squarely into any ing that this one is well received, will expand into established discipline. With the all-too-common cut- areas not covered here and, it is hoped, will lead to backs in budgets generally, science in archaeology more fruitful theoretical perspectives on how best will probably continue, for the foreseeable future, to integrate science with archaeology. to be carried out by widely scattered individuals and The terminological debate is largely a symptom the occasional research group, approaching the sub- of how defined poorly and amorphous the "field" ject from various scientific or archaeological perspec- is at present, as well as disillusionment with methods tives. Science in archaeology truly suffers from C.P. or approaches that promised more than they de- Snow's "two culture" split personality.8 It may seem livered. If an academic discipline constitutes an exciting to explore a borderline discipline (where autonomous body of knowledge, with recognized serendipitous discoveries so often occur9) and be- practitioners, places where research is carried out, come a polyglot interpreter of sorts,'0 yet the would- and appropriatejournals, publications, professional be practitioner must be prepared to be misunder- groups, and conferences to disseminate the find- stood and certainly underfunded. then ings,5 the "archaeological sciences" are still very To be fair, the sheer dimensions of possible inter- poorly developed. National, museum, and private actions between archaeology and the natural sci- laboratories6 do exist in the United States, Europe, ences, ranging from the subatomic to the astrophys- and elsewhere, providing a context for specific ap- ical level, preclude any simple definitions and hence of to plications science archaeology, but these facil- a more systematic approach. Some may choose to ities a primarily play support role, either focusing divide up the field by physicochemical techniques their efforts on individual collections and in-house (whether neutron activation analysis, mass spec- or a commercial projects providing service to archae- trometry, or optical microscopy)," others may opt ologists (especially dating and geophysical prospect- for a materials science approach (ceramics, metal- Academic which ing). programs, might serve to foster lurgy, etc.),12 while still others will argue for a gen- research and a tradition of develop scholarship, are eral problem approach (such as establishing trade nonexistent.7 Public and virtually private funding networks, reconstructing palaeodiets, or elucidating

5See ER. Matson, "Archaeological Ceramics and the demonstratethe desirabilityand need of coupling archaeol- Physical Sciences: Problem Definitions and Results,"inJ.S. ogy and naturalsciences. SeeJ. Riederer ("TeachingArchae- Olin and A.D. Franklin eds., ArchaeologicalCeramics (Wash- ometry as a Basis of Archaeometric Research")and S.E. ington, D.C. 1982) 19-28; U. Franklin, "The Science of An- Warren ("TheEducation of the Archaeological Scientist") cient A Materials: New Scholarly Field,"Canadian Mining in Olin (supra n. 3) 34-35 and 36-38, respectively,and the and MetallurgyBulletin 70 (1977) 207-10. discussion session 34-46; also "Towarda 6 seeJ.A. Sabloff, Olin (supra n. 3) 109-45 (section on the "Rolesof Mu- FutureArchaeological Ceramic Science: Brief Observations seum, University, Government, and Industrial Labora- from a Conference," in Bishop and Lange (supra n. 4) tories")and van Zeist (supra n. 4). A recent British Museum 394-99. S. 8 publication, Bowman ed., Scienceand the Past (Toronto C.P.Snow, The TwoCultures and the ScientificRevolution 1991), provides an excellent overview of interdisciplinary (New York 1963). 9 research in the Department of Scientific Research of the R.M.Roberts, Serendipity: Accidental Discoveries in Science British Museum that will be readily comprehensible to (New York 1989). the nonspecialist. " C.S. Smith, "Measurement and History," in Olin 7New and Old World archaeology, incorporating nat- (supra n. 3) 49-51. ural scientific to some training extent, are taught in the " Textbooksof archaeometry,exemplified by M.S.Tite's same academic department (Archaeology) at Boston Uni- Methodsof Physical Examination in Archaeology(London 1972), versity. Several programs are also attached to materials have generally followed this format. science and/or anthropology departments in the United 12 This approach has much to commend it, since the States the (e.g., MassachusettsInstitute of Technology and materialssciences are now a recognizedacademic the discipline University of Arizona) and Canada (University of involvinginterdisciplinary scientific research.The detailed In and Toronto). England Germany,separate departments study of technological features of artifacts or art objects, of sciences the of archaeological (e.g., University Bradford as well as the elucidation of corrosion and other processes and the Institute of at Archaeology the University of of physicaland chemical change, have obvious applications London) exist or have natural scientific integrated studies in museum curatorship,art history, and archaeology gen- into their curricula. effectively archaeological Conserva- erally. Collaboration with and financial backing from pri- tion programs (e.g., at the Institute of Fine Arts in New vate industries is a natural extension of this academic York or the Institute of Archaeology at the University of liaison. London), although having more pragmatic goals, clearly 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 81

cognitive processes of ancient humans).13 Each ap- Archaeologists also aspire to generalized and de- proach has its advantages and disadvantages, and tailed reconstructions in time and space, as well as may seem relatively more interesting or boring to establishing cause and effect relationships, based on the archaeologist or natural scientist,14 but all share an analysis of its restricted data base. Unfortunately, the premise that information made available only because of the disciplinary schizophrenia already by the natural sciences can be used to shed light on mentioned, most archaeologists are not trained in issues ranging from the most fundamental - for ex- how to extract natural scientific information from ample, dating an archaeological site or artifact-to their sites and the artifacts that they recover. Lack- the most ambitious and potentially important, viz., ing a basic knowledge of the natural sciences, archae- the origins and development of humans and their ologists are at a disadvantage in properly recover- cultures. ing and interpreting materials from sites that have It difficult is not to understand why science should certainly been altered by geological and biological play an important role in archaeology. The general processes and of which now mostly inorganic ma- and principles empirical procedures of stratigraphic terials remain. Some archaeologists, recognizing the excavation and record-keeping, as well as site survey deficiency in their training, have the good sense to and landscape archaeology, themselves embody the enlist the help of natural scientists in a multidisci- empirical observation and systematization that char- plinary effort, which is the hallmark of most mod- acterize science. Unlike chemistry and physics (the ern scientific projects. Unless the natural scientist's "hard sciences"), experiments in archaeology can- role is to be no more than "window-dressing', how- not be like or repeated, but, geology astronomy, ar- ever, there has to be a very serious attempt by all chaeology is concerned with evidence of past events involved, archaeologist and natural scientist alike, the short of earth (during relatively span history over to articulate the goals of the project in their respec- the past several million years) and the interpretation tive "languages" and develop an effective research of that evidence within a more general theoretical design for answering some significant cultural ques- context. In the historical natural a limited sciences, tions.15 Placing specialist studies with little if any re- of materials is to a of range subjected battery analyses lationship to the archaeological interpretations at and and (material, imaging, statistical), interpreta- the end of an excavation report illustrates how not tions are based on scientific "laws" general (uniformi- to do interdisciplinary research. Equally reprehen- tarianism, the structure and mutation rates of DNA sible is a scientific study of unprovenienced, possibly strands, the of and so Even with speed light, forth). fake, archaeological material parading masses of data their tools the Hubble tele- sophisticated (like space that may have been generated by the most sophis- there is room scope), for disagreement on how the ticated analytical tools available but which are ar- data should be As one interpreted. just example, not chaeologically meaningless.16 all scientists that the dinosaurs were agree warm- The communication gap between natural scien- blooded, social creatures, or that became extinct they tists and archaeologists is exacerbated by the human when an asteroid collided with the earth. dimension, which cannot be easily factored into an

13 Such studies are interdisciplinary almost by defini- and Mesopotamia-but where is the evidence for these tion. For example, a recent conference on "The Origins developments, and how is it to be recovered from excava- and Ancient of Wine" under History (in press, the same tions and scientifically verified? By attempting to tailor title, and edited P.E. by McGovern, SJ. Fleming, and S.H. our survey,excavation, and analytical strategies to specific in Katz) brought together specialists palaeoethnobotany, research objectives, the advantages of collaborative re- food archaeology, genetics, enology, art, science, chemis- search, despite the specialization and fragmentation of textual and try, analysis, history. Besides reviewing and de- modern knowledge, will become apparent. the available evidence for viticulture and bating vinicul- 14E Widemann, "WhyIs Archaeometry So Boring for were ture, participants encouraged to look at this beverage, Archaeologists?"in Olin (supra n. 3) 29-36. which played an important role in the diet, economy, social 15Supra n. 13. Also see S.P.De and R.L. and Atley Bishop, structure, religion of ancient societies, from a variety "Toward an Integrated Interface for and of and Archaeology perspectives develop innovative approaches to Archaeometry,"and De Atley, "Potter'sCraft or answer Analyst's culturallysignificant questions. Asjust one example, Tool: A Century of Ceramic Technology Studies in the centuries of in many experimentation plant domestication American Southwest,"in Bishop and n. 4) and wine Lange (supra crossbreeding, making itself, and in pottery tech- 205-23 and 358-80, respectively. nology (to produce relatively airtight, stoppered vessels 16J.A.Moore and A.S. Keene eds., ArchaeologicalHam- of dense fabrics) were presumably required to reach the mersand Theories(New York 1983). level of expertise that is evident by ca. 3000 B.C. in Egypt 82 PATRICK E. McGOVERN [AJA 99 interpretative schema and which makes archaeol- Lacking most of the material evidence that once ogy a very "soft"science. Archaeological remains often existed, especially the organics that comprised appear to be an extension of the natural world, humans themselves, their personal belongings and simply needing to be subjected to thorough physical buildings, food, etc.,21 archaeological interpreta- and chemical investigation for their significance to tions are perforce extremely weak. A deficiency of be elucidated. In some instances, this may be true. data, however, should not be taken as an excuse for The microstructure of a ceramic or metallurgical fuzzy thinking. The consequences of an interpreta- artifact may reveal how it was made, and by the tion based on the available data should be deduced; cautious use of ethnographic analogy, even some if borne out, the hypothesis gains in credibility.22 facets of the organization of the industry.17 Cer- Tests that demand a tangible outcome, such as a certainly, the radiocarbon reservoir in the oceans and tain microstructure in a metal or a specific artifact atmosphere was little affected by human interven- distribution, can provide extremely powerful sup- tion before the industrial revolution, so that one can port for a hypothesis, because archaeological evi- have confidence in dates based on this technique dence is unintentional and contemporaneous (with (assuming adequate tree-ring calibration, elimination the rare exception, e.g., conspicuous consumption of contaminants, and statistical evaluation). On the in a burial). Thus, it was not "planted" to achieve some other hand, what may appear to be the result of nat- ulterior purpose in the distant future nor to rewrite ural processes (e.g., pollen rain, a soil lens, or pati- history after the fact. nation on glass) might also have been affected by Archaeological interpretations will never achieve human activity, and cannot be explained solely by the same level of confidence as those in the natural physicochemical factors. sciences-- there are far too many interacting and un- Archaeologists understandably seek cultural inter- knowable factors to assess-but by making testing pretations that even the natural scientist should be procedures explicit, archaeologists and natural sci- willing to admit are at a higher level of abstraction18 entists can share a common ground and language than, for example, the reconstruction of an ancient of scientific inquiry. Fuzzy archaeological thinking, regional environment or the significance of some of course, may continue to thrive, because its effects group of artifacts for the history of science. Anthro- are not as immediately obvious as in the natural sci- pologists, as social scientists, may seek to make gen- ences where, for example, bridges fall and rockets eralized statements about social and economic struc- explode if a theory or its application is incorrect. tures, religious ideology, or cross-cultural interactions Moreover, for some people, rhetoric and politically that are derived from their archaeological data correct paradigms, serving to preserve disciplinary bases.'9 Historians may attempt to interrelate ar- power structures and financial support, are more per- chaeological findings to information-whether psy- suasive than probabilistic statements. Well-thought- - chological, social, or environmental gleaned from out and tested ideas, which have profound implica- contemporaneous and noncontemporaneous docu- tions for how we define ourselves and our cultures, ments that have been subjected to critical study.20 often are lost in the process. Art historians in evaluating specific objects may em- Clearly, a middle way needs to be found-what phasize aesthetic canons ofjudgment. Each kind of in the parlance of anthropological archaeology is interpretation has its place, with the proviso that they called middle-range research23- to bridge the prac- should be inferred from as careful and thorough an tical and theoretical divide between natural scien- appraisal of the field and laboratory data as possible. tists and archaeologists. The essays that follow are

17 W.D.Kingery, "Possible Inferences from Ceramic Arti- (Garden City 1959). 21 facts,"in Olin and Franklin (supra n. 5) 37-45. W.R. Biers and P.E. McGovern eds., OrganicContents '1 Smith (supra n. 10). of AncientVessels: Materials Analysis and ArchaeologicalInves- 1'1E.g., supra ns. 13 and 15; also see P.E. McGovern, tigation(MASCA Research Papers in Science and Archaeol- "Ceramics and Craft Interaction: A Theoretical Framework," ogy 7, Philadelphia 1990) passim. in P.E. McGovern ed., Cross-Craftand Cross-CulturalInteractions 22 Kingery (supra n. 17). in Ceramics(Ceramics and Civilization 4, Westerville, Ohio "'J.A. Sabloff, L.R. Binford, and P.A.McAnany, "Under- 1989) 1-11. standing the Archaeological Record,"Antiquity 61 (1987) 21 E.g., M. Bloch, The Historian's Craft (New York 1953); 203-209. and H. Meyerhoff ed., The Philosophy of History in Our Time 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 83

offered in that spirit. For the first installment of this The following essays take the reader from locat- newsletter, contributors were asked to summarize for ing and situating sites within an environmental set- the educated layman past accomplishments, as well ting (Remote Sensing, Aerial Photography, Geophys- as failings that can be equally revealing, in their fields. ical Prospecting, Archaeobotany, Palynology, and By focusing on examples of past or recent interdis- Archaeozoology) to dating them (Dendrochronol- ciplinary successes, together with practical advice ogy, Radiocarbon Dating Calibration, Accelerator on how to collect samples for analysis, apply correc- Radiocarbon Dating), analyzing a range of materi- tion factors, and so forth, it is hoped that the reader als recovered from them (Ceramic Ecology, Ceramic will be able to extrapolate and begin to apply simi- Petrography, Ceramic Petrology and Petrography in lar approaches to his/her own research. the Aegean, Vitreous Materials, Xeroradiographic To reiterate, this newsletter is necessarily selective Imaging, Amber, Physical Anthropology, Ancient Im- in its coverage of a vast, poorly developed "field"'and munochemistry, and Palaeogenetics), and, finally, many gaps still remain. If greater attention than usual preserving the finds for future scientists and hu- is paid to the biological, chemical, and earth sciences, manity in general (Archaeological Conservation). that is because less is known about these interdisciplinary endeavors that are generally at the "cutting MUSEUM APPLIED SCIENCE CENTER FOR edge" of current research. Each contributor, by stand- ARCHAEOLOGY (MASCA) ing at the interface of two or more disciplines, epito- UNIVERSITY OF PENNSYLVANIA MUSEUM OF mizes, as it were, how much archaeology has to ARCHAEOLOGY AND ANTHROPOLOGY its gain by emphasizing essential, interdisciplinary PHILADELPHIA, PENNSYLVANIA 19104 character. [email protected]

Remote Sensing

THOMAS L. SEVER

New windows on the past are being opened and vegetative cover ... that are either invisible or through the use of remote sensing technology.24 easily overlooked in surface reconnaissance."25 This Remote sensing is based upon the fact that all ma- capability subsequently led to the discoveries of an- terials emit energy along the electromagnetic spec- cient Roman villas and roadways in Europe, sites in trum. relevant Archaeologically information, most the Middle East, and earthworks in the Mississippi of which cannot be seen with the naked eye, can be River valley. recorded by detectors along this spectrum and pro- SATELLITE IMAGERY cessed for view on a computer. Sensors are mounted on satellites, space shuttles, airplanes, and balloons, The launch of the first land satellite (Landsat) in on the or dragged ground, simply manipulated by 1972 ushered in a new era in remote sensing. Com- hand. puters were now required to handle the digital data at the turn of the Beginning century, archaeology format and convert the information into photograph- was one of the first to disciplines employ remote like products. The multispectral capability of satel- black-and-white sensing. Using aerial photography, lite imagery enabled several regions of the electro- recorded ancient features that could archaeologists magnetic spectrum to be recorded simultaneously. not be seen or understood from level. Dur- ground Since archaeological features show up through soil World War for ing I, example, British archaeologists variations, moisture differences, plant stress, etc., described aerial photographic "features of long- multispectral information can be used to detect obliterated structures in the soil terrain, formations, subtle features. No part of the spectrum is necessarily

24C.A. Behrens and 25 T. Sever, Applicationsof Space-Age T.S.Schorr, "Aerial Ethnography in Studies: in Regional Technology Anthropology(Bay St. Louis, Miss. 1991);T.M. A Reconnaissance of Adaptive Change in the Cauca Lillesand and R. Valley Keifer, RemoteSensing and ImageInterpre- of Colombia,"in E.Z.Vogt ed., Aerial in Anthro- tation York Photography (New 1987). pologicalField Research(Cambridge, Mass. 1974) 163. 84 PATRICK E. McGOVERN [AJA 99 any better than any other part for detecting archae- between New Mexico and Costa Rica, both the desert ological features, since the material comprising the roads and jungle paths, invisible to the human eye feature, atmospheric conditions, and the time of from the air and ground level, were detected due the year result in different energy outputs. to minute differences in heat retention. Although the first Landsat satellites recorded information at 80-m current only resolution, foreign GLOBAL POSITIONING SYSTEM (GPS) and domestic satellite systems can record informa- GPS technology is revolutionizing archaeology and tion ranging from 30-m down to 1-m resolutions (e.g., enhancing the effectiveness of remote sensing re- using French SPOT satellite imagery).26 New ad- search because it enables ground positions to be de- vances in airborne remote sensing instrumentation termined to centimeter accuracy.32 The GPS system allow multispectral acquisition at resolutions of one consists of 24 satellites orbiting 11,000 miles above foot or less. Remote sensing analysis used to require the earth. GPS signals can be received directly with huge mainframe computers and expensive software; a hand-held receiver. Besides being extremely use- today, data can be processed on a personal com- ful in remote, poorly mapped regions, GPS locates puter using inexpensive and readily understandable features that have been software. archaeological detected in remote-sensing imagery but are invisible on As one example of the new high-tech view from the ground. space, the possible remains of the ancient city of Ubar were recently located through faint traces of cara- CONCLUSION van trails. Researchers could see various parts of these trails on Landsat, SPOT satellite, and shuttle imag- Although archaeologists pioneered the use of re- ing radar data. By excavating at a spot where these mote sensing, most mainstream archaeologists of the trails converged, archaeologists uncovered an eight- late 1970s and '80s were reluctant to invest in the sided fortress surrounded by smaller sites used by technology. By then remote sensing had evolved into caravans.27 an expensive enterprise, requiring knowledge of op- Satellite data have been used in western Greece tical physics, advanced computer analysis, and multi- to locate a variety of physical features, including stone variate statistics-disciplines generally outside the quarries, coal mines, oak and silver fir forests, and purview and funding of archaeological research pro- clay beds used for pottery-making. This information grams. Today, however, the technology is becoming provided greater insight into ancient fortifications, increasingly affordable and understandable. It is a hydraulic systems, and settlement patterns.28 On the nondestructive technology that protects our human other side of the globe, satellite data are currently legacy by allowing archaeologists to map entire revealing unmapped Mayan pyramids and roadways regions and prioritize areas for excavation while in the Peten region of northern Guatemala.29 simultaneously preserving cultural resources for Remote-sensing instruments can be flown in Lear future research. jets or Cessna aircraft to provide greater resolution. Aircraft data at 5-m resolution were able to de- NATIONAL AERONAUTICS AND SPACE tect ancient Anasazi roads in Chaco Canyon, New ADMINISTRATION Mexico.30 The same six-band thermal instrument EARTH SCIENCES PROGRAM OFFICE, JA 20 was also flown at 5-m resolution over the jungles of JOHN C. STENNIS SPACE CENTER northern Costa Rica to detect the oldest confirmed BAY ST. LOUIS, MISSISSIPPI 39529 footpaths.31 Despite the environmental differences [email protected] .NASA.GOV

26 Lillesand and Keifer (supra n. 24); B. Richason ed., 30T. Sever, TracingPrehistoric Human Impact upon the Envi- RemoteSensing of the Environment(Dubuque 1983). ronment(Ann Arbor 1990) 116-258. 27 W.E Allman, "Finding Lost Worlds," US. News and 31P. Sheets and T. Sever,"Prehistoric Footpaths in Costa WorldReport (13 September 1993). Rica: Transportation and Communication in a Tropical 28 EA. Cooper, M.E. Bauer, and B.C. Cullen, "Satellite Rainforest," in C.D. Trombold ed., Ancient Road Networks Spectral Data and Archaeological Reconnaissance in West- and SettlementHierarchies in the New World(Cambridge 1991) ern Greece,"in Behrens and Sever (supra n. 24) 63-79. 53-65. 29 32 E Miller,T Sever, and D. Lee, "Applicationsof Ecolog- D. Wells, Guide to GPS Positioning (Fredericton, New ical Concepts and Remote Sensing Technologies in Archae- Brunswick 1987); A. Leick, GPS Satellite Surveying (New York ological Site Reconnaissance,"in Behrens and Sever (supra 1990); N. Ackroyd and R. Lorimer, Global Navigation: A GPS n. 24) 121-36. User's Guide (London 1990). 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 85 Low-Altitude Photography

J. WILSON MYERS AND ELEANOR EMLEN MYERS

BEGINNINGS to be pulled down and reloaded for each new that used the short The first systematic use of a tethered photographic exposure-a tiring process up time in the when the of the balloon to record an ongoing excavation was made precious morning angle sun was and the air In a in 1931 at Megiddo, site of biblical Armageddon, right quiet. fact, Megiddo later told us that the balloon did not handle by Philip Guy (fig. 1).33Operating out of the Orien- colleague well in the and abandoned the tal Institute at the University of Chicago, field direc- wind, Guy quietly method as at the season's end when a tor Guy used a single-shot 8 x 10" cut-film camera impractical sudden crashed his camera. and a spherical hydrogen balloon to assemble de- gust learned firsthand about balloon site record- tailed mosaics at successive stratigraphic levels. This We in Greece in 1973 while with Michael bird's-eye view, he reported, allowed him to see con- ing working at his excavation of the underwater sanc- tinuities and patterns that went unobserved on the Jameson of at where ground. Guy used these vertical photographs, which tuary Apollo Halieis, Julian Whittlesey his balloon.34 Invited to included points of his surveyed grid, to eliminate brought spherical help him, we became interested ourselves in the see- much measuring on the ground and make lighter process, that much time was saved with a modern radio- work of the drawings. But his single-shot camera had ing controlled motor-driven camera. Our own 20 years of aerial archaeology in the Mediterranean started then and has since taken us to over 150 sites and area surveys in Italy, Sicily, mainland Greece, Crete, Yugoslavia, Israel, Turkey, and most recentlyJordan. :J;:! i; 0h ... !0 :: : Though much of the coverage has been scattered, carried out at the request of individual excavators, it has also been possible to fund work on a regional basis, producing a site atlas for reference and comparative study.35

APPLICATIONS AND ADVANTAGES

For exploration, salvage work, comparing successive levels of excavation, and preservation of visual information for future study, vertical photographs provide an expeditious unique perspective, consti- tuting a permanent record. In the raking light of early morning, even the slightest contours, as traced by their highlights and shadows, stand out in high relief. One is able to spot relationships not easily seen at ground level. Over a level site, vertical aerial photographs are the dimensional equivalent of a drawn plan. The obvious advantage of a balloon or blimp over Fig. 1. The pioneer photographic balloon used by P.L.O. a plane is that it can come low to capture details, at the excavation in 1931. It lifted a Guy Megiddo single- such as a single house or a mosaic floor. Helicopters shot view camera whose shutter was released electrically can fly lower than planes, but the powerful down- by a wire cable running to the right-hand reel and con- of rotors can remains and nected with a box of batteries below. (Courtesy Oriental wash their damage fragile Institute, University of Chicago) disturb the water over submerged sites.

33 P.L.O. Guy, "Balloon Photography and Archaeologi- American231:4 (1974) 110-19. cal Excavation," Antiquity 6 (1932) 148-55. 35J.W.Myers, E.E. Myers, and G. Cadogan eds., TheAerial 34 See Whittlesey's aerial photograph in M.H.Jameson, Atlas of AncientCrete (Berkeley 1992). "The Excavation of a Drowned Greek Temple," Scientific 86 PATRICK E. McGOVERN [AJA 99

size of the film, the proper altitude is derived from a ratio (fig. 4): focal length is to film size as altitude is to the size of target. For shots below 200 m, two tethers are generally used, angled down from op- posite sides of the gimbal to keep both cords and backpacks just outside the photograph. Thus, the frame of the photograph is closely fitted to the shape of the target. Simple calculations made on a working plan are used to decide exactly where each reel must be positioned and how much tether line let out. Above 200 m, two tethers would be difficult to control 2. A modern 10-m Twin motor- Fig. pressurized blimp. and in a breeze. With a driven cameras are held in a might tangle tricky single vertically precision gimbal the altitude of the camera is and operated by FM radio control. tether, judged by patches of colored yarn tied to the tether line at calibrated EQUIPMENT AND METHODS intervals. For the higher shots, the necessary fram- ing is done by cropping in the darkroom. With wide- Through much experimenting, we have gradually angle lenses, 60 mm for the Hasselblad and 28 mm settled on methods and equipment that are most suit- for the smaller camera, the focusing distance can able. Problems with a spherical balloon had suggested safely be set on infinity. that a blimp might be easier to handle in the wind. Accessory equipment has also proven useful in Working with design engineers at Raven Industries the field: a surveyor's tape and prismatic compass of Sioux Falls, South Dakota, we had a blimp made for making a working plan of unrecorded sites; a that meets our requirements (fig. 2). It is 10 m long, small turbine anemometer to help us decide whether with four fins that keep its streamlined shape headed a slight breeze is increasing and might cancel a into a breeze, offering less drag area than a spheri- planned inflation; heavy canvas ground cloths on cal counterpart. Inflated with 35 m3 of hydrogen or which to unroll and inflate the easily punctured helium, the blimp lifts 8 lb of cameras to 800 m- balloon fabric; a set of walkie-talkie radios, allowing the altitude from which a square kilometer can be crew members at widely separated tether positions photographed. Above 800 m, air photographs from to communicate with each other and with the oper- a plane would be more efficient. ator controlling the camera; a portable light table Equipped with an elastic dilation panel, the blimp expands without bursting as it rises into thinner air, and contracts again, holding its aerodynamic shape, when lowered. A still larger blimp, though more stable in the wind, would require heavy winching equipment and restrict movement. The hand-held system allows us to move quickly through shifting positions at a large site, while some remote sites can only be reached on foot. Twin cameras allow us to make both black-and- white negatives and colored slides at the same in- stant. The medium format Hasselblad ELM/500 produces 55 mm negatives, best for journal publication (fig. 3), while the 35 mm camera, a Canon AE-1 or a Nikon 2020, makes slides. The cameras are mounted in a precision gimbal - like that which holds the compass level on a heeling ship-thus stabilizing them vertically and eliminating the distortions in scale that appear in oblique views. The tethers of /s" braided polyester cord are carried on light backpack reels designed for taking up the slack as crew members haul down the balloon. The altitude at which the cameras are positioned Fig. 3. A Hasselblad medium-format vertical photograph is determined by the dimensions of the target on of the little theaterin the Sanctuaryof Asklepiosat Messene, the ground. Given the focal length of the lens and Greece. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 87

CAMERAHEIGHT = SUBJECT SIZE X FOCAL LENGTH if the crew can run toward a FILMSIZE only ground sinking blimp fast enough to slacken tether and allow it to rise again. Even then, the balloon can be pulled down gradually only when the wind lulls a bit. It is best CAMERA / to avoid these panic situations by hauling down as FILM FOCAL LENGTH soon as one feels an increasing pull on the tether. Delays in the photographic schedule are best CAMERALENS avoided by learning early what permissions a country requires from civil air or military authorities or what advance notice to authorities would be prudent and courteous. Sources of hydrogen or helium should be located and arrangements made early for prompt commercial delivery.

OTHER BALLOON SYSTEMS CAMERA HEIGHT We have regularly responded to requests for information from others who would like to start their own balloon systems and increasingly hear of successful recording. Good examples of balloon photography appear regularly in AJA.36A very simple and inexpensive 35 mm system, with a servo-motor to incline the camera, but limited in altitude to 100 m, is described by Dieter Noli.37 G.D. Summers reports flights of a tethered blimp as high as 850 m GROUND LEVEL to record a site in Turkey.38Andrew Heafitz has developed an ingenious radio-controlled servo-system Fig. 4. With vertical photography, the size of the subject that can incline and rotate the balloon camera in on the ground determines the proper height of the camera. One need only know the focal length of the camera lens any direction. A video camera, mounted together and the size of the film. with a still-camera that monitors the coverage, trans- mits the image to the ground, allowing the operator for studying the day's negatives with magnifiers; and, to see exactly what the still-camera will record.39 where remote sites are not easily located on maps, There is little doubt that archaeologists of the fu- a miniature global positioning device to measure ture will use increasingly sophisticated methods to and record latitude, longitude, and altitude. record and examine sites in minute detail at low altitude. The whole range of remote-sensing equip- CAUTIONARY NOTES AND PROBLEMS ment, operating in the infrared to radar ranges and We described above Guy's problems with the wind now used for sophisticated regional surveys by plane at Megiddo. Even with an aerodynamic blimp, one or satellite, may one day be miniaturized for low- must be careful. Because it may take 20 minutes to altitude suspension over archaeological sites. Much haul down the equipment from 800 m, it is impor- subsurface investigation might then be conducted tant not to have the blimp caught aloft in a rising without the traditional digging that has been de- wind. At a certain wind velocity, even a blimp will scribed with cautionary irony as the systematic begin to veer off to the side, its fins less and less able destruction of evidence. to head into the wind, and finally broach, turning broadside to the wind and heading straight for the RR 1 ground, all lift lost to the weight of the cameras and BOX 227 the horizontal force of drag. Recovery here is possible TAMWORTH, NEW HAMPSHIRE 03886

:" See AJA92 (1988) 124; 93 (1989) 130; 95 (1991) 22; 96 Yara?li,"AnatSt 42 (1992) 180-81. (1992) 140-45. 39 A. Heafitz, Appendix 3: "BalloonPhotography," inJ.E. 37 D. Noli, "Low Altitude Aerial Photography from a Coleman, "Excavationsat Halai, 1990-1991, Hesperia61 Tethered Balloon,"JFA6 (1985) 497-501. (1992) 287-88. 38 G.D. Summers, "An Aerial Survey of Cevre Kale, 88 PATRICK E. McGOVERN [AJA 99 Geophysical Prospecting

BRUCE BEVAN

A successful geophysical survey will allow a pre- ground. Conductivity surveys are difficult to carry diction of the location of sites or the location of fea- out near cities and in areas with metal trash in the tures within sites. This should help to minimize the soil, but wooded or rocky areas do not cause major cost of excavation and enable a wide variety of fea- difficulties. tures to be examined. Ground-penetrating radar is the most elaborate While remote sensing usually does not allow the of the commonly used geophysical instruments, and detection of a feature deeper than about 1 m, geo- will detect a wider variety of features than the other physical exploration can detect a feature at any depth, instruments.43 Radar generates an approximate although its maximum dimension must typically ex- cross-sectional image of the earth; while these images ceed its depth. are similar to sonar records, the radar emits a radio rather than a sound pulse. Radar is generally not THE INSTRUMENTS AND THEIR LIMITATIONS suitable for sites where the soil is saline or quite One of the first instruments to be applied to ar- clayey; it also cannot be used if there are many large chaeological geophysics was the magnetometer.40 A boulders or much brush on the surface. magnetometer measures slight changes in the earth's For special applications, seismic and gravity in- magnetic field; a commonly used instrument has a struments can also be employed. Seismic equipment sensor mounted on a vertical staff and connected measures the speed of sound in the soil, while a grav- with a wire to a small console where the measure- ity meter measures the density of materials that are ments are displayed. Point-by-point measurements, underground. Surveys with these two instruments, spaced 1-2 m apart, create a magnetic map of the however, are quite slow. area of interest. The magnetometer is excellent for CAPABILITIESFOR LOCATING DIFFERENT FEATURES locating iron artifacts as well as fired earth in the form of brick, rooftiles, kilns, or furnaces. Surveys The ancient ground surface may be buried below with a magnetometer are generally more rapid than a layer of modern soil. The depth of this deposit can those with other geophysical instruments, and are be estimated with a resistivity, ground-penetrating also more easily done in brushy, wooded, or rocky radar, or seismic survey. The entrances to rock shel- areas. They are less suitable for urban areas and ters, caves, mines, and quarries may be hidden by regions with igneous rock. soil, and can sometimes be detected with any of the Resistivity surveys are relatively easy to carry out. geophysical instruments. Tunnels or chambers that Wires connect a small resistivity meter to four elec- are air-filled cavities can be readily detected with trodes driven into the earth; the meter indicates how ground-penetrating radar and, in special circum- readily electrical current flows through the soil.41 stances, with a gravity survey. Resistivity surveys are ideal for locating concentra- The former channels of rivers, buried roads, or tions of stone in the soil (e.g., walls) and also for map- filled-in ditches can be mapped with any of these ping filled-in pits and trenches. Because of the elec- geophysical instruments. Because of the large size trodes and wires, resistivity surveys are difficult to of these features, aerial or satellite reconnaissance carry out in rocky or brushy areas. may be most suitable. Conductivity surveys are performed with instru- Tells and tumuli often have stratigraphy that is ments that operate somewhat like very sensitive metal too complex for geophysical surveys to resolve. While detectors.42 They will locate the same types of fea- structures in the upper few meters can be mapped tures that a resistivity survey will, but conductivity as at any other site, small and deep features cannot surveys are faster since no contact is made with the be detected. General mound stratigraphy, however,

4o A. Clark, Seeing beneath the Soil (London 1990). Geophysical Data," AmerAnt56 (1991) 41 Remote-Sensing G. Shapiro, "ASoil Resistivity Survey of 16th-Century 701-20. Puerto Real, Haiti,"JFA11 (1984) 101-10. 43R.A. Batey,"Subsurface Interface Radarat 42 Sepphoris, W.A.Martin,J.E. Bruseth, and RJ. Huggins, "Assessing Israel, 1985,"JFA 14 (1987) 1-80. Feature Function and Spatial Patterning of Artifacts with 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 89

Fig. 5. Elizabeth Raipn recording cesium magnetometer measurements at Malkata, Egypt, with an Egyptian colleague and assistants carrying the cesium magnetometer sensor and readout

GEOPHYSICALSURVEYS OF particularly on the sides of the mound, can be ap- THE K. RALPH proximated, and resistivity surveys are generally the ELIZABETH most appropriate technique. The stratigraphy of burial mounds is usually simpler and, if the burial Elizabeth K. Ralph, who passed away in 1993, was chamber is at least as large as its depth underground, a pioneer in the application of geophysical survey- it might be detected. ing to archaeology and an inspiration to this writer. Building remnants can be detected under ground Her excellent success in locating buried features at or under water. If a buried wall is surrounded by many archaeological sites in the Mediterranean re- rubble from the wall, it will generally be impossible gion is particularly appropriate to detail in this to isolate the intact wall with geophysical explora- review, since she received the AI's Pomerance Award tion. Brick walls or concentrations of rooftiles will in 1986 for her contributions to archaeological usually be easier to delineate than stone walls. Mud- science and her work is frequently referred to in AJA. brick or adobe walls may be detectable in sandy soil During the period from 1962 to 1976, Ralph did and limestone walls may be detectable in clayey soil. geophysical surveys at over 49 sites in 13 countries. If kilns, furnaces, or iron objects are sought, a mag- Her principal and favorite geophysical instrument netic survey is recommended. In some cases, con- was the magnetometer (fig. 5), and her application centrations of pottery or other fired ceramic mate- of the cesium magnetometer showed how speed and rials can be located. precision could be combined for a successful sur- Isolated artifacts will generally be difficult to lo- vey.44 Her sheer output-about 750,000 magnetic cate with any geophysical survey. A large object such measurements that were plotted and contoured as a statue can be detected if it is close to the sur- by hand- has never been equaled. She also carried face; it would be easier to detect if carved in igneous out many surveys with resistivity meters and a stone rather than marble or some other nonmagnetic seismograph. stone. The largest single survey that Ralph undertook Conductivity surveys can locate artifacts made of was at the site of ancient Sybaris, in Italy, where the any metal. For example, lead pipes can be traced with Greeks established a colony renowned for its this technique. "sybaritic" lifestyle. Over the period from 1962 to

44E.K. Ralph, "Comparison of Proton and Rubidium try 7 (1964) 20-27. Magnetometerfor Archaeological Prospecting,'Archaeome- 90 PATRICK E. McGOVERN [AJA 99

Fig. 6. Plan (left) of excavated room (B) in large building at Tall-iMalyan, Iran. The room, which was filled with burnt mudbrick wall material, was detected as the magnetic high near the top middle of the magnetic contour map (right),with intervals at 5 nanotesla. The magnetic measurements on which the contour map is based were spaced 2 m apart, and the cesium magnetometer's sensor was at a height of about 0.7 m above the ground. (Plan of building, courtesy W.M.Sumner)

1967, she worked on site in Italy for a total of about bricks had not been fired, the alluvial clay from the two years. She made between 300,000 and 400,000 Nile River is quite magnetic and the bricks made magnetic measurements, which enabled the Archaic from it were detectable in the nonmagnetic sand.48 rooftiles of Sybaris to be located at a depth of 4 m At the ancient Elamite capital of Tall-i Malyan, beneath the alluvium that had accumulated over Iran,49 Ralph's magnetic survey was remarkably suc- 2,500 years.45 cessful in locating significant archaeological remains Because of the huge area of search, the great depth in every area that was followed up by test soundings of the structures, and the presence of shallower and (fig. 6). Unfortunately, the Iranian revolution inter- more recent Roman structures, the survey at Sybaris vened to prevent further work at this site. was extremely difficult. The mapping of ancient Elis, Although carried out 20-30 years ago, Ralph's geo- a contemporaneous site in Greece, was easier and physical surveys have never been surpassed in terms required fewer measurements (only 100,000!).46 of their success or quality. Recent improvements in Ralph was able to show the plan of this city, for the magnetometers enable surveys to be completed more brick and reused rooftiles used to construct the walls quickly, but no significant increase in the accuracy here were clearly delineated. While the written mea- of the measurements has been possible. Conductiv- surements look like a mass of dots, the contour lines ity meters and ground-penetrating radar have been of the magnetic maps trace the lines of underground developed since Ralph did her surveys, and with these walls. instruments, geophysical surveys can be carried out Ralph did magnetic surveys at many other sites. at a wider range of archaeological sites. In the former Yugoslavia in 1969, burnt Neolithic house floors were located.47 At Malkata, Amenhotep GEOSIGHT III's palace in western Thebes, she located mudbrick P.O. BOX 135 structures buried in the sand (fig. 5). While these PITMAN, NEW JERSEY 08071

45 See EG. Rainey, "The Location of Archaic Greek (1970) 10-17. 48 Sybaris,"AJA 73 (1969) 260-73; and 0. Bullitt, Searchfor E.K.Ralph, "Magnetometer Survey at Malkata,Egypt," Sybaris(Philadelphia 1969). MASCA Newsletter 9:2 (1973) 3-5. 46 E.K. Ralph, "ArchaeologicalProspecting," Expedition 49WM. Sumner, "Tall-iMalyan," Iran 12 (1972) 155-80; 11:2 (1969) 14-21. E. Carter and M.W.Stolper, "Middle Elamite Malyan," 47 See A. McPherron and E.K. Ralph, "Magnetometer Expedition18:2 (1976) 33-42. Location of Neolithic Houses in Yugoslavia,"Expedition 12:2 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 91 Archaeobotany: Macroremains

NAOMI F. MILLER

Palaeoethnobotany (or the shorter term, archaeo- manually, by screening, and by flotation (fig. 7). Flota- botany) is the study of the "directinterrelationships tion enables the archaeologist to concentrate macro- between humans and plants for whatever purpose remains dispersed in the site matrix, usually by dis- as manifested in the archaeological record."50 No solving a soil sample in water.52 matter what the time period or geographical area, No single category of remains provides a full pic- plants played an important role in human culture. ture of ancient plant use. When one considers the As primary data about the natural environment, land- total amount of plant material intentionally brought use practices, diet, architecture, and trade in exotic to a site by ancient people (for food, fuel, fodder, plant materials, plant remains also reflect many as- construction, tools, and other artifacts), plus mate- pects of society, including social practices, such rial unintentionally incorporated in the archaeo- as eating, the organization of labor, and status botanical record, one realizes that it is ordinarily differentiation. the discards and residues of plant use that get de- The three major categories of archaeobotanical posited initially, a subset of which is eventually pre- materials are macroremains, pollen, and phyto- served (usually through carbonization, but some- liths.51 Macroremains are relatively large items that times under dry or waterlogged conditions).53 Texts, generally comprise the bulk of plant remains re- too, are an important source of information that de- covered from archaeological sites. They include seeds scribe many aspects of the relationships between and seed-like plant structures, fruits, wood, leaves, people and plants (e.g., agricultural treatises, receipts, tubers, etc. Typically, macroremains are recovered recipes, and medical prescriptions). Yet such sources are often too limited or too general to provide more than a narrow window onto agricultural practices, the effects of land and ir- :~~~~~~~~~~~~.;4:0: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~...:0 clearance, fuel-gathering, rigation, and all the other ways in which plants were integrated into the daily lives of ancient peoples. Thus, especially for the later periods, the information gleaned from texts complements, but does not supplant, that gained from detailed archaeobotanical studies. Although archaeologists have been saving plant remains from archaeological sites since the mid-19th century, the systematic sampling of archaeological sediments by means of flotation is a relatively recent development. Prior to the pioneering work of Hans Helbaek54 atJarmo in Iraq, and later at Ali Kosh in southwestern Iran, botanists were brought in to identify obvious concentrations of plant remains, usually crops. It was not until the late 1960s that flotation were to the attention of Fig. 7. Flotation system used to recover ancient plant techniques brought remains at Gordion, Turkey,in 1988 archaeologists in the Old and New Worlds, and

50 R.I. Ford, "Paleoethnobotanyin American Archaeol- 53:1 (1990) 55-60. 54 ogy," in M.B. Schiffer ed., Advances in Archaeological Method H. Helbaek, "The Palaeoethnobotany of the Near and Theory2 (New York 1979) 285-336. Eastand Europe,"in RJ. Braidwoodand B. Howe,Prehistoric 51 Palynology is discussed in the next section of this Investigations in Iraqi Kurdistan (Chicago 1960) 99-118; and review. Helbaek, "Plant-Collecting,Dry-Farming, and Irrigation 52 Paleoethnobotany:A Handbook of Procedures (San Diego Agriculture in Prehistoric Deh Luran,"in E Hole et al., 1989) by D.M.Pearsall is a comprehensive, practical intro- Prehistory and Human Ecology of the Deh Luran Plain (Ann duction to palaeoethnobotany. Arbor 1969) 383-426. 53 C.W.Haldane, "ShipwreckedPlant Remains,"BiblArch 92 PATRICK E. McGOVERN [AJA 99 through the 1970s, flotation was not routinely prac- ReconstructingAncient Vegetationand Human Influence ticed. Most of archaeobotanical work concentrated Over the past 3,000 years, human activities have on the origins of agriculture, the major problem as had a more profound influence on the vegetation defined in the United States by anthropologically of the Sakarya valley than climate.59 Land clearance trained archaeologists and in Europe by prehisto- for fuel and agriculture, the grazing of domesticated rians. Now, in the 1990s, the aceramic Neolithic is animals, and, in the Phrygian period, construction increasingly well understood, but comprehensive seem to have had the cumulative but gradual effect syntheses of the later Neolithic and beyond have yet of reducing whatever natural tree cover there was. to be written. Even the early civilizations of the third Gordion lies at the edge of the central Anatolian millennium B.C.,which have been given a fair amount steppe, where remnants of oak andjuniper woodland of archaeobotanical attention, are poorly known. and pine forest still exist. Based on the modern dis- Later historical periods have been particularly ne- tribution of trees, we infer that the impressivejuniper glected, probably because of undue reliance on writ- and pine timbers found in Phrygian burial mounds ten records.55 and the settlement probably originated in woodland Several reviews of research in the Near East and 20-50 km away. Europe summarize decades of work on plant remains To trace the history of ancient vegetation in more from sites dating between Palaeolithic and medieval detail, less dramatic evidence from occupation de- times.)56 A detailed example from recent work at bris must be gathered and analyzed. This plant ma- a site that Gordion, culturally straddled the classical terial, nearly all of which is carbonized, comes pri- world and the ancient Near East, illustrates the kinds marily from the remains of fuel (wood, brush, and of questions one can ask of archaeobotanical data. dung) and consists of wood charcoal and charred seeds. Many species are found that are unknown from RECENT RESEARCH AT GORDION the tombs or from the constructional and food re- Gordion, located on the Sakarya River in central mains of the burnt buildings. Since fuel is rarely trans- Turkey, was the capital of ancient Phrygia. Excava- ported from far away, fuel remains enable one to tions in early this century and more recent research monitor the vegetation growing relatively close to directed by Rodney S. Young between 1950 and 1973 a settlement. At Gordion, the analysis showed a de- were completed before the systematic search for plant cline in juniper relative to oak. The virtual absence remains became standard practice. Plant remains of juniperfuel in contemporary Phrygian deposits recovered team by Young's were primarily construc- suggests that juniper timber had already become a tion material and food remains from the massive fairly rare material, reserved for or limited to use destruction the Early Phrygian level, log structures in the royal tombs. Trees that characteristically re- at the base of the "Midas Mound" (Tumulus MM), place the climax vegetation of oak, juniper, or pine, other burial mounds, and tomb furniture, also from along with components of riparian forest, show a the 700 Early Phrygian period (ca. B.C.).57Renewed gradual increase between the Late Bronze Age and excavations in 1988 and 1989 and archaeobotanical the medieval period, though they never surpass 20% have study begun to fill out the picture of ancient by weight of the assemblage. and land-use plant practices at Gordion between the Brush and dung fuel are potential sources of seeds Late Bronze Age and medieval times.58 in the archaeobotanical record, and the charred seed

.5 For a review of recent archaeobotanical research, see mat6riaux en bois du tombeau royal de Gordion),"Istanbul N.E "The Miller, Near East,"in W. van Zeist, K.-E.Behre, UniversitesiOrman Fakiiltesi Dergisi 18, series A (1968) 37-54; and K. Wasylikowaeds., Progressin Old WorldPalaeoethno- B. Aytug, "Le mobilier fun6raire du roi Midas I,"PACT 22 botany(Rotterdam 1991) 133-60. (1988) 357-68. 56 For a topically and geographically organized work 58 M.M. Voigt, "Excavationsat Gordion 1988-89: The that includes exhaustive discussions of the European Yassihoyfik Stratigraphic Sequence," in D. French and archaeobotanical see van record, Zeist et al. (supra n. 55). A. Cilingiroglu eds., Proceedingsof the 3rd International Domestication of Plants in the Old World(Oxford 1988) by AnatolianIron Age Symposium, 1990 (Oxford, in G.K. D. press); Zohary and M. Hopf provides a botanically oriented Sams and M.M.Voigt, "Workat Gordion in 1988,"XI. Kazz plant-by-plantdiscussion, and Man'sRole in the Shapingof SonuclarzToplantisz 1 (Ankara 1990) 77-105; and Sams and theEastern Mediterranean Landscape (Rotterdam 1990) by S. Voigt, "Work at Gordion in 1989," XII. Kazi Sonuflari Bottema, G.Entjes-Nieborg, and W.van Zeist is particularly Toplantisi1 (Ankara 1990) 455-70. informative on around the 59 developments Mediterranean. Cf. S. Bottema and H. Woldring, "AnthropogenicIn- 57E.g., H. Kayacik and B. Aytug, "Gordion Kral dicators in the Pollen Record of the Eastern Mediterra- Mezarl'nn Agal Malzemesiuzerinde Ormanclliky6niinden nean," in Bottema et al. (supra n. 56) 231. Arastirmalar(Recherches au point du vue forestier sur les 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 93 - assemblage is a useful indicator of these alternative or riverside vegetation may be indicated by the ap- fuel sources; an increase in the ratio of seeds to char- parent increase in the proportion of sedge seeds, coal suggests a decline in the use (i.e., availability) which is consistent with the evidence of increased of tree wood. At Gordion, there is no dramatic shift use of riparian vegetation. As trees by the river were in this ratio, which suggests that fuel use practices cut, a sunny riverbank habitat would have opened up. were relatively stable, despite some long-term dis- Stability characterizes Gordion crop choice. Small turbance in the tree cover. shifts in the proportion of einkorn wheat relative to six-row barley and bread wheat are therefore par- Reconstructing Ancient Agricultural Practices ticularly intriguing. Einkorn was one of the earliest The seeds provide more than just evidence of fuel domesticated plants, but by 2000 B.C. it had dropped use. In the absence of cess deposits, seeds from burnt out of favor as an important cereal in the Near domestic structures provide the strongest evidence East.60In southern Europe, the presumed homeland that a crop plant was grown for food, though fiber of the Phrygians, it seems to have retained its value and fodder can usually not be ruled out. well into the Iron Age.61 Thus, the apparent slight Six-row barley and bread wheat dominate the crop increase in einkorn coincidental with construction seed assemblage in all periods. Einkorn wheat is a and ceramic shifts, suggestive of the Phrygian cul- minor cereal, and rice occurs in only one medieval ture, may be further evidence of the arrival of these deposit. Lentils and bitter vetch comprise the bulk newcomers from Europe.62 of the pulses. A burnt early Iron Age house had what CONCLUSION appears to be baskets of barley, wheat, and bitter vetch on the floor. A small of jar tiny flax seeds found in Despite several decades of research, the full po- the destruction level of Terrace Building 2A might tential of archaeobotany for the investigation of an- be seed stock for the fiber plant, but the same room cient culture is yet to be realized. For both prehis- small yielded jars of other food crops, wheat, barley, toric and historical periods, plant remains enable and lentils, so the flax might have been human food. us to assess human impact on the environment. As few Grapes (a seeds) were also found as were nut- direct, site-specific evidence of agricultural and culi- from shells, perhaps wild-growing almonds. nary activities, they can enrich our understanding Plant remains may point to changes in irrigation of how people lived. Archaeobotanical research at as practices, indicated by crop choice, seed size/shape, Gordion is meant to show both skeptics and the con- and characteristic weeds. At Gordion, despite the verted how bits and fragments of charred remains little is unpredictable climate, very "progress" visible help create a picture of the lives of ancient people in the archaeobotanical record. For example, barley and the landscape they shaped and inhabited. is more drought-tolerant than wheat, yet the proportion of these two crop plants remains constant MUSEUM APPLIED SCIENCE CENTER FOR time. through Irrigated grains tend to be plumper ARCHAEOLOGY (MASCA) than unirrigated ones of the same species; at UNIVERSITY OF PENNSYLVANIA MUSEUM OF Gordion, size and shape of both wheat and barley ARCHAEOLOGY AND ANTHROPOLOGY are stable the remarkably throughout occupation. PHILADELPHIA, PENNSYLVANIA 19104 The expansion of a moist habitat- irrigation ditches [email protected]

Ancient Palynology

S. BOTTEMA

The of micro- and study macrofossils (including wood of the University of Chicago in the early 1960s. agricultural products such as carbonized hard He sought to integrate archaeology and the natural - see the grains preceding section on Archaeobotany) sciences in his work on early prehistoric sites in Iran in the Near East was stimulated by RobertJ. Braid- and Turkey. The botanical investigations of this proj-

60 Miller n. (supra 55) 146-48. nomics, and Ceramic Continuity at Gordion in the Late 61H. in van Zeist et al. Kroll, "Siidosteuropa," (supra Second and FirstMillennia B.C.'in W.E.Kingery ed., Social n. 55) 167, 174-75. and CulturalContexts New Ceramic 62 of Technologies(Ceramics Voigt (supra n. 58); R.C. Henrickson, "Politics, Eco- and Civilization 6, Westerville, Ohio 1993) 89-176. 94 PATRICK E. McGOVERN [AJA 99

swamps incorporate enormous numbers of pollen, which can be well preserved if kept constantly wet. Yet, these pollen need not correlate with the activities of ancient peoples, whose settlements and en- campments can be located away from such bodies of water. Samples from the archaeological site itself, on the other hand, have the disadvantage that they are dominated by Liguliflorae, mostly yellow flower- ing composites, which comprise a relatively small percentage of the total pollen rain. Furthermore, the accumulation of debris in a Near Eastern tell is often the result of the disintegration and leveling of mudbrick houses. Such mudbrick is made from clay that has its own history, i.e., it may contain pollen that derives from a time preceding the structure in which it was used and which therefore cannot be used to reconstruct the palaeo- 8. Pollen of Morina of the teasel contemporaneous Fig. grain persica family, environment. measuring ca. 100 , in length (90 x magnification), with Pollen from water sediments en- prominent protuberances on the sides from which the samples usually pollen tubes grow.From a Bronze Age tin mine in Kestel, able the general vegetational development of a re- Turkey,excavated under the direction of Aslihan Yener, gion to be reconstructed. The best sequences occur this Morina is the one recovered the author grain only by where rainfall exceeds 300 mm per year. This iso- in 30 years of palynological investigation. hyet appears to be the minimum for the formation of pollen-bearing sediments. An exception is a pollen ect were carried out a team by Groningen University core from the salt flats of Bouara on the Syrian-Iraqi led Willem van and were ex- by Zeist, subsequently border,64 where precipitation amounts to only tended to other of the Near East.63 many regions about 150 mm. The Bouara salt flats form part of An aim of ancient re- important palynological the Khabur valley, a region that was densely inhab- search is to reconstruct the of palaeoenvironment ited during Assyrian times.65 The Assyrians, who which includes the human on early humans, impact dry-farmed and irrigated the fields elsewhere in the the environment. To obtain the information optimal Khabur, evidently used the Bouara exclusively for from the nature of micro- pollen samples, typical salt-winning. fossils needs to be understood. Thousands of pollen The collection of pollen samples is done by man- are on each inch grains (fig. 8) precipitated square ually coring the sediments. The samples are iden- of Unless are under ground per year. they preserved tified in the laboratory, using a light microscope, gen- anaerobic conditions under will (e.g., water), pollen erally under 400 x magnification. very rapidly disappear. The various pollen types are not equally sensitive to degradation, some being far PALAEOENVIRONMENTS IN PRE- AND more resistant than others. The identifiability of POSTGLACIALTIMES different pollen types also varies; while some pollen retain their characteristic features even after deg- Near Eastern pollen sequences or profiles (e.g., radation, other pollen are impossible to identify even fig. 9) show a marked contrast in palaeoenviron- under weakly oxidative conditions. mental development from the glacial period (Pleisto- Other factors also need to be considered in any cene) to postglacial (Holocene) times, i.e., pre- and palynological investigation. For example, the grad- post-10,000 B.P. (uncalibrated radiocarbon years). As ually accumulating sediments of lakes, peatbogs, and dated by radiocarbon or by correlation with other

63 See W. van Zeist and S. Bottema, Late Quaternary Vege- rezenteUmwelt von Tall Seh Hamad und Daten zur Umweltrekon- tation History of the Near East (Beihefte zum Tiibinger Atlas struction der assyrischen Stadt Dur-katlimmu (Berlin 1991) des Vorderen Orients A18, Tiibingen 1991). 105-16. 64W.H.E. Gremmen and S. Bottema, "PalynologicalIn- 65See Kiihne (supra n. 64). vestigations in the Syrian Gazira,"in H. Kuhne ed., Die 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 95

dated pollen profiles, the general picture for lower elevations (e.g., the Ghab valley of northwest Syria or Yenisehir in the Bursa area of western Turkey), as well as the higher Anatolian plateau of Turkey and the Zagros Mountains of western Iran, is that of a steppe landscape giving way to forest. This cli- matically induced change is locally influenced by developing farming communities, but the general trend of steppe herb pollen gradually being replaced by tree pollen has been demonstrated. The process starts as early as 15,000 B.P. in northern Israel where relatively dense Tabor oak forests established themselves, only to decrease abruptly around 11,500 B.P. A climatic belt of rain that encouraged tree growth apparently moved farther north and east, leaving Israel much drier after this time.66 The moist zone arrived in the Pisidian Lake district of southwestern Anatolia around 9000 B.P. In eastern Turkey, the Van district shows some increase in deciduous oaks at about 7000 B.P. In north- western Iran, optimal conditions for tree growth were established around 5500 B.P.The forest development of the Pontic part of Turkey is very similar to that of northern Greece and large areas of Europe. If such vegetational patterns are translated into climatic terms, two main systems can be observed: a general European pattern that is uniform over a large area, and a shifting system that moves from the southern part of the Near East to the north and northeast. The latter moisture belt might have been caused by the gradual retreat of the large ice cap in northern Europe. This retreat, which started in the west and south, is likely to have caused a shift in the polar front that contributed to a moving moisture belt in the Near East. 9. of a selection of from a Fig. Percentages pollen types EARLY AGRICULTURE 5.5-m long core from Lake Beysehir, Turkey, beginning about 6000 B.P. (bottom of the graph) and indicating an The pollen record also informs us about the im- with amounts of edible fruits occupation phase, greater pact of ancient man on the vegetation of a region, and nuts available, ca. 3200 B.P. (middle). The cumulative as well as the kinds of agriculture that were initiated percentages of the most frequent arboreal types (AP) in the Holocene In what kind of land- each sample, Cedrus (cedar) and Pinus (pine), can be read during period. along the top scale from left to right. On the left side of scape did ancient agriculture develop, and what were the diagram are shown less frequent arboreal types, includ- the consequences for the environment? Pollen analy- Olea Fraxinus ornus ing (olive), (manna-ash), Quercus (oak), sis provides answers to such questions if so-called Vitis (grape); individual percentage scales read from left indicator types (pollen that can be ascribed to hu- to right. Non-arboreal types (NAP), including Artemesia man which derive either from (composite herbs and shrubs) and Cerealia-type (cereals), activity), crops (pri- are shown to the right; their percentages are read along the bottom scale from right to left. The sum of the less 66 frequent arboreal types is the difference between the U. Baruch and S. Bottema, "Palynological Evidence cumulative percentages of AP and NAP. Dashed horizontal for Climatic Changes in the Levant ca. 17,000-9,000 B.P.," lines separate periods having similar vegetation and sub- in O. Bar-Yosef and ER. Valla eds., The Natufian Culture in to similar environmental ject constraints, as inferred by the Levant (International Monographs in Prehistory, Archae- the palynologist. ological Series 1, Ann Arbor 1991) 11-20. 96 PATRICK E. McGOVERN [AJA 99

mary types) or from weeds (secondary types), are pres- 4000 B.P., the first effects of the degradation of for- ent. The available pollen profiles generally show that ests, which were burned for pasture and grazing land, these types increase slowly during Neolithic times are evident over large areas of the Near East. This (near the beginning of the Holocene period). Some- development intensifies around 3200 B.P. Along the times agriculture is known to have been practiced, Mediterranean coast, the typical xerophytic vegeta- as evidenced especially by carbonized cereal grains tion replaces the former deciduous oak forest. In of wheat and/or barley that are known to have been western Anatolia, arboriculture based on walnut, early domesticates, but indicator pollen are lacking. sweet chestnut, manna-ash, grape, and olive appears. This circumstance often arises when pollen types At the same time, the plane tree spreads all over cen- of the wild ancestors of our domestic cereals cannot tral and western Anatolia.67 be distinguished from those of a group of wild grasses. In addition, wheat and barley often dissemi- CONCLUSIONS nate little pollen into the air, because the pollen of An important focus of future re- these self-fertilizers remain in their glumes. Bread palynological search in the Near East will be to define the made from these cereals actually contains far more specific constraints for human in the pollen than what is recovered from an ancient con- settlement, especially forest-steppe regions. In general, the evidence text exposed to pollen rain. pollen needs to be with and in In sediment pollen profiles with no plants of eco- integrated interpreted light of the results from other archaeo- nomic importance represented, types related to the disciplines (e.g., botany) and the available data to draw grazing of animals are often found. Weedy pollen archaeological well-based conclusions. types, which occur in the Near East and Europe (e.g., Plantago lanceolata, Sanguisorba minor, and Rumex) are good indicators. BIOLOGISCH-ARCHAEOLOGISCH INSTITUUT Another noticeable change in pollen profiles that STATE UNIVERSITY OF GRONINGEN can be attributed to human impact on the environ- GRONINGEN, THE NETHERLANDS ment is a decrease in forest pollen species. Around [email protected]

Faunal Analysis with a Focus on Anatolia

HITOMI HONGO AND RICHARD H. MEADOW

INTRODUCTION GOALS of Analysis animal bones (faunal analysis) has be- Perception of what faunal analysts do and should come common in Near increasingly Eastern archae- do varies among archaeologists and even among ology.68 Much of the first research focused on iden- faunal specialists themselves. At one end of a con- animals tifying exploited by Palaeolithic hunters and tinuum is faunal analysis as a set of procedures to on the beginnings of animal domestication during identify and record animal bone remains with a view the Neolithic. Recently, however, increasing numbers toward documenting the history of human impact of faunal studies have been carried out on sites later on animals. People who work in this way often call than the Neolithic. Because analysis of animal bones themselves "archaeozoologists." At the other end is as began early as the 1930s in Anatolia, that area analysis and interpretation of faunal remains in the a useful source of provides examples to underline context of particular archaeological problems with some of the possibilities and problems of research a focus on interactions between humans and ani- that have changed over time. mals within specific social and cultural contexts. In-

67Bottema and Woldring (supra n. 59) 231-64. "The Origin of Pig Domestication with Particular Refer- 68This is dedicated to the essay respectfully memory ence to the Near East"(Institute of Archaeology, Univer- of Berrin Kusatman whose death at (Dogan), tragic the sity College London, 1991) represents a remarkable of 36 in 1993 robbed of a dedicated piece age May Turkey faunal of research on a difficult topic. analyst with a bright future. Her Ph.D. dissertation titled 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 97

Fig. 10. Faunal analysis at Kaman Kaleh6oyuk,Kirsehir, Turkey:a) In the laboratory, measuring a distal humerus, and b) on the excavation, uncovering a late second-millennium B.C. bone dump. (Courtesy R.H. Meadow) vestigators who approach the field in this fashion stage to help develop an effective sampling method often call themselves "zooarchaeologists." There is while taking into consideration time, budget con- a parallel continuum in the ways that faunal analysts straints, and the overall goals of the project. At what- are related to excavation projects. Some have tended ever stage an analyst becomes involved in a project, to work as technicians/specialists who identify bones however, it is important that he or she be fully in- and present the results to archaeologists. Others try formed about the stratigraphy of the site, the details to be an integral part of projects and employ a more of archaeological context, and the sampling meth- holistic approach to analysis and interpretation.69 ods employed.70 In faunal studies, recovery techniques and archae- What can be classed under the rubrics of"experi- ological context are crucial (fig. 10). Animal bones mental" or "actualistic" studies form important as- themselves, unlike potsherds and other artifacts, gen- pects of faunal research. These include preparing erally do not contain intrinsic clues to dating or a modern comparative collection to assist in iden- social/cultural affiliation (unless they can be char- tification of the archaeological fauna, carrying out acterized isotopically). Therefore faunal remains studies on modern animal keeping and hunting or from mixed or disturbed contexts are best avoided, fishing practices in the local area in order to under- because the data may be misleading if they are inter- stand possibilities and limitations, and testing the preted uncritically. In addition, there are various cul- efficacy of recovery techniques. An example of sig- tural practices and postdepositional factors that can nificant work in these areas has been that of Sebas- affect the distribution of animal bones across an ar- tian Payne in Anatolia and southeastern Europe. In chaeological site. Careful recovery incorporating a a study of sampling methods, he demonstrated that program of sampling and sieving combined with de- bones of medium and small animals can be signifi- tailed information about archaeological context of cantly underrepresented in a hand-picked faunal as- the material will help the investigator to evaluate the semblage when compared to a sieved assemblage.71 biases involved. Ideally, the faunal analyst should be For the material from Asvan Kale, he developed a brought into a project during the research design technique for recording tooth wear in sheep and

69 SJ.M. Davis, The Archaeologyof Animals (London 1987) of which there are many,the best for Europe and the Near provides a good introduction to some of what has been East,however, still being the now out-of-printbilingual Atlas accomplished in the field as well as a useful bibliography. ofAnimal Bones/Knochenatlas(Amsterdam 1972) by E. Schmid. For an introduction to the basic techniques for identifying 70 R.H. Meadow, "AnimalBones: Problems for the Ar- mammal bones and teeth, see S. Hillson, MammalBones chaeologist together with Some Possible Solutions,"Paleori- and Teeth(London 1992);note, however,the author'swarn- ent 6 (1980) 65-77. ing on the cover of the book that "it should be used in 71S. Payne,"Partial Recovery and Sample Bias: The Re- conjunction with a reference collection of bones and teeth sults of Some SievingExperiments," in E.S.Higgs ed., Papers and with the help of an experienced zooarchaeologist." in Economic Prehistory (Cambridge 1972) 49-64. This is true of all published guides to bone identification 98 PATRICK E. McGOVERN [AJA 99

goats and, subsequently, studied tooth wear patterns at such sites traditionally has focused on texts, ar- in hundreds of living Angora goats in order to be chitecture, and objects of art and on the establish- better able to determine age at death of animals rep- ment of chronology, and little attention has been resented in the archaeological record.72 From aging paid to questions of subsistence. There is the ten- data such as these, it is possible to describe a "kill-off dency to think that we are already well informed pattern" that reflects hunting or husbandry practices about the kinds of animals and their uses in early employed in the past. historical times, because trade in livestock and animal products and aspects of animal sacrifice are de- ANATOLIAN FAUNAL STUDIES scribed in ancient texts. In reality, however, very little In Anatolia, modern faunal research can be said is known about practices of animal keeping and con- to have begun in the late 1960s with the work at sumption, especially the practices of the general pub- Qay6nfi, Suberde, and Can Hasan.73 At each of these lic as opposed to those of the elites. Neolithic sites, study of the animal remains was For Anatolia, most studies of animal bones of the closely coordinated with other aspects of the projects, protohistoric and historical periods have been ar- and faunal analysts were present on site for at least chaeozoologically oriented. During the 1970s and part of the excavation. Such work has shown that 1980s, German researchers published data on large the transition from hunting to husbandry in Anatolia assemblages of animal bones from Bogazk6y, Fikir- took place between about 7000 and 6000 B.C. in the tepe, Hassek-H6yuik, Korucutepe, Lidar H6yiik, context of settled agricultural villages. The keeping Nor?un-Tepe, and Demircih6yuk.76 They usually of domestic animals was not immediately accepted presented species lists and skeletal part frequencies, everywhere, however. At a number of contemporary discussed kill-off patterns for domestic animals and sites (e.g., A?ikli and Cafer Ho6yiik), the faunal re- changes in animal husbandry through time, and used mains came from wild relatives of the stock that was measurement data to characterize animal size and already being kept and bred in captivity elsewhere.74 proportions. There was little discussion, however, of At sites of later periods where faunal remains are variability in the distribution of faunal remains across dominated by domestic forms, research focus is on a site, with the archaeological period being the prin- husbandry practices and the nature of animal econ- cipal unit for defining an assemblage. In addition, omies. Topics include selective breeding, site pro- as excavation and recovery techniques were seldom visioning, exchange of animal products, and animal mentioned, intersite comparisons required assump- use by different social groups. Investigators recog- tions of comparability that may not be justified. nize that ethnicity, social hierarchy, and differences Faunal research is even rarer in later periods, such in accumulation of wealth can affect the distribution as the Hellenistic, Roman, and Islamic periods in and consumption of meat and other animal prod- Anatolia. Although there is an exceptional study ucts, and they have even employed faunal remains of the "Sacrificial Layer" at Halikarnassos,77 the to monitor the course of state formation.75 practice of animal husbandry during the Iron Unfortunately, faunal remains often have been ig- Age and medieval period at the site remains largely nored at sites of the Bronze Age and later. Research unknown.

72 S. Payne, "Kill-offPatterns in Sheep and Goats: The Village Site in Southeast Turkey,"MASCAJ 4 (1987) 191-203; Mandiblesfrom A?vanKale," AnatSt 23 (1973)281-303; and P. Wattenmaker and G. Stein, "EarlyPastoral Production E. Deniz and S. Payne,"Eruption and Wearin the Mandibu- in SoutheastAnatolia: Faunal Remains from KurbanHoyuk lar Dentition as a Guide to Ageing Angora Goats," in and Gritille H6yfk,"Anatolica 13 (1986) 90-96; M.A. Zeder, B. Wilson, C. Grigson, and S. Payne eds., Ageingand Sexing FeedingCities: Specialized Animal Economy in theAncient Near AnimalBonesfrom Archaeological Sites (Oxford 1982) 155-205. East (Washington, D.C. 1991). 73B. 76 Lawrence,"Principal Food Animals at Qay6ni," in Publications listed in A. von den Driesch and J. L.S. Braidwood and R.J.Braidwood eds., PrehistoricVillage Schaffer,20Jahre Institutfiir Palaeoanatomie, Domestikations- Archaeologyin South-EasternTurkey (Oxford 1982) 175-99; forschungund Geschichte der Tiermedizin der Universitdt Miinchen D. Perkins,Jr.,and P. Daly,"A Hunters' Village in Neolithic 1965-1985 (Munich 1985);J. Boessneck, 25 Jahre Institut Turkey,"Scientific American 219:5 (1968) 97-106; D.H.French, fur Palaeoanatomie,Domestikationsforschung und Geschichteder "Excavationsat Can Hasan III 1969-1970," in E.S. Higgs Tiermedizinder UniversitdtMiinchen 1965-1990 (Munich ed., Papersin EconomicPrehistory (Cambridge 1972) 181-90. 1990). Unfortunately, only Cay6nii has been published in any 77F. H0jlund, "The Deposit of Sacrificed Animals at the detail. Entrance to the Tomb Chamber,"and K. 74 Aaris-S0rensen, D. Helmer, La domesticationdes animauxpar les hommes "Zoological Analysis,"in The Maussolleionat Halikarnassos prehistoriques(Paris 1992). 1: The 75 SacrificialDeposit (Copenhagen 1981) 21-90 and P. Wattenmaker, "The Organization of Production 91-110, respectively. and Consumption in a Complex Society: A Study of a 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 99

RESEARCH POTENTIAL 4) Change in size and body proportions of domestic The Middle East has always been a crossroads for animals through time can show whether differ- peoples and cultures that are sometimes documented ent breeds of animals were developed or introduced. in the texts, but are usually difficult to trace archae- Similar observations on wild animals can help iden- ologically. Faunal remains can be an effective tool tify human pressure on the environment.79 in this respect, because people belonging to all so- 5) Frequencies of different body parts and butch- cial groups, and not just the elites, discard bones; ery techniques can be related to ethnic differences and how people raise animals, as well as what they and to different types of provisioning. eat, can reflect ethnic and social differences. The 6) Intrasite distributions can provide information following kinds of observations are useful in docu- on social and functional differences. Animals associated with menting culture-specific practices of animal keeping: higher status (e.g., horses) or particular 1) The use of domestic animals, for traction or activities (e.g., camels) may only be found at specific for their various products (meat, milk, wool, hides), locations. and their contribution to the pastoral economy can Thus, there is great potential in the study of ani- be seen in the range of animal species used, their mal bones from archaeological sites of all periods, relative importance, and the kill-off pattern em- to shed light not only on animal exploitation pat- ployed. The presence or absence of certain species terns but on sociallcultural practices that other (e.g., pigs) can indicate ethnic differences. archaeological materials cannot reveal. It is partic- 2) Season of slaughter can be determined by ex- ularly regrettable that there is general indifference amining incremental structures in the cementum to animal bone studies among many archaeologists of teeth through the preparation of microscopic working at early historic and medieval sites in the thin-sections.78 Since animals often appear in asso- Middle East.80 We hope that in the next decade ciation with gods in season-specific ritual contexts faunal analyses will become more common and in ancient texts and art, it may be possible in some better integrated into research strategies developed instances to identify the remains from sacrifices or to investigate the nature of complex societies.81 other periodic events through seasonality studies and perhaps even identify the sacrificial occasion. ZOOARCHAEOLOGY LABORATORY 3) The presence of foreign species may reflect PEABODY MUSEUM trade or alliances between geographically distant HARVARD UNIVERSITY places and even the migration of peoples. The in- 11 DIVINITY AVENUE troduction of the domestic horse into Anatolia, per- CAMBRIDGE, MASSACHUSETTS 02138 haps through the Caucasus, is a good example. [email protected]

Dendrochronology

PETER IAN KUNIHOLM

Over 6,000 years of tree-ring chronologies cover- anthropologists may date finds of wood or charcoal, much of the ing period back to about 7500 B.C. have theoretically to within one year. been developed over the past 20 years for the Aegean, METHOD Balkans, and Near East. The goal is to construct an unbroken from the chronology Neolithic to the pres- Tree-ring sequences from trees that grow in a sea- ent which art and against archaeologists, historians, sonal climate, i.e., with one growth increment per

78D.E. Lieberman and R.H. Meadow, "The Biology of portive of all kinds of bioarchaeology. We wish to thank Cementum Increments an (with Archaeological Applica- Dr. Omura and the MECCJ for supporting our own par- Mammal Review tion)," 22 (1992) 57-77. ticipation in the project. 79The standard for bone measurements 81 professional The professional society for ArchaeozoologylZoo- is A. von den Driesch, A Guide to the Measurement of Animal archaeology is the International Council for Archaeo- Bones Sites from Archaeological (Peabody Museum Bulletin zoology (ICAZ), which can be contacted c/o Dr. A.T. Clason, Mass. 1, Cambridge, 1976). General Secretary, Biologisch-Archaeologisch Instituut, 80 One is the excavations of the Middle East exception Poststraat 6,9712 ER Groningen, The Netherlands. Bibliog- Cultural Center in at Kaman where the Japan Kalehoyuk raphies are compiled each year and published in the jour- field Sachihiro has director, Omura, been particularly sup- nal of ICAZ, ArchaeoZoologia(Grenoble, France). 100 PATRICK E. McGOVERN [AJA 99

year, with the size of that growth dependent upon years with the possibility that up to 3,000 floating some climatic stimulus such as cold in the polar re- years will be added in the reasonably near future. gions, drought in the Aegean, and various combi- The European oak and pine chronology, a compos- nations of the two stimuli in regions in between, can ite of work done in Germany and Northern Ireland, be compared so that these increments, more pop- is now over 11,000 years long.84 Of particular inter- ularly known as "rings,"can be dated to the calendar est to many AJA readers is the recent development year in which they were formed. Crossdating, match- of a 1,000-year oak chronology in Poland, which has ing patterns of ring growth from one tree to another demonstrated that panel paintings in Western col- and assigning rings to specific years, is possible only lections, signed by artists such as Rubens, Rembrandt, among trees growing in the same general climatic etc., were painted on oak boards imported from region. Crossdating can sometimes be achieved in Gdansk in the eastern Baltic.85 spite of human interference to ring growth by thin- Significant work, but outside the scope of this re- of ning stands, resin gathering, fire damage, and port, is going on elsewhere: some archaeological, other traumas such as severe weather effects, pollu- some climatological, and some palaeoclimatologi- tion, lightning damage, etc., not to mention shaping cal. Notable progress has been made in recent years of the wood at the time of construction and decay in South America with the development of long chro- afterward. Both visual and statistical techniques are nologies from Fitzroya cupressoidesin the vicinity of to employed guarantee the accuracy of the matches. the Patagonian glaciers, in China with attempts to In addition to simple ring-width analysis, X-ray den- link the tree-ring record with the Chinese archival sitometric methods are used to reconstruct past envi- records, in Russia with the study of tree growth at ronmental conditions.82 Wood or charcoal samples the northern timberline, and in Spain with the study taken from standing buildings or excavated from of medieval monuments. archaeological sites can be crossdated with each other DENDROCHRONOLOGY and with wood from living trees to extend the tree- IN THE AEGEAN the date of ring chronology beyond the oldest ring My own work has been focused on the Aegean for of the oldest tree in the living region. Dendrochronol- the last 20 years. Progress as of spring 1993 is shown is the archaeometric ogy only technique for which in figure 11. We have about 6,000 years of chronol- determination of absolute dates accurate to the year ogies spread out over the last 9,500 years in a region is either or theoretically practically possible. For a bounded by the Turkish-Georgian frontier in the east, thorough treatment of recent progress in dendro- the mountains of northern Lebanon in the south, and work chronological dendroclimatological world- including all of Turkey, Cyprus, Greece, parts of Bul- wide, see EH. Tree Basics and Schweingruber, Rings: garia and the former Yugoslavia, and extending to Applications of Dendrochronology(Boston 1988). the instep of the Italian boot at Mt. Pollino in Calabria. Whether we can northward into the DENDROCHRONOLOGY IN THE AMERICAN push Crimea, northeastward into the Caucasus, and south- SOUTHWEST AND IN EUROPE ward into northern Syria and other Near Eastern studies have been a of Tree-ring staple anthropo- countries remains to be seen. Mesopotamia and Iran in the American Southwest83 logical investigation are for the moment inaccessible, but may some day since the decades of this and in early century Europe yield useful information. We expect imported cedar since World War II. The bristlecone chronol- pine and juniper from the Lebanon, found in Egypt, to of the American Southwest now exceeds ogy 8,500 crossdate with Anatolian chronologies.

2 F.H. Schweingruber, H.C. Fritts, O.U. Braker, L.G. bon Calibration,"Radiocarbon 35 (1993) 201-13. For a re- Drew, and E. "The as Schar, X-RayTechnique Applied to cent archaeological application, which typifies the uses Dendroclimatology,"Tree-Ring Bulletin 38 (1978) 61-91. of the method, see B. Schmidt, H. Kohren-Jansen,and K. 83 For a recent summary,seeJ.S. Dean, "Dendrochronol- Freckmann, KleineHausgeschichte der Mosellandschaft(Cologne ogy,"in M.R. Zimmerman and J.L. Angel eds., Dating and 1990). Determination Age of BiologicalMaterials (London 1986) 85 D. Eckstein, T. Wazny,J. Bauch, and P. Klein, "New Evi- 126-65. dence for the Dendrochronological Dating of Netherland- 84J.R.Pilcher, M.G.L.Baillie, B. Schmidt, and B. Becker, ish Paintings," Nature 320 (1986) 465-66. Also see Klein "A 7,272-YearTree-Ring Chronology for Western Europe," and Wazny, of Nature "Dendrochronological Analyses Paintings 312 (1984) 150-52; and now Becker, "An11,000-Year of GdanskPainters of the 15th to the 17th Dendro- German Oak and Pine Century," Dendrochronology for Radiocar- chronologia 9 (1991) 181-91. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW

Oak U mu -E_a_ __ Boxwood U co 1.. cu () 0) Cedar of Lebanon - a.

C')0 Pine U 0

I- Juniper mI I

Conifer Combined m* I I-I

-7000 -6000 -5000 -4000 -3000 -20)00 -1000 B.C/A.D. 1000 2000

* Aegean Tree-RingChronologies as of Spring 1993 LII Crossdatingstill tentative

Fig. 11i Schematic representation of current Aegean dendrochronologies by tree species and/or genera. Note that "Conifer Combined" includes pine, cedar, and juniper.

Absolute chronologies for several genera of trees prehistoric period, the most notable advance in extend back for a millennium. Our oak sequence the last year has been the development of almost ends in A.D. 927. An eighth/ninth-century gap in 700 years of chronologies for the Neolithic site of the oak chronology may be filled by timbers from Catal Huyiik. Amorium that were collected during the summer PRACTICAL MATTERS of 1993. A post-Justinianic gap exists just after the primary timbers from St. Sophia in Istanbul were For the dendrochronological method to succeed, cut. Another gap exists around the time of Constan- long ring sequences are needed. We have measured tine. Indeed, the millennium from roughly 500 B.C. junipers with as many as 918 annual rings. Qatal to A.D. 500 is the most problematic of the last 4,200 Huyiik charcoal fragments no larger than a half- years, although the first half may have been sorted golfball have as many as 250 rings preserved. Cross- out by the recent construction of a 513-year ring se- dating material like this is relatively easy. Trying to quence from boxwood timbers in the Comacchio date samples with fewer than 100 rings, on the other (Ferrara) shipwreck.86 The sequence, with which a hand, is generally not worth doing. Quantities are number of other ring chronologies crossdate, is dated important. A set of 100 samples is vastly preferable to the last decades B.C. by three and a half tons of to a set of 10, and single samples are to be avoided lead ingots stamped with the name AGRIPPA. A except in desperation. One cannot tell from internal 1,761-year continuous ring sequence from around evidence whether a single sample has been reused 2259 B.C. to around 498 B.C. is the longest we have. from an earlier construction, cut particularly for the Early Bronze Age sequences are still under construc- purpose to which it was finally put, or is some later tion Studia Troica (see III, Tiibingen 1993). For the repair. Species are important. Oak, pine, juniper,

86 E Berti ed., Fortuna Maris: La nave romana di Comacchio chronology for the Roman Ship at Comacchio (Ferrara)," (Bologna 1990);P.I. Kuniholm, C.B.Griggs, S.L. Tarter, H.E. forthcoming. Kuniholm, and M.I. Pezzo, "A 513-YearBuxus Dendro- 102 PATRICK E. McGOVERN [AJA 99

fir, boxwood, yew, spruce, and occasionally chestnut estimate of the felling date may be made. If only have been crossdated. Olive is impossible to work heartwood is present, the date of the last preserved with, as are willow, poplar, and fruit trees. Large rings ring is, at best, a terminus post quem date.87 in these genera may mean merely that the gardener in the orchards in which they grew was unusually industrious that year. Cypress is usually undatable DEPARTMENT OF THE HISTORY OF ART because the latewood cannot easily be distinguished AND ARCHAEOLOGY from an individual annual ring. Finally, the condi- G-35 GOLDWIN SMITH HALL tion of the sample is important. If the bark is pres- CORNELL UNIVERSITY the ent, precise felling year may sometimes be de- ITHACA, NEW YORK 14853-3201 termined. If some sapwood rings are present, only an [email protected]

Radiocarbon Calibration: Current Issues

S.G.E. BOWMAN AND M.N. LEESE

Radiocarbon has made a dating major contribu- from the moment the excavation is mooted. Only tion to archaeology for more than 40 years. For at then can the correct type, size, and number of least the last decade and a an half, immense amount samples be dated for key contexts having well- of effort has been invested in providing calibration understood sample-context-event associations.88 The in and data curves, ensuring evaluating quality, and archaeologist can also assess the funding needed, in results. The sheer volume of interpreting infor- the support he or she will receive in the interpre- mation is and much of it is bewildering seemingly tation of the radiocarbon chronology, and the qual- as new data are often complex, especially presented ity of work produced by a given laboratory.89 without reference to the implications for archae- The need for accurate results (i.e., those with no In this review we are concerned ological application. systematic bias) is self-evident, and every laboratory with the calibration of radiocarbon only dating ought to be able to provide evidence for its accuracy. results and with the status of recent particularly Equally important is the need to estimate realistically calibration data and the use of emergent Bayesian the precision (i.e., the random variability) of the re- statistics. sults, since an assessment of this, together with the It must be stressed that calibration is often viewed error on and shape of the calibration curve in the as a final after the radio- step, requiring thought only region of interest, determines the calendar age carbon results have been the supplied by laboratory. range(s). Use of an error multiplier is often suggested On the the need and effect calibra- contrary, for, of, because of concern that the quoted error, which may tion are essential considerations in the sampling be based only on counting statistics, does not fully even influence the choice of lab- strategy. They may reflect true variability (assessed by replication ex- for if oratory, example, high precision proves nec- periments or intercomparisons between labora- Discussion the radio- essary. among archaeologist, tories). As an alternative, the current update of the carbon scientist, and statistician is needed virtually program CALIB suggests the incorporation of ad-

87 A accessible is P.I.Kuniholm and readily survey C.L. The Malcolm and Carolyn Wiener Laboratory for Striker,"Dendrochronological Investigations in the Aegean Aegean and Near Eastern Dendrochronology is and supported Neighboring Regions, 1983-1986"JFA14 (1987)385-98. by the National Endowment for the Humanities, the Na- More recent summariesare P.I.Kuniholm and M.W.Newton, tional Science Foundation, the Malcolm H. Wiener Foun- "A 677 Year for Long Tree-Ring Chronology the Middle dation, the National Geographic Society, the Samuel H. Bronze Age," in Studiesin Honorof TahsinOzgiif (Ankara Kress Foundation, the Wenner-Gren Foundation for 1990) 279-93; P.I.Kuniholm, S.L.Tarter, M.W. Newton, and Anthropological Research, and individual Patrons of the C.B. Griggs,"Preliminary Report on Dendrochronological Aegean Dendrochronology Project. at Investigations Porsuk/Uluki?la,Turkey 1987-1989," Syria 88 See, e.g., S. Bowman, RadiocarbonDating (London 69 (1992)379-89; and P.I.Kuniholm, "A Date-List for Bronze 1990); S. Bowman and N. Balaam, and "Using Radiocarbon," Iron Age Monuments Based on Combined Dendro- Antiquity64 (1990) 315-18. and Radiocarbon 89 chronological Evidence,"Aspects of Art E.M. Scott, M.S.Baxter, D.D. Harkness, T.C. Aitchison, and -Anatolia and Its Iconography Neighbors:Studies in Honor and G.T.Cook, "Radiocarbon:Present and Future Perspec- Nimet 371-73. of Ozgii (Ankara 1993) tives on Quality Assurance,"Antiquity 64 (1990) 319-22. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 103

Stuiver& Pearson + Pearson & Stuiver 4r 5000 BC 6000 BC 20 years 4 1840 AD Pearson et al. 7890 BC

Stuiver& Becker 10 years 6000 BC

Stuiver 1 year . 1510 AD

Vogel & Van der Plicht 1-4 years 1930 BC 3900 BC

Kromer& Becker 2-10 years (tentative) 4 ------7145 BC 9439 BC 2i0 I i I 0 70 8 1I950 1000 1000 2000 3000 4000 5000 6000 7000 8000 9000

AD Calendar Years BC

Fig. 12. Summary of calibration curves based on the 1993 Radiocarbon calibration issue (vol. 35:1), showing the date ranges covered and the number of tree rings used to construct the data points on each curve. Notes: 1) These data have largely superseded previous curves; the precision is typically ? 20 radiocarbon years back to about 6000 B.C., and ? 30 for older samples. 2) For the period 5000 B.C.-A.D. 1950 shown as a broader shaded line, the Belfast and Seattle data (Stuiver and Pearson and Pearson and Stuiver, respectively) agree statistically and are totally independent, being based on different dendrochronologies: these data, at least, are likely to be internationally recommended at the 1994 radiocarbon conference. Beyond 5000 B.C.: a) most measurements are based on the German oak sequence; b) the German pine linkage to the oak chronology is tentative (Kromer and Becker); c) there are statistically significant differences between laboratories for some time intervals; and d) other data (e.g., Linick et al., Radiocarbon 28 [1986] 943-53) provide cross-checks for some, relatively short, time periods. 3) Vogel et al. (Radiocarbon35 [1993] 73-86) suggest that 41 ? 5 radiocarbon years should be subtracted from southern hemisphere results prior to calibration. 4) Also see Bard et al. (Radiocarbon35 [1993] 191-200) for a uranium- series versus '4C results for corals back to 30,000 B.P. ditional laboratory error terms.91 Somewhat inex- CALIBRATION DATA plicably, however, the values suggested are the errors on a long superseded calibration curve; thus, we The publication in 1986 of a calibration issue of strongly recommend against this procedure. While Radiocarbon (vol. 28:2B) and recommendation92 of it may seem better to over- rather than underesti- the consensus curves of the Belfast and Seattle lab- mate precision, in fact, this may not be erring on oratories for the period 2500 B.C.-A.D. 1950 was a the side of caution. For example, a X2-test9l (a statis- considerable breakthrough. This provided a much- tical test of "agreement") could give an entirely needed single, and seemingly definitive, calibration erroneous confirmation of assumed contemporane- curve with the promise of its extension to earlier ity. Again, only the laboratory itself can give the nec- periods. The picture presented in the 1993 Radio- essary information on the reliability of its error carbon calibration issue (vol. 35:1), however, appears estimates and should be requested to do so. considerably more complex. Figure 12 summarizes

:'0M. Stuiver and P.J. Reimer, "Extended 14CData Base which assumes a priori evidence for contemporaneity, is and Revised CALIB 3.0 14C Age Calibration Program,' relevant. "Case II" is unrealistic, as it does not take account Radiocarbon 35 (1993) 227. of "wiggles" in the calibration curve. 92 '1See G.K.Ward and S.R.Wilson, "Proceduresfor Com- W.G. Mook, "Business Meeting: Recommendations/ paring and Combining Radiocarbon Age Determinations: Resolutions Adopted by the Twelfth International Radio- A Critique," Archaeometry20 (1978) 19-31. Their "Case I," carbon Conference," Radiocarbon 28 (1986) 799. 104 PATRICK E. McGOVERN [AJA 99

some of the 1993 curves based on dendrochronol- by probability distributions that fully take account ogy. At least three of the data sets contain revisions of both the error term on the radiocarbon result of previous data, the maximum correction being and the effect of the wiggles in the curve; the wiggles about 30 radiocarbon years. Regrettable though the indicate that any one radiocarbon result can corre- need for these changes may be, they illustrate the spond to more than one calendar age range. Unfor- extreme care taken by the high-precision laboratories tunately the simplest method of calibration, the to check and recheck their experimental procedures "intercept method,"96 does not properly represent and resultant data. Neither the revision of data nor those probabilities that can be calculated only with the apparent proliferation of calibration curves a computer program. Several such programs are avail- should be taken as an excuse, as was previously prev- able for dealing with dates individually, most of alent, not to calibrate. which, explicitly or implicitly, use the Bayesian In choosing a calibration curve, it is best to match methodology.97 Their underlying model assumes the age span of the sample to the time interval be- a priori that dates on the calendar scale are equally tween points on the curve. Curves based on single- probable,98 which seems eminently reasonable in year samples are limited, but it has been shown that the absence of any information to the contrary. When calibration of a single-year sample against decadal combined with a radiocarbon result using Bayes's or bidecadal curves can lead to an underestimate theorem, this model gives rise to the probability dis- of the calendar age range.93 For long-life samples, tributions produced by programs such as CAL15, having an age span of, e.g., 100 years, a moving av- CalibETH, and CALIB.99 In contrast, those pro- erage of the calibration data is needed and some grams that "divide"radiocarbon probabilities before computer programs provide this option, but extreme transferring them to the calendar scale are, in effect, care obviously needs to be taken in interpreting what assuming a priori that the true radiocarbon values archaeological event such long-life samples repre- rather than the calendar dates are equiprobable.100 sent. The decadal or bidecadal curves, however, are In the interpretation of groups of radiocarbon the most suitable for many of the more archaeolog- results, the simplest approach is to use charts of con- ically appropriate radiocarbon samples such as bone fidence bars or probability distributions for the in- and round-wood. In the absence of a recommended dividual sample,101but these provide only a "by eye" consensus calibration data set, currently available indication of trends. Ideally, one should be able to calibration programs use different ones, ranging combine all of the available data, both radiocarbon from the 1986 recommended curves94 to a combi- and archaeological, into a single statistical model. nation of curves95 largely based on those summa- Bayesian methodology is particularly suited to this rized in figure 12. aim and can deal with, for example, calibration of a single result combined with an or CALIBRATION METHODS archaeological historical terminus (post or ante quem), or calibra- Like calibration data, methods of calibration are tion of groups of dates with stratigraphic ordering under review. A consensus is emerging, however, that or phasing.102 The end product consists of, i.a., calibrated dates can be faithfully represented only probability distributions similar to those already

3:M. "A Stuiver, Note on Single-YearCalibration of the al. (CalibETH) (supra n. 94); Stuiver and Reimer (supra Radiocarbon Time Scale, AD 1510-1954,"Radiocarbon 35 n. 90) 215-30. 100 (1993) 67-72. In such programs,the probability(p) associated with 94J. van der Plicht and W.G. Mook, "The Groningen a given radiocarbon result is divided by the number (n) Radiocarbon Calibration Program,"Radiocarbon 35 (1993) of calendar dates corresponding to that result before con- 231-37. T.R. G. Nicklaus, Bonani, M. Simonius, M. Suter, verting to the calendar scale. By contrast, programs that and W. "CalibETH:An Interactive Wolfli, Computer Pro- do not divide probabilities assign the whole probability for the Calibrationof Radiocarbon gram Dates,"Radiocarbon (p) to eachof the n calendar dates. For the former programs, 34 (1992) 483-92. the accumulated on the calendar scale sum 95 probabilities Stuiver and Reimer (supra n. 90) 215-30. to unity; for the latter, they must be standardized to do so. 6 101 E.g., G. Pearson, "How to Cope with Calibration," Examples are given by J. Ambers, S. Bowman, A. Antiquity61 (1987) 98-103. Gibson, and I. Kinnes, "RadiocarbonResults for the Brit- 97 Pioneered in radiocarbon dating by J.C. Naylor and ish Beakers,"Radiocarbon 34 (1992) 916-27. A.EM. "An Smith, Archaeological Inference Problem,"Jour- 102Several examples illustrating the types of problem nal theAmerican Statistical Association 83:403 of (1988) 588-95. with which Bayesian methods can deal are described by '9 Discussed by H. Dehling and J. van der Plicht, "Sta- C.E. Buck, J. Kenworthy,C.D. Litton, and A.FM. Smith, tistical Problemsin CalibratingRadiocarbon Dates,"Radio- "CombiningArchaeological and RadiocarbonInformation: carbon35 239-44. (1993) A Bayesian Approach to Calibration,"Antiquity 65 (1991) {'('Van der Plicht and Mook (CAL15) and Nicklaus et 808-21; also see C.E. Buck, C.D. Litton, and A.EM. Smith, 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 105

familiar from many calibration programs, but incor- sidered and vice versa. For example, models that in- porating any additional chronological information corporate hypotheses about changing activity levels available. Bayesian methodology also allows a variety at a site depend on having a reasonably large set of of other inferences to be made (e.g., derivation of samples selected independently and at random time spans). throughout the period under study. The outcome What are the practical implications of this type of the radiocarbon measurement, of course, may lead of approach for the archaeologist? Sets of results to reevaluation of the original model. Thus, for ex- relating to the same event and shown to be contem- ample, a strategy aimed at dating a single event porary can, generally speaking, be dealt with using through multiple samples may nevertheless produce existing calibration programs. Extending the Bayes- non-contemporaneous radiocarbon results. It may ian approach to dates relating to several events, be valid in specific circumstances to combine the linked stratigraphically or otherwise, however, re- individual calibrated probability distributions,103 more quires complex analysis. The mathematical but it is perhaps more likely that the sample-context- formulation of the problem is not straightforward event association has not been fully understood and and its solution requires extensive computing re- needs to be reassessed. sources. At present, the necessary software is not CONCLUSIONS widely available, but with recent improvements in numerical it will methods, probably become more Like any dating technique, the use of radiocarbon accessible. The crucial contribution of the archae- requires care in sample selection and measurement. to the is to define ologist model-building process Radiocarbon dating, however, has special problems the a priori information that links the samples, such in interpretation, because of the need for calibra- as the information stratigraphic relationships, from tion. The continually growing body of calibration historical texts, or, perhaps more controversially, hy- data and the variety of statistical models used to deal about the scale of and how potheses likely activity with the calibration process are daunting to assimi- it changes within and between phases. late. These factors, however, underline the value of Whether or not calibration is based on Bayesian early and continued collaboration among archae- methodology, the broad principles outlined above ologists, radiocarbon scientists, and statisticians. the highlight why sampling strategy adopted by the Only through such cooperation can the potential is of fundamental archaeologist importance, requir- of Bayesian analysis be realized, a technique that consideration the ing throughout calibration and holds considerable promise because of its general- In interpretation process. assessing possible sampling ity and its ability to incorporate archaeological strategies prior to submission for dating, simulation data explicitly. can often be of assistance. By calibrating feasible results and errors based on educated guesswork, it DEPARTMENT OF SCIENTIFIC RESEARCH is possible to judge the likely success of the strategy, BRITISH MUSEUM and indeed of radiocarbon dating, in resolving the LONDON WC1B 3DG chronological problem. The sampling strategy will UNITED KINGDOM determine the chronological models that can be con- [email protected]

Radiocarbon Dating by Accelerator Mass Spectrometry

R.E.M. HEDGES

The of technique measuring radiocarbon using chaeological, I estimate that well over 10,000 AMS Accelerator Mass has Spectrometry (AMS) been in archaeological dates have been produced. This short existence for 15 and radiocarbon dates nearly years, review attempts to draw some very general trends have been this method for over a de- produced by and conclusions from such abundance. I apologize cade. Although only about a of these are ar- quarter in advance for drawing so frequently on the expe-

"Calibrationof Radiocarbon Results to Pertaining Related tributions for "related"samples. While not explicitly stated, Events,"Journal Science19 Archaeological of Archaeological such a procedure seems to be based on the assumption (1992) 497-512. that a single event has been dated by a number of samples, '3"E.g., CALIB and CAL15(supra ns. 90, 94, and 99) pro- each of which, while not is vide contemporary, equally likely an option that simply sums calibrated probability dis- to represent that event. 106 PATRICK E. McGOVERN [AJA 99

rience of the Oxford Laboratory, but I know its work ADVANTAGES OF GREATER SELECTIVITY best, it has published the most archaeological dates, and it is the most specialized of the AMS laboratories The advantages of much greater selectivity gen- in archaeological dating.104 erally fall into two categories: an increase in the archaeological reliability of the date (nos. 1-4), and THE BASIS AND SIGNIFICANCE OF the generation of new chronological information THE AMS TECHNIQUE (nos. 5-6). To obtain a radiocarbon date, it is necessary and 1) Recheckingdates. If alaboratory date seems ques- sufficient to measure the relative abundance of the tionable, for whatever reason, sufficient sample is carbon isotopes 12C, 13C,and 14C in a suitable sam- often available for a second measurement, which ple. The measurements must have an accuracy ap- might help to confirm that the original measure- proaching 0.5% to hope to achieve a dating accuracy ment was not in error. Notoriously problematical of 50 years. The main difficulty is the extremely small dates, e.g., those of the Theran volcanic eruption"'6 amount of "4C,which is therefore hard to detect, and the (Pleistocene) "Red Lady of Paviland,"1"7can and especially so in the quantities necessary to give thus be checked. the statistical precision required for an accurate date. 2) Improved chemical "pre-treatment."When only The "conventional" method detects 14C from its own 1 mg of carbon is required for analysis, it is relatively radioactivity, but since it has a half-life of 5,730 years, easy to find material that can be better chemically a only tiny fraction of 4C atoms is detected in a characterized and/or be subjected to more stringent reasonable time, and even samples containing as chemical procedures. Therefore, reasonably well pre- much as 1 g of carbon are barely sufficient for a mea- served bone has turned out to be the sample mate- surement. This sets a limit of sample size, and thereby rial of preference, because it contains the chemically of sample selection and sample chemical treatment well defined protein collagen."'8 Poorly preserved procedures. The AMS method detects 14C atoms in- bone, all too frequent on hot and arid sites,1"9 re- dependently of whether they radioactively disinte- mains problematic. The question of chemical treat- grate, measuring about 1% of all 14C atoms and re- ment becomes especially important for dates beyond quiring samples of only 1 mg of carbon (and often 30,000 years, and only consistent stratigraphic se- less). quences can demonstrate its effectiveness. The main outcome is that archaeologists now have 3) Comparison of differentfractions. Related to the far more possibilities as to what samples can be dated. above is the ability to compare different fractions the Therefore, value of the technique depends very (chemical or otherwise) from the same sample. Differ- much on how well this choice is exercised. In other ent sources of carbon in sediments can be sorted respects, the AMS method does not differ greatly out using this approach. Of particular interest has from the conventional method. The cost is some- been the comparison of the "charcoal" and "humic" what higher, the measurement error similar (though fractions in charred carbonaceous material."" Their the results are more reliable due to better selection), agreement obviously strengthens the reliability of and the age range much the same (though again, the date obtained. This approach has been used in older dates are undoubtedly more reliable because several situations, including the rather controversial samples have been better freed from modern con- issue of contamination in the Theran seed material. Both methods are tamination). subject to calibra- In many ways, it is one of the most powerful meth- tion.'10 smaller Making samples by 1,000 times, how- ods available for establishing reliability, although, broadens the for ever, scope many new approaches. of course, the cost of dating is thereby increased.

104I would like to thank all the members of the Oxford Bronk, "RadiocarbonDates from the Oxford AMS System," Radiocarbon Accelerator Unit for their enthusiasm and ArchaeometryDatelist 9, Archaeometry31 (1989) 207-34. support, and in particular Rupert Housley for reading a R18R.E.M. Hedges and GJ. van Klinken, "A Review of draft of this review.The Unit is partially supported by the CurrentApproaches in the Pre-treatmentof Bone for Radio- Science and Engineering Research Council. Archaeometry carbon Dating by AMS,"Radiocarbon 34 (1992) 279-91. Datelists 1-16 appear in Archaeometry26-34 (1984-1992). 10'S. Weiner and 0. Bar-Yosef,"States of Preservation 105M. A. and Stuiver, Long, R.S. Kra eds., "Calibration of Bones from Prehistoric Sites in the Near East:A Survey," 1993,"Radiocarbon 35:1 (1993). JAS 17 (1990) 187-96. 106R.A. Housley, R.E.M. Hedges, I.A. Law, and C.R. "1 RJ. Batten, C.R. Bronk, R. Gillespie, J.AJ. Gowlett, "Radiocarbon Bronk, Dating by AMS of the Destruction R.E.M.Hedges, and C. Perry,"A Review of the Operation of Akrotiri,"in D.A. Hardy and A.C. Renfrew eds., Thera of the Oxford Radiocarbon Accelerator Unit,"Radiocarbon and the Aegean World III (London 1990) 207-15. 28:2A (1986) 177-85. 107 R.E.M. Hedges, R.A. Housley, I.A. Law, and C.R. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 107

A useful spin-off is that more is learned at the the only material available for dating was carbonized same time about the processes of environmental seeds, is another example of an early agricultural contamination. site that could be dated by AMS. 4) Selecting more directly relevant material. Small 6) Directly datable samples. Many archaeological charcoal samples generally enable short-term growth finds are precious, due to their inherent information material to be selected, avoiding mistakes due to content. Often they may still be dated by AMS if a reuse, or differences between heartwood growth and small sample can be taken. Another dimension is felling times. On the other hand, small charcoal frag- thus added to the chronological framework inferred ments (or seeds) are fragile and all too mobile, and for the sample's archaeological context. As one clear can be used only with great caution to date the strata example, direct dating by AMS has shown that many from which they have been excavated. The dating human inhumations (in caves, for instance) are in- of the late Upper Palaeolithic (Tjongerian) site of trusive, and of later date than the cultural remains, Rekem (Belgium), whose sandy deposits contained which are often stratigraphically indistinguishable. charcoal fragments loosely associated with fires, as In general, the more information attached to the well as microliths (one with attached arrow shaft ad- sample, the better. For example, dating a snowshoe hesive), is an interesting case. The charcoal dates all hare bone bearing cut-marks not only dates the de- proved to be stratigraphically incoherent and archae- positional stratum, but also dates a human presence, ologically useless, while the adhesive was able to sup- and the dating refers both to human cultural prac- ply a clear and useful date."' In general, larger tice and also to the ecological and climatic setting. samples (e.g., bone) are found to be stratigraphically Typically about 200 mg of bone is sufficient for such more static. We have found that finely disseminated a date. Evidence for animal domestication or changes charcoal, often collected into sedimentary lenses, in plant morphology due to cultivation may also be is an especially difficult sample material from which directly dated through measuring a single charred to obtain consistent dates. For the dating of sedi- seed or a pig tooth. Such dates, however, can turn terrestrial ments, preserved macrofossils are of in- out to be later than expected because of problems in creasing importance establishing the regional and of sample movement and stratigraphic uncertainty. ecological context of an archaeological site.112 We have dated two grape pips found on different New or 5) better datings. Since AMS enables more Neolithic sites. One was from the excavators' lunch, to be samples dated, despite smaller sample size, and the other is the first occurrence of Vitis vinifera many sites can be dated, either de novo, or else much in Great Britain. more than before. This is thoroughly arguably the One of the most important information-bearing with the benefit to category greatest general archae- artifactual materials in archaeology is pottery. The In ological dating. particular, open sites with limited dating of pottery is reliable only if it contains definite such as the French stratigraphy, Upper Palaeolithic traces of food residues, or if any of the original car- sites ofPincevent, Etiolles, and Marsangy, have been bonaceous temper survives and can be extracted.15 able to be dated. One site that has benefitted from AMS dating has identified the earliest pottery so far a sustained and intensive AMS is dating program found in the Americas,16 and confirmed early Neo- Abu Hureyra in Syria, which was occupied during lithic dates in China. the and Epipalaeolithic Neolithic periods."13 The Artifacts with virtually no context have also been of the as well as dating stratigraphy, specific seeds dated. For example, the Oxford Laboratory has dated and burnt animal has in bones, helped greatly piec- numerous bone points and harpoons of uncertain the evidence for the of ing together development provenience, in order to establish a general typolog- in for early agriculture. Jeitun Turkestan,14 which ical sequence, particularly through the Mesolithic

"'J.AJ. Gowlett, R.E.M.Hedges, I.A. Law,and C. Perry, van Klinken, "RadiocarbonDates from the Oxford AMS "RadiocarbonDates from the Oxford AMS System:Archae- System: ArchaeometryDatelist 15,"Archaeometry 34 (1992) ometryDatelist 5,"Archaeometry 29 (1987) 125-55. 337-57. "2 T.E.Tornqvist, A.EM. deJong, W.A.Oosterbaan, and ll5 R.E.M.Hedges, C. Tiemei, and R.A. Housley,"Results K. van der "Accurate of Gorg, Dating Organic Deposits by and Methods in the Radiocarbon Dating of Pottery,"Radio- AMS 14C Measurement of Macrofossils,"Radiocarbon 34 carbon34 (1992) 906-11. 566-78. (1992) 115A.C. Roosevelt, R.A. Housley, M. Imazio da Silveira, ll3 A.M.T. Moore, "The Impact of Accelerator Dating at S. Maranca, and R. Johnson, Millennium the "Eighth Pottery EarlyVillage of Abu Hureyraon the Euphrates,"Radio- from a Prehistoric Shell Midden in the Brazilian Amazon," carbon34 (1992) 850-58. Science254 1621-24. 14 (1991) R.E.M. Hedges, R.A. Housley, C.R. Bronk, and G.J. 108 PATRICK E. McGOVERN [AJA 99

and Neolithic periods of northern Europe. More and smaller samples are able to be analyzed and as spectacular is the dating of rock paintings, which our understanding of the processes of organic deg- seldom contain sufficient carbon or well-character- radation and environmental contamination im- ized organic materials. Several French Upper Palaeo- proves. With deepening understanding, reliable dat- lithic cave paintings have been dated from their char- ing beyond 50,000 years may eventually prove coal content by the French AMS Laboratory at possible. To date, AMS's chief contributions have been Gif."7 More controversial is the dating of what are to provide much greater reliability in radiocarbon believed to be blood proteins from Australian rock dates and to forge a closer relationship between spe- paintings.18 Here, reliability is again the crucial cifically archaeological information and chronolog- issue, for the chemical "pre-treatment" is being asked ical data. to perform at, or perhaps beyond, its limits. It is, however, an indication of the direction of future research. OXFORD RADIOCARBON ACCELERATOR UNIT CONCLUSIONS RESEARCH LABORATORY FOR ARCHAEOLOGY The full archaeological potential of radiocarbon AND THE HISTORY OF ART dating by AMS depends on a comprehensive grasp 6 KEBLE ROAD of how its selectivity may best be exploited. On the OXFORD OX1 3QJ technical side, selectivity can be increased as smaller UNITED KINGDOM

Ceramic Ecology

FREDERICK R. MATSON

Archaeologists are increasingly including consid- raw materials and technologies that the local potter eration of ecological aspects in their studies of Near has available to the functions in his culture of the Eastern, Mediterranean, and European ceramics, but products he fashions.""9 This characterization of perhaps not as much as in other parts of the world. the field has met with approval, and been recently In addition to shape and decoration, long reported discussed in some detail by Rice, who also comments in detail, pottery can be examined in terms of on the potential value of a ceramic ecological ap- mineral and chemical composition, variations in proach in archaeological research: methods of production and firing, and, of course, The final of a ceramic stratigraphic and regional distributions. Such data, step ecological investigation is relating the accumulated data on the environ- together with cautiously used knowledge of the prac- mental and socio-technological factors of pottery mak- tices of can at times be present-day village potters, ing to the broader role of pottery in a culture. This of use in better understanding the social, economic, includes such features as economic organization (local and political aspects of past cultures. The potters and long-distance trade arrangements), kinship structure, settlement cere- and the pottery they produced were insignificant in patterns, demographic factors, monial or ritual activities, and so forth. the broad cultural perspective, but the almost in- Pottery manufacture, like any other destructible nature of fired and the subtle productive ceramics, technology, represents a point where a cultural record potsherds and vessels retain when most other system interacts directly with the environmental sys- material remains have long vanished, make it essen- tem.... Ceramic ecology can be linked with ceramic to show tial that they be carefully excavated and studied in technology pottery production as one of the many patterned of envi- many ways. ways exploiting particular ronments and as one of a variety of economic "Ceramic be considered as one facet adjust- ecology may ments in a network of productive relations in a so- of cultural ecology, that which attempts to relate the ciety. Ceramic ecology emphasizes the potter's role

117H. H. Valladas, Cachier, P. Maurice, E Bernaldo de ing of Human Blood Proteins in Pigments from Late Pleisto- V.C. Quiros,J. Clottes, Valdes, P. Uzquiano, and M. Arnold, cene Art Sites in Australia," Antiquity 64 (1990) 110-16. "Direct Radiocarbon Dates for Prehistoric 119 Paintings at the ER. Matson, "Ceramic Ecology: An Approach to the Nature Altamira," 357 (1992) 68. Study of Early Cultures of the Near East," in ER. Matson ll T.H. R. Loy, Jones, D.E. Nelson, B. Meehan, J. Vogel, ed., Ceramics and Man (Chicago 1965) 203-17. J. Southon, and R. Cosgrove, "Accelerator Radiocarbon Dat- 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 109 as an active and controlling agent in the procedures Examples of ceramic ecological concerns dealing of manufacture (resource selection, pottery forming with the Near Eastern and Mediterranean regions as these are revealed techniques, firing strategies) can be subsumed under the to which through technological analyses of both ancient and following topics, others well be modern pottery.120 might added. ENVIRONMENT Publications on ceramic ecology are scattered widely in the literature, and few of them until re- J.N. Postgate makes specific use of the voluminous cently have dealt with Old World pottery. This may historical records found on cuneiform tablets in dis- be because many archaeologists interested in the sub- cussing Mesopotamia from 3000 to 1500 B.C.123His ject have an anthropological background that has discussions help to place potters in their ecosystem, been more directed toward New World studies. The and aid in the more effective initial study of the raw range of non-Old World studies that appear in the materials that the potters had available and of the materials cited here should provide a basis for se- markets that they supplied. Similarly, in synthesiz- lective approaches that can be applied anywhere in ing the archaeological evidence for the early cultures the world. of western Iran, Hole and his colleagues relied on A volume edited by van der Leeuw and Pritchard a detailed knowledge of the landscape and of the contains several papers related to Near Eastern excavated pottery and architectural remains; in the ceramic ecology. In their preface, they state: "The final chapter of the book, G.A.Johnson provides an conference which resulted in this volume ... held excellent example of the selective synthesis of field in 1982 . .. was deliberately planned as a sequel to data to delineate a broad picture of change, includ- an earlier symposium entitled 'Ceramics and Man' ing developments in ceramic production.124 This is in 1962 ... The primary aim of the 1982 conference a far different approach from the disdainful or per- was to attempt to elicit an assessment of what had haps puckish characterization of abundant potsherds been achieved in the field of ceramic research since on Near Eastern sites as "fairly durable rubbish," both in 1962, archaeology and anthropology, and also which was made by a distinguished anthropologist to suggest new directions for further research."'12 over 50 years ago. Ceramic ecology has been the topic of at least four TECHNOLOGICAL STUDIES symposia at successive annual meetings of the Ameri- can Anthropological Association from 1986 through Detailed laboratory analyses of ceramics are wel- and the 1989, papers presented at the first three have come and necessary aspects of archaeological reports, been published.122 New World ceramics are high- but their results too seldom are integrated into sub- in these lighted publications. Technological studies stantive discussions. Several well-illustrated reports of Old World ceramics in their social contexts, how- on the Scarlet ware of the Early Dynastic period in the five ever, appear frequently volumes published found at Uch Tepe in the Hamrin Basin of the Upper between 1986 and 1990 by the American Ceramic Diyala River in northeastern Iraq show, in addition in the series Ceramics Society and Civilization, edited to the technological data presented, a knowledge of W.D. and P.E. by Kingery McGovern. Ceramic tech- the social or cultural aspects of the problems.125 was the of an nology general subject entire issue of Results from the several analytical techniques used, WorldArchaeology(vol. 21:1, 1989). Many of the papers while complementing one another, also provide in this issue are for pertinent the Old World, spe- unique perspectives on the pottery together with the Near Eastern ceramic cifically ecological studies. Art cultural and natural landscape in which it was pro- and Technical which Archaeology Abstracts, are now pub- duced. As an example of a very different approach, lished by the Getty Conservation Institute, often in- abundant kiln wasters and finished ceramic ware were clude abstracts of ceramic research in which one or found and carefully documented at Tell Leilan in more of an aspects ecological approach appear. northeastern Syria, an important urban center dur-

120 P.M. Rice, PotteryAnalysis: A Sourcebook(Chicago 1987) IS 513, Oxford 1989). 314-17, from 317. passage quoted p. 123J.N. Postgate, Early Mesopotamia: Society and Economy 121 S.E. van der Leeuw and A.C. Pritchard eds., The Many at the Dawn of History (London 1991). Dimensions Ceramics in and of Pottery: Archaeology Anthropol- 124G.A.Johnson, "The Changing Organization of Uruk xv. ogy (Amsterdam 1984) Administration on the Susiana Plain," in E Hole ed., The 122 C.C. Kolb and L.M. A Pot All Reasons: Lackey eds., for Archaeologyof WesternIran: Settlement and Societyfrom Prehis- Ceramic Revisited 1987: The Ecology Technology and Socio- tory to the Islamic Conquest (Washington, D.C. 1987) 107-39. economics Oxford Kolb Ce- of Pottery (BAR-IS346, 1988); ed., 125 M. Gibson ed., Uch TepeII: TechnicalReports (Chicago ramicEcology, 1988: CurrentResearch on CeramicMaterials (BAR- 1990). 110 PATRICK E. McGOVERN [AJA 99

ing the third millennium B.C. On the basis of com- The ecological aspects of the early phases of Neo- positional analyses and measurements of the vessel lithic ceramic production in the Aegean world are dimensions, together with statistical studies using briefly considered in Vitelli's exceptionally thorough several indices of standardization, it was shown that, report'31 on the pottery excavated at Franchthi Cave with careful spatial and chronological controls, "one in southeastern Greece. In her concluding chapters, can use the standardization hypothesis as an effec- she comments on cooking pots that were probably tive methodology in reconstructing the productive used for other purposes, specialist potters who pro- organization of complex societies."126 duced Urfirnis ware, potters who may have been shamans, and pots as markers of social change. CERAMICALLY DEFINED CULTURES CERAMIC ETHNOARCHAEOLOGY A sampling of recent publications concerned with ecological aspects of ceramics indicates, to some ex- Kramer's thorough survey and discussion of tent, the wide range of existing interests. The 'Ubaid ceramic ethnoarchaeology'32 focuses on studies period in lowland Mesopotamia with its well-known "which explicitly consider contemporary pots and ceramics is the connecting link in time between the potters in terms of particular problems with which earliest farming communities and the more com- archaeologists frequently struggle." Her discussions plex, regionally organized societies of the Uruk of ceramic production, use, disposal, and change help period, which were the forerunners of the Sumerian place Near Eastern pottery studies in a world per- city-states. A recently published group of papers on spective, broadening the range of possible areas of the 'Ubaid127 relies greatly on the ceramic evidence ceramic inquiry for the Near East and the Mediter- in discussing trade and incipient state formation. ranean regions. Longacre's broad-ranging compila- One diagnostic vessel type of the Uruk period is the tion of papers from an advanced seminar at the bevel rim bowl, which occurs in great abundance at School of American Research in 1985 includes only many sites. There are many suggestions concerning one article that pertains to our present areas of dis- the use of these bowls, but few that are convincing. cussion.133 His authors, all archaeologists, concern Is it possible that the bowls were used to lightly bake themselves with identifying social and behavioral bread, which in turn was used in the production of sources of ceramic variation in societies all over the beer, a staple food product? Chazan and Lehner world. The bibliography in this volume is exception- make a cogent argument for this hypothesis, sum- ally thorough. marizing previous studies and citing pottery paral- Village potters in Pakistan, and until recently in lels, especially as illustrated in tomb drawings in Afghanistan, continue to produce their wares un- Egypt.128 impeded by modern technical practices. They pro- The pottery of medieval Nubia has been thor- vide current examples of long-standing techniques oughly studed by Adams,129 who discusses the de- of pottery making. Rye and Evans's detailed report tailed information he has obtained from both archae- on Pakistani pottery134 is exceptionally well illus- ological and ethnographic materials. The trade of trated and documented, and includes analytical re- widely distributed Egyptian waterjars, made for the sults from laboratory studies. most part at Ballas in Upper Egypt, is one facet of Theoretical considerations, as well as field docu- a detailed study of pottery manufacture at this mentation, have great merit. The way in which site. 130 Arnold135 organizes the ceramic data obtained from

126 MJ. Blackman, GJ. Stein, and P.B. Vandiver, "The Bey III and C.A. Pool eds., CeramicProduction and Distribu- StandardizationHypothesis and CeramicMass Production: tion (Boulder 1992) 25-47. 131 Technological,Compositional, and MetricIndexes of Craft K.D. Vitelli, Franchthi Neolithic Pottery 1: Classification Specialization at Tell Leilan, Syria,"AmerAnt 58 (1993) 77. and Ceramic Phases 1 and 2 (Bloomington 1993). 127 132 E.E Henrickson and I. Thuesen eds., Upon This Foun- C. Kramer, "Ceramic Ethnoarchaeology," Annual Re- dation:The 'UbaidReconsidered (Copenhagen 1989). view of Archaeology 14 (1985) 77-102. 128 M. Chazan and M. Lehner, "An Ancient Analogy: Pot 133 C. Kramer,"Ceramics in Two Indian Cities,"in W.A. Baked Bread in Ancient Egypt and Mesopotamia," Paleori- Longacre ed., CeramicEthnoarchaeology (Tucson 1991) 205-30. ent 16 (1990) 21-35. 134O.S. and C. Evans, Traditional 129 Rye Pottery Techniques W.Y.Adams, "The Social and Economic Background of Pakistan:Field and LaboratoryStudies (Smithsonian Con- of Nubian Pottery Manufacture,"in W.Y.Adams, Ceramic tributions to Anthropology 21, Washington, D.C. 1976). Industries of Medieval Nubia (Lexington, Ky. 1986) 34-35. 135D.E. Arnold, CeramicTheory and Cultural Process (Cam- '3( P.T.Nicholson and H.L. Patterson, "The Ballas Pot- bridge 1985). tery Project: Ethnoarchaeology in Upper Egypt,"in GJ. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 111

his own fieldwork in Mexico, Guatemala, and Peru, reconsider from an ecological point of view the pot- together with that culled from ethnographic and ar- tery that is available in museums and extensively chaeological reports, leads to generalizations and reported upon in publications. Materials now in theorizing about the massive literature on ethno- storage or on exhibit might be reexamined. Ques- graphic ceramics. Arnold is also concerned with what tions could then be posed that supplementary stimulates or hinders ceramic production. The rela- fieldwork might be able to answer when excavation tively few Near Eastern entries in his index suggest and site surveying resume on a larger scale. that there is still much left to be done with Near Eastern ceramics in this regard. MATSON MUSEUM OF ANTHROPOLOGY As a final note, since archaeological fieldwork is CARPENTER BUILDING not possible at present or severely limited in many THE PENNSYLVANIA STATE UNIVERSITY parts of the Old World, it may well be the time to UNIVERSITY PARK, PENNSYLVANIA 16802

Ceramic Petrography

IAN C. FREESTONE

The petrography of archaeological ceramics in- thickness of the section. These are most commonly volves the description, classification, and interpre- rock or mineral fragments, ranging up to several milli- tation of ceramic pastes, or fabrics, using techniques meters in diameter and occupying a large volumetric derived from those used in geology to describe rocks percentage of the fabric. Inclusions may occur nat- (petrography).136 The primary research tool is the urally in the clay, in which case they are described petrographic, or polarizing, microscope, and the ce- as "intrinsic" or "incidental." Alternatively, they may ramics are examined as thin sections, prepared from have been added deliberately by the potter to im- slices or fragments of pottery that are fixed to glass prove the working or firing properties, in which case slides and abraded to a standard thickness (0.03 mm). they are commonly described as "temper." In addi- At this thickness, many of the more common min- tion to materials derived from rocks, tempers may erals become translucent, and may be identified on include a range of biological and man-made mate- the basis of their characteristic optical properties, rials such as grog (crushed pottery), chaff, bone, slag, such as color, refractive index, and cleavage (fracture and shell. pattern). Petrography is invaluable in the study of paste In ceramic petrography, attention is focused pri- preparation techniques137 and can yield useful in- the identification of the marily upon nonplastic information on methods of forming138 and firing clusions that are set in the fine-grained clay matrix, parameters.'39 The interest of most archaeologists, as well as the determination of their textural char- however, is in the utility of the method in the deter- acteristics such as abundance, shape, and size. The mination of provenience. In this review, provenience inclusions are defined as typically those inclusions studies are emphasized, together with some guide- of the that be paste may characterized effectively- lines that are of assistance for designing a successful in those that are than the mm practice, larger 0.03 project or in evaluating a proposed project design.

l36 This essay has benefited from many discussions Britain: A Case Study,"in E.V.Sayre et al. eds., Materials membersof among the CeramicPetrology Group. The views Issuesin Artand Archaeology (Materials Research Society Sym- expressed remain my own, however.I thank Sheridan Bow- posium Proceedings 123,Pittsburgh 1988) 109-15. Also see man and Andrew Middleton for their comments on the B. Vincent, "CeramicTechnology in Thailand,"Indo-Pacific draft. PrehistoryAssociation Bulletin 10 (1991) 341-48. A recent collection of applications and methodological 138 A. Woods, "AnIntroductory Note on the Use of Tan- is A. papers Middleton and I. Freestone, RecentDevelop- gential Thin Sections for Distinguishing between Wheel- mentsin Ceramic Petrology(BMOP 81, London 1991).Petrog- Thrown and Coil/Ring-BuiltVessels," Bulletin of the Experi- raphy and other mineralogical approaches to pottery are mentalFiring Group3 (198411985)100-14. in a collection of integrated together papers edited by :39Many authors have noted changes in the optical S. Sciencesde la terreet Mery, ceramiquearcheologiques (Docu- characteristics of minerals in fired pottery. For an account ments et Institut Travaux, G6ologique Albert de Lappar- of such changes, seeJ.C.Echallier and S. Mery,"Ievolution ent, no. 16, Cergy 1992). mineralogique et des calcaires au 137 physico-chimique pates See, e.g., I.C. Freestone and V. Rigby,"The Introduc- cours de la cuisson: Experimentation en laboratoire et tion of Roman ap- Ceramic Styles and Techniques into Roman plication archeologique,"in Mery (supra n. 136) 87-120. 112 PATRICK E. McGOVERN [AJA 99 PROVENIENCE STUDIES

In the broadest sense, the term "provenience" is usually understood to involve the subdivision of ceramic assemblages into production-related groups, without necessarily locating the sources themselves, although this remains the ultimate goal. Petrography may be considered useful on a number of levels. First, it is invaluable in paste classification, enabling the identification of wares produced from the same raw materials in the same technological tradition, e.g., grog-tempered ware, sandy ware, etc.140The discrim- ination between likely production groups is more convincingly demonstrated using petrography than Fig. 13. Pastes containing abundant inclusions of quartz examination and is best by macroscopic alone, sand are unlikely to be immediately diagnostic of source. carried out on a carefully selected sample at an early In the case of this potteryfrom the Iron Age site of Hengist- stage in the processing of large bodies of excavated bury Head (Dorset, southern Britain), however,it has been to two pottery. The close relationship between the obser- possible distinguish important production groups on the basis of grain size distribution, a distinction that vations in thin section and the appearance of a sherd has been confirmed by trace element analysis. The pho- in fracture allows defined petrographically paste tomicrograph,with a field of view 6 mm across,shows abun- groups to be used as standards against which the dant subangular grains of quartz (pale) in a fine-grained remaining bulk of the pottery may be sorted using fired clay matrix (dark). low-power binocular microscopy. Outliers are readily identified in this way. nature of the coarse fraction of the ceramic paste is Second, petrography may be used in paste char- a limitation, so that even quantitative petrographic acterization. A detailed petrographic description approaches of this type lack the precision and sen- may be used to fingerprint a paste, establish a paste sitivity (hence the discriminating power) of modern group, and compare it with ceramics from a known elemental techniques such as neutron activation source.141Within a relatively homogeneous geolog- analysis (NAA) and inductively coupled plasma spec- ical environment, however, the differences between trometry (ICPS). NAA and ICPS routinely achieve a pastes produced at different workshops may be slight precision of about 2% on 20 or more elements. There and not distinguishable qualitatively. Therefore, at- are rarely more than three or four mineral species tempts have been made to improve the precision of present in a ceramic paste that can be quantified with petrographic descriptions by estimating the volu- such a degree of precision. If paste groups cannot metric proportions of the minerals present as vol- be distinguished by qualitative or semi-quantitative ume percentages (modal analysis) or by measuring petrographic methods, then recourse to trace ele- the grain size distributions of the inclusions (fig. 13). ment analysis rather than quantitative petrography These measurements can be time-consuming, but is the approach most likely to be successful.143 offer the possibility of applying statistical techniques Finally, the potential of petrography as a predictive to establish paste groups and discriminate between provenience technique has resulted in the wide- sources. In this way, petrography may be used to spread application of the method. The rock and min- provenience ceramics in a manner similar to trace eral inclusions within a paste are a reflection of the element analysis.142Nevertheless, the heterogeneous geology of the source area of the ceramic. Therefore,

140 Supra n. 137. Activation Analysis,"in M6ry (supra n. 136) 49-60; G. 141This type of approach is illustrated in many pub- Schneider and E. Wirz, "ChemicalApproaches to Archae- lished applications; see Middleton and Freestone (supra ological Questions:Roman Terracotta Lamps as Documents n. 136) passim. of Economic History,"in Mery (supra n. 136) 13-48, also 142 For a discussion of some of these approaches, see found the chemical classification replicated in a subset I.C. Freestone, "ExtendingCeramic Petrology,"in Middle- of their sample subjected to thin-section analysis.Y. Mani- ton and Freestone (supra n. 136) 399-410. atis, R.E.Jones,I.K. Whitbread, A. Kostikas,A. Simopoulos, 143Petrography and elemental analysis have frequently C. Karakalos,and C.K.Williams, "PunicAmphoras Found been found to show reasonable agreement when applied at Corinth, Greece: An Investigation of Their Origin and to the same material.See, e.g.,A.P. Middleton, M.R.Cowell, Technology,"JFA11 (1984) 205-22, find good agreement and E.W.Black, "Romano-British Relief-Patterned Flue Tiles: in a range of characterization techniques. A Study of Provenance Using Petrography and Neutron 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 113 it is desirable to understand the constraints that act upon the petrographic method before embarking upon a research program.

PETROGRAPHIC RESOLUTION

The success of a project is in general determined by what may be termed the resolution of the petrographic technique-viz., the degree to which the petrographies of the ceramics under study allow dis- crimination between production groups or potential raw material sources.145 The petrographic resolution can vary greatly, depending on a number Fig. 14. Inclusions of trachyticvolcanic lava (center, com- of factors that are discussed below. An awareness of posed of elongate laths of feldspar) in a first-centuryB.C.- these factors not only enables the evaluation of the A.D. found in first-century flagon, Braughing,Hertfordshire, likely success of a proposed research program, but clearly suggest a nonlocal origin. Associated fragments of also facilitates good project design. The geograph- granite and metamorphic schist (not shown) suggest a source in the ancient volcanic area of the Massif Central, ical limits of a postulated source area also depend France, rather than Italy, where the three rock types are on a number of these factors and are closely related = not commonly juxtaposed. Field of view 3 mm. to the petrographic resolution. 1) The geology of the study area. The more variable it may be possible to predict the geology of the source and diverse, the more likely are production groups area from the ceramic petrography and, from a to have qualitatively different fabrics. Of course, the knowledge of the regional geology, predict the lo- geology is likely to be more diverse on an interna- cation of the source. In some circumstances, only tional scale than a local one, which is reflected in a single thin section may be needed to make such the success of the technique in identifying inter- a prediction, and this characteristic distinguishes regional movement in some ceramics, such as Roman petrography from other provenience techniques that transport amphoras. depend on statistical matching with reference groups 2) A well-characterizeddatabase. A good background based upon the analysis of large numbers of samples. knowledge of the petrographies of other ceramic There are many classic examples of this type of types from the region and period as well as of the study.144 It is particularly successful when the ce- local geology (backed up by fieldwork and sampling ramic raw materials have been obtained from a local- of potential raw materials, particularly where maps, ized outcrop of rocks of unusual composition, such memoirs, and reference collections are not compre- as from an igneous intrusion or a metamorphic hensive) can be of great value in improving the petro- inlier surrounded by sedimentary rocks (fig. 14). Un- graphic resolution so that useful conclusions may be fortunately, successes are outweighed by failures. It made even in relatively unpromising situations.146 is typically not possible to predict the source loca- 3) Ceramictechnology. In general, pastes with coarse tion when the geologies of the source area and the rock and polymineralic sand tempers are more likely findspot are similar, when the paste is fine-grained, to provide evidence of the source geology than are or when the prevailing ceramic technology is domi- very fine-grained pastes.147There are, however, some nated by the use of an undiagnostic temper type, outstanding examples of fine-grained pastes that are such as grog or organic material. For this reason, highly diagnostic of source. For example, certain fine

144The studies of Peacock have been notably success- 146See, e.g., T. Kilka, "AnExample of Study Where the ful. See D.P.S.Peacock, "A Contribution to the Study of PetrographyPrevails over the Chemistry:The Bronze Age Glastonbury Ware from South-WesternEngland," AntJ 49 Ceramics from Fiave (Italy),"in Mery (supra n. 136) 61-72. (1969) 41-61; D.P.S.Peacock and D.E Williams, Amphorae Also see WK. Barnett, "The Identification of Clay Collec- and the RomanEconomy (London 1986); M.G.Fulford and tion and Modification in Prehistoric Potting at the Early D.P.S.Peacock, Excavationsat Carthage:The British Mission Neolithic Site of Balma Margineda, Andora,"in Middle- 1, pt. 1 (Sheffield 1984). ton and Freestone (supra n. 136) 17-38. 145The term resolution is used here in a slightly differ- 147The traditional view that, in contrast to fine wares, ent sense than that suggested by P.A. Wardle,Bronze Age coarse pots were not widely traded has been overturned PotteryfromEastern Yorkshire (Diss. Univ. of Bradford 1991), to a large extent. Analytical studies demonstrate that cook- who uses it to indicate the geological limits, expressed in ing pots, for example,sometimes move over long distances. kilometers, for locating a pottery source. 114 PATRICK E. McGOVERN [AJA 99

Fig. 15. Angular fragments of granite temper in this Late Fig. 16. Slag temper in Iron Age ceramic sample from Bronze Age pot from Yorkshire might suggest a foreign Timna, a Bronze Age copper-smelting site in the Negev origin, as the local geology is sedimentary, but they, in fact, of Israel. The local geology is not particularly promising represent the preferential utilization of hard pebbles and for provenience studies, but the choice of slag temper boulders from glacial drift in the area as temper. The photo- clearly supports local production. Field of view = 3 mm. micrograph shows a central fragment of granite containing three minerals: feldspar (cloudy), quartz (white), and biotite mica (dark, striated). Field of view = 6 mm. 6) A sufficient sample size. Where the differences between paste groups are subtle or not immediately wares produced in southern Italy in the Hellenistic apparent, it is often essential that multiple examples and Roman periods are characterized by the pres- of each group are represented in the analytical ence of numerous very fine fragments of volcanic sample. The worst type of sample upon which to base glass in the matrix. It is essential that the analyst a petrographic study is a selection of 40 or 50 sherds, take full advantage of the information offered by each of which represents a different ceramic type the petrography to understand the ceramic technol- or form. Where groups are established on the basis ogy, since pottery-making traditions can mislead the of statistical analysis of quantitative data, then the analyst (for example, the potter might have mixed minimum size of a group to ensure that it is valid clays or used as temper pieces of erratic boulders may well be 10 or more. that had traveled far; see fig. 15). It will be recognized that the degree of resolution 4) Petrologicalinterpretation. Experience has shown required for the successful outcome of a project de- that a good understanding of the modes of forma- pends upon the questions to be answered. To the tion and occurrence of rocks can be very significant archaeologist working in prehistoric Britain or in interpreting the ceramic petrographies of pots. France, the identification of a volcanic sand in a For example, the compositions of certain relatively ceramic paste is very significant, pointing to an origin common mineral types, such as feldspars, reflect the in southern Italy. To the excavator of a villa in the geological environment from which they are derived, vicinity of Rome or Naples, such information is often whether plutonic, metamorphic, or volcanic. The of no assistance as volcanic sands are ubiquitous term "ceramic petrology" is sometimes used to de- there. Thus, in project formulation, it is necessary scribe the broader theoretical framework of this ap- to balance the resolution anticipated on the basis proach. The implication is that the analyst possesses of geology, ceramic technology, and the available or has access to a level of interpretative skill beyond number of samples against that required to answer the purely descriptive.148 the questions of interest. 5) Reducing background"noise." By comparing like Even when all other controlling factors appear with like and restricting the sample to ceramics that favorable, pottery traditions can be critical in deter- have been closely defined in terms of typology, better mining the extent to which petrography is useful petrographic results can be achieved. Many of the (fig. 16). If calcined bone or some other widely avail- most successful provenience studies have been based able material was used to temper a clay, then there on carefully restricted ceramic types, such as "Glas- may be no possibility of proveniencing a ware, even tonbury Ware," "Pompeian Red Ware," etc. if production took place over the outcrop of a unique

148 An outstanding illustration of the relationship be- ofAmericaBulletin, pt. 1, 90 (1979)993-95, with the full paper tween ceramic petrography and geological environment in part 2 of the same journal, 90 (1979) 1644-1701 (mi- is given by W.R. Dickinson and R. Shutler, "Petrography crofiche only). of Pacific Islands Potsherds," summary in Geological Society 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 115

rock type. For this reason, a pilot study of up to 20 or characterization. The petrographic resolution may thin sections is always to be recommended before be improved by systematic collection of reference any major piece of work is undertaken. An informed materials, including geological data, raw material judgment of the likely outcome can then be made, samples and comparative ceramics from the study and the optimal sample can be selected. area. Pilot studies may be carried out on selected groups of material. Finally, it should be CONCLUSIONS emphasized that an experienced analyst is best fitted to advise With an appreciation for the factors that influ- on and carry out a project if he/she is involved in ence a petrographic project, a researcher should be research formulation at as early a stage as possible. able to make a realistic assessment of the potential of an analytical program in his/her problem area DEPARTMENT OF SCIENTIFIC RESEARCH and the levels of interpretation that are possible. Proj- BRITISH MUSEUM ects may be structured so that, if direct provenience LONDON WC1B 3DG prediction is not possible, then useful information UNITED KINGDOM will be obtained at the level of paste classification [email protected]

Ceramic Petrology and Petrography in the Aegean

SARAH J. VAUGHAN

INTRODUCTION rock types and their constituent minerals. One of the earliest Ceramic petrological and petrographic tech- applications of petrography to archaeological niques, which are derived from the geological sci- materials was undertaken by G.R. Lepsius,150 ences, have proved to be valuable tools for both the who characterized the marbles of museum artifacts and characterization and proveniencing of ancient pot- major quarries of the classical period. The problem of tery and other ceramics (including building mate- mineralogical variation within single quarries rials such as concrete, mortar, plaster, etc.). Petrol- was not addressed in this early work, however, and the ogy is broadly defined as the study of rocks according selective use of one or two of Lepsius's petro- to their chemical, physical, and optical attributes, graphic characteristics by later art historians led to what to elucidate their occurrence, mineralogy, structure, appeared to be overlapping source attributions. origins, history, and interrelationships. It involves This in turn led to dissatisfaction with the technique. The considerable fieldwork in mapping and sampling pioneering work of 19th-century scientists went rock formations in a given region, so that potential largely unappreciated by archaeologists, who were source deposits and quarries used in antiquity can working out artifact typologies based primar- on be characterized. Petrography is more narrowly ily stylistic criteria. Indeed, up until the last 25 defined (see the preceding section by I.C. Freestone), years, relatively few petrological and petrographic and involves the systematic study of geological and studies of ancient Aegean materials had been carried archaeological samples by describing and interpret- out.151 ing their rock and mineral composiiton and tex- As for any developing discipline, some of the early ture in hand specimens and, especially, in thin work suffered from cursory stylistic and technical sections.149 descriptions of the pottery, minimal petrographic detail (which is essential for future reference), and little correlative fieldwork for HISTORICAL OVERVIEW meaningful interpretation of the petrographic data. For example, while The thrust of original petrographic techniques, her preliminary petrographic data may be fine, such as they evolved in the 19th was the assem- limitations century, are evident in Pittinger's summary of detailed blage sufficiently information to classify analyses of Cycladic pottery,152 which also did not

149See P.E Kerr, York and Optical Mineralogy4(New 1977), graphic Examination of Potsherds from Ancient Troy,"AJA C.S. Hutchison, LaboratoryHandbook ofPetrographic Techniques 46 (1942) 237-44; G. Guerreschi, "Ceramica al York preistorica (New 1974). microscopio,"Sibrium 8 ER. "Could 15( (1966) 151-60; Matson, G.R. Lepsius, GriechischeMarmorstudien (Berlin 1890). Have Been Made at Kea?" 151 Pottery AJA 71 (1967) 191 E.g.,L. Courtois, "Note prliminaire sur l'origine des (abstract). differentes de la fabriques poterie du Chypriote recent," 152J.Pittinger, cited as personal communication in R.E. RDAC1970, 81-85; M.Farnsworth, "Greek A Miner- Pottery: Jones ed., Greekand CypriotPottery: A Review of ScientificStudies alogical Study,"AJA 68 (1964) 221-28; W.M.Felts, "APetro- (Athens 1986) 263-64. 116 PATRICK E. McGOVERN [AJA 99 include any material benchmarks for each island's on the Cycladic island of Siphnos, I made briquettes domestic ceramic fabrics against which variants could from the recipes of some of the potters. A common have been assessed. Underfunded and poorly con- mixture was a dark red clay derived from the local ceived petrographic projects, which have not been schist and a highly altered, pale chloritic clay from incorporated into the archaeological research design weathered schist exposures, in a ratio of 2:1. Photo- of a site from the beginning, have also resulted in micrographs of the thin section of a briquette made undigested, largely irrelevant appendices at the end from this mixture show a fine micaceous fabric, with of archaeological reports. no particular clue that it represents a mixture, much Despite the persistent methodological and finan- less any suggestion of the relative ratios of the known cial problems, petrographic research on ancient components. Aegean pottery has seen some notable recent ad- By analogy, mixed materials in thin sections of vances in methodology,153 terminology,154 ethno- ancient pottery are generally difficult to identify. graphic analogy,155 experimental work in establish- Contrasting mineralogical features, however, can be ing agreed-upon criteria for temper identification,156 suggestive. For example, significantly larger and more deriving technological inferences from petrographic angular rock fragments of mineralogy contrasting data,'57 and the archaeological and geological with that in the fabric groundmass could well be the rationale of preliminary petrological and petro- result of crushed rock temper having been added graphic research.'58 to the clay. But the analyst must be cautious. A thin section of a briquette made from a settled sample PRACTICALCONSIDERATIONS of a granodiorite clay from Naxos also contains An important distinction must be kept in mind angular, heterogeneous rock fragments, and clays de- when comparing the petrographic data of stones and rived from some formations can exhibit marked clays that have been collected in the field and those mineralogical heterogeneity, which might be mis- of ceramic artifacts. Mineral and rock inclusions in interpreted by an analyst as evidence of materials pottery can be directly altered by the potter. For ex- mixed by the potter. It is important to determine ample, in refining a clay by settling or sieving out the properties of the available clays near an ancient relatively heavier or larger materials, respectively, production center, since specific clays were either or in adding temper that may have been sorted or suitable or unsuitable in unmixed condition for mak- crushed, the petrography of the pottery fabric will ing certain items (e.g., water jars, cooking pots) or appear to be inconsistent with the unmodified clay using a specific manufacturing technique (such as of its source. wheel-throwing or hand-building). The decision to In the Aegean, modern potters using traditional temper or not temper a clay reflects the potters' con- methods typically mix clays, even adding in soils, siderations of the material and technological prop- to achieve certain working and firing properties for erties of the available resources. the paste. Such mixtures are notoriously difficult to A petrographer must also be alert for other kinds distinguish in thin sections, even when the ingredi- of alterations in pottery sherds, such as the presence ents are present in known percentages. In a recent of secondary calcite deposited by groundwater dur- unpublished study of clays used by traditional potters ing burial (frequently marked by concentric rings

)15 Freestone (supra n. 142);R.W. Dell'mour, "Keramikan- 21-40. alyse mit dem Polarisationsmikroskop: Methodik, Inter- 157 SJ. Vaughan and D. Guppy, "Statistics and the Ar- pretation, Beispiele,"Archaeologia austriaca 73 (1989) 17-34. chaeological Sample,"in C.L.N. Ruggles and S.P.Q.Rahtz 1'4I.K. Whitbread, "The Characterisation of Argilla- eds., Computerand QuantitativeMethods in Archaeology1987 ceous Inclusions in Ceramic Thin Sections,"Archaeometry (BAR393, Oxford 1988) 55-59; Vaughan,"Late Cypriot Base 28 (1986) 79-88; Whitbread, "AProposal for the System- Ring Ware:Studies in Raw Materials and Technology,"in atic Description of Thin Sections towardsthe Study of An- Middleton and Freestone (supra n. 136) 337-68; S.J. cient Ceramic Technology,"in Y. Maniatis ed., Archaeome- Vaughan,"Material and Technical Characterizationof Late try:Proceedings of the25th International Symposium (Amsterdam Cypriot Base Ring Ware:A New Fabric Typology,"in J.A. 1989) 127-38. Barlow,D.R. Bolger, and B. Kling eds., CypriotCeramics: Read- 155 P.M. Day, "Technology and Ethnography in Petro- ing the PrehistoricRecord (University Museum Monograph graphic Studies of Ceramics,"in Maniatis (supra n. 154) 74, University Museum Symposium Series 2, Philadelphia 139-47. 1991) 119-30. I5 N. Cuomo di Caprio and SJ. Vaughan, "Differenti- 158P.N. Hunt and D.R. Griffiths, "Optical Petrology in ating Grog (Chamotte) from Natural Argillaceous Inclu- the Field," WorldArch21 (1989) 165-72. sions in Ceramic Thin Sections,"Archeomaterials 7 (1993) 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 117

of deposition around voids), and the loss of a cer- represented for each pottery class or ware, and that tain percentage and/or type of inclusion due to post- the part of each vessel that is sampled is most uni- excavation treatment of the pottery (especially, acid- formly representative of the vessel's fabric. For ex- cleaning in Greece) or to "plucking" during the ample, body sherds are usually adequate for miner- abrasive preparation of the sherds as thin sections. alogical comparisons. If the parent vessels are of The of petrography archaeological pottery can different dimensions, however, the petrographic provide information on a range of technological is- profiles of the sherds may not be comparable, since sues. For example, firing temperatures can be esti- the fabric of a larger vessel often contains more in- mated by the relative birefringence of clay particles clusions, providing support for the wider, taller walls, and the condition of primary carbonate minerals than that of a smaller vessel. as in the (such calcite) fabric, because temperatures Coarse wares are particularly amenable to petro- over 830? C contribute to the dissociation of primary logical and petrographic research, and are impor- carbonates and destroy clay particle birefringence. tant in elucidating both long-distance trade (e.g., Pottery fabrics fired as high as 1000? C, however, can using storagejars and pithoi) and local activities (such contain whose primary carbonates, dissociation be- as employing different clay bodies for cooking and havior in a was, fact, governed by number of vari- storage vessels). Fine fabrics and, most recently, more ables, including inclusion dimension, calcite crystal utilitarian tools and products of coarser fabrics- matrix the relative size, clay composition, vitrifica- rooftiles, drains, bricks, basins, beehives, tuyeres, tion of the ceramic and the (glassiness) surface, prox- crucibles, spindle whorls, etc.- have been profitably of inclusions to the surface. In thin imity section, studied by petrography, providing an excellent per- one can also distinguish vessel surfaces finished by spective on the range of ceramic raw material ex- from those applied slips simply wet-smoothed, and ploitation within a defined geographic region. The evidence of or is at- burnishing polishing frequently full potential of ceramic petrology and petrography tested the orientation of by finer particles (partic- will be realized, however, only when well-conceived and to the ularly, platey clays micas) parallel object's archaeological projects are coupled with programs treated surface. of field exploration and sampling of relevant clays The size requirements of a petrographic sample, and geological deposits. an approximately 2-cm2 sherd, which is significantly more than that required for isotopic or elemental analyses (as little as 20-200 mg), can sometimes pose THE WIENER LABORATORY a problem in obtaining permission from museum AMERICAN SCHOOL OF CLASSICAL STUDIES and antiquity authorities. Smaller pilot projects, with 54 SOUIDIAS STREET careful research designs and limited sampling, are 106 76 ATHENS especially valuable initially. The analyst should take GREECE care that vessels of different size and function are [email protected]

Ancient Vitreous Materials

JULIAN HENDERSON

Vitreous materials, such as and cov- glass glazes to scientific terminology, glass is described as a super- stones and crushed have been ering quartz (faience), cooled liquid whose structure is normally noncrys- or for produced deliberately adventitiously thou- talline and lacks a long-range, ordered structure.159 sands of from at least as as ca. years, early 4000 B.C. Included under the heading vitreous, in addition Worked a formed obsidian, naturally glass, extends to glass, are materials that are referred to as faience, the human use of a vitreous material considerably "paste," enamel, frit, and glaze. Faience consists of further back in time. Vitreous means that a material both glassy and crystalline components in which the is made of, derived or contains from, glass; according crystals are almost always silica (which occurs most

159W.A. and E.C. The Weyl Marboe, Constitution of Glasses: J. Henderson, "Some Chemical and Physical Characteris- A Dynamic Interpretation (London 1962); R.H. Brill, "ANote tics of Ancient Glass and the Potential of Scientific on the Analy- Scientist'sDefinition of Glass,"JGS4 (1962) 127-38; sis," The Glass Circle 7 (1991) 67-77. 118 PATRICK E. McGOVERN [AJA 99 ROSEDALE ANNEALING , _- 16. FURNACE A .o1 rD

N 'NEALING

" I'"-~

' F NAC 4 . _ FURNACE " 1'1

0 . ',! X :

4 i i ' 1::::::::: SPILLE

- 1 !me/ o__ s 1 -- AS * URy (-i ! ' -, 5t iF///,N PACKED /. Cl, ''. feet 20 CLAY

the northerntype,wimt s a S: SIEGES 1:: ILLE: Gl.ASS Fig. 17. Plan of an excavated 17th-century A.D. glass-melting furnace of the northern type, with separate annealing furnaces, at Rosedale, York- shire, England. (D.W. Crossley and EA. Aberg, Post-Medieval Archaeology 6 [1972] fig. 57)

abundantly as the mineral quartz). The term "paste" amount and rate of expansion and contraction of is often used in technologically imprecise ways. For the glaze and substrate is critical for its structural example, on close examination, some "paste" objects integrity. A family of vitreous materials known as are found to be made or molded from an opaque fuel-ash slags is produced accidentally as by-products glass, which is composed of fused particles of ground of many high-temperature industries. glass. Enamel, on the other hand, is clearly defin- MANUFACTURE, RAW AND PROPERTIES able as translucent or opaque glass set into a metal MATERIALS, or glass surface - most commonly in antiquity by cloi- Vitreous materials are produced using a range of sonn6 or champlev6 techniques on metal. Frit is com- raw materials.160 These include silica, an alkali such posed of the basic raw materials of glass production as soda or potassium oxide, and a calcium-rich raw that are only partially fused. Again, the archaeologi- material (e.g., lime), which, when fused, form a soda- cal usage of the term "frit" can be quite ambiguous. lime-silica glass. Lead oxide, mineral colorants, Glazes are simply glasses applied to pottery or stone opacifiers, clarifiers, and opalizers are used for creat- surfaces, and often contain high lead oxide levels. ing and modifying the color and physical appear- Their "fit"or adhesion to a surface is especially im- ance of vitreous materials. Waste glass (called cullet) portant and, as with vitreous enamels, the relative is often added to the "batch" of raw materials and

160W.E.S. Turner, "Studies of Ancient Glass and Glass- "TheRaw Materials of EarlyGlass Production," OJA 4 (1985) Making Processes,"parts III and V,Journal of the Societyof 267-92. Glass Technology40 (1956) 39-52, 277-300; J. Henderson, 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 119 reduces the overall melting temperature; its use is therefore economically advantageous. Obviously, quite specific temperature regimes are necessary to melt or sinter raw materials (the latter involves heat- ing the raw materials below their melting points until they form a solid mass), as well as to recycle glass, apply enamels and glazes effectively, anneal glass and glazes (i.e., reheat them following manufacture, in order to allow them to "relax" or stabilize), manufacture faience, and develop or retain color and opacityl clarity in vitreous materials. Furnaces and kilns were designed quite specifically in keeping with the close control of temperatures demanded by the industrial processes. For example, one principal glass-melting furnace type (the so-called southern type) is comprised of a stoke hole, melting chamber, and lower- Fig. 18. Backscatteredelectron micrographof fluorite crystals, seen as black 1-5 i in size, in a temperature annealing oven as separate chambers particles 16th-century A.D.Chinese opaque turquoise cloisonne enamel. Discrete of a construction, whereas the so-called north- single clusters of different-sizefluorite crystals indicate that the ern type has an annealing oven that is separate from enamel was fused within the cloisson in situ. the main furnace (fig. 17). SCIENTIFIC ANALYSIS Lower temperatures were also involved in fritting glass raw materials-that is, partially melting pri- A wide range of modern physicochemical tech- mary raw materials and removing any impurities- niques have been used to study vitreous materials.161 than for full fusion, and such operations were some- Even though earlier investigations provided evidence times carried out in special furnaces. Experiment- for meaningful chemical compositional groups,162 ing with a range of manufacturing techniques and the techniques used up to about 1970 tended to be conditions reveals the complexities of ancient vitre- slow and time-consuming. Consequently, a data base ous material technology. As one example, the effect for ancient vitreous material compositions only of varying the percentage of oxygen on the color slowly developed. Recently, faster and more auto- of the finished product can be studied and then re- mated techniques of data collection and analysis have lated to the colors of ancient artifacts. It is very im- enabled ancient vitreous materials to be character- portant that such investigations spring from a close ized more exactly over broader geographical areas consideration of the ancient materials in their proper and longer time spans. In some cases, the provenience archaeological contexts. of an artifact can be assigned only on the basis of Excavation of sites where ancient vitreous mate- its chemical composition. rials were made into artifacts can potentially pro- The available scientific techniques provide a range vide valuable evidence for raw materials, furnaces, of information about vitreous materials. Scanning kilns, crucibles, and fuel used, in addition to the vitre- electron microscopy (SEM) is particularly useful for ous products and by-products themselves. Such a photographing and identifying opacifying crystals study would normally be carried out for an entire and frits as small as 1 t in size in glasses and glazes site or region, and the organization of the vitreous (fig. 18). The chemical compositions of vitreous ma- material industry should be linked to other high- terials can be determined using X-ray fluorescence temperature activities for which different pyrotech- analysis (XRF), electron-probe microanalysis (EPMA), nological expertise and equipment (e.g., fuels, fur- and proton-induced X-ray emission spectrometry nace or kiln design, and the use of ceramic materials) (PIXE). These surface techniques are minimally de- might have been shared or influenced vitreous ma- structive or nondestructive. If surface layers have terial technology. been weathered, however, they must be removed by

161J. Henderson, "The Scientific Analysis of Ancient 19,UCLA Institute of Archaeology,Archaeological Research Glass and Its Archaeological Interpretation,"inJ. Hender- Tools 5, Oxford 1989) 30-62. son ed., ScientificAnalysis in Archaeologyand Its Interpretation 162E.V. Sayre and R.W.Smith, "CompositionalCategories (OxfordUniversity Committee for ArchaeologyMonograph of Ancient Glass,"Science 133 (1961) 1824-26. 120 PATRICK E. McGOVERN [AJA 99 14-

Glassof 11 -7 centuries B.C. date 12 LMHKcomposition from Northern Weight% Italy, Switzerlandand Ireland K20

0 High MgOglass of 13thcentury to 7th century B.C. England,Germany, Yugoslavia, Czechoslovakia, Hungary Greeceand Rhodes a -

. 0 ....' '"'""""" 1 I I I 0 1 2 3 4 5 6 Weight 0/o MgO Fig. 19. Bivariate plot of magnesia (MgO) versus potassium oxide (K20) by weight percentage for 14th-7th century B.C. European glasses. Near Eastern and Egyptian glasses of the same time span group together with the high magnesia, low potassium examples. polishing before analysis. An additional advantage though important, may not always contribute to of these techniques is that one can see what is being the archaeological interpretation in a meaningful analyzed and thereby avoid impurities and structural way. Fully integrating archaeological and scientific irregularities. Neutron activation analysis (NAA) has aspects is essential for resolving specific techno- the drawback that a ca. 200 mg sample must be pul- logical and cultural issues, as the following case verized; silica, the predominant constituent of vitre- study demonstrates. ous materials, is also not measured, although the A CASE STUDY: BRONZE AGE GLASS IN EUROPE concentrations of other important trace and minor elements can be precisely determined. Mass spec- Much ancient glassmaking before the first millen- trometry, another destructive technique requiring nium A.D. was dominated by soda-lime-silica tech- very small samples, is particularly useful in sourcing nology. One interesting exception, however, occurred any lead that is present.163 It is often advisable to at the turn of the millennium (ca. 1100-1000 B.C., use more than one technique, since each relies on as dated by dendrochronology), when an entirely new different physical and chemical principles that re- vitreous technology emerged in parts of Europe. The sult in different sensitivities. industry is characterized by an innovative use of raw Behind equipment paraphernalia and complex- materials. Relatively high potassium oxide levels of ity, however, the most important consideration in up to 13% by weight are the earliest recorded in- any study of ancient vitreous materials is research stances of such glass; in soda-lime glass, potassium design. To structure a clear and concise set of archae- oxide is typically ca. 0.5% or 2-3% depending upon ological and technological problems to be investi- the soda source. The new glass is also characterized gated is essential. To do science for science's sake, by low calcium oxide and magnesia levels.164 High

163R.H. Brill, L. Barnes, and B. Adams, "LeadIsotopes 164J. Henderson, "Glass Production and Bronze Age in Some Ancient Egyptian Objects,"in A. Bishay ed., Re- Europe,"Antiquity 62 (1988) 435-51; and Henderson, "Elec- centAdvances in Scienceand Technologyof Materials3 (London tron Probe Microanalysis of Mixed-Alkali Glasses,"Ar- 1974) 9-27. chaeometry30 (1988) 77-91. 19951 SCIENCE IN ARCHAEOLOGY: A REVIEW 121

silica levels are caused by crystals dispersed through the use of high potassium glass, it also used glasses the glass, which reflect a relatively high proportion derived from probable recycled Roman tesserae of light and make the glass appear "brilliant." The and/or possibly early Islamic glass. low magnesia and high potassium oxide levels of the glass have led to it being labeled LMHK. The earli- CONCLUSIONS est glasses of this type are concentrated in northern The study of ancient vitreous materials already Italy (at the entrep6t of Fratessina at the head of ranges over a large area of time and space-from the Adriatic) and Switzerland (at a Bronze Age site fourth-millennium B.C. Egyptian faience to the earli- on Lake Neuchatel). This European glass is very est glass of the third-second millennium B.C. Near different from the ancient soda-lime glass of the Near East to European glazes and enamels of later periods. East and Egypt (fig. 19) and of later periods (from Outside of the Near East and Europe, the prehistoric the Hellenistic period to early medieval times) in high alumina soda-lime glasses of India and the Europe. Since it appears at about the same time that high barium oxide of Han China are civilization and trade in the Near East and glasses evidence for Egypt silicate innovation.166 break down, possibly this glass helped to fill an eco- Analytical techniques promise both to broaden nomic vacuum. Even the LMHK Late Bronze Age and deepen our understanding of vitreous technol- glass found in eighth-seventh century B.C. Ireland ogies and their roles in societies. PIXE and induc- (e.g., at Rathgall, Lough Gur, and Freestone Hill) can tively coupled plasma emission (ICPS) now be seen to be connected, however indirectly, to spectrometry enable chemical compositions to be measured at developments in northern Italy. By chemically ana- trace levels, providing very specific provenience data. lyzing well-provenienced and well-dated glass ex- Transmission electron microscopy (TEM) enables amples, it has thus been possible to shed light on minute inclusions, down to a thousandth of a milli- economic, technological, and cultural developments meter, to be and in European prehistory. photographed analyzed. In a sufficient number of Toward the end of the first millennium A.D. in general, closely datable artifacts is of overriding significance in the Europe, a similar shift from soda-lime glass to the study of ancient vitreous materials. Analytical high potassium "forest" glass of the high medieval equipment can provide high-quality data, but the interpretation period occurred.'65 The technological change ap- of the results is, in the end, on re- pears to have been relatively fast, and was due to eco- strongly dependent search design and whether or not the nomic and/or political disruptions in alkali (soda) archaeological materials form coherent supply, which forced glassmakers to use plant ashes archaeological groupings. that have a higher potassium oxide content. The enormous demand for stained glass windows in churches, DEPARTMENT OF ARCHAEOLOGY which now had to be made from the "forest" glass, AND PREHISTORY must have caused major dislocations in the organi- UNIVERSITY OF SHEFFIELD zation of the industry. Scientific analyses of medieval SHEFFIELD S10 2TN "Limoges" enamels, a related vitreous technology of UNITED KINGDOM the period, show that while this industry shared in [email protected]

Xeroradiographic Imaging

PAMELA B. VANDIVER AND CHARLES S. TUMOSA

is a tech- Xeroradiography radiographic imaging source. Differences in charge density produce an similar to nique photocopying techniques pioneered image that is then rapidly transferred onto a 24.5 x the Xerox The is by Corporation. image produced 34.5 cm paper in a special copy machine. There is the of interest on a by placing object charged seleni- no film to develop. Typical exposures are lower in um and it with a standard plate irradiating X-ray energy and exposure time than film radiography, and

165 M. Szklo W 166 Dekowna, Europie wczesnosredniowiecznej See esp. J. Bhardwaj ed., The Archaeometryof Indian Henderson and I. (Warsaw 1980);J. Holand, "The Glass Glass(New Delhi 1990);and R.H. Brill andJ.H. Martin eds., from an Medieval Chieftain's Farm in North- Borg, Early ScientificResearch in EarlyChinese Glass (Corning, N.Y.1991). ern Norway," Medieval Archaeology 36 (1992) 29-58. 122 PATRICK E. McGOVERN [AJA 99

the results are available within 3-5 minutes of be- A positive xeroradiographic image will usually dis- ginning the imaging process.'67 play the porosity and details of manufacture, while As many studies have demonstrated, the images a negative image shows better the inclusions or are easy to "read" and understand because edges, higher-density features of an object.170 One of the joints, or pores are enhanced with a halo effect.168 limitations of xeroradiography, however, is a 20-g The researcher evaluating xeroradiographic images, spatial resolution, which is coarser than the 3-gireso- however, should understand the constraints of the lution of current X-ray film. technique. For example, the print is a mirror image of the object, unless reversed for publication pur- EXAMINATION OF A GAZELLE RHYTON poses. The images also superimpose edge-enhanced surface detail onto the internal structure, and the A ceramic rhyton of a gazelle head in the Arthur side nearest the charged selenium plate is imaged M. Sackler Gallery of the Smithsonian Institution in more detail than the side away from the plate. (fig. 20) provides an example of the technological This effect can be significant if the artifact is very information that can be obtained by xeroradiog- thick or is a hollow vessel. raphy.'71Although a gift to the Smithsonian and un- The mechanism of achieving contrast is different provenienced, the vessel is possibly from Iran, and from that of film radiography where the image is dated by thermoluminescence to the first century is proportional to incident X-ray intensity on the B.C.-first century A.D. film.'69 In electrostatic imaging, such as xeroradiog- The rhyton was clearly made in several pieces that raphy, charges accumulate at boundaries and around had been joined together. Visual examination also small details, and, much like a capacitor, a suffi- suggested that the beaker portion of the vessel was ciently large electric field will discharge across either wheel-thrown or hand-built with strips or coils, an edge. Any residual charge imbalance can dis- whereas the rhyton head was hand-modeled. Very charge again and again, thereby producing an edge- fine circumferential ridges, about 0.3-2.0 mm apart, enhancement. Because differing charge buildups and can be seen on the interior using an intense penlight discharges occur, areas of varying density on a xero- at a glancing or low angle to the surface, and indi- radiograph cannot be compared quantitatively. The cate the smoothing of the surface.'72 In addition, cir- technique has a wide dynamic range in which many cumferential grooves, about 3-4 cm apart, can be objects of diverse materials can be imaged in a single felt on the interior. Since these grooves are horizon- exposure; although densities are less well distin- tal and do not spiral to the rim as is observed on guished than with film radiography, discontinuities wheel-thrown vessels, they are most likely to have are enhanced. The wide range of densities that can been produced by hand-building. Because of weather- be imaged and seen in a xeroradiograph are often ing and pitting, no additional information could be obscured in a black-and-white print. ascertained from the exterior surface.

167We thank Jane Norman and Thomas Chase of the 169J.N.Wolfe, "Xeroradiography:Image Content and Freer Gallery of Art and Arthur M. Sackler Gallery, and Comparison with Film Roentgenograms,"AmericanJournal the staff of the Department of Radiography of the Alex- of Roentgenology17 (1973) 690-95. 170 andria (VA)Hospital, for their assistance in the xeroradiog- P.B.Vandiver, W.A. Ellingson, T.K.Robinson,J.L. Lo- raphy of the gazelle rhyton discussed below. D. Stoneham bick, and EH. Sequin, "NewApplications of X-Radiographic of the Research Laboratory for Archaeology and the His- Imaging Technologies for ArchaeologicalCeramics," Arche- tory of Art (University of Oxford) provided the thermo- omaterials5 (1991) 185-207. luminescent dating of the rhyton. A. Gunther, M. Good- 171The rhyton, inv. no. S1987.31,has been published in way, and R. Henrickson offered useful comments on an AsianArt in theArthur M. SacklerGallery: The Inaugural Gift earlier draft of this manuscript. (Washington,D.C. 1987) 24 no. 16, and 43; T.S.Kawami, An- For discussion of the technique,see T.L.Thourson, "Xero- cient Iranian Ceramicsfrom the ArthurM. SacklerCollections radiography,'Journalof theSociety of Photoand OpticalInstru- (Washington,D.C. 1992) 222 no. 141;and A. Gunter, "The mentationand Engineering56 (1975) 225-35. Art of Eating and Drinking in Ancient Iran,"Asian Art 1:2 168 A.P. Middleton,J. Lang, and R. Davis, "The Applica- (1988) 39. tion of Xeroradiographyto the Study of Museum Objects," 172P.B. Vandiver, "Sequential Slab Construction: A Con- Journalof PhotographicScience 40 (1992) 34-41; W.D.Glanz- servative Southwest Asiatic Ceramic Tradition, ca. 7000- man and SJ. Fleming, "Xeroradiography:A Key to the Na- 3000 B.C.,"Paleorient 13 (1987) 9-35; R.C. Henrickson, ture of Technological Change in Ancient Ceramic Produc- "Wheelmadeor Wheel-Finished?Interpretation of'Wheel- tion,"Nuclear Instruments and Methods in PhysicsResearch A242 marks' on Pottery,"in P.B. Vandiver,J. Druzik, and G.S. (1986) 588-95; S. Heinemann, "Xeroradiography:A New Wheeler eds., MaterialsIssues in Art andArchaeology 2 (Pitts- Archaeological Tool,"AmerAnt 41 (1975) 106-11. burgh 1991) 523-41. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 123

Fig. 20. Ceramicgazelle rhyton,possibly from Iran, ca. firstcentury B.C.-firstcentury A.D.(ArthurJ. Sackler Gallery,Smithsonian Institution S1987.31).Made of a soft (Mohs 2.5), tan clay body, the vessel balances on its handle, and has a spout hole below the mouth.

The xeroradiographs (fig. 21a-b) confirm that the a luxury item that would not have been produced beaker portion of the rhyton was hand-built with in large numbers. The method is unlike that used strips or coils. The process of throwing results in for other Greek zoomorphic rhyta in which the head the alignment of air pockets in the clay body at an section is molded and the beaker is thrown. Micro- angle of about 30-45? from the throwing grooves scopic examination of the Greek rhyton collection and ridges.173 In contrast, coiling techniques pro- at the Ashmolean Museum shows clear marks where duce a horizontal alignment of porosity, as is ob- the two molded halves of the heads were joined to- served in figure 21a. It should be noted that, if the gether, and spiral throwing-ridges and occasional vessel wall were shaped after coiling, porosity align- diagonal stretch marks in upper sections of the ment might also be angled off from the horizontal. beaker portions of the vessels. The uneven wall thickness of the carefully sculpted It is also surprising that the firing temperature head supports the hypothesis of hand-modeling as of the gazelle rhyton was so low that the body is quite its method of manufacture. Rounded fingertip-sized porous and permeable to liquids. Cracks that ap- impressions, but no indentations made by pointed peared during forming and drying are present at or blunt tools, are seen on the head's interior. Be- the top of the handle, the beaker joint of the extra cause some of the exterior features are undercut, reinforcement clay strip extending from the throat the head could not have been made in a single, open- to the base of the beaker (fig. 21a), and below the face mold. The lack ofjoints indicates that the head handle in the wall of the beaker. Four grooves had was made from a single piece of clay. been created with a rounded tool below and parallel Even though molding and throwing would have to the handle after the clay body was stiff and some- been more efficient, the care and excellence in crafts- what dry. Three of these grooves deformed the clay manship of the gazelle rhyton, in particular the qual- body sufficiently to have produced cracks in the ity of its sculpting using the labor-intensive methods grooves from which any liquid contents might have of hand-building and modeling, suggest that this was escaped.

173 P.B.Vandiver, "The Implications of Variation in Ceramic Technology,"Archeomaterials 2 (1988) 139-74. 124 PATRICK E. McGOVERN [AJA 99

Fig. 21. a) Xeroradiographof the left side of the gazelle rhyton (fig. 20), showing the spout hole beneath the mouth, a second hole through the mouth that was later covered over with clay, the uneven wall thickness of the carefully hand-modeled head, the extra clay strip added between the throat of the head and the base of the beaker, and the passage between the beaker and the head. The attached beaker is uniformlyshaped, with an attached strip of clay for the handle. b) Xeroradiograph of the top of the rhyton, showing the attachment of the head to the beaker, and the partial rounding of the beaker base where a passage opens between the latter and the head.

Does the gazelle rhyton represent an ancient ex- rhyton illustrates the effectiveness of this nondestruc- ample in which technical understanding did not tive technique in discovering ancient manufactur- match the artisan's expressive sculptural capabilities? ing methods. The technique can also be applied to Examination using xeroradiography combined with many other materials-- textiles, paper, wood, metals, other analytical techniques not only has allowed iden- corrosion products, etc.--and types of artifacts. tification of the methods and sequence of manufacture, but also has led to further questions about the CONSERVATIONANALYTICAL LABORATORY intended function and quality of craftsmanship em- SMITHSONIAN INSTITUTION ployed in the vessel. WASHINGTON, D.C. 20560 The xeroradiographic analysis of the gazelle [email protected] 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 125 The Provenience Analysis of Amber

CURT W. BECK

Amber (figs. 22-23) is the name originally attached many as 100 fossil resins occurring throughout to a fossil tree resin that occurs naturally over a large Europe as well as other continents. In 1872, the Italian part of northern Europe. It is thought to have origi- mineralogist Capellini first suggested that some of nated in a forested area of southern Scandinavia, these non-Baltic deposits, including those he him- but only secondary, tertiary, and higher-order de- self had found near Bologna, might well have served are posits known, and among these, the Jutland as raw material for amber artifacts in prehistoric and the shores peninsula of the eastern Baltic Sea times, and that a Baltic origin should no longer be are far the richest. by But due to later geological assumed.74 The suggestion was not well received by - events the formation of the Tethys Sea, the Ice Ages, most archaeologists and led to a quite heated dis- and the river systems that were formed when the cussion during the International Congress of Pre- glaciers melted-it was carried west to the coast of historic Anthropology and Archaeology in Stock- England, south to parts of the Netherlands, the North holm in 1874.175 German and plain, southeast throughout all of But the question had been raised, and the attempt Poland and well into European Russia. Because of the to answer it by scientific means constitutes an im- wide distribution of amber in archaeological con- portant and instructive chapter in the early history texts throughout the Old World, attempts to deter- of archaeometry. The German apothecary Otto Helm mine its provenience go back over more than a set out to identify Baltic amber by chemical analysis. century. The method he used was the quantitative determi- In the 19th the somewhat early century, mislead- nation of a characteristic component of Baltic amber, ingly named "Baltic amber" was held to be the only succinic acid, which can be liberated from the resin source of amber artifacts, and when these were found in excavations outside the natural range of distribution, they were ipso facto assumed to be imports from the north. In the course of the 19th century, mineralogists discovered, described, and named as

8 9 10 11

Fig. 23. Infrared spectrum (no. 425), over the diagnosti- cally significantregion from 7.5 to 12.0 pi (833-1333 cm-l), Fig. 22. Piece of worked amber from Palaeolithic deposit of amber piece from Goughs cave (fig. 22), showing that in Gough's cave, Cheddar, Somerset county, southwest it is of Baltic origin and must have been brought to south- England. (E.K. Tratman, Proceedings,University of Bristol Spe- west England by human activity. (C.W.Beck, Proceedings, laeological Society 6 [1953] pl. 26) University of Bristol Spelaeological Society 10 [1965] fig. 64)

174 G. Capellini, "Uber das Vorkommen von Bernstein dans l'antiquite,"and ensuing discussion, Congresinterna- im bolognesischen und anderen Punkten Italiens," ZfE, tional d'anthropologieet archeologieprehistoriques (Stockholm Verhandlungen 1872, 198. 1874) 777-817. 175 H. Stolpe, "Surl'origine et le commerce de l'ambre 126 PATRICK E. McGOVERN [AJA 99 by hydrolysis or pyrolysis in amounts ranging from wavelengths and thus furnishes a pattern in which 3 to 8%. Over a period of 25 years, Helm sought to they are diminished or missing. The resulting spec- show that Baltic amber was the only source of ar- trum gives information about the chemical structure chaeological amber artifacts found in the Old World, of the material, but it can also be used, purely em- including most famously the amber beads Schlie- pirically, as a "fingerprint" characteristic of this, and mann had found in Grave Circle A at Mycenae.176 only this, material. Helm was not quite the detached, objective scientist: In 1964, we could show that Baltic amber had a his explicit goal was to prove Capellini wrong. When unique infrared absorption spectrum.178 That spec- it became evident that amber-like fossil resins native trum, incidentally, proved that the age-old notion to Italy, Romania, France, and Portugal contained that Baltic amber derives from pine trees, as claimed as much or more succinic acid as Baltic amber,177 by Pliny the Elder, is wrong. The spectra clearly place he high-handedly dismissed that evidence and the botanical origin not in the genus Pinus but in claimed that he could recognize these resins as non- the closely related genus Araucaria.'79 For the pur- Baltic by sight. Apart from its central methodolog- poses of archaeological provenience analysis, how- ical flaw, this early provenience analysis of amber ever, the uniqueness of the "fingerprint" is enough. had other disadvantages. As much as a gram of an Learning from the shortcomings of Helm's work, archaeological amber find had to be destroyed for we proceeded with methodological rigor. The infra- a single analysis, and the natural reluctance of red spectra of more than 2,000 samples of fossil archaeologists to sacrifice what would often be an resins, collected from the mineralogical collections entire singular find limited the application of the of natural history museums in Europe and the United succinic acid method to a few dozen cases. Lastly, States, were determined. No European fossil resin the question of provenience was often cast too nar- matched the infrared spectrum of Baltic amber, rowly: finds from an excavation were compared to which is characterized by a single absorption in the Baltic amber, on the one hand, and to a single vari- wave number range between 1100 and 1300 cm-' ety of non-Baltic amber, such as Sicilian amber, on that is preceded by a broad shoulder (fig. 23). Infrared the other. If the finds were "more like" one than the spectroscopy thus offers a reliable way of identify- other reference source, they were assigned to it ing Baltic amber with absolute certainty. Like other in blatant violation of the fallacy of the excluded instrumental methods, the infrared test requires only middle. a very small sample, typically between 1 and 2 mg, The failure of this early instance of provenience and can be performed in about 20 minutes. That analysis by physicochemical means had two predict- has made it possible, over the course of the last 30 able results: it lowered the confidence of archaeol- years, to analyze more than 5,000 archaeological ogists in the usefulness of the natural sciences in amber finds from excavations throughout the Old the service of archaeology, and it discouraged further World, with the support of many private and public work toward solving the amber problem. No attempts foundations who have made the project possible, to determine the provenience of amber were made most notably the Division of Anthropology of the for more than half a century after Helm's death. National Science Foundation. The program has been When the search for a reliable method was resumed, conducted under the aegis of the Union interna- the arsenal of analytical chemistry had been enlarged tionale des sciences prehistoriques et protohisto- by a range of powerful instrumental methods. One riques since 1978, when the U.I.S.P.P. established a of these, infrared spectroscopy, has provided the "Committee on the Study of Amber" in recognition solution to a very old question. When infrared light of the potential of these analyses to elucidate the passes through a material, those wavelengths are ab- amber trade and the amber routes in prehistoric sorbed that correspond to the amount of energy re- Europe. quired to support the vibrations of atoms within Because of space limitations, a detailed account molecules. The emerging infrared light lacks those of our results cannot be provided here; a summary

178 1760. Helm, "Uber die Herkunft des in den alten C.W. Beck, E. Wilbur, and S. Meret, "Infrared Spec- Konigsgrabern von Mykenae gefundenen Bernsteins und troscopy and the Origin of Amber," Nature 201 (1964) uber den Bernsteinsauregehalt verschiedener fossiler 256-57. Harze,"Schriften der naturforschendenGesellschaft in Danzig, 179C.W. Beck, E. Wilbur, S. Meret, D. Kossove, and K. N.E 6:2 (1885) 234-39. Kermani, "The Infrared Spectra of Amber and the Iden- 177C.W. Beck, "Amber in Archaeology,"Archaeology 23 tification of Baltic Amber,"Archaeometry 8 (1965) 96-109. (1970) 7-11. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 127 up to 1986 of more than 100 publications is avail- Italy.181A presumed find of amber from Tell Asmar able.'80 It should be noted, however, that the over- (ancient Eshnunna), dated to 2500-2400 B.C., has whelming majority of the archaeological amber finds been shown to be not amber, but East African of south-central and southern Europe are indeed copal.182 Continued research on amber promises to exports of Baltic amber from the north, including shed additional light on its cultural and economic all of Schliemann's finds from Bronze Age Greece. importance in antiquity. The few exceptions are instructive: a find of amber in the Vayenas tholos at Pylos, for example, is of AMBER RESEARCH LABORATORY Sicilian, not of Baltic, amber, as is a find from the VASSAR COLLEGE Aeneolithic necropolis of Laterza in southern POUGHKEEPSIE, NEW YORK 12602

Skeletal Remains

PATRICIA SMITH

The study of human remains from archaeological clear DNA extracted directly from the skeletal re- contexts is one of the many research areas compris- mains, which provide direct information on the ge- ing physical anthropology. In contrast to archaeolog- nome and pathogens present. Evaluation of nutrition ical research that deals with the material culture re- and disease status, as well as evidence of trauma sulting from human activities, skeletal analyses focus (palaeopathology), provides additional information directly on the people responsible for such activities. on the life history of individuals and an estimate The methods used in skeletal analyses are based on of the quality of life for the population under study. those employed for diagnostic purposes in forensic Marked differences in incidence of disease between anthropology, medicine, epidemiology, and anthro- subgroups may result from differences in occupation pological studies of living populations. They are di- and/or access to available resources. This comprises rected toward determining population origins and an important element of mortuary studies that in- kinship, nutrition, disease status, and longevity of vestigate the correlation of social status to burial type. past populations. From a broader perspective, they The techniques used in the above analyses range provide the basic data for studying the nature and from the simple to the sophisticated. Age, gender, rate of human evolution. gross pathology, and phenotype can be determined A skeletal investigation begins by determining the from visual assessment, supplemented by measure- manner in which the individual(s) was interred, as ments made with calipers and tapes.'83 More sophis- evidenced the by position of the bones (whether an ticated studies using radiographs, computerized intact or disturbed burial). This is followed by the tomography (c-t) scans, and optical and scanning determination of and age gender, which are used electron microscopy improve the degree of accuracy to estimate life for expectancy the population studied achieved, especially for determination of age and (palaeodemography). Physical characteristics of in- pathology, while biochemical analyses of trace ele- dividuals are usually defined by measurement of the ments and isotopes can provide additional infor- size and shape of the skull and long bones (mor- mation on diet.184 as well as the phometry), presence of discrete traits. As in all archaeological studies, many factors affect Resemblances between individuals and populations the reliability of the available samples, including ex- are then used to evaluate kinship and population cavation priorities or constraints, burial practices affinities. More sophisticated methods now coming of the population under study, and soil conditions into use include of analysis mitochondrial and nu- causing poor preservation (especially of fragile in-

180 C.W. 183 Beck, "Spectroscopic Investigations of Amber," W.M. Bass, Human Osteology3 (Columbia 1987) is a AppliedSpectroscopy Reviews 22 (1986) 57-110. standardmanual for bone identificationand measurement. 181C.W. Beck and H. "Sicilian 184 Hartnett, Amber,"in J. For methods used in skeletal analysesand life history Bouzek and C.W.Beck Amberin eds., Archaeology(Prague, reconstruction, see Y.M.Iscan and K.A.R.Kennedy, Recon- forthcoming). structionof Lifefrom the Skeleton(New York 1989); and S.R. '82 C. and Meyer, J.M. Todd, C.W. Beck, "From Zanzibar Saunders and M.A. Katzenberg, TheSkeletal Biology of Past to Zagros:A Copal Pendantfrom Eshnunna,"JNES50 (1991) Peoples:Research Methods (New York 1992). 289-98. 128 PATRICK E. McGOVERN [AJA 99 fant bones). To these must be added the "blurring" Sample sizes for Natufian sites in Israel and the factor that is due to the fact that skeletal assemblages West Bank range from seven individuals at Erq el do not usually represent one point in time, but rather Ahmar to more than 100 at Eynan. At most sites, both the accumulated deaths of several generations. Migra- primary (intact) and secondarily disturbed burials tion, immigration, and/or differences in fecundity were found. Preservation of bones ranged from mod- over time may thus contribute to fluctuations in the erate to poor, and the frequency of infants varied age/sex profiles represented.185 from site to site. Because of poor preservation, age or gender could not be reliably defined for more A CASE STUDY FROM THE NATUFIANS: than half the adults excavated, while detailed mor- THE NEAR EAST phometric analyses could be carried out on even Skeletal remains from the Epipalaeolithic or fewer specimens. The teeth and mandibles were best Natufian period illustrate the potential and limita- preserved. tions of skeletal analyses in resolving specific issues, The extent to which the Natufian age distribution especially when dealing with small, biased samples. is biased by differential burial practices can be Dated between ca. 12,500 and 10,500 B.P., Natufian roughly estimated by comparing life-tables calculated sites show a marked increase in settlement size, per- for living populations with those for Natufians. As manent habitation, and architecture as compared might be expected, infant deaths in a modern so- with the preceding Kebaran period. These develop- ciety are inversely related to affluence, being most ments are coupled with an increase in artifacts and frequent in the first months of life and declining later features that are generally attributed to cereal col- in childhood. None of the Natufian assemblages so lection and utilization, such as pestles, querns, sickle far studied, however, fits this model. Diagenesis (dif- blades, and storage pits. In the succeeding Neolithic ferential preservation) cannot account for this dis- period, similar tools and facilities are definitely be- crepancy, since the relative number of infant remains ing used to process and store plant domesticates. recovered from sites with good bone preservation The Natufian period has been subdivided into is not any greater than that for sites with poor pres- three phases on the basis of tool types, and most re- ervation. The most economical explanation, which search on this culture has been directed toward has also been established for other periods, would understanding the "triggers" that were responsible appear to be that most Natufian infants were not for the transition from hunting and gathering to plant buried in the same location as older children and and animal domestication and the establishment of adults. The age distribution is then obviously skewed, permanent settlements throughout the Near East.186 limiting the validity of palaeodemographic analyses. Skeletal remains have been found at most Natufian A further confounding factor is the small sample sites, and research has focused on population affin- size. The discovery of only several hundred individ- ities, disease, and diet.187 uals for a ca. 2,000-year time span implies that there are many gaps in the skeletal record, which is in ac- SAMPLE SIZE AND REPRESENTATIVENESS cordance with the archaeological finding of periodic Natufian skeletal remains, which have been re- abandonment of sites. covered from the sites of Shukbah, Kebara, El Wad, While detailed palaeodemographic analyses of Eynan, Nahal Oren, Erq el Ahmar, and Hayonim in Natufian populations are clearly inappropriate, an Israel and the West Bank, are the primary focus here. alternative approach that provides some information Numerous sites inJordan (e.g., Beidha) and in Syria on longevity has been to assess the ratio of younger (e.g., Abu Hureyra on the Euphrates), however, have to older adults. In the Natufian period, as in most also yielded Natufian material. hunter-gatherer groups studied, very few adults sur-

185J.W.Wood et al., "The Osteological Paradox: Prob- lations in Israel,"pp. 411-24) and P. Smith ("The Dental lems of InferringPrehistoric Health from Skeletal Samples," Evidence for Nutritional Status in the Natufians," pp. CurrAnthr34 (1992) 343-70. 425-32). Also see 0. Soliveres-Massei,Les hommesde Mal- 186 For recent overviews of the Natufian period, see A. laha (Eynan)Israel, Pt. 2: Etudeanthropologique (Memoires Belfer-Cohen, "The Natufian in the Levant," Annual Review et travauxdu Centre de recherches prehistoriques francais of Anthropology20 (1991) 167-86; M.N. Cohen, The Food Cri- deJerusalem 7, Paris 1988) 157-204; and P. Smith, O. Bar- sis in Prehistory (New Haven 1977); and Bar-Yosef and Valla Yosef,and A. Sillen, "Archaeologicaland Skeletal Evidence (supra n. 66). for Dietary Change during the Late Pleistocene/EarlyHolo- 187 Recent summaries and comprehensive bibliogra- cene in the Levant,"in M.N. Cohen and G.J. Armelagos phies of skeletal analyses appear in Bar-Yosef and Valla eds., Paleopathologyat the Originsof Agriculture(New York (supra n. 66) by A. Belfer-Cohen, L.A. Schepartz, and B. 1984) 101-36. Arensburg ("New Biological Data for the Natufian Popu- 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 129

Fig. 24. Side and frontal views of a skull of a Natufian male from El Wad vived beyond age 50. By contrast, ancient agricultural somewhat dolichocranic (long) skulls, and short, societies in Israel and the West Bank had between broad faces. The teeth show a high incidence of 10 and 20% survival rates to this age.188 lingual tubercles on upper incisors and large Cara- belli's cusps on upper first molars. The Natufians MORPHOMETRY AND FUNCTIONAL ANATOMY differ markedly from contemporary populations in All who have studied the Natufians from these sites North Africa and the Nile Valley, which are extremely in Israel and the West Bank agree on the overall phys- robust, with very much larger skulls and teeth, and ical similarities of the populations. Individuals are well adapted to hunting and eating large game (of. characterized by short to medium stature, large, figs. 24-25).189

Fig. 25. Side and frontal views of a skull cAf a Nubian male from West Sahaba

188Smith et al. and Smith (supra n. 187). Communities,"Rivista di antropologia(Rome), suppl. 61 (1988) 189p. Smith, "EvolutionaryTrends in Pre-Agricultural 281-94. 130 PATRICK E. McGOVERN [AJA 99 At Hayonim, at least seven adults (29% of the sample population) have a congenital absence of a third molar, while its overall frequency in Natufians is of the order of 10%. This condition is inherited, so that the exceptionally high frequency at Hayonim indicates close kinship among at least some of those buried there. In a preliminary study, Ferembach reported that the Natufians from Eynan appeared to be taller and have larger heads than individuals from other sites, suggesting that these differences might be related to nutrition.190 This hypothesis, however, has not been supported by the findings on the relative incidence of disease at Hayonim and elsewhere, nor is the number of intact specimens on which detailed morphometric studies have been carried out sufficient to determine intra- and intersite variation. Fig. 26. Teeth with hypoplastic defects, present as parallel Highlighting the limited sample sizes available for grooves and pits on the enamel surface,from Achziv,Israel, comparative studies is the fact that stature estimates ninth century B.C. for the Lower Natufian phase at Eynan were based on only one complete male femur and three incom- can be gauged by reference to the presence of de- plete femurs.191 velopmental defects such as dental hypoplasia and Small sample sizes similarly limit intersite and growth arrest lines. interperiod analyses of cranio-facial parameters. For- A supplementary approach to population studies tunately, mandibles are better preserved than other has been the use of dental traits, which have been skeletal elements, and the number available for analy- found to be extremely reliable in studies of the popu- sis is sufficient for basic statistical inferences. The lation affinities of modern and ancient societies.196 data show that a significant reduction in mandibu- Renfrew's criticisms regarding the effect of environ- lar robusticity occurred during the Natufian period, mental stress on skeletal morphometry can then be thus corroborating the evidence for changing diets countered by careful evaluation of the severity of and reduced selective pressures on jaws based on developmental defects in the samples compared, as patterns of dental disease.192 well as by the use of parameters that show a high In a recent article, Renfrew stated that skeletal degree of heritability such as dental traits. For analyses are of limited value for studying population the Natufians, such studies have emphasized the origins, since skeletal parameters may be modified similarities of Natufian populations from all sites by environmental stress.193Certainly, environmental and phases. stress during childhood may depress growth, but PALAEOPATHOLOGIES WITH CHANGING DIET other skeletal and dental parameters are less affected. Indeed, in the classical study by Boas, usually quoted Environmental stress in the Natufians has been in support of plasticity of cranial measurements, the assessed in terms of developmental defects and other differences found in head length between immi- pathologies. Fortunately for the physical anthropolo- grants to the United States and their offspring were gist, the timing and severity of events, which are small.194Later studies have found that most param- sufficiently stressful to depress growth, result in per- eters of the cranio-facial complex show a high de- manent scars in the teeth and bones that can be gree of hereditability and so are reliable for studies readily identified in adults. The latter include hypo- of population distance.195 At the same time, the plastic defects of teeth (fig. 26) and hypercalcified possible influence of stressed conditions on growth growth arrest lines (Harris lines) in long bones. Simi-

190 D. Ferembach, "Squelettes du Natoufien d'Israel: 195S.O.Y. Keita, "AnAnalysis of Crania from Tell-Duweir Etude anthropologique,"Anthropologie 65 (1961) 46-66. Using Multiple Discriminant Functions,"American Journal 191 Soliveres-Massei(supra n. 187). of Physical Anthropology 75 (1988) 375-90. 192Smith et al. (supra n. 187). 196 The rationale and methods used in dental anthro- 193 C. Renfrew,"Archaeology, Genetics and Linguistic Di- pology are reported in a series of classic articles in Dental versity,"Man 27 (1992) 445-78. Anthropology,edited by D.R.Brothwell (New York 1963). Note 194 E Boas, "Changesin the Body Form of Descendents especially the article by the late A.A. Dahlberg, "Analysis of Immigrants,"American Anthropologist 14 (1912) 530-63. of the American Indian Dentition," pp. 149-78. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 131

the Natufians with hunter-gatherers, who show little pathology, rather than with agriculturalists. Some researchers, however, have argued that few signs of developmental lesions or other pathologies will be found if individuals succumb rapidly to disease rather than surviving long enough for the body to respond.198 Thus, they hypothesize that a low frequency of growth insults may equally characterize populations with high or low stress levels. Certainly, a catastrophe or severe epidemic may cause sudden death of large numbers of the population over a short period of time. Unless the population is decimated, however, some equilibrium is eventually reached, and survival for even two or three days is sufficient for a visible response to infection or severe malnutrition to occur in the bones or developing teeth. For most Natufian sites, the samples extend over several generations, so that we are not dealing with a single episode. The frequency of developmental defects and other skeletal pathologies in samples from the different sites and periods is stable, indicating that the level of environmental stress affecting the bony tissues was fairly constant. In contrast, the severity of dental disease increased over time, pointing to a marked dietary change within the Natufian period. Hunter-gatherers typically eat foods that require prolonged mastication and are largely self-cleansing. Teeth of early Homo sapiens, like those of contemporary hunters and gatherers, are characterized by little caries or disease, while attrition Fig. 27. Radiograph of humeri, showing variation in cor- periodontal tical thickness of bones (most apparent on the second bone rates vary according to the abrasiveness of the diet. from the bottom, as the white bands along the length of Most agriculturalists, on the other hand, eat softer the bone), Dor, Israel, 15th-18th century A.D. foods, including large quantities of cooked carbo- hydrates that stick to the teeth. This predisposes agriculturalists to dental caries and periodontal disease, larly, loss of cortical bone (periostitis), resulting from while attrition rates vary not only with the abrasive- chronic malnutrition andlor disease in the weeks ness of the food but also with methods of food prep- preceding death, can also be diagnosed from the aration. For example, flour ground using simple mill- bones (fig. 27). The frequency of hypoplastic defects ing stones produces considerable grit that contributes in Natufian teeth is approximately 50%, compared to rapid tooth wear. For this reason, early agricul- with approximately 33% in Middle Palaeolithic Homo turalists show severe attrition, in addition to higher sapiens and 90% in later agricultural populations of rates of caries and periodontal disease than hunters Israel and the West Bank. The relative frequency of and gatherers. growth arrest lines in long bones shows a similar pat- Dental disease patterns in Natufian populations terning that demonstrates the intermediate status indicate increased consumption of cooked carbo- of the Natufians. Other pathological signs, such as hydrates over time. The dental disease patterns of reduction in bone mass (osteopenia) and inflam- the Natufians more nearly resemble those of early matory or degenerative lesions of the bones, also agriculturalists than those of hunter-gatherers in occur in lower frequencies in the Natufians than in rates of attrition, caries, and periodontal disease. later agricultural populations.197 Moreover, when specimens are separated out by The results obtained from the study of pathologies phase, the severity of dental disease can be seen to and developmental defects thus concur in aligning increase over time, suggesting a gradual increase in

197Smith et al. (supra n. 187). 198Wood et al. (supra n. 185). 132 PATRICK E. McGOVERN [AJA 99 cereal consumption. Studies based on strontium/ DNA analysis of ancient skeletal remains and mum- calcium (Sr/Ca) ratios of bones provide independent mified tissues, which promises to be a very powerful support for the hypothesis of increased cereal con- technique with wide application. While the cost of sumption in the Natufian period.199 Recently, such analyses presently prohibits their use on a rou- acorns have been proposed as the main source of tine basis, they should enable the physical anthro- the increased carbohydrate consumption in the Na- pologist to test hypotheses derived from morpho- tufian period,200 despite their absence from the metric and palaeopathologic analyses by relating a remains. This plant hypothesis still remains to be known pathology to a DNA mutation or to the pres- tested by dental microwear analysis using scanning ence of a specific pathogen as identified by its DNA. electron Since acorn microscopy. flour lacks the abra- Many questions involving the origins, relationships, sive in the phytates present husks and stalks of and descendants of prehistoric and historical popu- cereals, it should result in a smoother, more polished lations, as well as their behavior and standard of surface of the abraded teeth than that produced by living, should also eventually be answerable. cereal consumption.

CONCLUSIONS DENTAL DIVISION OF ANATOMY AND EMBRYOLOGY Research on the skeletal remains of the Natufians FACULTY OF DENTAL MEDICINE is ongoing. As this brief review has shown, skeletal HEBREW UNIVERSITY analyses offer unique perspectives on past societies HADASSAH EIN KAREM and individuals, and can provide specific answers P.O. BOX 1172 to questions that cannot be addressed by other means. JERUSALEM, ISRAEL The latest innovation is nuclear and mitochondrial [email protected]

Immunochemistry Applied to Archaeology

A.M. CHILD AND A.M. POLLARD

THE IMMUNE RESPONSE the host creature (referred to as in vitro), to detect and quantify specific compounds, such as the pro- is the Immunology study of the reaction between teins in blood. Immunochemistry normally triumphs the immune system of a living organism (the host over conventional organic analysis because its detec- animal) and a foreign substance (i.e., an infectious tion limits are much lower. agent or substance that the organism does not rec- The recognition process itself works on the basis as Most ognize "self"). living creatures possess an in- of molecular geometry (in much the same way as nate immune which system, does not require prior the docking of a space shuttle!). The foreign sub- contact with a foreign substance (i.e., an infectious stance (or antigen -the molecule that generates the in order to be effective. agent) Acquired immunity- antibody) enters the host via the bloodstream or by the to build resistance to ability up infection by an transport across a mucous membrane (e.g., the cells immune is a characteristic of response- vertebrates lining the lungs or gut). It then encounters partic- humans. including ular cells called B-lymphocytes. Each B-lymphocyte The immune includes a response recognition sys- is capable of producing only one type of antibody tem in which the host animal creates "designer mole- that will have a particularly shaped "docking mecha- cules" called antibodies that are capable of recog- nism." The antigen selects the most suitable B- and with the substance nizing reacting invading (the lymphocyte cells, and triggers them not only to pro- is antigen).201 Immunochemistry the application of duce antibodies, but also to reproduce themselves, this reaction in contexts outside antibody-antigen thus enabling the host to respond more quickly to

199M. "The Schoeninger, Agricultural 'Revolution':Its ranean Forest:Implications for the Origins of Cultivation Effect on Human Diet in Prehistoric Iran and Israel," in the Epipalaeolithic Southern Levant,"American Anthro- Paliorient 7 (1981) 73-92; A. Sillen and J.A. Lee-Thorp, pologist95 (1993) 420-35. in the "Dietary Change Late Natufian," in Bar-Yosef and 201C.A. Janeway, "How the Immune System Valla Recognizes (supra n. 66) 399-410. Invaders,"Scientific American 269:3 (1993) 61-67. 200 D.L. Olszewski,"Subsistence Ecology in the Mediter- 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 133

Ae..* Recognitionsite ( of surface Atiny fraction of the total antibodyreceptor lymphocytepopulation v

ACTIV

ANTIBODYSECRETING PLASMACELL z Secretedantibody m combineswith antigen z

Fig. 28. Schematic diagram of antibody-antigenbinding and activation. The invading antigen binds only to the antibody receptor to make a good geometrical fit. This binding reaction causes the lymphocyte whose receptor has been selected to activate other plasma cells to produce more antibody with the same receptor geometry. (I. Roitt, EssentialImmunology7 [Oxford 1991] fig. 2:10) similar invaders in the future (fig. 28). Different parts techniques have been used: radiolabeling, known as of the foreign invader may trigger different B- RIA (radioimmunoassay, using a low activity radio- lymphocytes to produce a range of antibodies, all active compound attached to the antibody), or en- of which will react with the original antigen.202 This zyme labeling. The latter method (ELISA-Enzyme- is the molecular basis of the resistance to disease. Linked Immunosorbant Assay) is now becoming more popular because it does not require the use DETECTION METHODS of radioactive material. It has the disadvantage, how- For immunochemical work, the molecule to be ever, that a further step is needed, usually the ad- identified or quantified (e.g., the human bone pro- dition of another chemical that will change color tein osteocalcin) is injected into the bloodstream of when it comes in contact with the enzyme. The a host animal such as a rabbit and becomes the amount of antigen detected can then be quantified antigen. This stimulates the rabbit's immune system because the depth of color change is proportional to produce antibodies to human osteocalcin (de- to the amount of antibody-antigen complex pro- scribed as rabbit anti-human osteocalcin). These anti- duced. One problem posed by archaeological ma- bodies can be collected and purified, and are then terial is that extracted solutions are often colored used to bind with human osteocalcin wherever it may by humic compounds from the soil, which may mask be encountered (for instance, in mixed protein ex- the color change. tracted from archaeological bone). Both these detection systems can be used in con- In order to be certain that this binding has taken junction with gel separation techniques, in which place, it is important to be able to demonstrate the the molecules extracted are separated according to existence of the antibody-antigen complex thus size and electric charge (electrophoresis), followed formed. This can be done by a variety of methods, by transfer onto a suitable supporting membrane but in archaeological immunochemistry, two main (blotting) prior to detection. This gives increased

202 GJ.V.Nossal, "Life,Death and the Immune System,"Scientific American 269:3 (1993) 21-29. 134 PATRICK E. McGOVERN [AJA 99

specificity, since the molecular weight range of the this research at present is largely driven by curiosity antigen can also be measured (dot-blotting or West- about the length of time that biomolecules can sur- ern blot). vive in archaeological human tissue from a variety of contexts. Proteins in human bone that have been ARCHAEOLOGICAL APPLICATIONS studied include apohaemoglobin206 (which, together The principal use of immunochemistry in archae- with iron, is responsible for oxygen transport in the ology has been to demonstrate the presence of a parr bloodstream) and albumin207 (the most abundant ticular biological compound in material from an dissolved protein in serum). archaeological context. A typical example would be Complications arise with the immunochemical de- the detection of apohaemoglobin (a blood protein) tection of degraded protein (see below), but poten- in archaeological bone. To date, much of this work tially this approach could be used for the diagnosis has largely been directed toward discovering how of a range of diseases that are not currently visible long biomolecules can survive in an immunologically in the archaeological record. recognizable form. So far, the direct archaeological 3) A third area of application is much more benefits of this work have yet to be seen, but hold controversial -the use of immunochemical tests to some promise for the detection of diseases that leave identify blood residue proteins both on stone tools no lesions in bony tissue. and as a pigment in rock art. The subject was first In general, the applications of immunochemistry investigated in 1983, when T. Loy208 identified the to palaeobiology and archaeology fall into the fol- species of origin of blood residues on stone tool sur- lowing three broad categories: faces from recrystallized haemoglobin, after confirm- 1) The demonstration of protein survival in "dino- ing the presence of blood using test-strips. The latter saurs" and other fossil species. More specifically, the are used as a very presumptive screening method degree of affinity between modern antibodies and for the detection of albumin and apohaemoglobin extracted fossil antigens has allowed a phylogenetic in fresh urine samples. Fresh samples are required, study of certain fossil and modern animals, such as since, after one day, there is contamination by the mammoth, mastodon, and modern elephants or seals products of bacterial metabolism that can give false and terrestrial carnivores.203 Archaeologically more positives. Myoglobin and chlorophyll, along with relevant are the studies of Neolithic and Bronze Age other porphyrin-ring containing substances, also give equids,204 and the preliminary work on Neander- false positives.209 Because of the caution with which thal, Homo erectus, Australopithicus robustus, and Cro- dried blood residues are treated by forensic scien- Magnon man.205The assumption is that the affinity tists and because it was unclear whether Loy's samples or degree of binding between an antibody raised were uncontaminated, his results were greeted rather against a particular protein from the modern species skeptically. Further work by Loy and others has now and an ancient antigen (the comparable protein ex- proved beyond a reasonable doubt that recognizable tracted from the ancient sample) is a measure of the proteins can indeed survive for long periods, al- genetic similarity between the two species. Arguably, though a number of investigators still express con- a better measure of this may now be provided by cern about the techniques used in some of these DNA homologies. blood residue studies.210 The oldest reported blood 2) The detection of proteins in archaeological hu- residue dates to 90,000 years ago, from Tabun Cave man bone andlor mummified tissue. As noted above, in Israel.211

2"3J.M.Lowenstein and G. Scheuenstuhl, "Immunolog- Journal of PhysicalAnthropology 87 (1992) 365-72. ical Methods in Molecular Paleontology, Philosophical Trans- 208T.H. Loy, "PrehistoricBlood Residues: Detection on actions of the Royal Society of London B 333 (1991) 375-80. Stone Tool Surfaces and Identification of Species of Ori- 204 A.S. Gilbert, J.M. Lowenstein, and B.C. Hesse, "Bio- gin," Science220 (1983) 1269-71. chemical Differentiationof ArchaeologicalEquid Remains: 209 R.E. Gaensslen, PJ. Desio, and H.C. Lee, "Genetic- Lessons from a First Attempt,"JFA17 (1990) 39-48. Marker Systems: Individualization of Blood and Body 205J.M.Lowenstein, "Immunological Reactions from Fluids,"in G. Davies ed., ForensicScience (Washington, D.C. Fossil Material," Philosophical Transactionsof the Royal Society 1986) 209-40. of London B 292 (1981) 143-49. 210See A.M. Child and A.M. Pollard, "AReview of the 206P.R. Smith and M.T. Wilson, "Detection of Haemo- Applicationsof Immunochemistryto ArchaeologicalBone," globin in Human Skeletal Remains using ELISA,"JAS 17 JAS 19 (1992) 39-47, with references. (1990) 255-68. 211T.H. Loy and B.L. Hardy,"Blood Residue Analysis of 207C. Cattaneo, K. Gelsthorpe, P. Phillips, and RJ. Sokal, 90,000-year-old Stone Tools from Tabun Cave, Israel," "Reliable Identification of Human Albumin in Ancient Antiquity66 (1992) 24-35. Bone using ELISA and Monoclonal Antibodies," American 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 135

(i.e., degraded) proteins may still be recognized by an antibody raised against the complete molecule, provided that the particular epitope is intact. Con- versely, and more likely, it also follows that a partially degraded molecule may have lost the particular sequence or shape that the antibody recognizes, and therefore go undetected. This is a problem peculiar to archaeological and palaeobiological proteins, and gives rise to a number of possibilities that must be considered. If antibodies are raised against intact protein, what are the chances of missing slightly degraded proteins? Alternatively, antibodies raised against degraded proteins are likely to have a high affinity for proteins other than those against which they were raised (i.e., they give false positives).212 These problems, when coupled with those of contamination, which is a characteristic of any biological study of archaeological material, make the immunochemical study of prehistoric human bone a challenging field.213 Fig. 29. Schematic drawing of a folded protein molecule showing how the epitopic region recognized by a single antibody (marked by the symbol o) is discontinuous MUMMIFIED TISSUE AS A CASE STUDY throughout the protein chain as a whole, depending Although most archaeological human remains are strongly on the exact three-dimensional shape of the chain. there is a whole class of If the protein is degraded, it is unlikely that the individual skeletonized, mummified components of the epitopic region, even if they are all still tissue that is characterized by the survival of a sig- present, will retain the same geometry, and therefore the nificant amount of soft tissue, which is of great in- chances of are reduced. recognition occurring drastically terest to the palaeobiologist and Child and A.M. 19 palaeoserologist. (A.M. Pollard,JAS [1992] fig. 1) Mummies-both natural and artificial-have now been extensively studied, and are probably the most THE PROBLEM OF DEGRADED PROTEIN fruitful area for the application of immunochemi- Although antibody-antigen recognition is based cal techniques.214 It is here that immunochemical on a three-dimensional geometrical "matching," it detection of protein, in addition to providing infor- actually involves only a small region of the antigen. mation about the survival of particular proteins, can In other words, even in a relatively large molecule also be expected to give evidence of infectious such as apohaemoglobin, recognition involves only diseases. Antibodies to disease are themselves pro- a very small fraction of the total structure, which teins (called immunoglobulins), which, if produced is known as the epitope (fig. 29). The latter may be by the host in vivo may survive in mummified tissue, either a specific short sequence of the amino acid and therefore be detectable by immunochemical chain that makes up the protein, or it may be a methods. number of nonsequential parts of the chain thatjust The amino acids that link together to form pro- to lie in happen together space because of the three- teins can also be studied, either individually in dimensional nature of the molecule. An antigen may providing a potential dating technique (known as have several epitopes, which is why one antigen may amino acid racemization215) or collectively for con- induce many different antibodies. firming the identity of proteins by matching their Given that these recognition sites are only a small amino acid profile with modern standards. Another of the total part structure, it follows that incomplete class of biomolecules, the lipids (fats), are potential

212 I.A. Wilson, D.H. Haft, E.D. Getzoff,J.A. Tainer, R.A. 214 R.A. Borraco, "Paleobiochemistry,"in A. Cockburn Lerner, and S. Brenner, "Identical Short Peptide Sequences and E. Cockburn eds., Mummies, Disease and Ancient Culture in Unrelated Proteins Can Have Different Conformations: (Cambridge 1980) 312-26. A Ground for Testing Theories of Immune Recognition," 215 P.M. Masters, "Amino Acid Racemisation Dating-A the National Proceedings of Academyof Sciences of the USA 82 Review,"in M.R. Zimmerman and J.L. Angel eds., Dating 5255-59. (1985) and Age Determination of Materials (London 213 Biological 1986) Child and Pollard (supra n. 210). 39-58. 136 PATRICK E. McGOVERN [AJA 99 sources of information about tissue integrity, diet, pear that if population genetics are required, the lifestyle, and evidence of disease. best approach is now to use DNA homologies. Po- Palaeoserology, in particular the study of ancient tentially, therefore, it would seem that useful palaeo- blood groups, is reported to work best when soft tis- anthropological information can be obtained from sue is preserved.216 Since blood groups, as defined the palaeobiology of mummified tissue, although by the ABO antigens, can be determined from cells most authors stress that this must be used in con- extracted from bone, hair, skin, or muscle, as well junction with other information. as blood cells, there have naturally been a number of studies in which blood grouping has been at- SCHOOL OF CHEMISTRY AND APPLIED CHEMISTRY on mummies.217 Standard tests for free tempted UNIVERSITY OF WALES ABO have results, but tests antigens yielded poor COLLEGE OF CARDIFF for tissues devoid of blood are claimed to adapted CARDIFF CF1 have results.218These data have been 3TB given adequate WALES used to between and study relationships living pre- UNITED KINGDOM historic populations in the Aleutian Islands, southwestern United States, Peru, and Chile. More recently, DEPARTMENT OF ARCHAEOLOGICAL SCIENCES however, it has been realized that blood grouping UNIVERSITY OF BRADFORD on material extracted from soil is extremely dubi- BRADFORD BD7 1DP ous due to the ubiquity of interfering material, and UNITED KINGDOM it is not now recommended.219 Again, it would ap- [email protected]

Palaeogenetics: DNA for the Archaeologist

INGOLF THUESEN

In 1981, Chinese scientists reported the extraction pects of ancient biological life is more far-reaching of nucleic acids, the genetic material of all living than dating such remains. Thus far, most palaeo- cells, from a body found in the Changsa Han genetic research has been concentrated on the de- tomb.22" Despite the considerable implications of velopment of analytical methods. Considerable effort the discovery, the result was hardly recognized at the has also gone into finding the oldest genetic mate- time. Four years would pass before scientists in the rial. A weevil trapped in amber, which is dated to Western hemisphere presented similar results from 120-135 million years B.P., has been reported, and this new field of science, which now is materializing plant remains in amber have also produced DNA.221 in an interdisciplinary space between archaeology, Even if a very conservative estimate is assumed for molecular biology, genetics, biological anthropology, the preservation of ancient DNA (5,000-10,000 years), palaeozoology, palaeobotany, and palaeontology. For these discoveries demonstrate that it can survive reasons mentioned below, the discipline is here called under special circumstances for much longer times. palaeogenetics, but other names have been applied to GENERAL BACKGROUND it, such as genetic archaeology, biomolecular archaeology, or simply molecular archaeology. The discov- Organic life takes shape due to a coded record ery of the method and its impact on archaeological in DNA molecules (Deoxyribo-Nucleic Acid), which science have been compared to that of radiocarbon are located in the chromosomes of the cell nucleus. dating, although the potential of reconstructing as- The four "building blocks" of DNA molecules are nu-

21i Borraco (supra n. 214). of Nucleic Acids of Liver from a Corpse from the Changsa 217 R.L. Henry, "Paleoserology," in Cockburn and Cock- Han Tomb," Shen Wu Hua Hsueh Yu Shena Wu Li Chin Chan burn (supra n. 214) 327-34. 39 (1981) 70ff [Chinese]. 218 Borraco (supra n. 214). 221 E.g., RJ. Cano, H.N. Polnar, NJ. Pieniazek, A. Acra, 219 W.F. Rowe, "The ABO Grouping of Human and GO. Polnar, "Amplification and Sequencing of DNA Remains--A Review,"in G.C. Llewellyn and C.E. O'Rear eds., from a 120-135-million-year-old Weevil," Nature 363 (1993) Biodeterioration6 (Proceedings of the 6th International Bio- 536-38; H.N. Polnar, R.J. Cano, and G.O. Polnar, "DNA from deterioration Symposium, Slough, Eng. 1984) 134-42. an Extinct Plant," Nature 363 (1993) 677. 229 G.H. Wang and C.C. Lu, "Isolation and Identification 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 137

cleotides that are labeled A, T, C, and G according targeted or a result of contamination, will be mul- to their base contents (A = adenine, T = thymine, tiplied to several million copies by this technique. C = cytosine, and G = guanine). The nucleotides On the other hand, the strength of the method in are joined in pairs (A-T and C-G) to form a long generating ancient DNA is apparent. In theory, double helix, which through the interaction with one surviving ancient molecule or segment is suffi- RNA (Ribo-Nucleic Acid) determines and regulates cient for characterizing some biological aspect of a the synthesizing of proteins in particular enzymes. plant, animal, or human individual (e.g., part of A particular sequence of nucleotides, a gene, deter- a Y-chromosomal DNA-segment can establish that mines a specific protein. DNA molecules, which store a human individual is male). the biological information, are transmitted through Radiocarbon dating of ancient DNA assumes that reproduction among individuals. Thus, all the in- contamination factors have been excluded. For mu- herited characteristics of the individual (the geno- seum specimens, contamination from handling can can be type) described by its DNA. Defects or changes be ignored when non-human animal or plant species in the genes occur (e.g., by ionizing radiation), lead- are being tested, since specific non-human DNA se- ing to mutations and inherited diseases such as cystic quences are targeted. For human samples, contami- fibrosis and The hemophilia. evolution of a domes- nation must be avoided or removed (e.g., by sampling ticated or animal plant species is due to human ex- from body regions that have never been exposed or and selection ploitation of individuals or races that handled by humans, or by cleaning the exposed sur- have optimal genetic characteristics. faces of the samples). At the termination of life, enzymatic activity nor- Although the discovery of ancient DNA from initiates destruction of DNA mally and RNA. Under mummy tissue in museum collections was ground- one set of extraordinary conditions, however, caused breaking, its archaeological applications are re- either by nature itself or by human intent, some of stricted. Only a finite number of mummies are avail- the nucleic acid in cells or tissue may survive by the able for analyses. Therefore, attempts were made to process of mummification. extract DNA from ancient bone and teeth. In 1989 and 1990, two research re- ARCHAEOLOGICAL APPLICATIONS groups independently ported successful extraction of human DNA from AND PROCEDURES bones.224 Because of its very broad applicability to An to extract and characterize an- early attempt human and animal bone remains, this discovery has cient DNA was made on mummified tissue from an important implications for future archaeological extinct zebra species, the quagga.222 The successful research. extraction of DNA from an soon Egyptian mummy Since the discipline of palaeogenetics is barely 10 followed.223 The results showed that it was possible years old, its archaeological accomplishments have to extract small segments of the genome. An obstacle been limited. There are a few instances of sex de- in these pioneering efforts was to prove the authen- termination and ethnic characterization of human of the DNA extracted from the ticity specimen. archaeological material.225 Biological topics, such as Mummies in museums have often been handled by taxonomy and general evolutionary theory, have gen- a number of and a cell from individuals, just single erally received the most attention. Egyptian mum- a conservator or scientist may contaminate the mies have already been mentioned. Broader-based, This is if the am- sample. problem greatly magnified more systematic research programs are now in prog- method known as PCR Chain plification (Polymerase ress.226 The prehistoric and historical populations Reaction) is used. A of whether single sequence DNA, of central Italy and Spain are being studied using

222R.G. B. M. O.A. Higuchi, Bowman, Freiberger, Ryder, Material from Mummified Tissue and Bone,'JAS17 (1990) and A.C.Wilson, "DNASequence from the Quagga, an Ex- 679-89. tinct Member of the Horse Family,"Nature 312 (1984) 225 E.g., S. Hummel and B. Herrmann, "Y-Chromosome- 282-84. Specific DNA Amplified in Ancient Human Bone,"Natur-- 223S. Paabo, "Molecular of Ancient Cloning Egyptian wissenschaften78 (1991)266-67; H. Nielsen,J. Engberg,and MummyDNA," Nature 314 (1985) 644-45; for a recent over- I. Thuesen, "Frozen DNA from Arctic Human view Samples: by the same author, see "AncientDNA," Scientific Ameri- Burials,"in B. Herrmann and S. Hummel eds., AncientDNA can 269:5 (1993) 86-92. (New York 1993) 119-37. 224 E. B. E.g., Hagelberg, Sykes, and R. Hedges, "Ancient 226See R.K. Wayne and A. eds., Ancient DNA Bone DNA Nature Cooper Amplified," 342 (1989) 485; I. Thuesen Newsletter,Institute of Zoology,Regent's Park, London NW1 andJ. Engberg,"Recovery and Analysis of Human Genetic 4RY,England. 138 PATRICK E. McGOVERN [AJA 99

palaeogenetic methods.227 A multidisciplinary project has been initiated for the Guanche mummies of the Canary Islands.228 Successful extractions of DNA from carbonized plant remains have been reported for ancientJordan (Tell es-Sa'idiyeh).229 Our palaeogenetic research group has been engaged in pilot studies since 1986 to adapt palaeogenetic methods to archaeological issues, both in analyzing museum specimens and in developing appropriate field methods.230 The scientific procedure begins with the formulation of an archaeological problem that can conceiv- ably be answered on the basis of genetic information. The individual is sampled from a well-preserved part. For example, for a human skeleton, a piece of a femur or a tooth is excellent. Any contamination must be avoided. The DNA in the sample is then extracted according to protocols, which may differ depending on the type of tissue, skin, bone, etc.231 If the extracted DNA is damaged, it can be repaired by other procedures to obtain adequate ancient DNA, i.e., DNA that can be routinely handled by molecular biological procedures. Sometimes the extracted DNA contains substances that inhibit the PCR amplification; this problem can be solved by further purification procedures. The next step in the analysis is genetic characterization of the extracted DNA, which requires knowl- of the that characterize edge particular sequences Fig. 30. Sampling of human remains for DNA analysis in sex, biological kinship and ethnicity, and species the field in eastern Syria. A tooth, after being removed variation or defects (such as inherited diseases). from a cranium, is placed in a tube with a DNA-extraction For determination of human sex, the X- and Y- buffer. chromosomes are obvious targets. For species variation, particular highly variable regions of the genome sequences in order to establish the species and other are relevant. In that regard, particular attention has biological characteristics. With these results, the been directed to so-called mitochondrial DNA archaeological problem has been resolved or must (mtDNA). These DNA molecules are located in be reassessed for further research. organelles (mitochondria) outside the cell nucleus, A CASE STUDY FROM ANCIENT SYRIA and are inherited only maternally. The targeted DNA sequence from the sample is In 1990 and 1991, a Danish archaeological expe- amplified by PCR. The nucleotides of the PCR prod- dition excavated remains of a settlement and ceme- uct are sequenced and compared to reference DNA tery at Tell Mashnaqa in the middle Khabur River

227 R. Mariani-Costantiniand colleagues at the Institute 230 I coordinate a palaeogenetic research group at the of Pathology,Universita Gabriele D'Annunzio, Chieti, Italy; University of Copenhagen and the National Museum in and A. Perez-Perezand colleagues at the Secc.Antropologia, Denmark.Many of the ideas and the case study presented Universidad de Barcelona, Spain. here are based on the work of this group, whose members 228A.C. Aufderheide (Departmentof Pathology,Univer- include Henrik Nielsen (Department of Biochemistry), sity of Minnesota, Duluth), C. Rodriguez Martin (Museo S0ren N0rby (Departmentof ForensicGenetics),Jens Peder arqueol6gico de Tenerife,Santa Cruz,Canary Islands), and Hart Hansen (Laboratory for Biological Anthropology), colleagues. DNA analyses have also been carried out by all at the University of Copenhagen, and Bent Aaby,who P.Rogan (UniversityHospital, Hershey,Penn.), and W.Salo is in the Science Unit of the National Museum. (University of Minnesota, Duluth). 231 See B. Herrmann and S. Hummel eds., Ancient DNA 229T.A. Brown and K.A. Brown, "AncientDNA and the (New York 1993). Archaeologist,"Antiquity 66 (1992) 10-23. 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 139

region, Syria.232 The finds have been radiocarbon extraction buffer (fig. 30). After a few hours, DNA- dated by accelerator mass spectrometry (AMS) to extraction was initiated in the camp headquarters. ca. 5000 B.C. Palaeogenetic methods were employed This routine produced a large series of samples to develop field methods and to obtain culture- from the burials. Although the laboratory analyses historical information. How long would DNA in are still in progress, the preliminary results indicate fragile 7,000-year-old human bones be preserved that specific palaeogenetic routines can be carried in a hot and mostly dry environment? If preserved, out in the field, even under the difficult and trying palaeogenetic information on sex and ethnicity conditions of the east Syrian desert. might be obtained. FUTURE PERSPECTIVES In 1990, the samples of bones, which were brought back to the laboratory in Copenhagen, gave negative The application of palaeogenetics to archaeolog- results for DNA, and the observed chemical reactions ical remains depends upon the close collaboration indicated that destructive enzymatic activities might of archaeologists and geneticists. Such research have been triggered by exposure of the bones to air promises to contribute significantly to the reconstruc- and light. Therefore, a procedure was developed in tion of past human life and environmental adapta- the next field season to reduce the risk of post- tion. Determination of human sex, biological eth- exposure degradation and modern contamination. nicity, and kinship are realistic objectives given the Burials were carefully located before bone material rapidly growing knowledge of the human genome. was exposed. A team of scientists (including molec- For other animal and plant species, ancient DNA ular biologists and physical and dental anthropol- analysis should contribute significantly to traditional ogists) excavated the human remains. The position morphological identification. Since DNA from micro- of the body and large bones were identified before organisms will also eventually be isolated and iden- the skeleton was completely exposed. A few centi- tified, new perspectives on inherited and infectious meters of bone were removed and placed in tubes diseases, the fermentation of ancient foods and bev- with DNA-extraction buffers as soon as the skeleton erages, etc., should emerge. was uncovered. Gloves were worn to avoid contamination. Teeth were especially important, since it is be- CARSTEN NIEBUHR INSTITUTE lieved that DNA in the interior, sealed environment UNIVERSITY OF COPENHAGEN of the tooth might be better preserved. After record- NJALSGADE 80, DK-2300 S ing and photographing, a tooth would be pulled out DENMARK from the jaw and placed in a tube with a DNA- [email protected]

Archaeological Conservation

CATHERINE SEASE

Every civilization has had people repairing and struction of a considerable amount of excavated ma- conserving objects of cultural importance. It is not terial. By the early 19th century, reaction by archae- uncommon, but always fascinating, to excavate arti- ologists to these restorations precipitated a change facts that were repaired in antiquity. The conserva- resulting in a preference for antiquities in their tion of archaeological material as we know it has original condition. At this time, publications also slowly developed into a discipline over the past 200 began to appear that dealt with the treatment of years.233In the 16th, 17th, and 18th centuries, much antiquities,234 as well as the analysis of the materi- cleaning, repairing, and restoring of antiquities was als of which they were made. done empirically by craftsmen or archaeologists and In 1888, the Royal Museums of Berlin established was not based on scientific principles. Heavy-handed their Chemical Laboratory, and Friedrich Rathgen, restorations led to the alteration and sometimes de- its first director, became the first scientist hired to

232 See, e.g., I. Thuesen, "Tell Mashnaqa," in H. Weiss, Its Publications,"Journal of the American Institutefor Conser- "Archaeologyin Syria,"AJA 95 (1991) 691-92 and AJA97 vation 26 (1987) 85-104. (1993) 111-12. 234 H.G. Bennet, "An Account of the Ancient Rolls of 233 N.L. Caldararo,"An Outline History of Conservation PapyrusDiscovered at Herculaneum and the Method Em- in Archaeology and Anthropology as Presented through ployed to Unroll Them,"Archaeologica 15 (1806) 114-17. 140 PATRICK E. McGOVERN [AJA 99

Fig. 31. Conservatorin the process of consolidating and lifting two onager skeletons from a burial in Iraq work in a museum laboratory. He recognized the excavated material safely from the ground and to need for a systematic approach to conservation and a laboratory where it could be studied. In 1888, a scientific understanding of how and why artifacts Flinders Petrie published a short article in the deteriorate. Over his 39-year career, Rathgen was ac- ArchaeologicalJournal(vol. 65, pp. 85-89) in which he tively involved in developing and applying physical described treatment methods he employed in the and chemical methods to the preservation of archae- field on freshly excavated material. Today, three man- ological materials, and he thus played an important uals and numerous publications provide the archae- role in the development of archaeological conser- ologist with basic field conservation techniques.236 vation as a science and profession.235 As similar lab- In the early years, no formal training for conser- oratories were established at other museums, the vators existed. Conservators received their training number of scientists working on the conservation through an apprenticeship system working in mu- of artifacts grew. seum laboratories. In 1957, the Institute of Archaeol- At the same time, the literature pertaining to ar- ogy, University of London, established the first uni- chaeological conservation grew. Rathgen's handbook, versity course in archaeological conservation. Die Konservierung von Altertumsfunden (Berlin) ap- Archaeological conservators today are highly peared in 1898; an English translation appeared in trained specialists with a broad knowledge of all ma- 1905 entitled The Preservation of Antiquities: A Hand- terials found on excavations. Ancillary disciplines, bookfor Curators (Cambridge). This was followed in including archaeology, materials science, chemistry, 1934 by the publication of Harold Plenderleith's The ancient technology, and art history, are important Preservation of Antiquities, which in its revised form parts of the conservator's training. Conservators need (London 1971) has until recently been a standard to understand the different materials from which reference for English-speaking conservators. artifacts are made and their chemical and physical Most early conservation treatment took place in structures. By understanding how these materials laboratories, and field conservation consisted pre- deteriorate and under what conditions, conservators dominantly of rudimentary techniques to remove are able to treat artifacts to prevent further deteri-

235 I. Gilberg, "FriedrichRathgen: The Father of Mod- ologist2(Archaeological Research Tools 4, Los Angeles ern Archaeological Conservation,"Journal of the American 1992);D. Watkinsoned., FirstAid For Finds (London 1987); Institutefor Conservation26 (1987) 105-20. and K. Singley,The Conservation ofArcheological Artifactsfrom 236C. Sease, A ConservationManual for the FieldArchae- FreshwaterEnvironments (South Haven, Mich. 1988). 1995] SCIENCE IN ARCHAEOLOGY: A REVIEW 141

Fig. 32. Heavy, fragile pottery vessels, here examples from an excavation in Iraq, can be bandaged and moved to the laboratory for careful removal of soil, consolidation, and reconstruction oration from taking place. Excellent manual skills and a sensitivity for objects and materials are also prerequisites for a conservator. In the field, a conservator is typically responsible for cleaning all artifacts, stabilizing metals and fugi- tive paints, piecing together broken objects, and lifting delicate objects out of the ground (figs. 31-32). In some instances, treatment can be considered first-aid measures for merely safely excavating objects Fig. 33. Detail of an Anglo-Saxon sword. Wood, leather, and shipping them to a conservation facility where and fleece have been preserved by the iron corrosion prod- they can be examined. A series of lifting techniques ucts, and could easily have been lost by injudicious cleaning. has been developed over the years for this purpose. More and more frequently, however, due to laws gov- erning the removal of material from the country of and careful cleaning techniques enable a conserva- origin, the only conservation treatment that artifacts tor to bring to light evidence that could easily be receive will be that done in the field. This places destroyed by inexperienced hands. greater pressure on the conservator to treat artifacts Conservators can also help in planning and im- more fully in the field, so that the maximum infor- plementing the storage of artifacts, of particular mation can be retrieved from each object (see fig. 33), importance for multiseason excavations that provide research carried out, and publication drawings and on-site storage for years before artifacts go to the photographs made before the artifacts disappear into local or national museum. By assuring optimum stor- museum storerooms. age conditions, particularly for metal artifacts, the Documentation is an important part of any con- long-term preservation of the excavated material is servation treatment. Conservators maintain written greatly increased. Conservators can also help pack and photographic records detailing the condition objects safely to ensure their safe transport whether of an object before and after treatment, the various to the local museum or back to a laboratory or re- steps in its treatment, the materials used, and any search facility in another country. Taking time and observations that might be of interest to the archae- care over the packing of artifacts can mean the differ- ologist, conservator, and other scientists who may ence between their survival or destruction. subsequently work on and study the object. For ex- In addition to their knowledge of conservation, ample, textiles and other organic materials are fre- conservators bring additional expertise to an exca- quently preserved only in the corrosion products vation. Experience working on known materials fre- of associated metal artifacts (fig. 33). A trained eye quently enables the conservator to identify the ma- 142 P.E. McGOVERN, SCIENCE IN ARCHAEOLOGY terials from which objects are made. Sometimes this A conservator may be called upon to make casts or information can be of importance to the archaeolo- impressions of objects to aid in their study. For ex- gist when exotic materials unusual to the site are ample, cylinder seals or coins cannot usually be taken found. For example, at a site on Crete, material that out of a country for study. Rollings of the seals or was first labeled as fine ware ceramics was eventually plaster casts of the coins, however, often offer a more identified by the author as fragments of ostrich cost-effective means of studying this material. Numis- eggshell. matists also often prefer to publish photographs of A knowledge of ancient manufacturing processes coin casts, as they frequently show more detail than frequently helps a conservator make observations photographs of the coins themselves. about objects that other members of the team cannot. In cleaning an object, the conservator is the first person in perhaps thousands of years to examine FIELD MUSEUM OF NATURAL HISTORY it carefully, noting details of manufacture and use ROOSEVELT ROAD AT LAKE SHORE DRIVE that add to the information the object reveals. CHICAGO, ILLINOIS 60605