An Iron Age ritual site near Tara is approved for demolition.
On June 14, 2007, construction resumed on a four-lane highway near the Hill of Tara in central Ireland. Traditionally the seat of the high kings of Ireland, the landscape is littered with burial mounds, rock art, earthen enclosures, and stone monuments. Tara, which has been described as Ireland's equivalent of Stonehenge, was named one of the 100 most endangered sites by the World Monuments Fund this year.
Given Tara's cultural significance and national monument status, it is not surprising that the Irish government met resistance when it announced plans for a 60 km road running straight through the Gabhra Valley between Tara and the nearby Hill of Skreen. Archaeologists and historians claimed that the entire valley, not just the hill, contains historical monuments and artifacts and should therefore be protected. In its defense, the National Roads Association (NRA) argued that a new road was necessary because the existing N3 highway is deteriorating, thereby making travel dangerous and inefficient for drivers between Dublin and Navan. A deal was signed with Eurolink, an independent contractor, and construction began in Spring 2006.
The M3 proposal was heavily criticized, especially after the recent discovery of Lismullin, a ceremonial enclosure located on the edge of the valley, just 2 km (1.24 mi) away from Tara. It is thought to be from the Early Iron Age, which would make it at least 2,000 years old. The site consists of an outer enclosure 80 m in diameter and an inner enclosure 16 m in diameter. Both are bounded by two rings of stakeholes, suggesting that they were initially made from timber. It has been argued that the presence of a ritual site in the Gabhra Valley confirms earlier claims that Tara is a complex of historical monuments, and not only an isolated hill.
After the discovery of Lismullin, all works near the site were put on hold. Section 14 of the National Monuments Act of 2004 requires that road development stop when a historically significant monument is discovered in its path. The road authority must also report the find to the minister for the environment, who is in charge of providing directions to secure its preservation. In the case of Lismullin, Minister Dick Roche ordered that the site be preserved "by record." In other words, archaeologists record their findings as they excavate, and then the site is demolished to make room for the new highway.
Several concerns were raised in response to Roche's plan of action. First, many questioned the validity of the NRA's refusal to protect the entire Tara complex, including Lismullin. Prior to construction, the NRA conducted surveys to determine the best highway route from an archaeological point of view. The surveys revealed 38 sites on the chosen route, none of which they said were culturally or historically significant (click here for map). The NRA still says on its M3 motorway website that, "An unprecedented level of archaeological study and investigation has been carried out as part of the planning process and is continuing prior to construction. It is, therefore, unlikely that any major archaeological site would be uncovered during the construction stage." The M3 was chosen and given the go-ahead largely because of the NRA's claim that the route would not disrupt culturally significant areas.
Although the NRA insists on the quality and rigor of its initial surveys, the discovery of Lismullin exposes the shortcomings of that work. Irish politician Olivia Mitchell notes that Lismullin, "isn't a small [fortification] or a single standing stone, it's the size of three football fields." Indeed, if preliminary surveys missed a site as large and significant as Lismullin, then there is a very real possibility that road developers will unexpectedly run into other historically significant sites as the project continues.
So what's the harm with discovering new sites along the way? After all, only a few sites have ever been excavated in the area. The NRA therefore argues that road construction is a positive development that spurred archaeological research which may not have otherwise occurred. Ronan Swan, the acting head archaeologist at the NRA, states, "The intense archaeological work being done along this route would not have been done. ...Without the road going through, you wouldn't have had this high level of excavation taking place."
However, archaeologists and activists are not so optimistic. According to Vincent Salafia of Tarawatch, an organization committed to protecting Tara Hill, one problem is that severe time constraints make it highly unlikely that the site will be recorded properly. John Waddell, head of the archaeology department at the National University of Ireland, Galway, worries about the use of 22-ton mechanical diggers. (Click here for the university's Tara website.) Although they provide quick access to lower layers of soil, removing upper layers believed to contain few remains, mechanical diggers are likely to destroy delicate artifacts close to the surface. Save Tara, another preservation group, echoed this concern, and requested an independent assessment of the damage caused by mechanical diggers at Lismullin. In general, archaeologists are upset with Roche's decision because they fear that the information will not be documented as thoroughly as it would be in an independent research project. Anthropologist Ronald Hicks of Ball State University warns, "Archaeology is by its very nature highly destructive. And any data not recovered in the process are lost forever." (Hicks's full statement is online here.)
Aside from attacking the archaeology, many argue that the M3 is simply unnecessary given the availability of more reasonable alternatives. The Save Tara organization, along with Ciaran Cuffe, environmental spokesperson of the Green Party, would both prefer to reinstate the Navan-Clonsilla railway, which would provide a link between Navan and Dublin. Rather than building the M3 to bypass newly populated towns, they suggest reducing congestion through improvements in public transportation. The rail line was closed in 1963, but could be restored in a five-year period.
Salafia is convinced that there is a more practical solution to the problem. Since the contract to build the M3 has already been signed, he argues that moving the highway is more feasible than abandoning it altogether. Salafia recommends a route farther west than the planned M3 course. A western road would avoid major archaeological sites, provided it is placed outside of Ringlestown Rath, which delimits the Tara complex on the west. The NRA warns that a western route would "visually obstruct" the panoramic view from atop the Hill of Tara, but Salafia maintains that the road could be hidden given the topographical features of the area.
Accusations that the NRA implemented flawed archaeology and overlooked reasonable alternatives made many uneasy about Roche's decision to demolish the site after it had been documented. Interestingly, after all of the controversy surrounding his decision, Roche will not have the final word on the issue. John Gormley of the preservation-conscious Green Party recently took office as Roche's successor. He began serving on June 15, just one day after Roche's decision. According to Section 22 of the Interpretation Act of 2005, the Minister for the Environment can amend or overturn previous decisions. Gormley therefore has the power to reverse Roche's controversial decision.
Curiously, Gormley does not seem terribly eager to do so. He initially stated, "I will be looking at the documentation in the coming days, but I think it is fair to say that I cannot really do anything about our previous minister's decisions." Later--perhaps after the Interpretation Act was brought to his attention--he stated that, "based on the advice received, the decision cannot be reversed." According to Salafia, the Green Party has begun to accept their minister's reluctance to reroute the M3. Salafia himself admits that political action from Gormley is unlikely.
Many speculate that both ministers are tied down by political negotiations. At the end of the general election in May, the reigning party, Fianna Fail, lost seven parliament seats, six of which went to the Green Party. The two sides subsequently entered into negotiations, ultimately deciding that Fianna Fail would stay in power, provided they granted certain concessions to the Green Party. Other Green issues, such as pollution and global warming, were apparently pushed at the expense of protecting Tara. It may therefore be the case that Gormley cannot reverse the decision without violating the contract between the two parties.
To ensure a constitutional decision, Tarawatch will continue to protest, and even take legal action if necessary. In court, Salafia would attack Roche on grounds that he did not follow legal procedure correctly. He states, "The decision that was made by the minister is a decision that is very specifically prescribed in the National Monuments Act itself. ...It's all clearly mapped out for him. A judicial review is not a review of the substance of the decision--say, whether it's a good or bad decision--but a review of the procedure." Salafia hopes to show that a proper ruling under Irish law would entail the preservation of the entire Tara complex.
There are eight weeks left to protest, at which point legal action must be taken, or else the opportunity will expire under Ireland's statute of limitations. In this eight-week period, Salafia says that Tarawatch will do everything it can to pressure Gormley into making a decision. "We don't want to go to court. We want the minister to make the decision himself," he says, "But if push comes to shove and we have to go to court, then we will obviously change gears and put most of our energy into that arena." The fate of Tara, a monument more than 2,000 years old, may come down to a mere matter of weeks.
Laura Sexton is an undergraduate majoring in History, Philosophy, and Social Studies of Science and Medicine at the University of Chicago.
Figure 1: (a) Warrior # T18G21-08, a kneeling archer. The pigment samples in this study have been taken from this terracotta warrior. (b) Close-up picture of the purple paint on the terracotta warrior. (c) Images of the purple paint samples used in this study.
In March 1974 during the sinking of wells for farmland irrigation near Xi'an, China, nine farmers made one of the world's most remarkable archaeological finds: the discovery of an army consisting of more than 8000 life-size terra cotta figures of warriors and horses of the First Emperor of Qin. One of the most intriguing puzzles is the purple synthetic pigments ("Chinese Purple" or "Han Purple" [1]) found on the terra cotta soldiers (figure 1). Until the 19th century, most pigments were based on naturally occurring colored minerals and dyes, with three significant exceptions: Egyptian Blue (CaCuSi2O10), Chinese Blue (BaCuSi2O10)/ Purple (BaCuSi2O6) and Maya Blue. The former two are alkaline-earth copper silicates, and because of this similarity it has been proposed that the Chinese pigments were derived from Egyptian Blue [2].
This supposition, however, leaves many open questions. First, it is unlikely that the Chinese chemists could have acquired the technology (not just the pigment) from Egypt well before the official "silk road" (125 BC). Some earliest Chinese Purple samples date back to the "Warring States" period (479-221 BC). Considering the time needed to switch a calcium-based technology to a barium-based one, this technology transfer, if there was one, must have happened well before the "Warring States" period. But even if there existed a connection between China and Egypt, it does not explain why the Chinese decided to substitute Ba for Ca and face the challenges associated with the consequent elevation of the synthesis temperature. An additional problem with this theory is that, to our knowledge, no Ca-bearing Egyptian Blue has been found in China.
Figure 2: (a) SEM image of the pigment clump taken at 20KeV. (b) Lead (Pb La) concentration EDX map of the same clump is taken at 15keV. (c) We show an overlapping mXRF (1.5mm spot size) concentration map of Pb (light green, yellow, and orange regions) and Cu (dark green and purple regions) taken at 14KeV. mXRF provides more bulk sensitive information than the EDX microanalysis. (d) The detailed crystallographic map derived from the mXRD (1.2mm spot size) scan. It shows that there are two pigment grains (in orange and red) in the clump which have slightly different crystallographic orientations. The Pb compounds are found either in between the two grains or on the boundary of the grains.
In our study, we analyzed clumps of pigment (figure 2) from the Qin warriors and discovered that in spite of the structural similarity to Egyptian Blue, the micro-structural morphology of Chinese Purple is very different. Based on the morphology and the phase distribution in the clumps of the pigment, it appears that the process by which Chinese Purple was synthesized is very similar to that of barium-containing glasses [3] Combining these results with other archaeological evidence, we propose that the synthesis technology for the Chinese pigments was in fact a by-product of high-refractive index glasses (artificial jades) produced by Taoist monks. Furthermore, the disappearance of these pigments from Chinese art and monuments concurrently with the decline of Taoism substantiates the link between the two.
In summary, we argue that Chinese Purple was invented by Taoist alchemists as a by-product of the technology originally developed for synthesizing barium-containing glasses, which, in turn, were invented for the purpose of imitating jade. The barium compounds were added to increase the refractive index of the glass, thus giving the glass a similar appearance as jade. The development of this process also benefited from two well-developed technologies in ancient China: the earlier Bronze making (adding lead compounds to reduce the melting temperature) and pottery making (advanced pottery kilns) technologies.
It is remarkable that three ancient civilizations, Egypt, China and Maya, invented their own blue pigments independently. The evolution of Chinese purple and blue pigments is also a good example of how cultural changes in the society affected the science and technology development in ancient China.
Primary Citation Z. Liu, A. Mehta, N. Tamura, D. Pickard, B. Rong, T. Zhou, P. Pianetta, "Influence of Taoism on the invention of the purple pigment used on the Qin terracotta warriors", J. Archaeol. Sci. (2007), doi:10.1016/j.jas.2007.01.005
References
1. FitzHugh, E. W. and Zycherman, L. A., "An Early Man-made Blue Pigment from China - Barium Copper Silicate". Stud. Conserv 28, 15-23 (1983); FitzHugh, E. W. and Zycherman, L. A., "A Purple Barium Copper Silicate Pigment from Early China". Stud. Conserv 37, 145-154 (1992). 2. Berke, H. and Wiedemann, H. G., "The Chemistry and Fabrication of Anthropogenic Pigments Chinese Blue and Purple in Ancient China". East Asia Sci. Technol. and Medicine 17, 94-120 (2000); Berke, H., "Chemistry in Ancient Times: The Development of Blue and Purple Pigments". Angew. Chem. Int. Ed. 41(14), 2483 (2002). 3. Beck, H. C. and Seligman, C. G., "Barium in Ancient Glass". Nature, 133, 982 (1934); Brill R. H., Tong, S. C., and Dohrenwend, D., in Scientific Research in Early Chinese Glass, (Ed. Brill, R.H and Matrtin, J. H.) The Corning Museum of Glass, Corning, 31-64 (1991).
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SSRL is supported by the Department of Energy, Office of Basic Energy Sciences. The SSRL Structural Molecular Biology Program is supported by the Department of Energy, Office of Biological and Environmental Research, and by the National Institutes of Health, National Center for Research Resources, Biomedical Technology Program, and the National Institute of General Medical Sciences.
Last Updated: 26 March 2007 Content Owner: Z. Liu and P. Pianetta Page Editor: L. Dunn
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