Transcript
MARK MCCOY: The reason I conducted this research is a happy coincidence of a number of advances in the technology that we can use to study these sites, that I was able to bring to bear to be able to ask the question essentially - when were the first chiefs of the island, when were they first coming into power?
SALLY ROUND: Yes, because it's been a bit of a mystery up til now.
MM: It has and we've had a lot of good - I wouldn't call them guesses, because there's scientific and historical research into the oral histories of Pohnpei and using radio carbon dating to try to sink in, to work out as precisely as we can when that happened - but the inherent lack of precision in those methods means that we archaeologists have to live with these wide error bars and say 'well, we think it's around this time.' What I was able to do with this particular research was to be able to say quite precisely that the major monumental burial at the site of Nan Madol dates to around 1180 to 1200AD which makes it the earliest construction of its type by at least a century for the Pacific islands.
SR: And how did you actually do it?
MM: We used two different methods. One method we used to try to work out where the stones to construct the site came from and that really lets us, gives us an idea, not just that this is a big site, that's obvious when you visit it, but the amount of area that the person who is buried there, sort of had control over and could harness the labour and the building material to build it and the method we used for that, it's called x-ray fluorescence and we used a portable machine that looks like a ray gun from a 1950s sci-fi movie and what it does is it tests the chemistry of the stone and lets us match that to its geological source. The other piece of the puzzle or methodological thing that we used is this high precision uranium series dating methodology. It's been successfully applied to things like coral reefs over long, long periods of time, hundreds of thousands of years and important for climate reconstruction dating and that sort of thing. It's been much more useful to archaeologists working in the Pacific over the last ten years or so because we can now use it to say precisely within just a few years of when that coral died and was placed into a site. We can talk about things with a lot more precision.
SR: These are huge structures, a large area, big stones. Did you find out how the material actually got there and what were the methods of construction?
MM: We learnt a little bit more about its construction but I have to say, if I'm honest, it's still a mystery to me how a lot of the engineering went into it. I can speculate, just as anyone could, how it was built. One thing I can say about it for certain is it's built to impress you and it still does that. When you walk up to these little artificial islets you really get the sense that this is meant to leave an impression on you. The burial island itself is just one of 98 of these little offshore artificial islets that are made of ... you get these basalt framing stones, these large megaliths that people have dragged out onto the reef and built up and framed out the islets and then crushed tonnes of coral and heaped it up into ... to make the artificial islets and then they started building fantastically large architecture on top of that. The burial (site) of the first chief of the island for example is this huge enclosing wall that's eight metres tall, several metres thick. It is remarkably impressive. The Pohnpeian oral histories are really quite specific about these first chiefs of the entire island and the dynasty, the leaders that come afterwards, and tell us about the ceremonies that they used, that were centred at Nan Madol and the kind of leaders that they were and specifically where they're buried. And that's all great detail that I could never dig up as an archaeologist but what I can do to add to that is to try and put that on a precise clock and while that seems like a mundane sort of a thing to do, what it lets us do is to scale it out to world history, world pre-history, before written records and when we do that ... when Nan Madol was built, not only was it built to impress you, it was like nothing anyone had ever seen on any Pacific island and that says to me that whatever turned over, whatever changed in society, changed there in isolation. There are other sorts of societies that would make these huge monuments to their leaders, to the dead and you know when we look around the world, these are things that gave us some of the most iconic archaeological sites in the world, the pyramids of Egypt and so on and so forth. That's why I think this is an important finding because it lets us zero in on a time and a place where people made this big shift in their society and controlled that labour.