Humans, as I read recently, look for patterns, even meanings, in things. Archaeologists are used to dealing with things and we certainly like pattern. Half (a generalization) of our data is derived from material culture, the ‘things’ of the Continue reading The Patterning of Things
I’m still on my high horse about type fossils, seriation and dating.
Unlike our predecessors in the early days of archaeology, we have the luxury of several different techniques by which we can provide dates for our sites that approximate, within envelopes of accuracy, calendar years. The most commonly used is radiocarbon dating, but various technicalities about the way in which radiocarbon isotopes accumulate and decay mean that the dates have to be carefully calibrated.
Recently, the accuracy and usefulness of radiocarbon dates have been refined by the introduction of a technique known as Bayesian Dating. It is a complex statistical process by which known information about the sample to be dated can be added into the process to increase the resolution of a date. Thus, for example, if we are dating a carbonized hazelnut shell we might also consider the types of tool with which it is found, the stratigraphy of the sample in comparison to other samples, and our interpretation of the site in comparison to similar sites.
Bayesian dating reduces the size of the envelope of accuracy meaning that we get determinations that approximate more closely to human events. It has been used very successfully to help interpret sites in a way which is more meaningful. Instead of saying that a site might generally have been in use between say 3500 – 2900 BC, we can now incorporate a close analysis of the stratigraphy of different structures on that site, and the finds within the site in order to tease out more precise dates and a sequence for individual structures to suggest that while some of the earlier structures may have been built between 3100 – 3050 BC, the last building activity on site occurred between 3000 – 2950 BC. It is a revolution in the way in which we can think about the use of the sites that we study.
But, I’m concerned that some of the analyses that I see appear to go to considerable lengths in order to reconcile the type fossils and the dates. If we only use type fossils in combination with Bayesian dating in order to confirm our preconceptions, then we will never be able to expand our understanding of the peoples of the past.
For example, a recent study looked at assemblages from 61 sites in order to produce a chronology of the sites in relation to one another. The hypothesis was that these sites fell into a sequence of five different cultural types. The type fossils from each site were identified and used to refine the dating. But there were problems. Several of the sites had combinations of type fossils that apparently fell into more than one of the periods. Others had type fossils that did not appear to be in the right chronological group. So, the study had to start by excluding sites where the type fossils did not easily conform to the hypothesised chronology. Thirty-one sites (half of the original number) were excluded. In this way, it was possible to confirm a tight and interesting chronological sequence for the sites and the type of material they held. But, some of the phases in that sequence comprise very few sites indeed.
I’m just wondering whether a phase that apparently holds good across the UK but only comprises two or three sites, is really valid as a phase? Could it possibly be a regional development? And what about all the sites that were excluded because their type fossils did not conform to the pre-existing pattern? Could they possibly identify new patterns – either a local pattern or a chronological one (or both)? Reading the paper, I came away with the impression that the authors were struggling hard to make the data produce the results they wanted.
It is difficult because we tend to publish only positive results, but I would like to have seen some analysis and discussion that tried to make sense of all the material. Even if it did not seem to confirm accepted wisdom. Bayesian dating is a wonderful new tool but we should be using it to push the boundaries of our interpretation forward, not to confirm our existing thoughts.
The real import behind all this is that we can’t just undertake quick projects to double check our old ideas. In a project like this, we need to go right back to basics and look at the stratigraphy and content of all the sites that relate to our study, whether or not they conform to our pre-existing ideas. And perhaps look for some new ideas? Even when the uncertainties are acknowledged, it often does not stop people from publishing reports wherein they point out how the results from one site can skew the results.
It is also clear that we need to stop looking for patterns that appear to work across the whole of the UK. Of course, the political boundaries that we use today are meaningless in terms of prehistory, but that is not to say that people lived in some bland uniformity across the British Isles. Research suggests that life has got more uniform, not less, with the passage of time.
One of my bug bears in 2016 came to be the way in which archaeologists use artefacts as archaeological type fossils. So, I am going to allow myself a little rant.
In order to understand the past, we need order. For this, we have constructed a framework into which we place different stages of human activity. So, we go from Mesolithic, to Neolithic to Bronze Age and so on. We have three ways by which we can identify where any one site sits on the chain of events.
- We make use of fashion: the use of type fossils
- We undertake radiocarbon and other forms of dating
- We examine the economic basis of life –not all aspects of the chain of events are sequential, so it can be helpful to investigate the use of farming as opposed to hunting and gathering, or the possible access to metal and other technologies.
But, these techniques each have their complications, and they don’t always agree with one another. For that reason, we tend to try to use more than one aspect of a site in order to assess how it relates to other sites and the ‘grand order of things’ that were taking place in that region at the time.
Type fossils are identified when a particular (usually notable) artefact recurs frequently enough for us to be able to judge it a preferred choice among members of a specific community. We are very aware today that people have preferred ways of doing things and that this tends to be a personal choice that is influenced by culture. Fashions in clothing provide one obvious example, though they change very frequently. Other examples range from the flashy, such as cars, to more subtle things, like the ways we decorate our houses. The goods we use, our material culture, help to define us and the groups with which we identify.
The same holds good for the people of the past. Of course, clothing rarely survives, so it is hard to pick out trends there, but we do have other things such as arrowheads and pottery, even styles of flint knapping.
Over the years, archaeologists have built up ‘pattern books’ of type fossils and they look out for them on sites in order to identify the period (and sometimes type) of site that they are investigating.
Sometimes, this can have unintended consequences. For example, when I was planning excavations I tended to look for a specific type of stone tool known as a ‘narrow blade microlith’ in order to identify a site as Mesolithic. When I found narrow blade microliths in a collection of stone tools from field walking I could be pretty certain that the site related to the period in which I was interested for my research. Now, the Mesolithic is a long period, in Scotland it lasted for roughly 5,000 years before the introduction of farming about 6000 years ago. So, I was surprised to find that all the sites I excavated turned out to have very similar dates: Kinloch, Rum – c. 8500 BP; Fife Ness – c. 8500 BP; Long Howe, Orkney – 7900 BP. Thinking of an explanation, I suspect that I must be biasing my choice of sites somehow, and the most likely way is that the specific microliths that I perceive as interesting conform to the type of microliths that were popular around that precise part of the Mesolithic in Scotland. There are other dates from sites with microliths like that that would seem to confirm this – though the picture is, of course, not simple.
It is important to remember that type fossils are a tool that speaks to us, rather than one that we should force to fit in. We need to look at our finds and think carefully about what they might mean. I’ve been surprised recently to find people complaining that the type fossils don’t fit the accepted archaeological pattern; they then try to make them conform to their preconceptions. What they are forgetting is that archaeology grows as we excavate more sites and get more information. Our narratives change. We need to remember this and be prepared to be flexible and think our way around new interpretations, new stories. That is one of the attractions of the discipline for me.
For example, we don’t tend to find those narrow blade microliths on many sites towards the end of the Mesolithic. Some archaeologists, considering that a site can only be Mesolithic if they occur, have asked me whether I think that this could mean the abandonment of parts of Scotland in the millennium preceding the introduction of farming. Of course, it might, but we would have to find some explanation for this. Personally, I think it more likely that, due to a change in technology, we have not been able to identify the everyday culture in use right at the end of the Mesolithic. I suspect that microliths become less common and people are using stone tools that just don’t stand out – there are many sites with nondescript stone tools that we have not been able to fit into any pattern, and I wonder if they date to this period. Their locations conform to Mesolithic find spots, but as we don’t tend to excavate ‘nondescript’ sites we have yet to find out.
Another example relates to finds of Grooved Ware style pottery across the UK. In the past, we have tended to assume that technological and cultural developments took place first in the south, then spread gradually across the country. So, it came as something of a surprise to find that sites with Grooved Ware in the north, specifically in Orkney, were earlier than those in the south. In this case, it has prompted a closer examination of the evidence with the result that many people are now working on an exciting theory related to the development of a dynamic cultural movement, evidenced by henge sites such as The Stones of Stenness in Orkney as well as finds of the pottery and other things, and its spread away from the islands to form other centres of power such as the Boyne Valley Neolithic and the Stonehenge area of Wessex. Perhaps these places were already significant, but the developments that took place in later Neolithic Britain seem to spring out of the north and turn existing geographical perceptions of remoteness on their head.
The archaeological evidence does not always do what we expect. It is interesting to think about how we make sense of the archaeological material that we find. We were given the tools by generations of archaeologists before us, but they did not expect us to follow them blindly, they expected us to use our nous…
One of the big, and fun, debates in British archaeology relates to the way in which farming was introduced some 6000 years ago. We know that there was already a population of hunter-gatherers well established in the islands, how did they react to new ways?
This week I went to a great lecture in Aberdeen which got me thinking about this. Robin Torrence and Jude Philp (from the Australian Museum and the Macleay Museum, respectively) were talking about their work researching the ethnographic collections of Sir William MacGregor, the first Administrator of British New Guinea in the late nineteenth century. Much of MacGregor’s material ended up in Aberdeen when he retired home. The interesting thing is how the material changed from first contacts to once the relationships had been established. Apparently when the British first came into contact with a new tribe the material they were given comprised mainly objects that reflected the uncertain nature of the contact, and the people they first met, like clubs and mace heads. Later on, when everyone had got the measure of each other, the material changed to more domestic items. So you can see a difference in the collections from different areas over time. Also it seems that here, at least, excavation of the mission settlements and the local settlements suggests that each had very few of the others’ artefacts. I’m wondering what it says about culture contact and material object and particularly to our archaeological evidence for the transition from the Mesolithic to the Neolithic in the UK. We need to be very careful of erroneously drawing direct analogies from ethnographic work, and in the UK it is likely that this period of transition saw many different scenarios. But it is obvious that we need to think outside the box a bit.
Sir William MacGregor (source: University of Aberdeen website)
MacGregor was very aware that the advent of colonial rule would change the way of life of the people he was living among and he was keen that the material he had collected be used for the education of people at home. I’m hoping that he would have been pleased to know that it is still provoking debate over 100 years later.
Back in 1982 I took part in an experimental archaeology expedition in Sweden. We recently unearthed the cine film footage of the expedition.
The project was initiated by Tomas Johansson of the Institute of Prehistoric Technology, Ostersund, Sweden.
The aim of the experiment was to introduce laboratory based archaeologists to the potential of intensive field based work. This short film documents the experiment over a week, tool making, butchering, fishing and gathering.