Thursday, September 19, 2013

'Run a carbon-black test on my jaw' | Catalogue of radiocarbon determinations & dendrochronology dates | September 2013 Update

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If you’ve ever met me, or spent any time around this blog, you’ll know that I’m pretty obsessed with radiocarbon dates (and dendrochronological dates, too, but to a lesser extent). It’s only in recent times that I learned that some people think that I’m a proper scientist and work somewhere with a radiocarbon laboratory, actually producing these dates. Would that it were so! Ernest Rutherford is often quoted as saying that ‘All science is either physics or stamp collecting’. Those who work to produce the dates – that’s physics. What I do is definitely the ‘stamp collecting’ end of the market! I’ve told the story before, but the short version is that when I worked in field archaeology I just started collecting radiocarbon dates for my own use as a research tool. Even though I now work outside of archaeology, I still maintain the project as I believe that it is ‘a good thing’.

At the last update to this Catalogue, in March 2012, there were 6093 radiocarbon determinations and 240 dendrochronological dates. In the following year and a half, I’ve increased the numbers to 7015 radiocarbon and 260 dendro dates. The dates currently in the catalogue span the range from 20±40 BP, at Rath Hill I, Co. Meath (Beta-246963), right back to 12480±130 BP, at Castlepook Cave, Co. Cork (OxA-3601). The 923 new dates added to the resource cover 30 Irish counties (along with a couple from Scotland and the north of England), and (if my math and failing eyesight are correct) 277 separate excavations.

Stamp Collecting ... know the difference!
The sources of the information come from wherever I can lay hands on them – some are older publications that I’m just getting around to; some are new books that I add as and when I can afford to buy them; and some – increasingly – are from PDF versions of papers and reports that have been made available for free download from the internet. In the latter category, I would like to pay tribute to so many archaeologists who have invested their time and energies in uploading documents to such repositories as etc. – your effort has increased the quality and quantity of dates I’ve been able to add to this Catalogue. On top of this, I’ve been delighted that a number of researchers have trusted me with their unpublished/largely unavailable dates. Among these is Marion Dowd (Institute of Technology, Sligo), who supplied dates from Moneen Cave, Co. Clare; CóilínO'Drisceoill (Kilkenny Archaeology) provided a number of dates from his company’s excavations around Kilkenny; and Prof P. C. Woodman (formerly of UCC) provided a substantial number of Mesolithic dates, many of which have not been published. However, a special note of thanks must be reserved for the generosity of Richard Warner (formerly of the Ulster Museum). He made his personal database of sites available to me for this project. The depth and detail of his work far outclasses what I have achieved in this much simpler format, and should be the template for future projects to collate this kind of information. On top of the dates already collected by both of our projects – but acting as means of error-checking – Warner’s research included a large number of unpublished dates that have never been widely available before. These include a number of museum pieces that were dated, along with a large collection of dates that I do not believe are available elsewhere from the hillfort at Rathgall, Co. Wicklow. However, the jewel in the crown of this collection must be – for me at any rate – the 26 dates from surface timbers recovered from crannogs. All but four of these dates are from Fermanagh sites, and the dates range from 130±65 BP (1666-1954 cal AD, UB-2516) at Drumlone, to 1715±60 (135-525 cal AD, UB-2500) at Mill Lough. Despite this one date in the Iron Age, there are only three dates from the Early Christian/Early Medieval period, and the rest are of, broadly, Medieval to modern ages. Although I cannot swear to it, my supposition is that these results – taken from surface materials – wrongly informed opinion on the generally late date of the Fermanagh crannogs. The recent excavations at Drumclay [also here & here] have shown that the more likely story is that these sites have significant periods of occupation from Early Christian foundations right through to Medieval times. Between them, these individuals have contributed 325 radiocarbon dates not available elsewhere. Of these 220 come solely from the material collected by Richard Warner.

Now that we have all this information, what can be done with it? My initial reason in collecting this data was to examine contemporaneity between sites. In particular, I was looking for a way of analysing burnt mounds that went beyond the simplistic ‘other sites in this county’ and ‘other sites that have rectangular/circular troughs’ etc. Not that there’s anything wrong with these approaches, but I thought that if you could pick out the other burnt mounds across Ireland that were dated to a similar narrow range, and then add in the contemporary burials, houses, trackways etc., you might have something interesting. So … yes ... you can use it for that type of analysis (and this will be the topic of a forthcoming blog post). But there are lots of other things you can do with the data – much more ambitious than my approach. You can read about some of them here. Whatever you want to do with the data, my aim is to provide as much as I can so that other researchers don’t have to spend countless hours trawling the 656 books, papers, and reports listed in the bibliography. The format in which the data is presented is another aspect that is quite important. It has been frequently suggested to me that I should present the data as an Access database, or even an online searchable resource. I’ll admit that both are attractive prospects, but I have found – by accident, and not design – that the majority of researchers who use this resource are happiest when it is available as an Excel spreadsheet.  That way they can dump my graphs, rearrange the columns, and generally slice it and dice it in any way they choose … even export it into their own custom-made databases etc. In this way it is pretty much the most ‘vanilla’ of data formats that can be adapted into any organisation or layout that best suits the needs of the individual researcher.

I suppose the next question is: where to from here? Despite the economic gloom, it appears that there is no shortage of available reports and books etc. I’ve currently got 190Mb of PDFs to sort through for dates … and those are just the ones I’ve had a look through and know that there are dates to be found in. The Downloads folder on my hard drive has become some form of academic holding pen for all the materials I’ve encountered around the internet. At a rough count, it contains 93 PDFs, weighing in at just under 1Gb. On top of all that I’ve also got a large, and largely unread, pile of physical books. I daren’t even begin the task of enumerating them – it’s probably too depressing! At a rough guess, I’d imagine that if stacked up, they’d be the best part of four … maybe five … feet tall. So, from that perspective, I’m sorted for the time being! That said, I’m always looking for more – and that’s where you can help! If you’re involved in archaeology in Ireland – in whatever capacity – and have access to radiocarbon/dendro dates that are not in the Catalogue, I’d be incredibly thankful if you could pass them this way. So that they can be properly cited, I’d prefer a copy the original book/report that they were published in – either in digital or paper format. Failing that, if they’re not published, even a list of the dates with as much meta data surrounding them as possible would be appreciated, too.

If you are a user of the resource, I would greatly appreciate it if you could take a few moments to drop me a line, giving me an outline of your research and how the Catalogue has been of use to you. I still feel that it is rather brash and distasteful to ask for testimonials of this type, but they may prove to be a necessity if this resource is to survive. In the competitive world of grant applications – should anyone ever have money again! – positive stories about how this simple resource has helped researchers is very necessary to demonstrate value for money and prove that a small investment in this project will create tangible ripples of positive influence for numerous students. Even if you’re not directly involved in archaeology, but you still want to help, you can use the Amazon portal at the end of each post. For every purchase that is made through it, I receive a small amount as commission. Admittedly, it’s not likely to make me rich, but it may just help to purchase a book or two to add to the Catalogue.

One way or another, I hope to continue this research and maintain this resource – so long as there are people out there who use it and believe it to be ‘a good thing’. It may just be ‘stamp collecting’, but it’s a useful collection that is worth much more than the sum of its parts!

You can access the latest version of the Catalogue through the IR&DD webpage or go directly to it on Google Docs. To download the document, just click on 'File' and 'Download'. If you have any problems with it, just sent me a message via the comments on this blog & I'll email you a copy.

Robert M Chapple

PS. I just realised that many readers won't get the title reference to REM's 'Hairshirt' from the Green album as it was released in 1988 ... that's 25 years ago! Where did the last quarter-century go?

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