Wednesday, August 29, 2018

Lusus Naturae or the real thing?: Cropmarks in Shannaragh & Cornamucklagh, Co Tyrone

As many readers of this blog are aware, I run a small project where I collect radiocarbon &dendrochronology dates into a single catalogue. Back in 2006 it started out as a personal resource for my own research needs, but I found that other people also saw value in it and it has been publicly downloadable since 2010. I’m currently in the process of updating the catalogue for release (hopefully) later this year. One innovation I introduced a few years back was to provide a geolocation (as decimal Lat/Long) for every date. The work of getting the geolocation and then checking its accuracy is painstaking, hugely time consuming, and frequently boring. But sometimes, just sometimes, it reveals a gem.

Cropmarks in Shannaragh
I use a number of sources to get the geolocation that include data provided in the original paper or report, or (more frequently) the information supplied by the wonderful site. However I get it, I always end up checking it by putting it into Google maps. While it’s not fool proof, it can sort out some easy errors like ensuring that the site isn’t in the wrong county or off the coast of Madagascar (this happens more frequently than I’d care to admit). The other evening, as I was making my way through the backlog of unread printed works that sit like a Kubrickesque sentinel in my office, I happened upon a paper in Archaeology Ireland by Walsh & O'Regan (2016) on excavations at Shannaragh, Co. Tyrone. It’s a lovely article, the dates were gorgeous – all that was left was to check on the location … no bother, right? Popped it into Google maps and the ubiquitous red pointer appeared. All fine! But then my eye moved out and I noticed a group of six or seven fields, noticeably different from the rest of the surrounding landscape – an off-white to grey colour rather than the usual greens and browns. I’m not entirely sure what makes these fields different – perhaps they were recently tilled or harvested? In any case, they’re clearly different from their neighbours and the appear to contain a series of crop marks that I can now confirm are not on the Northern Ireland Sites & Monuments Record.

Close up of the 3-C complex
To my mind, the most obvious cropmarks (in black) are in the central portion of this group of fields and appear to comprise a circular enclosure (approximately 30m across) with some form of central feature. A second curvilinear feature appears to be appended along the north-west edge (also c. 30m across), with another outside it again (c. 30m across). There’s even a hint of a feature at the centre of the ‘middle’ ring. Together, they form a group that is somewhat reminiscent of the logo for Canterbury sportswear or the triple ‘C’ of ‘Comber Commercial Centre’ and frequently seen across Northern Ireland – though, most usually on the sides of vans and not embedded into the landscape.

Cropmarks in Shannaragh: an interpretation
The second area is in the southernmost field and my interpretation (in green) is that these is a central circular/sub-circular feature (c. 18m across), with a larger sub-circular feature outside this. It takes the ‘eye of faith’ but there’s just a hint that there is a curvilinear feature appended to the northern edge of this large enclosure (c. 77m across). Beyond these two areas I think I can see some other features, but nothing particularly clear or striking (in indigo).

Close up of the 77m structure
I sometimes find looking at possible cropmark images like those ‘magic eye’ pictures that were so popular in the 1990s – look at them long enough, relax your eyes, and you’ll eventually see something … probably. Does it mean there’s anything actually there? Not always. I’ve tried to rationalise what these might be, if they’re not archaeological. My first thought was that they might be (especially the 3-C complex) tractor turning circles, but they just don’t appear to line up with any of the obvious wheel lines. I may not be the most expert of tractor drivers, but even in my youth I could manage a tighter turn that 30m diameter! I’m reluctant to offer any solid suggestions as to what these features might represent or to when they might date (if genuine). I will say that my first response was that we’re looking at a large barrow cemetery, possibly dating to the Bronze Age, but the size of these features is well beyond what one would expect for a ring-ditch. Perhaps we’re looking at one large defended settlement and a smaller enclosure, extended over several occasions. Put in some test trenches and prove me wrong!

Google Streetview image of the Shannaragh field from the south-west
I’ve looked at the same area on the current versions of Bing maps and the OSNI Orthophotography available on the Historic Environment Viewer and in both cases the area presents as an ostensibly uninteresting green field. Even the Google Streetview imagery currently available (dated June 2015) shows the area as open grazing land and nothing to indicate any difference from the surrounding landscape, large numbers of tractor tyre marks, or any indication of underlying archaeology. Indeed, looking at these features on Google Earth Pro indicates that although there is imagery going back to 2009, these features only appear on the most recent version, taken on July 17 2017.

Cornamucklagh cropmark enclosure
Although I don’t fully understand the reason for these fields being of a lighter colour, I did think that there may other potential sites to be identified in similar areas in the locality. While I found occasional areas that might have something in them, all were unconvincing. That was right until I found THIS in Cornamucklagh Townland! There are some features that require the ‘eye of faith’ to see, some that are pretty clear … and then there’s this! If what I’m seeing is correct, this black (peaty?) area contains the majority of a circular/sub-circular enclosure that measures c. 60.5m from south-west to north-east. The main external ditch appears to be around 4m across, though this varies. As this curvilinear feature is the same grey/off-white as the soil in the vicinity, this might represent the remains of a bank rather than a ditch. Either way, there appears to be a defined entranceway to the south-west (c. 5.3m wide) and (possibly, but I’m not convinced) to the north-east. Inside this clear curvilinear is a somewhat less distinct light band that may represent a second bank or ditch (c. 4m wide). Although clearest in the northern half of the enclosure, it can still be traced around the majority of the interior.

Close up of the Shannaragh enclosure
A small number of white specks suggest internal features of some sort, but they’re too slight to make any pronouncement on. As an aside, I must remark that there is something so charming about the seemingly fragile lattice of later drainage ditches that cover the entirety of this field. Seen from this remove they appear wholly insufficient for their intended task. In terms of function and dating, my initial feeling was that, with two banks and/or ditches, this was likely to be a rath/ringfort (enclosed farmstead) of the Early Medieval period … but at over 60m across (twice the average diameter of this site type) part of me is really reluctant to be drawn on this. However, another part of me is jumping up and down, shouting ‘It’s a really big, f*$#ing important rath ... oooh! or a Henge! maybe it's a henge!!!!!’ … again, want to put some trenches through this and prove me wrong? Like the previous sites in Shannaragh, there is nothing either on Google Streetview or Bing maps that gives any corroborating indication. Also similar to the previous, Google Earth Pro has imagery going back to 2009, but these features only show up on the most recent available, also taken on July 17 2017.

I would sound one slight note of caution as this potential site is particularly close to the route of the Great Northern Railway Portadown to Londonderry branch line. In fact, the former railway works form the northern boundary of the current field system. While everything about these sites in general, and this enclosure in particular, screams to me of our prehistoric and early historic past, I’m still prepared that these may be but the remains of much more recent times or just what the late Etienne Ryne used to describe as ‘Lusus Naturae’ … just an illusion of nature. Again, why don’t we put some trenches in (or better yet, some geophysics) and see what’s really there?

Walsh, F. & O'Regan, C. 2016 'Getting to the Point' Archaeology Ireland 30.4, 14-15.

As I mentioned at the beginning of this piece, I’m currently in the process of updating the IR&DD catalogue and while it now has over 9,000 entries, I’m still always after more and if you have any radiocarbon or dendro dates you can share from Irish sites, I’d love if you could make contact and discuss it. Thank you!

Finally - if you like this post, please feel free to share it where others will like it too. If you really like it, please feel free to drop the price of a pint in The Tip Jar, even if I'll only spend it on books!

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