A few thoughts on redeposited…

‘Redeposited’ is the shortened form of the technical term ‘redeposited subsoil’, meaning subsoil which has been taken up from elsewhere in antiquity, and spread or deposited over that area you’re excavating; a tricky obfuscation. Subsoil is also referred to as ‘the natural’ and indicates virgin soil, undisturbed by human agency. In East Clare, where I’m digging at the moment, the natural is referred to by everyone as the dhoib-bhuí (yellow daub) due to its use in the recent past as a binding mortar in the vernacular cottages and boundary walls of the district. Indeed, such is the level of knowledge of these things in the vicinity of Tulla, most visitors to the site were willing to comment intelligently on the great expanse of the stuff evident across the site before the rains of last week turned it into a viscous yellow soup. For here, a good proportion of the hillside had been trowelled clean, exposing several features clearly cut into the upper surface of what was confidently identified by all as the dhoib-bhuí .

Or was it? On urban sites where there is generally a good idea of where the bottom will be located, redeposited subsoil is rarely problematic and can be easily recognised by the fact that is is generally quite different in hue from the more organic occupation layers more usually encountered. It’s subsoil remember, brought onto the site from elsewhere, so it won’t yield any finds. It’s usually mattocked off after being planned and levelled (i.e. drawn on the site plan and its height relative to sea level measured with a level and staff). On rural sites however, redeposited tends to be a horse of a different colour, so to speak.

The trouble with the redeposited began when considering T.J. Westropp’s site plan of St. Mochulla’s Church, surveyed in 1909 and published in the JRSAI two years later. The field we’re excavating, in advance of an extension to the parish graveyard, is clearly indicated to the west of the church, its western edge incorporating the boundary of the early monastic enclosure (which itself is surely pre-historic, something I’ll return to later). Westropp employed a system of hachuring to depict the gradient of the slope on the hill, indicating a ‘platform’ to the south of the church and a ‘slight terrace’ to the north against the enclosure.

To misquote Pete Astor, my magpie eyes were hungry for the prize and I’d been looking at this field for years as the only area within the enclosure seemingly free of burials. Even at that, like a local TD I’ve been no stranger to funerals up on the hill and have been careful on several occasions to position myself close to the priest to have a better look at the section at the graveside. Prior to undertaking (typically inconclusive) geophysical survey and test trenching within the field in question, I’d failed to see Westropp’s scheme presenting itself on the ground. The field had been in use as a paddock for horses for years and prior to that it had been a garden associated with a line of labourers’ cottages defining the northern side of the Fair Green, an open area between the town and the church entrance. A slope was of course evident uphill to the boundary of the modern graveyard, however the break of slope indicated by Westropp, if indeed this is what he was trying to get across, was invisible to me. If I’d given it much thought, I’d have reckoned that the effect so evident to Westropp was created by sculpting the surface of whatever was there to begin with, adapting the hillside exactly indeed as described in the Vita Sancti Mochullei Episcopi, a text recovered from an Austrian archive at the close of the nineteenth century.

On excavation, a break of slope of anything between 200 and 350mm happily began to present itself, more or less where Westropp has drawn the western edge of his central assemblage of squiggles. So far so good. This potentially defined the activity we were beginning to encounter uphill, which for the time being appeared to consist of drainage channels cut from the modern surface to bring rain water (of which there is some sufficiency hereabouts) down the hill.

One such drain presented as a linear smear of dark silt about 1500mm wide, very evident against the yellow subsoil with a few large stones helpfully thrown in to the fill, to aid the more visually challenged digger along the true path of stratigraphical enlightenment. Unlike the other drains running down the hill, this one lacked a formal cut: when the dark silt and the stones were removed, the yellow subsoil was there underneath. Or was it? When trowelling off the silt, a slight variation was evident in the texture of the material below; however it made little sense in plan or section. By this stage, the drain was being excavated at two locations and within 10 minutes small voids began to appear in what we thought was the subsoil underneath. Fools.

In fairness though to both myself and Elaine, the possibility of there being a souterrain underneath us was quickly established: the slight remains of a foundation trench curving away at a tangent to the drain had already suggested an early medieval structure, often associated with souterrains. The water draining off the hill had simply found the path of least resistance and was channelled along something that had been there previously. There were no upright stones lining the sides of this particular souterrain and it took a while to find the ‘cut’, the formal sides of whatever underground imperative was directing the water. And herein the problem with the redeposited…

You see, it’s like this (probably): at some stage in the seventh century, the hill at Tulla is selected for monastic purposes. Soil is introduced at the upper levels to create a platform within an enclosure that’s much older. How much older? I’ll keep you posted but it’s not exactly impacting on my sleep patterns at the moment. There’s an internal ditch there, ok? You’ll know what I mean. Anyway, a church is built on the summit and a bit further down an inner enclosure is constructed and revetted with stone. Where we are, a round structure is built in association with an earth-cut souterrain. This has collapsed in on itself, leaving tiny voids and a semblance of parallel sides, some distance down it must be said from what we’d taken to be the surface of the subsoil.

Now here’s the crunch: the thing has been cut through the redeposited subsoil, which has been deposited on the natural subsoil which has also been penetrated by the souterrain cut and of course, it’s backfilled with re-redeposited subsoil to boot. They’re all bloody hard to tell apart. Usually, this type of distinction is established by a combination of visual and tactile perception, the sort of shit they don’t teach you in college. The ‘natural’ natural shouldn’t have flecks of charcoal within; it should be ‘stiffer’ and at the (in this instance vertical) interface with the redeposited, it should be harder. Of course, things aren’t always quite that simple…

Further up the hill, underneath a nineteenth-century field boundary, lies a linear feature comprising loose stones in a deep, well-defined trench. I had this as some sort of revetment holding back the dhoib-bhuí, visibly higher in section just further back, demarcating an inner enclosure evident closer to the eighteenth-century church at its northern and eastern sides. More experienced eyes saw a corn-drying kiln and I was happy to acquiesce until we started to dig it. Again, the subsoil below was nothing of the sort. However, as luck would have it, the redeposited has yielded a large chunk of charcoal which should provide a date for the activity.

Digging redeposited is disheartening at the best of times. Here, where there is hardly any discernible difference between the subsoil and the material above, it’s a murky nightmare, a hall of mirrors sketched out by Lewis Carroll or Kafka on a 3B pencil on the back of a packet of 20 Major. Westropp’s hachuring has however saved the day and we now know what we’re dealing with. Sort of. There remains nonetheless the possibility of more activity beneath, predating this particular phase of activity. I just hope the cavemen didn’t have the idea first, leaving us with more of this heavy, wet, sterile muck to shovel off and pointlessly ruminate over on- line.