Welcome to the Urban Archaeology blog. Freelance archaeologist Chiz Harward provides a range of on and offsite services to the archaeological profession, including running and working on excavations, post-excavation services, training and development work, and illustration work. This weblog will carry news of projects as and when they happen as well as wider thoughts on archaeological issues, especially recording, stratigraphy and training.

Not another negative watching brief....

Excavating the gas main diversion at the Thatched Barn

A recent project for Keevill Heritage proved that where archaeological watching briefs are concerned, you can't assume that you won't find something of archaeological value just because you are in late Victorian levels, and that you never know when something rather special may turn up. The work involved a watching brief on a gas main diversion around the mid 19th century Thatched Barn at Christ Church College, Oxford, and the trench was expected to mostly cut through Victorian dumps which had been used to raise the ground level above the meadows and winter flooding.
A masonry wall was the first find, bonded with Portland cement it was clearly not that old, but within the fabric of the wall were several medieval architectural fragments, including a Norman voussoir, and a fragment of a possible canopied tomb, as well as numerous plain and ashlar blocks and fragments of mouldings. Once past the wall and into the Victorian made ground, there were further surprises, alongside the expected Victorian crockery and bricks were over twenty pieces from a fine limestone balustrade.
Whether any of the architectural fragments derive from Christ Church college and its grounds is a moot point: it may be that they were brought in from outside the college in the cartloads of spoil used to raise the ground level, however it does seem probable that many of the pieces do derive from the college, and the architectural fragments may have been disturbed during Gilbert Scott's work on the cathedral in 1870s.  It is highly possible that the small vaulting fragment and the Romanesque voussoir are from the cathedral, or rather from medieval St Frideswide's  Priory as it was originally, and hint at architectural features destroyed over the passing centuries.
Romanesque voussoir

Late 12th century voussoir
The first piece to be found was a complete limestone voussoir carved with Romanesque chevron moulding, probably from a vault rib of the late 12th century. The decoration is finely carved, and relatively un-weathered; there are two rows of rolled chevron decoration on each side of the voussoir, with a diamond lozenge on the soffit. Christ Church College was founded on the site of the Augustinian St Frideswide’s Priory, which had been founded in the twelfth century. Could this voussoir be a remnant of the original Norman priory buildings? 
Vaulting fragment
Fragment from a vaulted canopy
A second finely carved limestone fragment is decorated with blind tracery. It has a splay of five round-headed trefoil lights. The fragment is quite small and would fit being from the internal corner of the canopy vault above a tomb. 
Canopied tombs are relatively rare, being reserved for the very wealthy or influential. Fragments of St Frideswide's 13th century canopied tomb were found in the 19th century, they had been dumped down a well at the Reformation, could this fragment be from another canopied tomb from Christ Church? Two fragments of Purbeck Marble from the site are also likely to be from a tomb, perhaps the same one?

Reconstruction of Purbeck Marble moulding
Found within late 19th century made ground were over twenty pieces from a finely turned limestone balustrade, all the baluster shafts (pillars) are sadly broken, however the original design can be reconstructed from the fragments and it is vasiform (vase-shaped) in style, with a torus below the lower belly, and a single roll moulding above the upper sleeve. Each baluster had a square terminal at each end, with a further square socket that would fit into a rebate in the top and base rails of the parapet, mortar is visible on some of the joints. There is small square mortice set into the ends to further fix the pillars in place, and setting out marks are visible on some of the bases.
Reconstruction of balustrade, shaded area is conjectured

The baluster shafts are quite badly eroded, with the profiles badly weathered on many of the examples but it is possible to reconstruct the full balustrade scheme: balusters are normally separated by at least the same measurement as the size of the square bottom section, and although we don't have any of the top or bottom rails these are usually fairly simple in design. The balustrade presumably dates to after the arrival of Palladian ideas in the early 17th century; vasiform balusters appear to date to after c1650.