Over a period of two weeks in mid-May a team from GGAT Projects excavated three trenches inside the walls of Oystermouth Castle, one in centre of the chapel block (Trench A) and two in the castle’s inner bailey (Trenches B and C). These exploratory trenches were dug in preparation for proposed visitor facility works to proceed in 2010.
The only structural remains found during the excavation were a well-laid cobbled surface, discovered in Trench A, 9cm below the gravel chippings that forms the buildings current ground surface. This surface was built from angular limestone cobbles varying in size between 19cm and 4cm. We think that the lime mortar bonding the cobbles together dates to the medieval period and that this surface may be the original floor of the chapel block.
Once the turf and underlying sub-soil in Trench B was removed a layer of loose demolition material was revealed, made up of fragments of limestone, broken slate and stone roof tiles, lime mortar and damaged masonry. This layer contained five sherds of medieval pottery; however these may have come from two earlier pockets of light brown sandy clay contained within the demolition material. As this layer was so loose and unstable we think that it may not be of any great age. If there were any medieval structures or signs of occupation in this area of the castle then they have been destroyed.
Below the turf and sub-soil of Trench C was a loosely compacted collection of shells contained within a light brown sandy-clay soil. An environmental sample from this layer was taken in order to identify the species that it contained. These were blue mussel (shown in grey on the plan), cockle, limpet (shown in light-green on the plan), whelk, oyster (shown in light-blue on the plan), periwinkle, pod razor and charcoal fragments (shown as black hatching on the plan). Underneath this collection of shells was a deposit of stone and slate building rubble; this deposit contained the base of a glazed jug made in Bristol dating to the 13th or 14th centuries. Scattered amongst the building rubble were numerous periwinkles, and a sample of these were taken for comparative analysis. The variety of shell species present in the first sample compared with the single species (periwinkle) in the later sample perhaps suggests that the local periwinkle population had been over-fished during the medieval period between the times when the two layers were formed. This theory is supported by a comparison of the size of periwinkle recovered from both samples, with those from the later sample being of a more similar size.
The only structural remains found during the excavation were a well-laid cobbled surface, discovered in Trench A, 9cm below the gravel chippings that forms the buildings current ground surface. This surface was built from angular limestone cobbles varying in size between 19cm and 4cm. We think that the lime mortar bonding the cobbles together dates to the medieval period and that this surface may be the original floor of the chapel block.
Once the turf and underlying sub-soil in Trench B was removed a layer of loose demolition material was revealed, made up of fragments of limestone, broken slate and stone roof tiles, lime mortar and damaged masonry. This layer contained five sherds of medieval pottery; however these may have come from two earlier pockets of light brown sandy clay contained within the demolition material. As this layer was so loose and unstable we think that it may not be of any great age. If there were any medieval structures or signs of occupation in this area of the castle then they have been destroyed.
Below the turf and sub-soil of Trench C was a loosely compacted collection of shells contained within a light brown sandy-clay soil. An environmental sample from this layer was taken in order to identify the species that it contained. These were blue mussel (shown in grey on the plan), cockle, limpet (shown in light-green on the plan), whelk, oyster (shown in light-blue on the plan), periwinkle, pod razor and charcoal fragments (shown as black hatching on the plan). Underneath this collection of shells was a deposit of stone and slate building rubble; this deposit contained the base of a glazed jug made in Bristol dating to the 13th or 14th centuries. Scattered amongst the building rubble were numerous periwinkles, and a sample of these were taken for comparative analysis. The variety of shell species present in the first sample compared with the single species (periwinkle) in the later sample perhaps suggests that the local periwinkle population had been over-fished during the medieval period between the times when the two layers were formed. This theory is supported by a comparison of the size of periwinkle recovered from both samples, with those from the later sample being of a more similar size.
No comments:
Post a Comment